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1
MENEGATOS (Ι. ΜΕΝΕΓΑΤΟΣ), J., E. XYLOURI (Ε. ΞΥΛΟΥΡΗ), A. AJOUTANTI (Α. ΑΓΙΟΥΤΑΝΤΗ), O. SABATAKOU (Ο. ΣΑΜΠΑΤΑΚΟΥ), E. PARASKEVAKOU (Ε. ΠΑΡΑΣΚΕΥΑΚΟΥ), and E. VAINAS (Ε. ΒΑΪΝΑΣ). "Two cases of freemartinism in Lacaune ewes." Journal of the Hellenic Veterinary Medical Society 55, no. 4 (December 6, 2017): 299. http://dx.doi.org/10.12681/jhvms.15119.
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In this study the anatomy of the genital system, the histology of gonads, the reproductive behavior and the chromosome examinations of two freemartin Lacaune ewes were described. The appearance of these ewes resembled that of a ram, but their external genitalia were female with an enlarged clitoris. The gonads were small testicles located subcutaneously in the prepubic region. In the case of the ewel the testicles were palpated with difficulty, while in ewe 2 they were almost atrophic. In both cases there were epididymides, but in ewe 2 the ends of vasa differentia were joined. In ewel there were vesicular and bulbo-urethral glands. In ewe 2 the vesicular glands were absent. The ewel had male sexual behavior, but the ewe 2 had a neutral one. The histological examination of the gonads of ewe 1 showed excessive development of the vassoconnective tissue, where a small number of seminiferous tubules and Sertoli cells were also visible. The gonads of ewe 2 showed excessive fibrosis. The results of chromosome examination showed chimaerism (54,XX/XY) in both cases. The XY cells were 63% and 61% for the ewes 1 and 2, respectively. The rest cells 37% and 39% were respectively XX ones.
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Schreurs, N. M., P. R. Kenyon, P. C. H. Morel, and S. T. Morris. "Meta-analysis to establish the response of having heavier mature ewes during gestation on the birthweight of the lamb and the weaning weight of the ewe and lamb." Animal Production Science 52, no. 7 (2012): 540. http://dx.doi.org/10.1071/an11292.
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There is much uncertainty about feeding ewes to maximise the performance of progeny and of the ewe itself to weaning. This includes questions about feeding the ewe to influence the lamb’s birthweight for lamb survival, feeding to augment the ewe’s lactation to maximise the lamb’s growth potential before weaning and feeding the ewe to increase the probability of having multiple offspring. The objective of this study was to carry out a meta-analytic study to consider the response of having heavier mature ewes during gestation on lamb and ewe performance measured by birth and weaning weights. The birthweight of singleton lambs was the greatest, twins were intermediate and triplets the lowest (5.8, 4.8 and 4.1 kg, respectively; P < 0.001). A similar trend (P < 0.001) was observed for the weaning weight of the lamb (29.1, 25.2 and 23.7 kg for lambs weaned as a single, twin or triplet, respectively). The liveweight of ewe at weaning was greater (P < 0.001) for those ewes that failed to wean a lamb (69.6 kg) or weaned a single lamb (67.8 kg) compared with ewes that weaned twin and triplet lambs (64.8 and 65.3 kg; respectively). A greater ewe liveweight during gestation gave different responses on the lamb birthweight, lamb weaning weight and the weaning weight of the ewe and this was dependent on birth and weaning rank category of the lamb (P < 0.05). Overall, the response of heavier ewes on lamb birthweights and ewe and lamb weaning weights was small compared with the effect of birth and weaning rank of the lamb.
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Vatankhah, M., and F. Zamani. "Phenotypic and genetic characteristics of longevity in Lori-Bakhtiari sheep." Biotehnologija u stocarstvu 23, no. 5-6-1 (2007): 323–29. http://dx.doi.org/10.2298/bah0701323v.
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Longevity records of 978 Lori-Bakhtiari ewes were collected from a research flock at the Lori-Bakhtiari sheep breeding station during 1989 to 2006. Single-trait animal model used to analyze trait, included fixed effects of year of production, ewe body weight as covariable and random effects additive genetic of animal and residual effects. Phenotypic and genetic trends were estimated as regression of average phenotypic value and breeding value by birth year of ewe. Results show that, 49.80%, 22.49% and 27.71% of breeding ewes left the flock for illness, low production and oldness respectively. The overall mean (? s.e.) of ewe's longevity was 1779.91 (22.10) days. The effect of year of production and ewe's body weight on longevity were significant (p<0.01), and longevity increased by 41.84 ? 2.80 days with 1 kg of ewe body weight. Estimation of heritability for longevity was 0.33 ? 0.07. The phenotypic and genetic trends of longevity were significant (P<0.01) and estimated as -84.65 and -19.02 days, respectively. Thus, illness is very important reasons to removed ewes from flock. Longevity could be improved by selection, but early life traits is needed to indirect selection for longevity.
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Alexander, G., D. Stevens, and LR Bradley. "Fostering in sheep: fostering lambs onto ewes whose lambs have died soon after birth." Australian Journal of Experimental Agriculture 27, no. 6 (1987): 765. http://dx.doi.org/10.1071/ea9870765.
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Fostering, in which the odour of the foster lamb was made similar to that of the ewe's own lamb, was attempted with Merino and crossbred (Border Leicester x Merino) ewes whose lambs had been killed 30 min post partum to simulate natural early post partum death. Hessian coats were fitted at the time of death to the lambs of 11 ewes, and 2-1 8 h later the coats were transferred to foster lambs which were then presented to the respective ewes. The dead lambs of another 11 ewes were smeared with neatsfoot oil at the time of death and were left with their mothers for 2-18 h at which time they were substituted by foster lambs freshly smeared with neatsfoot oil. In another group of 11 ewes the skin of the dead lamb was draped about a foster lamb that was given to the ewe 2-18 h post partum. Foster ewes accepted 73 and 91% respectively of lambs treated with hessian coats or neatsfoot oil, compared with 36% in control ewes with untreated lambs, while fostering by the traditional shepherd's method of draping the skin of the dead lamb over the foster lamb was 100% successful. However, the success rates in the 3 treatments were not significantly different. Some success was also achieved in a supplementary group of 8 ewes when application of neatsfoot oil to the dead lamb was delayed until about 2 h prior to fostering. There was no indication that success rates were influenced by the genotype of the ewe or by restraining ewes overnight with the lamb having access to the udder. The traditional method of skinning the dead lamb appears to be the method of choice, because the dead lamb does not have to be found and treated prior to fostering.
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Caroprese, Mariangela, Giovanni Annicchiarico, Laura Schena, Antonio Muscio, Raffaella Migliore, and Agostino Sevi. "Influence of space allowance and housing conditions on the welfare, immune response and production performance of dairy ewes." Journal of Dairy Research 76, no. 1 (October 16, 2008): 66–73. http://dx.doi.org/10.1017/s0022029908003683.
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The experiment used 45 Comisana ewes, divided into 3 groups of 15. The aim was to determine the effects of two different stocking densities and two different housing conditions on welfare, and on production performance of dairy ewes. The stocking densities tested were: high stocking density (1·5 m2/ewe, HD group) and low stocking density (3 m2/ewe, LD group); the two housing conditions tested were: ewes housed indoors (LD group, 3 m2/ewe) and ewes allowed to use an outdoor area (LDP group, 3 m2/ewe divided into 1·5 m2/ewe indoors and 1·5 m2/ewe outdoors). At the beginning of the experiment, and then every 2 months, the cell-mediated immune status of sheep was evaluated. One month after the beginning of the experiment, and 20 d later, the ewes were injected with chicken egg albumin (OVA) to assess their humoural immune responses. Starting from the beginning of the experiment and then monthly, behavioural activities of ewes were monitored using 15-min scans. After lamb weaning, milk yield from individual ewes was measured and milk composition analysed weekly. Housing conditions (low density reared ewes indoors v. low density reared ewes with free access to an outdoor area) affected cell-mediated response, which was higher in LDP than in LD ewes. Concentrations of anti-OVA IgG were mainly influenced by space allowance, with higher antibody titres in LD than in HD ewes throughout the experiment. Both housing conditions and space allowance affected sheep behavioural activities: a greater proportion of LDP ewes displayed standing and drinking behaviours than LD ewes, and a greater proportion of LD ewes was observed walking than HD ewes. Ewes allowed access to the outdoor area had a higher protein content and lower somatic cell count in their milk, whereas reduced space allowance led to a reduction in milk yield and an increase in somatic cell count of milk. Results indicate that both increased space allowance and availability of outdoor area can improve the welfare and production performance of the lactating ewe.
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Alexander, G., D. Stevens, and LR Bradley. "Fostering in sheep: experiences with the use of neatsfoot oil." Australian Journal of Experimental Agriculture 27, no. 6 (1987): 771. http://dx.doi.org/10.1071/ea9870771.
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This paper reports the results of 3 studies on variables associated with the use of neatsfoot oil for substitutive or additive fostering of lambs. In the first study, neatsfoot oil was applied at the rate of 60 mL/kg of liveweight to 3-day-old lambs from Merino and Border Leicester x Merino ewes, and the lambs were exchanged between pairs of ewes of the same breed 3.5, 7 or 24 h later. The proportion of ewes accepting the alien lamb from the other ewe of the pair within 17 h generally increased with the period from application to exchange. Crossbred ewes accepted the foster lambs more readily than did the Merinos. Acceptance rates with batches of neatsfoot oil produced by different methods were similar. We found no advantage in smearing the ewe's nose with neatsfoot oil at the time the oil was applied to the lamb. Additive fostering in 20 ewes that accepted the alien lambs and were left with their own lambs was 95% successful and appeared permanent. In the second study using similar methods, with lambs of 28 crossbred ewes anointed 24 h prior to exchange, no advantage was found in presenting the foster lamb to the ewe at night over presentation during the day. Most foster lambs were accepted within 12 h, and all ewes reaccepted their own lambs after a 13 h absence. The acceptance rate of foster lambs by the crossbred ewes ranged from 70 to 83%. In the third study, 27 Merino ewes whose lambs were anointed with neatsfoot oil 7-40 h after birth, were presented with freshly anointed foster lambs 24 h later. The rate of acceptance of the foster lambs within the next 24 h was 74%,but many ewes required prolonged restraint before reaccepting their own lambs after 5-26 h separation. The results show that most ewes can be induced to accept foster lambs 1-2 days post partum, if their offspring have been liberally coated with neatsfoot oil for 24 h, and then substituted with neatsfoot-treated foster lambs. For additive fostering, the ewes' offspring should be returned within a few hours.
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MAKOVICKY, PAVOL, MILAN MARGETÍN, PETER MAKOVICKÝ, MELINDA NAGY, and ANDREA PUSKÁS. "Study of mastitis in Slovak dairy sheep." Indian Journal of Animal Sciences 92, no. 4 (May 24, 2022): 517–19. http://dx.doi.org/10.56093/ijans.v92i4.124204.
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A trial was conducted on lambing ewes of Tsigai and Improved Valachian breeds in the 1st to the 3rd lactation in 2017 and in the 1st to 4th lactation in 2018. The lambing ewes were housed and managed under the same conditions over the experimental period. Milk samples for determination of SCC (Fossomatic 90, Foss Electric Co., Denmark) and contents of solids (% S), proteins (% P),fat (% F) and lactose (% L) (Multispec infrared analyzer) were taken by ewe milking in S period after intravenous application of oxytocin (5 i.u./ewe) and as part of milk recording at morning hand milking in M period. Milk samples were taken in such a way to be representative ones of the ewe’s whole milk yield. Daily milk production (MP) was also recorded in individual ewes on the day ofmilk sampling; in S period, it was calculated from a milk quantity produced within a 4 h interval and milked after
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Paganoni, B. L., M. B. Ferguson, G. A. Kearney, and A. N. Thompson. "Increasing weight gain during pregnancy results in similar increases in lamb birthweights and weaning weights in Merino and non-Merino ewes regardless of sire type." Animal Production Science 54, no. 6 (2014): 727. http://dx.doi.org/10.1071/an13263.
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Birthweight is the single largest determinant of survival in lambs and can be predicted from ewe liveweight at conception and liveweight changes during pregnancy. These prediction equations are known for Merino ewes, but it is unknown if they are applicable to non-Merino breeds. We tested the hypothesis that increasing conception weights of ewes will increase the birthweights, survival to weaning and weaning weights of their lambs, irrespective of ewe or sire breed, but that non-Merino lamb birthweights would be less responsive than Merino lamb birthweights, to changes in ewe liveweights during pregnancy. Ewe liveweight, lamb birth and weaning weight records from Merino sires mated to Merino ewes (MM), Border Leicester Merino (Maternal) sires mated to Merino ewes, Poll Dorset or Suffolk (Terminal) sires mated to Merino ewes (TM), and Terminal sires mated to Border Leicester Merino ewes (TMAT) were analysed from the 2007 to 2011 lambings of eight information nucleus flocks. Lamb birthweights increased by 0.032 ± 0.0012 kg from MM ewes and 0.024 ± 0.0026 kg from TMAT ewes with every 1-kg increase in conception weight (P < 0.001). Irrespective of breed, for every 1-kg increase in liveweight change during early and late pregnancy, lamb birthweights increased by 0.021 ± 0.0019 kg and 0.034 ± 0.0019 kg and weaning weights by 0.26 ± 0.013 kg and 0.09 ± 0.011 kg, respectively (P < 0.001). Survival to weaning of single, twin and triplet lambs was highest for lambs from TMAT ewes (89.3% ± 1.25, 84.6% ± 1.49 and 73.4% ± 2.35) and lowest for TM ewes (80.2% ± 1.89, 72.8% ± 2.09 and 57.4% ± 2.98; P < 0.001). Coefficients relating ewe liveweight change during pregnancy to lamb birthweights are similar for Merino and Maternal ewes, however conception weights of Maternal ewes are significantly heavier than Merino ewes when run together, and lamb birthweights from Maternal ewes are less responsive to ewe conception weights. The coefficients reported in this paper will enable development of optimum management guidelines for single-, twin- and triple-bearing Maternal ewes.
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Carson, A. F., L. W. McClinton, and R. W. J. Steent. "Effects of Texel or Rouge de l’Ouest genes in lowland ewes and rams on ewe prolificacy, lamb viability and weaned lamb output." Animal Science 68, no. 1 (February 1999): 69–78. http://dx.doi.org/10.1017/s1357729800050098.
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AbstractAn evaluation of the effects of the proportion of Texel or Rouge de l’Ouest (Rouge) genes in ewes (0, 0·5 or 1·0; the remainder being Greyface (Border Leicester × Scottish Blackface)) on prolificacy, lamb viability and lamb output was undertaken. A comparison of Texel and Rouge sires was carried out on Greyface, Texel and Rouge ewes. Prolificacy was higher in Greyface compared with Texel ewes (P = 0·06) but was lower in Greyface compared with Rouge ewes (P < 0·001). Prolificacy was similar in Greyface and Texel × Greyface ewes mated to Texel rams and in Greyface and Rouge × Greyface ewes mated to Rouge rams. The level of dystocia was similar in Greyface and Texel × Greyface ewes but significantly higher in Texel ewes (P < 0·001). The proportion of Rouge genes in the ewe had no effect on the level of dystocia. Litter weight of lambs at birth was significantly heavier in Greyface (P < 0·001) and Texel × Greyface (P < 0·01) ewes compared with Texel ewes. The proportion of Rouge genes in the ewe had no significant effect on litter weight. Lamb mortality (no. of lambs born dead and died birth to weaning) was significantly greater with Rouge ewes compared with the other ewe breed types (P < 0·001). The number of lambs which died from birth to weaning was lower with Texel × Greyface compared with Greyface ewes (P < 0·01). Expressed on a unit metabolic weight basis, Greyface ewes produced a significantly greater weight of lamb compared with Texel (P < 0·05) and Rouge ewes (P < 0·001). Texel × Greyface ewes produced a significantly greater weight of Texel-sired lamb compared with Greyface (P < 0·01) and Texel ewes (P < 0·001).Sire had a significant effect on a number of parameters. The number of productive ewes was significantly lower in ewes mated with Texel sires (P < 0·001). Lamb birth weights and pre-weaning growth rates were greater with Rouge sires (P < 0·05). Number of lambs weaned per ewe lambed was significantly greater with Texel sires (P < 0·01). Overall weight of weaned lamb produced per ewe was not significantly affected by sire breed.
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Clune, Thomas, Amy Lockwood, Serina Hancock, Andrew N. Thompson, Sue Beetson, Angus J. D. Campbell, Elsa Glanville, et al. "Abortion and Lamb Mortality between Pregnancy Scanning and Lamb Marking for Maiden Ewes in Southern Australia." Animals 12, no. 1 (December 21, 2021): 10. http://dx.doi.org/10.3390/ani12010010.
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The contribution of abortions to the overall mortality of lambs born to maiden (primiparous) ewes in Australia remains unclear. This cohort study aimed to quantify abortion and lamb mortality for ewe lambs and maiden Merino two-tooth ewes. Lamb mortality from pregnancy scanning to marking were determined for 19 ewe lamb and 11 Merino two-tooth ewe flocks across southern Australia. Average lamb mortality from scanning to marking was 35.8% (range 14.3–71.1%) for the ewe lambs and 29.4% (range 19.7–52.7%) for the two-tooth ewes. Mid-pregnancy abortion was detected in 5.7% of ewes (range 0–50%) in the ewe lamb flocks and 0.9% of ewes (range 0–4.4%) in the two-tooth ewe flocks. Mid-pregnancy abortion affecting ≥2% of ewes was observed in 6/19 ewe lamb flocks and 2/11 two-tooth ewe flocks. Lamb mortality from birth to marking represented the greatest contributor to foetal and lamb mortality after scanning, but mid-pregnancy abortion was an important contributor to lamb mortality in some ewe lamb flocks. Variability between the flocks indicates scope to improve the overall reproductive performance for maiden ewes by reducing foetal and lamb losses. Addressing mid-pregnancy abortion may improve the reproductive performance in some flocks.
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Hocking Edwards, J. E., E. Winslow, R. Behrendt, D. J. Gordon, G. A. Kearney, and A. N. Thompson. "Crossbred ewes gain more weight and are fatter than Merino ewes when managed together but similar coefficients predict lamb birthweight and survival." Animal Production Science 59, no. 4 (2019): 767. http://dx.doi.org/10.1071/an17686.
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Current Australian ewe management guidelines are based on research from Merino ewes and have been transposed to crossbred ewes. It is unknown whether guidelines developed for Merino ewes are applicable to crossbred ewe production systems. To investigate this, the effect of ewe liveweight and condition score profile during pregnancy on lamb birthweight and survival for Border Leicester × Merino (BLM) crossbreds was compared with Merino ewes. Condition score profiles of 720 Merino and 680 BLM ewes were managed from 50 days after ram introduction to achieve one of four target condition scores at lambing. There were three replicates of the four target condition score treatments and both breeds of ewes were in each plot. By Day 140 after rams in, the BLM ewes were fatter (P < 0.001) and heavier (P < 0.001) than the Merino ewes, despite being managed in the same plots. Liveweight at conception and change in liveweight in late pregnancy of the Merino and BLM ewes had a similar effect on the birthweight and weaning weight of their lambs. However, birthweight and weaning weight of lambs from BLM ewes was less sensitive to ewe liveweight change in early pregnancy. Birthweight survival curves were similar in lambs from Merino and multiple-born lambs from BLM ewes, and the survival of lambs from multiple-bearing BLM ewes responded to manipulation of condition score in a similar pattern to lambs from Merino ewes. Therefore, managing liveweight or condition score of multiple-bearing BLM ewes is likely to improve lamb survival in a similar fashion to lambs from Merino ewes, although the absolute response in survival will be smaller than that achieved in Merino ewes at the same condition score. In addition, it is important to manage liveweight of both single and multiple-bearing BLM ewes during pregnancy to optimise weaning weight of their lambs, as those lambs born to BLM ewes of low liveweight were significantly lighter at weaning.
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Dawson, L. E. R., A. F. Carson, and L. O. W. McClinton. "Comparison of the productivity of Texel and Rouge de l’Ouest ewes and their crosses." Animal Science 75, no. 3 (December 2002): 459–68. http://dx.doi.org/10.1017/s1357729800053224.
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AbstractAn experiment was undertaken to compare the productivity of crossbred ewes, produced by crossing Texel sires with Rouge de l’Ouest (Rouge) dams and Rouge sires with Texel dams, relative to purebred Texel and Rouge ewes. The purebred and crossbred ewes were crossed with Rouge and Texel sires. The proportion of productive ewes was similar in the purebred and crossbred ewes with an average figure of 0·92. Irrespective of crossing sire, Rouge ewes produced 0·48 more lambs per ewe lambed than Texel ewes (P < 0·001). The two crossbred ewe types (Texel ✕ Rouge and Rouge ✕ Texel) each produced similar numbers of lambs (on average 1·92 lambs per ewe lambed). Individual heterosis values for ewe fertility and prolificacy were small and not significant (–1·67 for the proportion of productive ewes and –3·14 for the number of lambs born per ewe lambed). Maternal heterosis values were also not significant but were of larger magnitude (6·26 for ewe fertility and 3·12 for prolificacy). Lamb mortality (number of lambs born dead per ewe lambed) at birth was similar for purebred Rouge (0·44) and Texel (0·30) ewes and was significantly reduced by crossbred matings and mating the crossbred ewes (individual heterosis –30·68, P < 0·10; maternal heterosis –80·23, P < 0·001). Individual and maternal heterosis values for lamb growth rate from birth to six weeks were 8 (P < 0·05) and 4 (P > 0·05) respectively. Lamb growth rate from birth to weaning was significantly lower in lambs from Texel ewes compared with those from the other genotypes (P < 0·05). Individual and maternal heterosis values for live-weight gain from birth to weaning were 5 (P < 0·10) and 5 (P < 0·01). The results of the current study demonstrate the superior performance of purebred Rouge ewes compared with purebred Texel ewes in terms of prolificacy and lamb growth rate from birth to weaning. However, both breeds had high lamb mortality at birth. Crossbreeding led to the production of hybrid ewes which had relatively high prolificacy with low levels of dystocia and lamb mortality.
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Croker, KP, RJ Lightfoot, TJ Johnson, NR Adams, and MJ Carrick. "The effect of selection for resistance to clover infertility on the reproductive performances of Merino ewes grazed on oestrogenic pastures." Australian Journal of Agricultural Research 40, no. 1 (1989): 165. http://dx.doi.org/10.1071/ar9890165.
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Rams were bred from ewes which had either maintained their fertility after grazing highly oestrogenic pastures for three to seven years. or, over the same period grazed �control� on or lowly oestrogenic pastures In 1977 and 1978 these rams were joined with a random selection of ewes, which had been grazed on lowly oestrogenic pastures, to produce contemporary Resistant and Control ewes.The Resistant and Control ewes were split at weaning into groups which subsequently were grazed on oestrogenic or non-oestrogenic pastures during each pasture growing season (May to October) of the experiment During the dry spring-summer period the ewes were regrouped and entire rams were joined with them for 42 days from early in January to determine whether resistance to the development of clover infertility had been inherited.The reproductive performances of the ewes were measured from two until eight years of age over the period from 1979 to 1986. In addition, the masculinization of the vulvas was monitored, mucus product ion was measured in the second last year, and the histology of the cervixes was observed when the experiment was terminated.The fertility of the Resistant ewes was affected by the oestrogenic pasture in the later years of the experiment, but the level of depression was significantly lower than that measured in the Control ewes grazed on oestrogenic pasture The realized 'heritability' of the ewes' fertile lifetime on oestrogenic pasture was estimated to be 0.73 with a standard error of 0.30.This resistance was associated with histological changes, which confirmed that the Resistant ewes were protected against oestrogen-induced damage. These results support the hypothesis that res istance to the development of clover infertility was present in these ewesA more intensive selection programme involving both ewes and rams may impart a higher level of resistance to ewes This would reduce the adverse effects of oestrogenic pastures on ewe flock productivity.
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Zywicki, Micaela E., Sharon E. Blohowiak, Ronald R. Magness, Jeffrey L. Segar, and Pamela J. Kling. "Impact of the ovarian cycle and pregnancy on plasma chemistry values in ewes." Journal of Veterinary Diagnostic Investigation 30, no. 2 (January 2, 2018): 238–44. http://dx.doi.org/10.1177/1040638717752217.
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Normative data for plasma chemistry values in pregnant and non-pregnant reproductive age ewes are scant. Availability of data would aid monitoring of ewe health for both research and veterinary medicine. We determined specific plasma chemistry 95% confidence reference intervals (RIs) in non-pregnant and pregnant ewes. Mixed Western-breed ewes were grouped based on phase of ovarian cycle: luteal ( n = 15), follicular ( n = 17), or late-gestation pregnant ( n = 102). Plasma samples were collected for analysis on a commercial biochemical analyzer. For RIs, chemistry panels for the 3 groups of ewes included nutrients and metabolites (glucose, triglycerides, cholesterol, urea, creatinine, total protein, albumin, and bilirubin), enzymes (lactate dehydrogenase, aspartate transaminase, gamma-glutamyl transferase, alanine aminotransferase, and alkaline phosphatase [ALP]), and micronutrients (calcium, phosphorus, iron, sodium, potassium, and chloride). Sample chemistry values for glucose and total protein in pregnant ewes were lower than in follicular ewes; cholesterol was lower in pregnant and luteal ewes than in follicular ewes. In addition, total bilirubin in pregnant ewes differed from that in luteal ewes, and that in follicular ewes also differed from luteal ewes. ALP in pregnant ewes was higher than other groups; phosphorus in pregnant ewes was lower than in luteal ewes. Iron was higher in pregnant ewes than in luteal ewes, with iron in luteal ewes lower than in follicular ewes. These data provide clinical RIs comparing pregnant and non-pregnant ewes for use in monitoring ewe health in both human research and veterinary medicine.
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Owen, J. B., Sarah R. E. Crees, Janet C. Williams, and D. A. R. Davies. "Prolificacy and 50-day lamb weight of ewes in the Cambridge sheep breed." Animal Science 42, no. 3 (June 1986): 355–63. http://dx.doi.org/10.1017/s0003356100018134.
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ABSTRACTThe paper describes the results of the analysis of over 3000 records of Cambridge sheep kept on 11 farms over a 12-year period. The heritability of the number of lambs born per ewe increased from a low value for the 1-year-old ewes to a high value for the 3-year-old ewes; the multiple age value for 2-, 3- and 4-year-old ewes was 0·33 (s.e. 0-121). Heritability estimates for number of lambs surviving were lower, but showed the same trend of increasing values with increasing ewe age. This trend in heritability was also evident for the mean 50-day lamb weight, as a trait of the ewe, which had a multiple age value of 0·20 (s.e. 0·151). The estimates of heritability of various measures of early lamb mortality were relatively low. Date of first oestrus showed a variable heritability although the multiple age value was 0·42 (s.e. 0·149).Prolificacy was strongly correlated with various measures of early lamb mortality although the correlation with the final number of lambs weaned was positive. Prolificacy was positively correlated with the ewe's mature weight and the ewe's date of first oestrus and the genetic correlation with mean 50-day lamb weight was slightly positive.The effect of increases in prolificacy on numbers of lambs weaned was markedly curvilinear with maximum numbers of lambs weaned at an intermediate level of prolificacy.
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Corner, R. A., P. R. Kenyon, K. J. Stafford, D. M. West, N. Lopez-Villalobos, S. T. Morris, and M. H. Oliver. "Effect of nutrition from mid to late pregnancy on the performance of twin- and triplet-bearing ewes and their lambs." Australian Journal of Experimental Agriculture 48, no. 5 (2008): 666. http://dx.doi.org/10.1071/ea07033.
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This experiment was conducted to determine the effect of two different feeding levels on ewes during mid and late pregnancy on lamb birthweight and growth to weaning. Twin- and triplet-bearing Romney ewes (n = 80 and 56, respectively) were allocated to one of two feeding regimes and provided pastures with an average sward height of less than 2 cm (~700 kg dry matter/ha) or greater than 4 cm (~1300 kg dry matter/ha). Ewes were allocated to these feeding regimes during mid pregnancy (day 70–107 of pregnancy; P70–P107) and were reallocated in late pregnancy (P108–P147). This resulted in four sward height treatments: 2–2, 2–4, 4–2 and 4–4. During mid pregnancy, ewes provided with >4-cm-high swards had liveweight gains of 262–290 g/day compared with 12–31 g/day for ewes provided with <2-cm-high swards. In late pregnancy, ewe liveweight gains were influenced by the ewes’ previous nutritional treatment. Ewes in the 2–4 treatment had higher daily gains (538 g/day) than 4–4 ewes (343 g/day). In addition, 4–2 ewes gained 90 g/day compared with 247 g/day for 2–2 ewes. Throughout pregnancy, triplet-bearing ewes were heavier (P < 0.05) than twin-bearing ewes, but during lactation ewe weights were similar. On P130, ewes provided with <2-cm-high swards (4–2 and 2–2) had greater β-hydroxybutyrate (P < 0.05) and lower glucose (P < 0.05) plasma concentrations than ewes provided with >4-cm-high swards (2–4 and 4–4). On P139, however, ewes provided with 4–4 swards had higher plasma non-esterified fatty acid and β-hydroxybutyrate concentrations than ewes in all other treatments. Lambs born to ewes in the 4–4 treatment had the greatest birthweights (P < 0.05), whereas lambs born to 2–2 ewes had the lowest birthweights. The birthweight of lambs born to 2–4 ewes was similar to that of lambs born to ewes provided with 4–2 and 4–4 swards. At weaning, ewe weights were similar between ewe nutritional treatments and ewes bearing twin or triplet fetuses. These findings suggest that when pasture growth is inadequate to provide pasture sward heights of 4 cm throughout pregnancy, restricted intake in mid-pregnancy may be partially compensated by providing additional pasture in late pregnancy.
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Younes, M. A., N. F. G. Beck, M. T. Rose, and B. Davies. "Comparison of ovarian oestradiol and progesterone secretion, in vitro, between ewe lambs and ewes." Proceedings of the British Society of Animal Science 2005 (2005): 149. http://dx.doi.org/10.1017/s1752756200010607.
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Reproductive performance of ewe lambs is lower than that of adult ewes (Quirke 1979). This is mainly the result of preimplantation losses, which can exceed 50% of fertilised eggs. Previous evidence from this laboratory suggests that these losses may be associated with abnormal ovarian hormone production (Davies and Beck 1993). Khan (1999) demonstrated that blood progesterone levels during the oestrous cycle and pregnancy were lower in ewe lambs than in ewes. Furthermore, both progesterone and oestradiol concentrations were lower in ewe lambs, than in ewes, following gonadotrophin stimulation (Khan, Beck and Khalid 1999). These results suggest that ewe lamb corpora lutea and follicles secrete less progesterone and oestradiol, respectively, than those of ewes. The aim of this study was to determine whether there is a difference in vitro steroid hormone production by corpora lutea and follicles, from ewe lambs and ewes.
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Fogarty, NM, DG Hall, and WR Atkinson. "Productivity of three crossbred ewe types mated naturally at 8-monthly intervals over two years." Australian Journal of Agricultural Research 43, no. 8 (1992): 1819. http://dx.doi.org/10.1071/ar9921819.
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Productivity is reported for 175 Booroola MerinoxPoll Dorset (BD), 288 Trangie Fertility MerinoxPoll Dorset (TD) and 248 Border LeicesterxMerino (BLM) ewes joined three times (February, October and June) in 2 years. Overall joining in February resulted in higher performances (153�3% lambs born, 118�3% lambs weaned, 24.7�0.6 kg weight of lamb weaned, per ewe joined) than were obtained following October and June joinings (129�4% born, 93�3% weaned, 15.3�0.5 kg weight weaned per ewe joined). The mean number of lambings per year was 1.28�0.02 with an annual lambing rate of 211�4% lambs born and 160�3% lambs weaned. For lambs born, BD ewes were consistently higher than the other ewes, with BLM ewes having fewer lambs born from October and June joinings (P < 0.01). From the October joining, TD ewes had a higher weaning rate than BD ewes which were higher than BLM ewes (P < 0.01), but ewe type was not significant for the other two joinings. Over the three joinings there were no differences between the ewe types in the number of lambings per year or percentage of lambs weaned, but BD had more lambs born (239� 7%) than TD (212�5%) and BLM (181�5%). Analyses of the components of reproduction that contributed to overall lamb production showed that although more than 95% of ewes expressed oestrus in each season, fertility and litter size were higher from the February joining, while lamb survival was lower following the June joining. Ewe crossbred type was significant (P < 0.01) for litter size in all seasons. Litter size for BD ewes was 1.9 to 2.0, and for TD ewes was 1.6 to 1.7 at all seasons, while that for BLM ewes was 1.7 from February and 1.2 and 1.4 from October and June joinings respectively. The effects of ewe liveweight at joining and liveweight gain over joining were variable over the three joinings, but were generally small. BD ewes carrying the F gene tended to have a higher percentage of lambs born and lower percentage of lambs weaned than non-carriers. There was also a decline in lamb production, especially fertility and lamb survival, with ewe age among BD and TD ewes. Implications for production systems in the lamb industry are discussed.
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DAWSON, L. E. R., and A. F. CARSON. "Effects of crossbred ewe genotype and ram genotype on ewe prolificacy, lamb viability and lamb output in the lowland sector." Journal of Agricultural Science 139, no. 2 (September 2002): 169–81. http://dx.doi.org/10.1017/s0021859602002381.
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A study was carried out on five lowland farms in Northern Ireland over 3 years to investigate the effect of crossbred ewe and ram genotype on ewe prolificacy, lamb viability and weaned lamb output. Four crossbred ewe genotypes were sourced from six hill farms involved in a previous study – Bluefaced Leicester×Blackface (BLXB), Texel×Blackface (TXB), Suffolk×Cheviot (SXCH) and Texel×Cheviot (TXCH). On each farm, groups of 20–30 of each crossbred ewe genotype were mated with Suffolk or Texel rams. Throughout the 3 years of the study, the ewe genotypes lambed at 1, 2 and 3 years of age. Within each of the ram breeds, high lean growth index rams sourced from UK sire reference schemes were compared with rams sourced from flocks not involved in objective genetic improvement programmes (control). BLXB ewes were the most prolific of the four ewe genotypes producing 1.73 lambs per ewe lambed compared with 1.47 for TXB, 1.46 for SXCH and 1.41 for TXCH (P<0.001). Lamb mortality was similar for the four ewe genotypes, thus number of lambs weaned was greatest for the BLXB ewes (P<0.001) with the other three crosses producing similar numbers of lambs. A greater proportion (P<0.05) of SXCH ewes lambed without assistance compared with BLXB and TXB ewes and a greater proportion of TXCH ewes had abundant supplies of colostrum compared with the other crosses (P<0.10). Output of weaned lamb per ewe lambed and per ewe metabolic live weight (P<0.001) was greatest in the BLXB ewes. Ewe productivity, prolificacy, number of lambs weaned and the proportion of ewes lambing without assistance increased with ewe age (P<0.001). Lamb growth rate from birth to 6 weeks and from birth to weaning increased with ewe age (P<0.05). Crossbred ewes lambing at 3 years old had a greater output of weaned lamb compared with ewes lambing at 1 and 2 years old (P<0.001). Ram genotype had no effect on ewe prolificacy, lamb viability or pre-weaning growth rates, although Texel-sired lambs had lower birth weights than Suffolk-sired lambs and control-sired lambs had lower birth weights than high lean index-sired lambs (P<0.05).
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Aktaş, A. H., Ş. Dursun, Ş. Doğan, Z. Kiyma, U. Demirci, and İ. Halıcı. "Effects of ewe live weight and age on reproductive performance, lamb growth, and survival in Central Anatolian Merino sheep." Archives Animal Breeding 58, no. 2 (December 10, 2015): 451–59. http://dx.doi.org/10.5194/aab-58-451-2015.
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<p><strong>Abstract.</strong> The aim of this study was to evaluate the effects of premating ewe weight and age on ewe reproductive performance, lamb growth and survival in Central Anatolian Merino (CAM) sheep. <br><br> The trial included 4935 ewes and 5548 lambs from 23 breeder flocks in Eskişehir Province. The live weights (LWs) and ages of the ewes were recorded 1 week before the mating season. The number of lambs born, fertility rate, multiple birth rate (MBR), and lamb survival rate (SR) at days 75 and 120 were determined. The effects of the LW and age of the ewe were found to be important for the reproductive performance of ewes and for the lamb's growth rate (<i>P</i> < 0.05–0.001). Ewe MBRs and the birth weight (BW) and LW of the lambs at days 75 and 120 increased proportionally with the increase in LW in ewes prior to mating. The fertility rate and MBR were lower (<i>P</i> < 0.05–0.001) in 1.5-year-old ewes than in older ewes. However, lambs' SR at days 75 and 120 were not affected by the premating LW and age of the ewe. In summary, a better reproductive performance and lamb growth rate in CAM flocks may be achieved by the selection of breeding ewes from ewes weighing more than 60 kg.</p>
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Kenyon, P. R., R. E. Hickson, P. G. Hutton, S. T. Morris, K. J. Stafford, and D. M. West. "Effect of twin-bearing ewe body condition score and late pregnancy nutrition on lamb performance." Animal Production Science 52, no. 7 (2012): 483. http://dx.doi.org/10.1071/an12085.
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This study aimed to investigate the effects of ewe body condition score and nutrition on twin-bearing ewes and their offspring. At maximum Day 112 of pregnancy (range 96–112 days), 185 twin-bearing ewes were allocated to either a ‘Medium’ or ‘ad libitum’ (Adlib) feeding treatment for the following 25 days (P112–P136). Each feeding treatment included ewes of body condition score: 2.0 (CS2.0, Medium n = 32, Adlib n = 28), CS2.5 (Medium n = 31, Adlib n = 33) or CS3.0 (Medium n = 30, Adlib n = 31). After P136 ewes were offered Adlib feeding conditions. Medium treatment ewes were lighter (P < 0.05) than Adlib ewes at P136 and P142 and displayed lower (P < 0.05) body condition score at P136 and back-fat depths at P142. CS2.0 ewes had lower (P < 0.05) liveweights and body condition score at P112, P136 and P142 than CS2.5 ewes, which in turn had lower (P < 0.05) liveweight and body condition scores than CS3.0 ewes. Ewe feeding treatment had no effect (P > 0.05) on lamb liveweight or apparent colostrum intake. Ewe body condition score had no effect (P > 0.05) on lamb birthweight or apparent colostrum intake. Lambs born to CS2.0 ewes had greater (P < 0.05) survival than lambs born to CS2.5 ewes. At the end of the study lambs born to CS2.0 ewes were lighter (P < 0.05) than those born to CS2.5 and CS3.0 ewes although, there was (P > 0.05) no effect of condition score on total litter liveweight. In conclusion, these results suggest twin-bearing ewes of body condition 2.0–3.0 can be offered restricted feeding levels to at least Day 136 of pregnancy with few implications for their lambs.
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Esmailizadeh, A. K., O. Dayani, and M. S. Mokhtari. "Lambing season and fertility of fat-tailed ewes under an extensive production system are associated with liveweight and body condition around mating." Animal Production Science 49, no. 12 (2009): 1086. http://dx.doi.org/10.1071/an09064.
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The objective of this study was to investigate to what extent fertility and lambing season of fat-tailed ewes raised under an extensive production system are related to liveweight, body condition and changes around mating. Ewe liveweight and body condition score (BSC) were recorded in June, July and August over a period of 3 years (1999–2001) in 11 flocks (eight flocks of Kurdi breed and three flocks of Kurdi × Sanjabi crossbred). Both Kurdi and Sanjabi are native fat-tailed breeds in western Iran. In total, 3278 lambing records relating to 1592 ewes and data on mating date, liveweight and BCS of 1930 ewes (3975 records) were used for statistical analyses. The statistical model for bodyweight and body condition data included fixed effects of breed group, flock nested within breed group, year, the future lambing status following summer breeding (barren, autumn lambing and winter lambing), ewe age and all two-way interactions. Breed group had a significant effect on ewe liveweight (P < 0.01). However, there was no significant difference between BCS of the two breed groups around mating. Ewe liveweights measured in June, July and August had significant effects on fertility and lambing season (P < 0.01). Ewes that produced lambs were generally heavier at mating than barren ewes (P < 0.01). Autumn-lambing ewes were heavier than winter-lambing ewes in June and July (P < 0.01). Effects of changes in liveweight on fertility and lambing season were significant (P < 0.01). The effects of BCS in June, July and August (P < 0.01) and changes in BCS during the mating period (P < 0.05) on fertility and lambing season were also significant. The mean BCS (in June and July) of autumn-lambing ewes was greater than that of the winter-lambing and barren ewes (P < 0.05). The proportion of autumn-lambing ewes significantly increased as BCS in July increased, whereas the proportion of barren ewes decreased (P < 0.01). Fertility was associated with age so that as the age of the ewes increased from 2 to 7 years, the proportion of barren ewes significantly decreased from 29 to 5% (P < 0.01). There was a relatively high proportion of very thin ewes of 2 and 3 years of age. These findings imply that low body condition is a particular problem in younger ewes suggesting the importance of giving special nutritional treatment to younger ewes to reduce the proportion of barren ewes.
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Flaherty, Kara, Branden J. Campbell, and Alejandro E. Relling. "240 Evaluating the Effect of Hay, Fed Ad-Libitum or Controlled, or Soybean Hulls During Gestation on Body Weight and Dry Matter Intake of the Ewe and Body Weight on the Offspring Until Weaning." Journal of Animal Science 100, Supplement_2 (April 12, 2022): 125. http://dx.doi.org/10.1093/jas/skac064.213.
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Abstract The objective of this experiment was to evaluate the effect of feeding different types and amount of fiber during gestation on ewe body weight (BW) and dry matter intake (DMI), and lamb BW at birth and weaning (60 d of age). Ninety Dorset × Hampshire ewes were blocked by BW and within each block randomly assigned to 1 of 3 treatments (10 ewes/pen; 3 pens/treatment): ad-libitum hay (CONT), limit-fed hay (LH), and soybean hulls (SH). The concentrate roughage ratio for the LH and SH diets was 1:3. From d 0 (28 d post mating) to d 63, LH and SH ewes were fed using slick bunk management. Ewes in the CONT diet were offered an equal amount of concentrate as LH ewes with ad-libitum access to hay. On d 63 ewes were offered the same diet to meet, but not exceed, maintenance requirements for late gestation. Feed offered and refused were collected daily for LH and SH ewes whereas hay refusal was collected weekly for CONT ewes. Ewe BW was collected on d 28, 34, 76, and 2-d after lambing. Lamb BW was collected at birth and weaning. Data, presented in Table 1, were analyzed as a mixed model considering the fixed effect of treatment and random effects of ewe (pen), pen, and block. Dry matter intake was similar the first 28 d (P = 0.13); however, SH ewes consumed more by d 62 (P = 0.02). As DMI increased, BW of SH ewes also increased during gestation (P ≤ 0.01) but was similar 2-d after lambing (P = 0.21). Lambs born of SH ewes were heavier at birth, but lighter at weaning (P ≤ 0.02). Despite each diet having the same forage concentrate ratio, forage source affected ewe BW during gestation and lamb BW at birth and weaning. Feeding hay ad-libitum or in a controlled manner did not change ewe or lamb BW.
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THOMAS, V. M., E. AYERS, K. HANFORD, and R. KOTT. "INFLUENCE OF LASALOCID ON THE PRODUCTION OF GESTATING EWES IN AN EXTENSIVE GRAZING SYSTEM." Canadian Journal of Animal Science 68, no. 2 (June 1, 1988): 439–44. http://dx.doi.org/10.4141/cjas88-049.
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A winter feeding trial was conducted to evaluate the influence of lasalocid (L) on the production of gestating ewes in an extensive grazing system. Six hundred and sixty ewes were randomized within age and breed and allotted to feed supplements (0.23 kg head−1 d−1) containing either no L (C) or L at 308 mg kg−1 and fed for 84 d during gestation. Ewe weight change within periods (three, 28-d periods) was similar (P > 0.10) with the exception of period 2 where L-supplemented ewes tended to gain more (P < 0.10) weight than C ewes. Total ewe weight change during the wintering period and yearly wool production were not affected (P > 0.10) by treatment. Treatment had no affect (P > 0.10) on the percentage or kilograms of lamb weaned for ewes starting the experiment. Ewes suckling twins and fed L during gestation had less (P < 0.05) lambs bummed (lamb removed from the ewe and sold) or grafted (lamb removal from the ewe and raised by a foster mother) than those in C group and suckling twins. In conclusion, providing L in a supplement to gestating ewes grazing winter range did not significantly alter production with the exception of less twin born lambs being bummed or grafted. Key words: Sheep, lasalocid, gestation, winter range, ewe, lamb
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Lambe, N. R., J. Conington, S. C. Bishop, A. Waterhouse, and G. Simm. "A genetic analysis of maternal behaviour score in Scottish Blackface sheep." Animal Science 72, no. 2 (January 2001): 415–25. http://dx.doi.org/10.1017/s1357729800055922.
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AbstractUnder field conditions, ewe behaviour was quantified by maternal behaviour score (MBS)-a six-point scale which assesses ewe flight distance when lambs are handled for the first time, within 24 h of birth (adapted from O’Connor et al., 1985). MBS was measured on 847 Scottish Blackface ewes on two experimental hill farms, over a maximum of four parities. Live weights of lambs born to these ewes were measured at birth, marking (average age of 42 days) and weaning (average age of 120 days).MBS was significantly higher ( P < 0·05) for ewes with more lambing experience (multiparous ewes), for older ewes and for twin-bearing ewes compared with ewes with single lambs. MBS was under genetic control ( h2 = 0·13, permanent environmental effect = 0·19, when analysed as the same trait across parities) and the repeatability was 0·32.MBS had no significant effects on weight gain of lambs. However, a moderate, positive genetic correlation was estimated between MBS and the average weight gained by lambs from birth to marking ( rg = 0·4, s.e. 0·22), although the genetic correlation estimated between MBS and weight gained to weaning was close to zero ( rg = 0·02, s.e. 0·16). Ewes with a MBS of 1 (ewe flees and does not return to her lambs) had significantly more lambs dying before marking and weaning than ewes with a higher maternal behaviour score. Selection to reduce the proportion of ewes in this category may therefore be beneficial.
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Parr, R. A., A. H. Williams, I. P. Campbell, G. F. Witcombe, and A. M. Roberts. "Low nutrition of ewes in early pregnancy and the residual effect on the offspring." Journal of Agricultural Science 106, no. 1 (February 1986): 81–87. http://dx.doi.org/10.1017/s0021859600061773.
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SUMMARYMature Merino ewes (n = 500) were allotted at random to embryo removal (day 35; day 0 = day of oestrus detection), foetal removal (day 90) or lambing groups. These groups were further randomly divided into four single-sire mating groups. From day 1 until day 35 ewes were individually penned and fed either 50 or 150% of a maintenance ration (0·5 M or 1·5 M respectively). At day 35 single embryos were removed from anaesthetized ewes in the embryo removal group and all other ewes were endoscoped to confirm pregnancy. These ewes were then returned to pasture. Plasma samples were taken from all ewes on days 2, 4, 16, 23, 30 and 35 for analysis of glucose concentration. At day 90, ewes allotted to the foetal removal group were anaesthetized and plasma samples were obtained from the ewe's jugular vein and the umbilical arteryand vein. Ewes were then hysterectomized and the foetus was weighed and measured. Functional cotyledons were dissected from the uterus and chorio-allantois and all tissues were weighed. The remaining ewes (lambing group) were supervised at lambing and lambs were identified, weighed and measured.Live-weight changes from weaning and wool production and quality were measured in ewe and ram lambs at their first shearing (11 months of age). Ovulation rates in the first two oestrous seasons of the ewes and wool production at their second shearing (2 years of age) were also measured.During the 35-day treatment period, mean live-weight changes of ewes were –4·9 and + 1·8 kg in the 0·5 M and 1·5 M groups respectively. Pregnancy rates were similar in both groups but embryos from 0·5 M ewes weighed less than those from 1·5 M ewes (1·7 ± 0·04 ν. 1·9 ± 0·05 g; P < 0·005). Foetuses taken at 90 days from 0·5 M ewes were smaller than those from 1·5 M ewes but these differences reached significance (P < 0·025) only in the measurement of chin–crown length (8·0 ± 0·09 ν. 7·6 ± 0·11 cm). Correlations between foetal weight and total cotyledon weight, chorio-allantoic weight and empty uterine weight were all significant. Plasma glucose concentrations of ewes in the 0·5 M group were significantly (P < 0·001) reduced by day 9. Differences between the two nutrition groups in maternal and umbilical plasma glucose concentrations at day 90 were not significant, though foetuses from 0·5 M and 1·5 M ewes removed a mean of 30 and 11% respectively of available glucose from the umbilical vein. Differences in live weight between 1·5 M and 0·5 M animals at weaning and in the post-weaning period were not significant (P > 0·05). Wool production and woolquality were similar for both groups. Spontaneous ovulation rates measured on four occasions during the postpubertal oestrous season and on three occasions the following year were not significant (P > 0·05). Treatment with pregnant mare's serum gonadotrophin (PMSG) increased ovulation rates in the ewes of both groups; however, the differences failed to reach significance (P > 0·05); mean (± S.e.) ovulations per ewe were 4·8 ± 0·61 ν. 4·6 ± 0·60 for 1·5 M and 0·5 M group ewes respectively.
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Rhind, S. M., W. A. C. McKelvey, S. McMillen, R. G. Gunn, and D. A. Eiston. "Effect of restricted food intake, before and/or after mating, on the reproductive performance of Greyface ewes." Animal Production 48, no. 1 (February 1989): 149–55. http://dx.doi.org/10.1017/s0003356100003883.
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ABSTRACTThe effect on the reproductive performance of Greyface (Border Leicester × Scottish Blackface) ewes of a low level food intake and associated loss of live weight from either 14 days before mating, or from the time of mating, until 11 to 26 days after mating, was investigated. Ewes (252) were allocated to one of three treatments with ewes within each treatment divided into two flocks (flock A: 16 ewes per treatment; flock B: 68 ewes per treatment). Ewes of treatment LL were given a ration providing proportionately 0·5 estimated metabolizable energy (ME) requirements for maintenance from 2 weeks before mating. Those of treatment HL were given a daily ration providing 1·5 estimated ME requirements for maintenance until mating and the restricted ration thereafter. Ewes of treatment HH were given the higher ration throughout the experimental period. Flock A ewes were slaughtered at 11 days post mating and flock B ewes at between 18 and 26 days post mating. Treatment differences in the ovulation rates of flock A ewes were not statistically significant but in flock B, ewes of treatment LL had a lower mean ovulation rate (1·81) than those of treatments HL (2·23) and HH (2·09) (P < 0·001). The lower ovulation rate of LL ewes relative to HL ewes in flock B was reflected in a lower mean potential lambing rate per ewe pregnant than in the HL treatment (1·58 v. 1·79; P < 0·01) and per ewe put to the ram (1·37 v. 1·65; P < 0·01). HL ewes had a slightly lower mean potential lambing rate per ewe pregnant (1·79 v. 1·97; P < 01) and per ewe put to the ram (1·65 v. 1·82; P < 0·05) than HH ewes. Ova wastage rates of LL + HL and HH ewes were 0·26 and 014 (P < 001) respectively at 24 days post mating. Values for LL and HL ewes (0·27 and 0·25 respectively) were not significantly different.Estimated mean conceptus lengths were 370, 500 and 1400 μin for LL, HL and HH ewes respectively (P < 0·05).It is concluded that low food intake before mating reduced the mean ovulation rate and low intakes after mating compromised embryo growth rate and induced a higher rate of ova wastage; this increase in the incidence of ova wastage was not significantly exacerbated by the low levels of intake prior to mating.
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Robertson, S. M., M. B. Allworth, and M. A. Friend. "Survival of lambs from maiden ewes may not be improved by pre-lambing exposure to mature lambing ewes." Animal Production Science 57, no. 6 (2017): 1112. http://dx.doi.org/10.1071/an15830.
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The survival of lambs born to ewes at their first (maiden) lambing is generally lower than for those born to ewes which have previously lambed, and poor maternal behaviour is a contributing factor. This study examined whether pre-lambing exposure of maiden ewes to multiparous lambing ewes would improve the survival of lambs born to maiden ewes. Pregnant maiden (n = 333, 2 years of age) Merino ewes were allocated to three replicates of two treatments: exposed – maidens were grazed with multiparous Merino ewes (n = 111, 5 or 7 years of age), which were due to lamb during the 2 weeks before the start of maiden lambing, with mature ewes comprising 50% of the mob size; and non-exposed – maiden ewes grazed in paddocks without mature ewes. The total number of ewes per paddock (74), number of ewes per hectare (14.0) and paddock size were the same in both treatments. The number of lambs born per ewe was similar between treatments, indicating a similar proportion of multiple births. The proportion survival of lambs from maiden ewes exposed to adults (0.53) tended to be lower (P = 0.091) than the survival of lambs born to maiden ewes grazing alone (0.61). The number of lambs marked per ewe lambing was similar (P = 0.284) in exposed (0.71) compared with non-exposed (0.78) maidens. The survival of lambs from maiden ewes was not improved by lambing in the same paddock with adults, even where the adults had largely completed lambing before the maidens commenced.
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Young, J. M., R. Behrendt, M. Curnow, C. M. Oldham, and A. N. Thompson. "Economic value of pregnancy scanning and optimum nutritional management of dry, single- and twin-bearing Merino ewes." Animal Production Science 56, no. 4 (2016): 669. http://dx.doi.org/10.1071/an15202.
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The nutritional requirements of twin-bearing ewes are ~25% greater than those of ewes with single fetuses during late pregnancy and nearly twice those of non-pregnant ewes. Underfeeding ewes, resulting in liveweight loss during late pregnancy, can have adverse effects on the production and survival of both the lamb and the ewe, and improving twin-lamb survival is critical to improving the overall reproductive performance of the National Merino flock. Scanning for pregnancy status and litter size allows for more precise management of the nutrition of the ewe flock according to the different nutritional needs of dry, single- and twin-bearing ewes. In the present paper, we tested the hypothesis that it is profitable to identify pregnancy status and litter size, and the optimum nutrition profiles are different for dry, single- and twin-bearing ewes. We tested this by examining a range of nutrition strategies for flocks where only the dry ewes were identified, or for flocks where the single- and twin-bearing ewes were identified. A MIDAS model set up for the Hamilton region in south-western Victoria was used for this analysis as it represents the whole flock and it includes a powerful feed-budgeting module that optimises animal and pasture management across the whole farm. The survival and production of the single- and twin-born progeny was adjusted on the basis of the liveweight profile of the single- and twin-bearing ewes. Our hypothesis was supported and profitability was increased by approximately AU$4630/farm or AU$0.80/ewe, by scanning ewes for pregnancy status and litter size, and the optimum liveweight profiles were different for dry, single- and twin-bearing ewes. The majority of the increase in profit was due to identifying litter size and being able to differentially manage the single- and twin-bearing ewes. When ewes are scanned for pregnancy status and litter size, the most profitable combination of profiles involves all ewes losing 4 kg in early pregnancy and single-bearing ewes regaining the 4 kg to lamb at their standard reference weight, twin-bearing ewes gaining 8 kg to lamb above their standard reference weight and dry ewes losing a further 4 kg to be 8 kg lighter than their standard reference weight at lambing time.
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Fogarty, NM, and DG Hall. "Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 3. Reproduction, liveweight and wool production of adult ewes." Australian Journal of Experimental Agriculture 35, no. 8 (1995): 1083. http://dx.doi.org/10.1071/ea9951083.
Full textAbstract:
Reproduction, liveweight and wool production are reported for 4 cohorts of 377 Trangie Fertility x Dorset (TD) and 261 Booroola x Dorset (BD) ewes over 6 years. The BD ewes were 3-4 kg lighter (P<0.001) and had a higher ovulation rate prior to joining in February-March (2.37 � 0.03 v. 1.65 � 0.03) than TD ewes. This resulted in a higher litter size (2.07 � 0.03 v. 1.66 � 0.04) and number of lambs born per ewe joined (1.92 � 0.04 v. 1.56 � 0.04) for the BD ewes. Lamb survival was lower from BD than TD ewes (0.71 � 0.02 v. 0.85 � 0.02), so that the 2 ewe strains weaned the same number of lambs. The growth rate of lambs was lower from the BD ewes and overall they weaned 3.8 kg less (P<0.001) weight of lamb than TD ewes. Chill (index of environmental conditions at lambing), litter size and average birth weight of lambs in the litter (linear and quadratic) affected (P<0.001) lamb survival. At moderate levels of chill there was little difference in survival of single and twin lambs from BD and TD dams when birth weight was 4-5 kg, but survival declined more rapidly for progeny of BD ewes at lower birth weight. Under severe lambing conditions survival was depressed more for lambs born from BD ewes than TD ewes. Almost all ewes expressed oestrus over the 3, 6-week periods, December-January, January-February and March (joining). There was significant variation (P<0.001) in incidence of oestrus due to year and age (linear and non-linear), but not liveweight at joining, and there was little difference between ewe strains. Similarly, for post-lambing oestrus (to fit 8-monthly joining) and post-lambing anoestrous interval, there was little difference between strains, but year and age were highly significant (P<0.001). BD ewes had a lower (P<0.001) greasy fleece weight (3.76 v. 3.86 kg), than TD ewes. BD ewes were classified as either carriers (F+) or non-carriers (++) of the FecB gene, which was significant (P<0.001) for ovulation rate (+1.14 ovulations), litter size (+0.8 lambs), lamb survival (-18%), lambs born per ewe joined (+0.64 lambs) and total weight of lamb born per ewe joined (0.5 kg, P<0.01). The effect of the FecB gene was non-significant for lamb survival when litter size and lamb birth weight (P<0.001) were included in the model. Repeatability estimates based on over 3 records per ewe were about 0.2 for lambs born, weight of lamb born, lambs weaned and weight of lamb weaned per ewe joined. Component traits ranged from 0.27 for litter size to 0.10 for lamb survival, with fertility intermediate (0.15). Greasy fleece weight (0.72) and ovulation rate (0.41) had high repeatabilities with post-lambing anoestrous interval being low (0.11). Repeatability for ovulation rate was reduced to 0.34 when F+ ewes were excluded.
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Williams, AJ, and J. Butt. "Wool growth of pregnant Merino ewes fed to maintain maternal liveweight." Australian Journal of Experimental Agriculture 29, no. 4 (1989): 503. http://dx.doi.org/10.1071/ea9890503.
Full textAbstract:
The wool production at the midside of 15 non-mated Merino ewes was compared with that of their monoctocous (n = 20) and dioctocous (n = 13) flockmates during the second half of pregnancy. The ewes were compared under experimentally controlled feeding conditions designed to maintain the liveweight of each ewe, exclusive of the weights of fleece and conceptus, by progressively increasing the quantities of a sorghum grain and lucerne chaff diet (1:1 by weight) offered to the pregnant ewes. During the latter half of pregnancy, each non-mated ewe consumed 42.1 kg of the diet. The single- and twinbearing ewes consumed 27 and 44% more of the diet than did the non-mated ewes. The adjusted liveweight of the non-pregnant ewes increased by 0.03 kg/week, while those of the monoctocous and dioctocous ewes changed by 0.11 and -0.05 kg/week (s.e.= � 0.04). These changes in liveweight were small but differed between the ewe classes (P<0.05). The rate of wool production per unit area of skin at the midside was 411 �g/cm2.day, with no significant differences between the ewe classes, and with no interactions between ewe classes and period of measurement. The wool produced on the midside had an average fibre diameter of 19.0 �m, again with no significant differences between ewe classes or periods. The length of fibre grown during the latter half of pregnancy was 26.1 mm, with no difference between the ewe classes. We conclude that a loss of wool production is not an obligate consequence of pregnancy, but can be prevented by nutritional management that recognises the additional requirements of the pregnant ewe for nutrients.
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Sarvinda, Diahanvika Tri, Sigit Bintara, I. Gede Suparta Budisatria, Kustantinah Kustantinah, and Endang Baliarti. "The Effect of Flushing Premating with Spirulina Platensis Supplementation on Ewes Postpartum Estrus." Buletin Peternakan 46, no. 1 (February 27, 2022): 31. http://dx.doi.org/10.21059/buletinpeternak.v46i1.67523.
Full textAbstract:
Lactating ewes require high nutrients for basic life requirements and milk production. If not fulfilled, it can have an impact on Negative Energy Balance (NEB) that reduces body weight, Body Condition Score (BCS), and extend the appearance of Postpartum Estrus (PPE). Premating flushing feed is an effort to improve ewe nutrients by adding high nutrition for preparation before mating so that after lambing and suckling, the ewe immediately estrus. This research aimed to evaluate the performance of ewes through premating flushing feeding. The research was conducted at Mendo Galak Farm, Sleman, Yogyakarta. Twenty ewes 2-3 years old with BCS 2-3 divided into two groups; the group with flushing treatment consisted of dried water spinach (Ipomoea reptans poir), concentrate feed with Spirulina sp. (14,92% crude protein, 60,28% total digestible nutrients), and the control group (PS) without Spirulina sp. (crude protein 11,82%, total digestible nutrients 53,20%). Flushing feed was given after a month postpartum as much as 3% dry matter of body weight. The recorded parameter was daily feed consumption, monthly body weight, BCS, and postpartum estrus. The data obtained were tested by an independent T-test with Statistical Product and Service Solution (SPPS ver. 22). The results showed the consumption and digestibility of CP, TDN, and ewe's ADG had a significant difference (P<0.05). Postpartum estrus (PPE) of flushed ewes had no significant difference (P>0.05), 73.90±11.55 vs. 77.60±14.65 days, respectively. The conclusion was that flushing premating treatment with the addition of Spirulina platensis increased the nutrient intake and digestibility of CP, TDN, and ADG but had not shortened on postpartum estrus of lactating ewes.
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Kassem, R., J. B. Owen, and I. Fadel. "A note on the characteristics of oestrus and ovulation in Awassi ewes." Animal Science 50, no. 1 (February 1990): 198–201. http://dx.doi.org/10.1017/s000335610000461x.
Full textAbstract:
The length of the oestrous cycle observed in 20 ewe lambs and 424 ewes of the Awassi breed gave mean values of 16·4 (s.d. 1·31) days for ewe lambs and 17·4 (s.d. 1·84) days for ewes. Plane of nutrition did not affect cycle length in ewe lambs and age of ewe (from 2 to 5 years) did not affect oestrous cycle length in ewes (P > 0·05). Of 40 ewes treated with progesterone intravaginal sponges 33 (83%) showed oestrus and 28 (70%) ovulated at the first (synchronized) and 31 (78%) and 30 (75%) at the repeat oestrus. Mean duration of oestrus was 40·0 (s.d. 16·37) h (range 8 to 72) for the first and 34·7 (s.d. 11·19) h (range 16 to 54) for the repeat oestrus. Ovulation rate, measured in the same ewes, gave mean values of 1·18 (s.d. 0·460) for the first and 1·223 (s.d. 0·440) for the repeat oestrus.
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Fogarty, NM, DG Hall, ST Dawe, W. Atkinson, and C. Allan. "Management of highly fecund ewe types and their lambs for 8-monthly lambing. 1. Effect of lamb weaning age on ewe reproductive activity in spring." Australian Journal of Experimental Agriculture 32, no. 4 (1992): 421. http://dx.doi.org/10.1071/ea9920421.
Full textAbstract:
The spring reproductive activity of ewes following a late winter lambing, and varying duration of suckling or lamb weaning age of 6-13 weeks, was investigated in 321 Booroola Merino x Dorset (BD) and 543 Trangie Fertility Merino x Dorset (TD) ewe records over 2 years and 238 Border Leicester x Merino (BLM) ewes in the second year. The ewes were joined about 12 weeks post-partum in November for 6 weeks, following lambing in July-August to conform to an %-monthly lambing regime. In the first year, ewes were run with vasectomised rams and oestrus, ovulation rate, and interval to first observed oestrus were determined under a simulated joining regime. In the second year entire rams were joined in spring following July-August lambing and oestrus, pregnancy, fetal number, lambs born per ewe joined and lambing interval were analysed. Amongst ewes rearing lambs, longer suckling significantly increased the interval to first oestrus and the lambing interval (P<0.01), but had no effect on the percentage of ewes expressing oestrus, percentage of pregnant ewes or lambs born. Significantly fewer ewes that lambed but failed to rear any lambs (LL), than ewes rearing lambs expressed oestrus, ovulated and became pregnant. This resulted in considerably lower lambing rates for LL ewes (95.8 v 137.2% lambs born, P<0.01). Reproductive activity was not greatly affected by ewe liveweight or liveweight gain during joining. BD and TD ewes had hgher pregnancy and lambing rates and a shorter lambing interval than BLM ewes. Ovulation rate and fetal number increased with the number of lambs being reared (0.20 � 0.08 and 0.11 � 0.04 per lamb, P<0.05). The results show that high pregnancy and lambing rates can be achieved from natural joining in the spring following late winter lambings within an 8-monthly lambing regime, when lambs are weaned prior to joining.
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M. H. Zebari, Hawar. "Factors That Influence on Reproductive Efficiency in Karadi And Awassi Sheep Raised under Traditional Conditions." Journal Of Duhok University 23, no. 2 (December 14, 2020): 169–81. http://dx.doi.org/10.26682/ajuod.2020.23.2.20.
Full textAbstract:
Poor reproductive efficiency is considered one of the main causes of declining sheep production in sheep raised under traditional farm conditions. Many factors contribute to declining reproductive performance in ewes. The objective of the present study was to investigate factors that affect reproductive efficiency in Karadi and Awassi sheep raised under farm conditions. Four hundred Karadi and Awassi sheep (200 Karadi and 200 Awassi) were used in this study. Of each breed 100 ewes were allowed to come into oestrus spontaneously and another 100 ewes were synchronized using intravaginal sponges. Ewes were injected with intramuscular injection of 500 IU of PMSG when sponges were removed at 14 days. This study revealed that the breed had a significant effect on twinning rate and lamb mortality rate in spontaneous ewes. Breed also had a significant effect on the rate of lambing, lamb mortality, abortion, and dystocia in synchronized ewes. In addition, parity had a significant effect on the rate of lambing, lamb mortality and dystocia in spontaneous Karadi and Awassi ewes. Furthermore, parity also had significant effect on the rate of lambing, lamb mortality, dystocia and barrenness in synchronized Karadi and Awassi ewes. Different ram to ewe ratio during the oestrus period had a significant effect on conception rate and barrenness rate in synchronized Karadi and Awassi ewes. In conclusion, breed had effect on some reproductive parameters in synchronized and spontaneous ewes. Parity 2 had higher reproductive performance than parity 1 and parity ≥3 ewes. Conception rate were higher in 1:8 ram to ewe ratio group, while 1:≥16 ram to ewe ratio group had higher barrenness rate.
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Hatcher, S., S. Hatcher, R. J. Lightfoot, R. J. Lightfoot, I. W. Purvis, and I. W. Purvis. "Mating Awassi rams to Merino ewes causes an initial level of fibre contamination which decreases to an insignificant level eight weeks post-mating." Australian Journal of Experimental Agriculture 40, no. 3 (2000): 363. http://dx.doi.org/10.1071/ea98169.
Full textAbstract:
The fleeces of Merino ewes mated by Awassi rams were analysed for the presence of contaminant fibres (pigmented, urine-stained and kemp). In a controlled shed mating, high numbers of contaminant fibres were found in the fleeces of the ewes, with the number of fibres transferred being proportional to the number of times the ram mounted the ewe. The number of fibres transferred during the shed mating were substantially higher than those found after paddock mating. In the latter instance, environmental conditions and contact with other sheep would have contributed to the loss of fibres from the recipients’fleeces. Each ram breed used in the paddock mating experiment, Merino, Awassi and Suffolk, transferred fibres into the fleeces of the mated ewes. The Suffolk transferred relatively more fibres than both the Awassi or the Merino rams, in addition the fibres from the Suffolk were significantly darker than those from the other breeds thus compounding the severity of the contamination. Both mating experiments demonstrated that the number of contaminant fibres remaining in the ewe’s fleece 8 weeks after mating was not different to that existing in the fleece of the ewes before mating. Therefore, in commercial flocks, the risk of contamination can be minimised by shearing breeding ewes 8 weeks after rams have been removed from the breeding flocks.
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WITTENBERG, K. M., and T. J. DEVLIN. "EFFECTS OF DIETARY MOLYBDENUM ON PRODUCTIVITY AND METABOLIC PARAMETERS OF LACTATING EWES AND THEIR OFFSPRING." Canadian Journal of Animal Science 68, no. 3 (September 1, 1988): 769–78. http://dx.doi.org/10.4141/cjas88-086.
Full textAbstract:
A trial was undertaken to determine ewe lactation, lamb growth and metabolic responses to varying concentrations of molybdenum (Mo) in the diet of ewes. Twelve lactating ewes with twin lambs were assigned to one of three dietary treatments for the first 6 wk of lactation. Ewes were individually fed a corn silage-barley diet supplemented to contain 0.9 (0 Mo), 18.4 (20 Mo) or 40.7 (40 Mo) mg Mo kg−1 dry matter (DM) using ammonium molybdate [(NH4)6Mo7O24∙4H2O]. No feed was offered to lambs. Ewe milk yield and composition, ewe and lamb body weight and blood samples were obtained weekly. Two ewes assigned to 40 Mo and one ewe assigned to 20 Mo developed a condition that was corrected by thiamin administration during their fourth to fifth week on test. Diet did not influence (P > 0.05) milk yield or composition with the exception of milk Mo which increased (P < 0.05) for ewes fed Mo-supplemented rations. Dietary Mo concentration did not influence (P > 0.05) ewe plasma copper (Cu), trichloroacetic acid soluble plasma Cu or ceruloplasmin activity in ewes. Ewe plasma Mo concentrations increased (P < 0.05) 11- and 16-fold, respectively, for ewes fed 20 Mo and 40 Mo relative to those fed 0 Mo. Ewe liver Cu and Mo concentrations at the end of the trial tended (P < 0.10) to be greater for the Mo-supplemented diets. Lamb plasma and liver Cu concentration were not influenced by ewe diet. Milk Mo concentration did not influence (P > 0.05) lamb weight gain but did influence (P < 0.05) plasma Mo. Lamb age influenced (P < 0.05) plasma Mo levels which peaked when lambs were 2–3 wk old and declined thereafter. Key words: Ewe, lamb, lactation, growth, molybdenum, copper
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FITZGERALD, J. A., G. A. EVERETT, and J. APGAR. "EFFECT OF LOW ZINC INTAKE DURING PREGNANCY ON PLASMA PROLACTIN, PROGESTERONE, PROSTAGLANDIN, CORTISOL AND PROTEIN CONCENTRATIONS OF EWES DURING THE PERIPARTURIENT PERIOD." Canadian Journal of Animal Science 66, no. 3 (September 1, 1986): 643–51. http://dx.doi.org/10.4141/cjas86-071.
Full textAbstract:
The effect of low dietary Zn intake upon several plasma endocrine and metabolic profiles was examined during late gestation in the ewe. Thirty adult, primiparous Finncross ewes were fed a low Zn diet with (+Zn, n = 14) or without (0Zn, n = 16) supplemental Zn in the drinking water starting day 1 of pregnancy. Although the mean prepartum progesterone and prolactin concentrations were lower (P < 0.05 and P < 0.01, respectively) in 0Zn than in +Zn ewes, the peak prolactin concentrations in 0Zn ewes at lambing were similar to +Zn ewes. Both basal and thyrotropin-releasing-hormone (TRH)-induced prolactin release were less (P < 0.01) in 0Zn ewes 2 d postpartum. Plasma concentrations of 13, 14-dihydro-15-keto prostaglandin F2α (PGFM) of ewes sampled within 45 min post-lambing were lower (P < 0.05) in 0Zn ewes. There was no difference in cortisol concentrations within 45 min after lambing between 0Zn and + Zn ewes. Plasma protein concentrations in 0Zn ewes were higher (P < 0.01) than those in +Zn ewes during pregnancy. In summary, these data show that low Zn intake in the pregnant ewe affected several endocrine and metabolic plasma parameters associated with normal pregnancy and parturition. Key words: Zinc, parturition, dystocia, feed intake, ovine
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Moore, L. G., K. P. McNatty, K. L. Isaacs, S. Lun, W. Ng Chie, S. McNatty, and N. L. Hudson. "Pituitary and plasma levels of growth hormone in Booroola sheep that are either homozygous carriers or non-carriers of the FecBB fecundity gene." Journal of Endocrinology 147, no. 2 (November 1995): 217–23. http://dx.doi.org/10.1677/joe.0.1470217.
Full textAbstract:
Abstract The aim of this study was to examine the effect of the FecBB fecundity gene on plasma concentrations and pituitary content of growth hormone (GH) in sheep. No differences were found between homozygous carriers (BB) and non carriers (++) of the FecBB gene with regard to pituitary GH contents in both ovariectomized and intact ewes. However, ovariectomized ewes had higher levels of pituitary GH than intact ewes (P<0·01). There were no differences between FecBB genotypes with respect to plasma concentrations of GH in 6-year-old ovariectomized ewes bled every 10 min for 12 h or in ram lambs bled weekly during their first year of life. GH levels in the rams decreased until week 27, increased to a peak at week 31 then decreased before increasing again at week 43. Mean plasma GH concentrations in the ewe lambs bled weekly for a year decreased until week 19 then remained at approximately this level for the remainder of the year. Mean GH plasma concentrations in the ram lambs were higher than in the ewe lambs (P<0·001). Ewe lambs that were homozygous for the FecBB gene had lower body weights (P<0·05) and had higher levels of GH (P<0·01) than non carrier ewe lambs during their first year. Before the average age of first behavioural oestrus (36 weeks) GH levels in the ewe lambs were negatively correlated with body weights (r=−0·69, P<0·001, n=22). When body weight was included as a covariate in analysis of variance the genotype difference in ewe lamb plasma GH concentrations was no longer significant. In summary, pituitaries from ovariectomized ewes had higher levels of GH than those from intact ewes. There were no FecBB gene specific differences in pituitary levels of GH, the profile of plasma GH in 6-year-old ovariectomized ewes or in ram lambs during their first year of life. BB ewe lambs had higher levels of GH than ++ ewe lambs during their first year; however, this difference was probably due to the BB ewes having lower body weights than the ++ ewes because body weight was negatively correlated with mean GH levels. Journal of Endocrinology (1995) 147, 217–223
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Beck, N. F. G., M. C. G. Davies, and B. Davies. "A comparison of ovulation rate and late embryonic mortality in ewe lambs and ewes and the rôle of late embryo loss in ewe lamb subfertility." Animal Science 62, no. 1 (February 1996): 79–83. http://dx.doi.org/10.1017/s135772980001434x.
Full textAbstract:
AbstractAn investigation was conducted to compare late embryonic losses in ewe lambs and ewes and to determine the effect of inducing embryonic mortality on day 15 of pregnancy on reproductive function in ewe lambs. Ovulation rate and embryo survival were determined, at 15 and 30 days after mating, in a total of 83 ewe lambs and 67 ewes. Ovulation rate was lower, at spontaneous oestrus, in ewe lambs (1·07) than in ewes (1·25; P < 0·05). There was no difference in embryo survival at day 15, as 79% of ewe lambs and 80% of ewes contained expanded conceptuses. However, embryo survival was lower in ewe lambs (69%) than ewes (88%) at day 30 (P < 0·05). Embryonic mortality was induced in an additional 18 ewe lambs with an intrauterine injection of colchicine on day 15 post mating. Four of these animals had normal length oestrous cycles, six had inter-oestrus intervals ranging from 22 to 35 days and eight did not return to oestrus. Overall, the results of this study demonstrate that low ovulation rate and late embryonic losses make a significant contribution to subfertility in ewe lambs. Moreover, conceptus death is associated with luteal persistence, which may reduce reproductive performance by preventing remating.
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Kenney, PA, and GB Roberts. "Productivity of ewes grazing lupin stubbles at mating in north-eastern Victoria." Australian Journal of Experimental Agriculture 27, no. 5 (1987): 619. http://dx.doi.org/10.1071/ea9870619.
Full textAbstract:
The liveweight gains, lambing performances and wool production of Border Leicester x Merino ewes grazed on sweet narrow-leafed lupin (Lupinus angustifolius) stubbles during mating in midsummer were compared with those grazed on annual pasture. Treatments and conditions varied during the 5 years of study. In years 1-3, the stubbles were stocked at rates of between 20 and 40/ha, in year 4, at 11 ewes/ha, and in year 5 at 24 ewes/ha. In the last year there was an additional pasture treatment when the ewes on dry pasture were divided, one half were given 400 g lupin grain/sheep daily and the remainder, none. Available dry matter on the pastures varied from 1.1 to 5.0 t/ha and lupin grain in the stubbles varied from 230 to 420 kg/ha. Vasectomised rams were joined with the ewes 1 week before they were put onto the lupin stubbles and, after 2 weeks, were exchanged for entire rams which remained with ewes for 17-33 days. As the stocking rates on stubbles increased there were decreases in liveweight gains, ewes lambing and lambs born per ewe joined. During the 5 years, ewes grazed on stubbles at less than 25/ha gained more weight (176 g/day more), had more lambs (0<26/ewe mated), while more of them lambed (0.07/ewe mated) than did ewes on pasture alone (P < 0.05). The ewes fed lupin grain at pasture in year 5 received less grain than those on the stubbles and their production was intermediate to those on pasture alone and stubbles. At the lowest stocking rate of ewes grazing stubbles (20/ha) average wool production increased by about 37% (years 2-3) and 58% (year 5) compared with ewes grazing pasture. We conclude that lambing percentages from a midsummer mating can be increased when crossbred ewes graze sweet lupin stubbles during mating.
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Glanville, J. R. D., and C. J. C. Phillips. "The effect of winter shearing welsh mountain ewes in the hill environment." Proceedings of the British Society of Animal Production (1972) 1986 (March 1986): 77. http://dx.doi.org/10.1017/s0308229600015865.
Full textAbstract:
Previous work on winter shearing has concentrated on lowland ewes in mild conditions. With increased emphasis in hill areas on housing ewes before lambing and resting hill pastures, the possibility of shearing ewes before lambing, rather than in the summer now exists. A review of work with lowland ewes has shown that winter shorn ewes produce lambs with a heavier birthweight (average +0.55kg) and increased liveweight gain (average +15g day-1) (Phillips, 1980), but it is not clear whether these benefits would be obtained with less prolific ewes under hill conditions.The experiment was carried out from February to July 1985. Twenty-two Welsh Mountain ewes were housed 45 days pre-lambing in a fully enclosed but well-ventilated shed with slatted flooring. At 42 days pre-lambing ewes were randomised for weight and age and half the ewes were shorn with a normal comb, and half left unshorn until the summer.Ewes in both treatments were offered and consumed the same level of concentrates (0.25kg ewe-1 day-1 post-shearing increased to 0.5kg ewe-1 day-1 before lambing). Medium quality hay was offered ad-libitum to both treatments. Water intake was measured daily. Ewe liveweight was measured weekly on five occasions between shearing and one week before lambing. Respiration rates of ewes were measured on 4 different occasions at 4 extreme environmental temperatures. Maximum and minimum house temperatures were recorded for the whole of the housed period. Lamb birthweights, liveweight gains and 84 day weights were corrected to male singles using additive correction factors derived from the mean of the flock over the previous two years.
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Hall, DG, AR Gilmour, and NM Fogarty. "Variation in reproduction and production of Poll Dorset ewes." Australian Journal of Agricultural Research 45, no. 2 (1994): 415. http://dx.doi.org/10.1071/ar9940415.
Full textAbstract:
Poll Dorset ewes were joined to Booroola Merino (n = 22) or Trangie Fertility Merino (n = 26) rams in single sire joinings during late summer/autumn of 1978, 1979, 1980 and 1981. Rams were changed each year and there were 1678 individual ewe joinings. A maximum of 527 ewes were used in any one year, and they represented 14 studs and varied in age, reproductive history and liveweight. The traits, litter size, maternal lamb survival, lambs weaned per ewe lambing and weight of lamb weaned per ewe lambing (kg at 100 days) were analysed for the effect of year, stud, age, lambs born and ewe liveweight. Litter size averaged 1-37, maternal lamb survival 0.70, and number of lambs weaned per ewe was 0.94. There were large variations in the reproductive traits due to year and stud and lesser effects due to age. Each extra kilogram of ewe liveweight at joining increased litter size by 0.012 and weight of lamb weaned by 0.39 kg, but had no significant effect on maternal lamb survival or number of lambs weaned. Multiple-bearing ewes weaned 0.72 more lambs and 16 - 2 kg more lamb weight than single-bearing ewes. Lamb survival was similar for singleand multiple-bearing ewes. Greasy fleece weight averaged 2.2 kg ewe-' and single bearing ewes produced 0.19 kg/ewe more than multiple-bearing ewes. Dystocia caused 53% and starvation/mismothering/exposure caused 23% of lamb deaths; the proportion of deaths due to starvation/mismothering/exposure increased with increasing ewe joining liveweight. The large variation between studs in reproductive performance partly reflected genetic differences between Poll Dorset flocks which could be exploited. Estimates of heritabilities ranged from 0.06 to 0.14 � 0.10 for the reproductive traits and were 0.10 � 0.12 for ewe liveweight and 0.16 � 0.20 for greasy fleece weight. However much of the between stud variation may also have arisen from early environmental effects. Estimates of repeatability ranged from 0.06 to 0.l5 � 0 05 for reproduction traits and were 0.44 � 0.06 for ewe liveweight at joining and 0.56 � 0.08 for greasy fleece weight.
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Haresign, W. "The effect of implantation of lowland ewes with melatonin on the time of mating and reproductive performance." Animal Science 54, no. 1 (February 1992): 31–39. http://dx.doi.org/10.1017/s0003356100020535.
Full textAbstract:
AbstractTwo trials, involving a total of 1006 Mule ewes and 1862 Suffolk-× ewes, were conducted to investigate the ability of implantation with melatonin to induce early breeding in lowland sheep flocks. Dates of implantation ranged from mid May to late June for Suffolk-× flocks and mid May to early July for Mule flocks.From the mating patterns obtained it is suggested that the optimum implantation date is mid May to mid June for Suffolk-× ewes and mid June to mid July for Mule-type ewes.Melatonin treatment also significantly increased the mean litter size per ewe exposed to the ram (resulting from a 6-week mating period) when the data were pooled across flocks, but the magnitude of this effect varied across flocks. Part of this overall mean increase in Mule ewes (+0·84 and +0·50 extra lambs per ewe in trials 1 and 2 respectively) was due to an increase in the proportion of ewes mating and lambing and part of it (+0·13 and +0·17 extra lambs per ewe, respectively) was due to an increase in litter size per ewe pregnant. In the Suffolk-× ewes there was evidence that the overall mean benefit following implantation with two implants (+0·31 extra lambs per ewe) was greater than that following implantation with one implant (+0·14 extra lambs per ewe), with all of the increase at the lower dose level and +0·21 extra lambs per ewe at the higher dose being due to an increase in litter size per ewe pregnant.
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Morris, C. A., S. A. Bisset, A. Vlassoff, C. J. West, and M. Wheeler. "Faecal nematode egg counts in lactating ewes from Romney flocks selectively bred for divergence in lamb faecal egg count." Animal Science 67, no. 2 (October 1998): 283–88. http://dx.doi.org/10.1017/s1357729800010043.
Full textAbstract:
AbstractFaecal nematode egg counts (FECs) were examined in lactating ewes from divergent flocks of Romney sheep which had been selectively bred from 1979 to 1996 for or against FEC in 4 to 7 month old lambs. Faecal samples were obtained from the ewes while under normal grazing management, 1 to 2 months after lambing in spring for each of 6 years between 1987 and 1996 (no. = 785 records; 298 animals). Analyses were carried out on loge (FEC + 100)–transformed data using animal-model maximum likelihood procedures, accounting for repeated records on ewes, within and between lactations. An examination of non-genetic effects indicated that there was no significant effect of age class of ewe on FEC but ewes which gave birth to single lambs had significantly lower post-parturient FECs than those bearing twins (back-transformed means of 184 v. 276 egg per g, respectively; P < 0·001). In relation to genetic effects, post-parturient FECs were significantly lower in ewes from the flock bred for low lamb-FEC than in their counterparts from the flock bred for high lamb-FEC, with ewes from the most recent birth years (1991 to 1994) showing a nine-fold difference (back-transformed means of 33 and 305 eggs per g faeces respectively; P < 0·001). This was equivalent to 69% of the divergence observed between loge (FEC + 100) in their lambs in the same years. Heritability and repeatability estimates for loge (FEC + 100) in ewes were 0·37 (s.e. 0·06) and 0·46 (s.e. 0·03) respectively. Genetic correlation estimates between a ewe's post-parturient loge (FEC + 200) and her loge (FEC + 100) as a lamb, based on analysis of (co)variance or realized responses, were 0·70 or 0·58 respectively. The phenotypic correlation between a ewe's loge (FEC + 100) and that of her lamb(s) in the same lactation was 0·29 (s.e. 0·06) (P < 0·001). From the results it is clear that substantial genetic changes in post-parturient FECs of breeding ewes can be induced through a correlated response to selective breeding for or against reduced FEC in lambs. This may have important implications for the epidemiology of nematode parasite infections in spring-born lambs, a possibility which is currently being investigated.
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Pettigrew, Emma, Rebecca Hickson, Steve Morris, Paul Kenyon, Rene Corner-Thomas, Emmanuelle Haslin, and Hugh Blair. "The Effect of Age of Dam and Birth Rank on the Reproductive Performance of Ewes as One- and Two-Year-Olds." Animals 11, no. 3 (March 10, 2021): 770. http://dx.doi.org/10.3390/ani11030770.
Full textAbstract:
Currently, 30–43% of New Zealand sheep farmers breed their ewe lambs, but few retain the offspring as replacements for their flock. No difference in lamb production as a yearling among singletons and twins born to ewe lambs and twins born to mature ewes has been reported, provided the ewe lambs had reached the 60–65% of their likely mature weight prior to breeding at seven to eight months of age. The aim of this experiment was to determine the lamb production from singletons and twins born to ewe lambs and twins born to mature ewes during their first two years of lambing. The experiment included 8-month-old ewes born as twins to mature ewes (M2, n = 135), singletons born to ewe lambs (L1, n = 135), and twins born to ewe lambs (L2, n = 88), bred during the same period to the same rams, over two years. The efficiency of lamb production (total litter weight at weaning divided by the pre-breeding weight of the ewe, for all ewes presented for breeding) after two years of production was not significantly different (p > 0.05) among the groups (0.40 ± 0.02, 0.39 ± 0.02, and 0.39 ± 0.03, for M2, L1, and L2, respectively).
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Rodríguez Iglesias, R. M., N. H. Ciccioli, and H. Irazoqui. "Ram-induced reproduction in seasonally anovular Corriedale ewes: MAP doses for oestrous induction, ram percentages and post-mating progestagen supplementation." Animal Science 64, no. 1 (February 1997): 119–25. http://dx.doi.org/10.1017/s1357729800015629.
Full textAbstract:
AbstractExploiting the ‘ram effect’ is an inexpensive alternative for out-of-season breeding in moderately seasonal breeds. For maximum efficacy in Corriedale sheep, oestrous ewes have to be introduced together with the teaser rams. Successful applications depend upon timely manipulation of the animals to induce oestrus in most ewes and to minimize the likelihood of successfully induced non-pregnant ewes returning to anoestrus during the mating period.In the first of two experiments, the effects of two alternative ram: ewe ratios (1:6 or 1:12) and five different doses (0, 15, 30, 45 or 60 mg) of medroxy-progesterone acetate (MAP) applied in intravaginal sponges for 9 days were assessed on seasonally anovular adult Corriedale ewes. Control ewes (0 MAP) did not receive sponges, but were injected with 20 mg progesterone at ram introduction. A second experiment tested the efficacy of post-oestrus intravaginally applied MAP (30 mg; 7-day treatment starting on days 3 to 6 after oestrus) for improving reproductive variables of successfully induced ewes exposed to entire rams.Proportions of ewes ovulating and ovulation rates (assessed through laparoscopy) did not differ significantly (P > 0·05) in ewes treated with various MAP doses (213/220 = 96·8% and 1·26 (s.e. 0·031) respectively) or injected with progesterone (56/58 = 96·6% and 1·21 (s.e. 0·058) respectively). The MAP content of the sponges did not affect (V > 0·05) the proportion of ewes ovulating (269/278), marked by the rams (197/213), returning to oestrus (81/197) or lambing among those not returning to first oestrus (87/119). More ewes were marked in the groups exposed to a higher ram percentage (79·7 to 70·6%; P < 0·001) but no other reproductive variable was affected by the ram: ewe ratio at ram introduction (P > 0·05). In the second experiment, post oestrus progestagen supplementation reduced the proportion of ewes returning to first oestrus from 27% to 16% (P < 0·05) but failed to improve lambing rate or the number of lambs born per ewe lambing. Thus, MAP doses as low as 0·25 of the commercial formulation (60 mg) induced oestrus in seasonally anovulatory Corriedale ewes exposed to rams and oestrous ewes. Increasing the ram: ewe ratio augmented the proportion of marked ewes but did not affect any other reproductive variable. Supplementing MAP after oestrus did not improve reproductive rate in Corriedale ewes induced to ovulate during the seasonal anoestrus.
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Brand, T. S., F. Franck, A. Durand, and J. Coetzee. "Use of varying combinations of energy and protein sources as supplementary feed for lambing ewes grazing cereal stubble." Australian Journal of Experimental Agriculture 37, no. 1 (1997): 1. http://dx.doi.org/10.1071/ea95168.
Full textAbstract:
Summary. Three feeding trials compared production of lambing ewes grazing stubbles and fed different combinations of energy and protein supplements as loose licks. Each experiment had 2 treatments in a 2 x 2 factorial design. Experiment 1 compared urea (12.5 g/ewe. day) with fish meal (100 g/ewe. day) when fed with molasses (100 g/ewe. day) for 38 days during late pregnancy. Fish meal increased liveweight gain (from 2.0 to 5.7 kg) and wool growth (20%) but urea had no effect. In experiment 2, urea (12.5 g/ewe. day) was fed in combination with molasses (200 g/ewe. day) or barley meal (200 g/ewe. day) for 63 days during late pregnancy (last 6 weeks) and early lactation. Ewes supplemented with the barley–urea combination gained 5.6 kg during the last 6 weeks of pregnancy compared with 0.40 kg for barley and the 1.02 and 1.34 kg weight loss for ewes receiving molasses and the molasses–urea combination, respectively. Experiment 3 compared urea (12.5 g/ewe. day) with sweet lupin meal (106 g/ewe. day) when fed with barley meal (200 g/ewe. day) for 56 days during late pregnancy (last 4 weeks) and lactation. Sweet lupin meal improved the liveweight change of ewes during pregnancy (from 160 to 200 g/ewe. day) as well as the birth weight of lambs (400 g) but urea had no effect. The performance of lambing ewes grazing low-quality pasture at a high stocking density (>4.5 ewes/ha) for a long period (>130 days) can be improved by relatively low amounts of supplements such as fish meal, sweet lupin meal and barley–urea.
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Khan, T. H., N. F. G. Beck, and M. Khalid. "Comparison of luteal function between ewe lambs and ewes during breeding and non breeding season." Proceedings of the British Society of Animal Science 1998 (1998): 184. http://dx.doi.org/10.1017/s1752756200598366.
Full textAbstract:
Reproductive performance of ewe lambs is lower than that of adult ewes (Quirke. 1979). This is mainly the result of preimplantation losses which can exceed 50% in ewe lambs as compared with 20-30% in ewes (Quirke et al.,1981). Previous evidence from this laboratory suggests that these losses may be associated with inadequate luteal function in ewe lambs (Davies and Beck, 1993). Inadequate luteal function may not only delay the embryo development but also impair the ability of the embryo to communicate its presence to the maternal system. There is also a possibility that inadequate corpora lutea may be refractory to luteotrophic factors produced by the developing embryo. The present study was designed to investigate whether the luteal function varies between ewe lambs and ewes. Another objective of this study was to compare the luteal response to hCG challenge between ewe lambs and ewes and its variation with season.
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Khan, T. H., N. F. G. Beck, and M. Khalid. "Comparison of luteal function between ewe lambs and ewes during breeding and non breeding season." Proceedings of the British Society of Animal Science 1998 (1998): 184. http://dx.doi.org/10.1017/s0308229600033973.
Full textAbstract:
Reproductive performance of ewe lambs is lower than that of adult ewes (Quirke. 1979). This is mainly the result of preimplantation losses which can exceed 50% in ewe lambs as compared with 20-30% in ewes (Quirke et al.,1981). Previous evidence from this laboratory suggests that these losses may be associated with inadequate luteal function in ewe lambs (Davies and Beck, 1993). Inadequate luteal function may not only delay the embryo development but also impair the ability of the embryo to communicate its presence to the maternal system. There is also a possibility that inadequate corpora lutea may be refractory to luteotrophic factors produced by the developing embryo. The present study was designed to investigate whether the luteal function varies between ewe lambs and ewes. Another objective of this study was to compare the luteal response to hCG challenge between ewe lambs and ewes and its variation with season.