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1
Liang, Hui, Zhiqiang Ma, Ziying Wang, Peiyu Zhong, Ran Li, He Jiang, Xin Zong, et al. "Structural Insights into the Binding of Red Fluorescent Protein mCherry-Specific Nanobodies." International Journal of Molecular Sciences 24, no. 8 (April 9, 2023): 6952. http://dx.doi.org/10.3390/ijms24086952.
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Red fluorescent proteins (RFPs) have broad applications in life science research, and the manipulation of RFPs using nanobodies can expand their potential uses. However, the structural information available for nanobodies that bind with RFPs is still insufficient. In this study, we cloned, expressed, purified, and crystallized complexes formed by mCherry with LaM1, LaM3, and LaM8. Then, we analyzed the biochemical properties of the complexes using mass spectrometry (MS), fluorescence-detected size exclusion chromatography (FSEC), isothermal titration calorimetry (ITC), and bio-layer interferometry (BLI) technology. We determined the crystal structure of mCherry-LaM1, mCherry-LaM3, and mCherry-LaM8, with resolutions of 2.05 Å, 3.29 Å, and 1.31 Å, respectively. In this study, we systematically compared various parameters of several LaM series nanobodies, including LaM1, LaM3, and LaM8, with previously reported data on LaM2, LaM4, and LaM6, specifically examining their structural information. After designing multivalent tandem LaM1-LaM8 and LaM8-LaM4 nanobodies based on structural information, we characterized their properties, revealing their higher affinity and specificity to mCherry. Our research provides novel structural insights that could aid in understanding nanobodies targeting a specific target protein. This could provide a starting point for developing enhanced mCherry manipulation tools.
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Scott, Phil. "Lamb dysentery in Suffolk lambs." Livestock 11, no. 3 (May 2006): 65–66. http://dx.doi.org/10.1111/j.2044-3870.2006.tb00030.x.
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Hay, Deborah. ""Lamb, Lamb, Lamb, Lamb, Lamb",... A Movement Libretto for 42 Individuals." TDR (1988-) 36, no. 4 (1992): 58. http://dx.doi.org/10.2307/1146216.
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Schreurs, N. M., P. R. Kenyon, F. J. Mulvaney, P. C. H. Morel, D. M. West, and S. T. Morris. "Response of additional ewe lamb liveweight during gestation on birth and weaning weight of offspring and liveweight of the ewe lamb at weaning." Animal Production Science 50, no. 6 (2010): 528. http://dx.doi.org/10.1071/an09185.
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Increasing the liveweight of ewe lambs during gestation may have positive effects on lamb birthweight and weaning weight and also on ewe lamb liveweight at weaning. Specific times during the gestation period of the ewe lamb may be more responsive to improved nutrition and increases in liveweight. The objective of this work was to use a meta-analytic approach to investigate the effects of ewe lamb liveweight at mating and during pregnancy on lamb birth and weaning weights, and the ewe lamb’s liveweight at weaning. Increasing ewe lamb liveweight in early gestation and in particular before mating gave the greatest increases in the birth and weaning weight of the lambs, and also of the ewe lamb’s liveweight at weaning compared with increasing liveweight in the second and third trimester of gestation. This indicates that management practices for ewe lambs that generate higher liveweight at mating are likely to result in increased lamb survival, higher weaning percentages, greater lamb weaning weights and create rising 2-year-old ewes with better liveweight for mating in the subsequent season. Compared with ewe lambs that gave birth and reared singletons to weaning, those ewe lambs that gave birth to twins and reared twins had greater increases in lamb birthweights, lamb weaning weights and ewe lamb weights at weaning for each extra kilogram of ewe lamb liveweight during gestation. For ewe lambs, especially those that birth and rear twins, management options that increase the pre-mating weights will have the greatest response in lamb birthweight, weaning weight and liveweight of the ewe lamb itself at weaning.
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Daly, Ann. "The Play of Dance: An Introduction to "Lamb, Lamb, Lamb, Lamb, Lamb,..."." TDR (1988-) 36, no. 4 (1992): 54. http://dx.doi.org/10.2307/1146215.
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Jaborek, Jerad R., Henry N. Zerby, Macdonald P. Wick, Francis L. Fluharty, and Steven J. Moeller. "Effect of energy source and level, animal age, and sex on the flavor profile of sheep meat12." Translational Animal Science 4, no. 2 (April 1, 2020): 1140–47. http://dx.doi.org/10.1093/tas/txaa081.
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Abstract The effects of dietary energy source, energy level, sheep age, and sheep sex on flavor and off-flavor intensity were evaluated. Consumer panelists, with previous lamb-eating experience, assessed lamb flavor and off-flavor intensity on a 100-point, end-anchored scale (0 = very mild to 100 = very intense), with off-flavor being defined as anything different than lamb flavor. Lamb longissimus thoracis (LT) and whole, boneless ground shoulder (GS) formed into patties were evaluated. Trial 1 was a randomized complete block design with a 3 × 2 factorial arrangement of treatments. Sheep age (ewe lambs, yearling ewes, and mature ewes; n = 16/age) and ad libitum access to diets [alfalfa pellets (AP) or whole-shelled corn (WSC100)] were treatments. The LT from mature ewes had a greater (P ≤ 0.02) off-flavor intensity when compared with yearling ewes and ewe lambs. Ground shoulder from sheep raised on AP had a greater lamb flavor (P ≤ 0.04) and off-flavor (P ≤ 0.04) intensity than GS from sheep consuming WSC100. Trial 2 was a randomized complete block design with a 3 × 2 × 2 factorial arrangement of treatments. Three dietary treatments [AP, WSC100, and restricted intake of whole-shelled corn to 85% of ad libitum (WSC85)], lamb sex (ewes and wethers; n = 48/sex), and lamb age [short fed, 177 ± 16.6 d of age and 93 ± 20.5 d on feed (DOF); long fed, 294 ± 7.0 d of age and 219 ± 3.8 DOF]. Flavor intensity of the LT was greater (P ≤ 0.05) from lambs offered AP when compared with lambs offered WSC85, whereas lamb flavor of the LT from lambs fed WSC100 was intermediate and not different from the lamb flavor of the LT of lambs fed AP or WSC85. The LT of long-fed lambs had a greater (P ≤ 0.01) lamb flavor and off-flavor intensity when compared with short-fed lambs. Lambs offered AP resulted in a GS with greater lamb flavor intensity (P ≤ 0.01) when compared with lambs offered WSC85 and WSC100, with no diet influence on GS off-flavor intensity. Long-fed lambs produced GS with a greater lamb flavor (P ≤ 0.01) and off-flavor (P ≤ 0.01) intensity when compared with GS from short-fed lambs. Results from the two trials indicate lamb flavor and off-flavor intensity were greater from sheep offered a high-forage (AP) diet when compared with a high-concentrate (WSC) diet. Lamb flavor intensity increased as age of the sheep at harvest increased, suggesting dietary management and associated age-related effects at harvest will influence consumer perception of lamb flavor.
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O'Connor, C. E., and A. B. Lawrence. "Relationship between lamb vigour and ewe behaviour at parturition." Animal Science 54, no. 3 (June 1992): 361–66. http://dx.doi.org/10.1017/s000335610002081x.
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AbstractMaternal behaviour and lamb vigour are both considered major variables affecting lamb survival, but there are few data to describe their relative importance. To investigate the relationship between lamb vigour and maternal behaviour this study compared the behaviour of pure Scottish Blackface lambs with Mule (Bluefaced Leicester ♀. × Scottish Blackface ♂) lambs, all born indoors. Anecdotal accounts suggested a significant reduction in lamb vigour in Mule lambs, a matter also of significant practical importance given the current incease in Mule numbers. Observations on the grooming behaviour of 32 single or twin-bearing ewes, and on the general activity and udder-seeking behaviour of their lambs were made at parturition. In this study, neither ewe grooming behaviour nor general lamb activity were directly related to lamb sucking success. It was shown that, although Mule lambs had high birth weights and stood as quickly as Blackface lambs, they showed significantly fewer sucking attempts (P < 0·01) and took longer to suck successfully (28 min for Blackface v. 55 min for Mules). The inability of Mule lambs to suck successfully was due to their failure to show proper udder-directed behaviour. These results indicate the importance of considering the behaviour of both ewes and lambs as it would seem that it is not ‘poor’ maternal behaviour but inappropriate lamb behaviour that is a limiting factor in lamb survival in the Mule breed.
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Dwyer, C. M., and A. B. Lawrence. "Interactions between ewe and lamb genotype and sucking success in neonatal lambs." Proceedings of the British Society of Animal Science 1998 (1998): 105. http://dx.doi.org/10.1017/s1752756200597579.
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Perinatal lamb mortality remains a major economic and welfare concern in sheep farming with 80-90% of pre-weaning lamb losses occur in the immediate postnatal period (Haughey, 1993). One of the predominant factors in the death of neonatal lambs is failure of ewe-lamb bonding leading to delay or lack of sucking. Successful sucking requires the co-ordinated expression of appropriate behaviour from both the ewe and lamb. Previously we have demonstrated an interaction between ewe and lamb breed in the rate of successful sucking (Dwyer et al., 1996) with Blackface lambs having a higher rate than Suffolk lambs but also a higher rate with Suffolk ewes than with Blackface ewes. In the present study we investigated the role of ewe responses to lamb sucking attempts in determining the sucking success of neonatal lambs.
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Dwyer, C. M., and A. B. Lawrence. "Interactions between ewe and lamb genotype and sucking success in neonatal lambs." Proceedings of the British Society of Animal Science 1998 (1998): 105. http://dx.doi.org/10.1017/s0308229600033183.
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Perinatal lamb mortality remains a major economic and welfare concern in sheep farming with 80-90% of pre-weaning lamb losses occur in the immediate postnatal period (Haughey, 1993). One of the predominant factors in the death of neonatal lambs is failure of ewe-lamb bonding leading to delay or lack of sucking. Successful sucking requires the co-ordinated expression of appropriate behaviour from both the ewe and lamb. Previously we have demonstrated an interaction between ewe and lamb breed in the rate of successful sucking (Dwyer et al., 1996) with Blackface lambs having a higher rate than Suffolk lambs but also a higher rate with Suffolk ewes than with Blackface ewes. In the present study we investigated the role of ewe responses to lamb sucking attempts in determining the sucking success of neonatal lambs.
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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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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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Haslin, Emmanuelle, Rene A. Corner-Thomas, Paul R. Kenyon, Emma J. Pettigrew, Rebecca E. Hickson, Steve T. Morris, and Hugh T. Blair. "Effect of Breeding Heavier Romney Ewe Lambs at Seven Months of Age on Lamb Production and Efficiency over Their First Three Breeding Seasons." Animals 11, no. 12 (December 7, 2021): 3486. http://dx.doi.org/10.3390/ani11123486.
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This experiment examined the effect of breeding heavier ewe lambs on lamb production and their efficiency over their first three breeding seasons. Two groups of ewe lambs were bred at seven months of age at an average pre-breeding live weight of either 47.9 ± 0.36 kg (heavy; n = 135) or 44.9 ± 0.49 kg (control; n = 135). Ewe live weight, number of lambs born and weaned, and lamb live weight were recorded until 39 months of age, and efficiency was calculated for each ewe. Although the number and lamb weaning weight did not differ between treatments over three years, when data were pooled, heavier ewe lambs at breeding weaned a greater number of lambs over the three-year period. The total lamb weaning weight over the three-year period increased by 2% for each additional kilogram at ewe lamb breeding. Breeding heavier ewe lambs had no effect on efficiency. These results suggest that although breeding heavier ewe lambs had a positive effect on lamb production over the three-year period, it had no effect on efficiency. Before final recommendations can be made, lifetime performance and longevity to five years of age of heavier ewe lambs at breeding are required.
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Brien, F. D., M. L. Hebart, D. H. Smith, J. E. Hocking Edwards, J. C. Greeff, K. W. Hart, G. Refshauge, et al. "Opportunities for genetic improvement of lamb survival." Animal Production Science 50, no. 12 (2010): 1017. http://dx.doi.org/10.1071/an10121.
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Data on lamb survival and associated traits involving records from 15 192 lambs, 6308 dams and 284 sires from the Sheep CRC’s Information Nucleus were studied. Lamb survival to 3 days of age and to weaning was 85 and 80%, respectively, and heritability (±s.e.) was 0.014 ± 0.010 and 0.010 ± 0.010, respectively. Of the 14 traits recorded at birth, time taken for the lamb to bleat, rectal temperature and crown–rump length had the highest genetic correlations with lamb survival to weaning (–0.43 ± 0.32, 0.56 ± 0.33 and –0.38 ± 0.36, respectively). Under selection for a multi-trait objective including net reproduction rate (but not lamb survival), survival was predicted to decline genetically by 0.25 lambs weaned per 100 lambs born.year, although this was reversed to a gain of 0.20 lambs weaned per 100 lambs born.year by including the trait in the breeding objective and using 50 half-sib and 50 progeny records per selection candidate. Accuracy of selection for lamb survival was improved to 0.735 with a selection index of lamb survival to weaning, lamb ease, birth coat score, time taken to bleat, rectal temperature and crown–rump length, with the addition of 50 half-sibs and 50 progeny records per candidate. Our results suggest that unless actively incorporated into breeding objectives, lamb survival may genetically decline; however, gains are possible with direct selection using half-sib and progeny records. The addition of indirect selection criteria for lamb survival can further improve accuracy, up to 93.4%, but requires further investigation.
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Dwyer, C. M., and A. B. Lawrence. "EFFECTS OF MATERNAL GENOTYPE AND BEHAVIOUR ON THE BEHAVIOURAL DEVELOPMENT OF THEIR OFFSPRING IN SHEEP." Behaviour 137, no. 12 (2000): 1629–54. http://dx.doi.org/10.1163/156853900502754.
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AbstractSignificant breed differences in grazing, activity, social and other affiliative behaviours are known to exist in sheep. The roles of maternal and offspring genotype in determining the development of breed-specific behavioural differences in lambs were investigated using embryo-transfer. Two breeds of sheep (Suffolk and Scottish Blackface) were chosen as they differ markedly in social and affiliative behaviours. Sixty ewe-lamb pairs (15 each of the four combinations of ewe and lamb) were observed over the first 3 days after lambing, then when the lambs were aged between 2-5 months old and during the first 6 weeks after weaning. Lamb breed was the main factor affecting lamb activity at birth and play behaviour over the first postnatal days, with Blackface lambs being significantly more active than Suffolk lambs. Lamb sucking behaviour during this period, however, was significantly affected by ewe breed with a higher frequency of sucking interactions observed with Suffolk ewes. When out at grass the two breeds of ewe differed in their use of the field, with Blackface ewes using upland areas whilst Suffolk ewes were found almost exclusively in the lowland parts. Ewes also differed in their spatial relationship to their lamb, with Blackface ewes maintaining a closer relationship to their lamb than Suffolk ewes, regardless of lamb breed. Blackface ewes were also more active than Suffolk ewes and were more frequently observed grazing. The breed of their mother significantly influenced the behaviour of the lambs, and their spatial relationships to other sheep, both before and after weaning. Lambs with Blackface mothers were more active than lambs with Suffolk mothers and this difference persisted after weaning. Blackface-reared lambs also had a shorter nearest neighbour distance after weaning, aggregated into smaller subgroups and were significantly more likely to be in upland areas of the field, regardless of lamb breed, than lambs reared by Suffolk ewes. Maternal influence, therefore, plays an important role in shaping the behaviour of their offspring in sheep, although neonatal lamb activity is not affected by maternal behaviour.
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Monori, István, Alajos Fehér, and Róbert Czimbalmos. "Feeding questions of organic lamb fattening." Acta Agraria Debreceniensis, no. 33 (June 5, 2009): 155–60. http://dx.doi.org/10.34101/actaagrar/33/2864.
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Organic farming has done in line with conventional farming in the Karcag Research Institute of DU CASE since 2001. Our organic farming activities were enhanced with sheep farming andgrassland management in 2005. We started our study of technology development of organic lamb fattening and the treatment of its economic effect this year. Our goal was to developthe elements of the technology to reach a more efficient organic lamb fattening. We also studied what economic advantages the organic sheep farming could realize in the present economic environment. Our studies were carried out between 2005 and 2007. We established that the excellent ewe feeding (good quality of fodder and silage) can decrease the lamb feeding cost between the 2nd and 8th weeks of the lambs’ life. We established that theyield of convention lambs are significantly higher than the yield of organic lambs. The cost of organic lamb fodder is significantly lower than the cost a convention lamb fodder, but the profit was higher in the case of convention lamb fattening. The organic lamb fattening technology (without extra price) is not competitive to the conventional lamb fattening technology. We think that the profitability of organic lamb fattening is significantly less than of the convention one. The organic lamb price should be 20-30% higher than the other price to be competitive. Unfortunatly there is only a little demand for organic lamb and there is no difference between the prices of organic and convention lambs, so organic sheep farmers have worse economic circumstances than conventional sheep farmers.
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Rowland, J. P., M. D. Salman, C. V. Kimberling, D. J. Schweitzer, and T. J. Keefe. "Epidemiologic factors involved in perinatal lamb mortality on four range sheep operations." American Journal of Veterinary Research 53, no. 2 (February 1, 1992): 262–67. http://dx.doi.org/10.2460/ajvr.1992.53.02.262.
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Summary Four shed-lambing operations in western Colorado were monitored during the 1984 spring lambing season to determine the causes and rates of perinatal lamb mortality. The number of lambing ewes per flock ranged from 513 to 1,712, and lambing percentages ranged from 131 to 180%. Overall perinatal lamb mortality ranged from 8.2 to 12.2%. Most lamb deaths occurred during parturition or within 24 hours after parturition. More than 85% of all lamb deaths were in lambs born to ewes having 2 or more lambs. The leading causes of lamb death were starvation, dystocia, stillbirth (unknown cause), and infectious diseases. A wheel model was used to categorize factors causing lamb deaths into 4 groups: physical, social, host, and biological, and to present data on perinatal lamb mortality in a simple visual model. In all flocks, social and biological factors resulted in most of the lamb deaths. On the basis of our findings, we suggest that interventions designed to improve ewe-lamb bonding and to reduce infectious agents and the incidence of prolonged parturition may reduce lamb mortality.
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Morel, P. C. H., S. T. Morris, and P. R. Kenyon. "Effect of birthweight on survival in triplet-born lambs." Australian Journal of Experimental Agriculture 48, no. 7 (2008): 984. http://dx.doi.org/10.1071/ea07401.
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Lambing percentage is the main contributor to higher profit on New Zealand sheep farms and has increased from 98% in 1960 to 124% in 2006. As ewe litter size increases so does the proportion of triplet-born lambs and consequently preweaning mortality rate. The purpose of this study was to investigate the effect of birthweight (BWT) on survival in triplet-born lambs within and among litters. Data from a total of 594 triplet crossbreed lambs born to mixed-age ewes was analysed. For the statistical analysis, the lambs were allocated according to their BWT, and within the litter were then allocated to three BWT groups (light, medium and heavy). The following parameters were calculated: total litter BWT (TBWT), percentage of TBWT for each lamb (PBWT = BWT/TBWT), coefficient of variation for BWT within litter and lamb average daily gain from birth to weaning. The mortality rate for the light, medium and heavy lambs was 56, 40 and 28%, respectively, and consequently the lightest lamb in a litter was 3.2 times more likely to die than the heaviest lamb. In the light lamb group, as BWT increased mortality decreased (P = 0.006), for medium lambs BWT did not influence mortality (P = 0.88) and in the heavy group there was a trend of increased BWT associated with increased mortality (P = 0.10). The negative relationship between lamb mortality and PBWT was identical in the three BWT groups (P < 0.0001). The effect of BWT on lamb mortality became non-significant when PBWT was fitted in the same model. This means that, in triplet-born lambs, mortality is not influenced by the BWT of the lamb itself, but by the BWT of its littermates. It can be calculated that a 4-kg lamb has a 24% chance of surviving in a litter of 16 kg, a 60% chance in a litter of 12 kg and an 87% chance of surviving in a litter of 8 kg. It is concluded that reducing the variation in BWT within a litter, or specifically managing the lightest lamb at birth, will increase the competitive ability for survival of each lamb and, therefore, decrease overall mortality and further improve farm profitability.
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Jordan, DJ, and DG Mayer. "Effects of udder damage and nutritional plane on milk yield, lamb survival and lamb growth of Merinos." Australian Journal of Experimental Agriculture 29, no. 3 (1989): 315. http://dx.doi.org/10.1071/ea9890315.
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A pen study investigated the effects of udder damage and 3 levels of nutrition (110, 90 and 70% of maintenance requirements) during the pre- and post-natal period on the performance of Merino ewes and lambs. Udder damage (only 1 functional teat) significantly reduced (P< 0.05) estimated daily milk yield of ewes (1 139 v. 963 mL/day), growth rate (180.5 v. 143.7 g/ day) and liveweight of lambs (10.1 v. 8.8 kg) at 4-6 weeks of age. Lamb survival was significantly reduced only in the 70% of maintenance treatment (82.2 v. 64.8%). Nutrition level significantly (P< 0.05) affected ewe and lamb performance. Estimated daily ewe milk yield (1146, 1070 and 938 mL/day), ewe liveweight (40.4, 39.2 and 37.1 kg) at lamb marking, and lamb growth rate (178.1, 169.5 and 138.8 g/day) and liveweight (10.2, 9.6 and 8.6 kg) at 4-6 weeks were significantly higher for ewes fed on 110 and 90% of their requirements than for ewes fed at 70% of their requirements respectively. Lamb survival (89.9%) from ewes fed at 110% of requirements was significantly higher than lamb survival (75.3 and 73.5%) from ewes fed at 90 and 70% of requirements respectively. There was no significant interaction between the level of nutrition and udder damage in any parameter of ewe or lamb performance. Birth weight (3.0 v. 3.8 kg) and survival (49.3 v. 84.2%) were significantly (P<0.01) lower in twins than in single birth lambs. Growth rate of single lambs and single survivors of twins reared as single lambs were similar (167 and 160 g/day respectively); both of these groups grew more rapidly (P< 0.01) than lambs reared as twins (91 g/day). Lamb growth rate was positively correlated with ewe milk yield (r=0.75; P<0.01), ewe weight (r = 0.37; P< 0.01) and lamb birth weight (r = 0.24; P< 0.05). Lamb birth weight and ewe milk yield were also significantly and positively correlated with ewe weight. Male lambs were significantly heavier at birth and grew significantly faster than female lambs.
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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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Cho, Andrew Inhyuk, Caroline Lee, and Alison Small. "Attention behaviours but not pain-related behaviours are modified by the presence of a twin in lambs undergoing castration by rubber ring." PeerJ 8 (October 6, 2020): e10081. http://dx.doi.org/10.7717/peerj.10081.
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The social context of social species such as sheep can modify their physiological and behavioural responses to stressors, through social buffering and social facilitation. Social buffering can lead to amelioration of stress, while social facilitation can lead to stress responses in an observer animal in the presence of a conspecific in distress. The current study investigated twin lambs undergoing ring castration, grouped either homogeneously with a castrated lamb (actor), or heterogeneously with a non-castrated lamb (observer) to examine the impact of social grouping on behavioural responses. Each lamb was scored for two classes of behaviour: pain-related behaviours and postures that are putatively related to the response to castration; and attentional behaviours directed at its twin. Thus, each lamb participated in the experiment as an actor exhibiting pain-related behaviours and postures, and as an observer of its twin. When behaviours of lambs were assessed as actors, there was a significant (P < 0.05) effect of castration but no significant effect of social grouping on expression of pain-related behaviours. When behaviours of lambs were assessed as observers, homogeneous grouping of castrated lambs increased attention towards the other twin in comparison to non-castrated lambs grouped homogeneously or lambs grouped heterogeneously (P < 0.01). Non-castrated lambs grouped homogeneously demonstrated significantly lower numbers of head direction changes (P < 0.001) and lower number of ear posture changes (P < 0.05) than heterogeneously grouped or castrated lambs. This study indicates that social attention between twin lambs is not clearly dependent on pain status of the actor lamb. It suggests that in order for the observer lamb to provide significant attention to the actor lamb displaying pain-related behaviour, the observer lamb also needs to be experiencing pain concurrently. Furthermore, there is some evidence that the presence of pain-related behaviours can lead to increased attention to the surrounding environment in non-castrated lambs. Understanding the effect of concurrent experience and varying social context assists us to improve our understanding of results of other experiments on pain-related behavioural responses.
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McHugh, Noirin, Thierry Pabiou, Kevin McDermott, Eamon Wall, and Donagh P. Berry. "Genetic and nongenetic factors associated with the fate of maiden ewe lambs: slaughtered without ever lambing versus retained for breeding1." Translational Animal Science 4, no. 1 (September 24, 2019): 242–49. http://dx.doi.org/10.1093/tas/txz156.
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Abstract The decision on which ewe lamb to retain versus which to sell is likely to vary by producer based on personal preference. What is not known, however, is if any commonality exists among producers in the characteristics of ewe lambs that influence their eventual fate. The objective of the present study was to determine what genetic and nongenetic factors associate with the fate of maiden ewe lambs. The fate of each ewe lamb born in the present study was defined as either subsequently: 1) having lambed in the flock, or 2) was slaughtered without any recorded lambing event. A total of 9,705 ewe lamb records from 41 crossbred flocks were used. The logit of the odds of the ewe lamb being retained for lambing was modeled using logistic regression. Variance components were then estimated for the binary trait representing the fate of the ewe lamb using animal linear and threshold mixed models. The genetic correlations between fate of the ewe lamb and preweaning, weaning, or postweaning liveweight were also estimated. From the edited data set, 45% of ewe lambs born entered the mature flock as ewes. Ewe lambs reared as singles, with greater levels of heterosis but lower levels of recombination loss, born to dams that lambed for the first time as hoggets, with greater breed proportion of the Belclare, Suffolk, Texel, and Llyen breeds were more likely (P < 0.001) to eventually lamb in the flock than be slaughtered without ever lambing. Irrespective of the age of the animal when weighed, heavier ewe lambs were more likely to eventually lamb (P < 0.001). The genetic SD and direct heritability of fate of the ewe lamb estimated in the univariate linear model was 26.58 percentage units and 0.31 (SE = 0.03), respectively; the heritability was 0.30 when estimated using the threshold model. The corresponding direct heritability of fate of the ewe lamb estimated in the bivariate analyses with liveweight ranged from 0.29 (SE = 0.03; preweaning weight) to 0.35 (SE = 0.04; postweaning weight). The genetic correlations estimated between fate of the ewe lamb and the liveweight traits were weak to moderate but strengthened as the age of the ewe lamb at weighing increased. Results from this study provide an understanding of the factors producers consider when selecting females for retention versus slaughter which may form useful parameters in the development of a decision support tool to identify suitable ewe lambs for retention.
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Dwyer, C. M., A. B. Lawrence, and S. C. Bishop. "The effects of selection for lean tissue content on maternal and neonatal lamb behaviours in Scottish Blackface sheep." Animal Science 72, no. 3 (June 2001): 555–71. http://dx.doi.org/10.1017/s1357729800052097.
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AbstractBritish hill sheep are required to give birth to and rear their lambs under harsh extensive conditions. The aim of this study was to investigate whether genetic selection for increased (LEAN) or decreased (FAT) carcass lean content in the Scottish Blackface breed over 7 years had affected the ability of ewes to rear lambs by altering the expression of maternal and neonatal lamb behaviours. The behaviour of 61 ewes (32 LEAN and 29 FAT) and their 119 lambs were recorded at parturition and over the first 8 weeks of life. Overall there were very few effects of selection on the behaviour of the ewes. LEAN ewes were significantly faster than FAT ewes to start grooming their lambs after birth and FAT ewes tended to withdraw more frequently from their lambs than LEAN ewes. There was, however, a highly significant effect of selection line on lamb behaviour. LEAN lambs were significantly quicker than FAT lambs to perform all righting movements (median latency to stand (mins): LEAN = 11·7, FAT = 23·4, P < 0·01), were more likely both to suck (percentage that sucked: LEAN = 81·0%, FAT = 57·1%, P < 0·05), and to play within the first 2 h of birth. The higher rate of sucking in LEAN lambs persisted over the first 3 days after birth (percent observations where lambs were sucking: LEAN = 7·8 (s.e. 0·8), FAT = 5·1 (s.e. 0·6), P < 0·05), when LEAN lambs were also significantly closer to their mothers than FAT lambs. Thereafter, there were no significant effects of ewe or lamb line on behaviours recorded up to 8 weeks after birth. Overall lamb mortality to 8 weeks was 19·3% and was not significantly affected by lamb line. However, lambs that were slow to perform early behaviours had a reduced survival to 8 weeks of age. These data suggest that, although ewe maternal behaviour has not been significantly affected by selection for lean growth, the activity of the neonatal lamb has been affected. Lamb activity was related to lamb survival, even in our indoor lambing conditions. It is likely that the speed with which newborn lambs stand and suck will be even more important for survival under extensive conditions.
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Bickell, S. L., R. Nowak, P. Poindron, D. Ferguson, and D. Blache. "Maternal behaviour at parturition in outdoor conditions differs only moderately between single-bearing ewes selected for their calm or nervous temperament." Animal Production Science 50, no. 7 (2010): 675. http://dx.doi.org/10.1071/an09118.
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Maternal and lamb behaviours play a major role in lamb survival and there is evidence that selection for calm temperament may help improve lamb survival by improving maternal behaviour. However, the apparent better maternal behaviour of calm ewes might be due partly to their lower reactivity to the presence of the human observer rather than to better maternal behaviour per se. The extent to which the selection for temperament influenced the behaviour of the ewe and lamb after parturition with minimal human disturbance was investigated in the present work. Single-bearing multiparous and primiparous ewes were observed to determine any interactions of temperament with maternal experience on ewe and lamb behaviours. Postpartum ewe-lamb interactions under outdoor lambing conditions were captured by continuous video recordings by a remote controlled recording device for up to 2 h postpartum. Calm ewes licked their lambs more and tended to stay longer on the birth site. Nervous lambs stood up earlier and were quicker to start performing exploratory behaviour. However, duration of suckling during the observation period did not differ between the calm and nervous lambs. There were no effects of maternal experience on the behaviour of the lamb and there were no interactions between temperament and maternal experience on the behaviour of the ewe or lamb. Our study indicates that temperament does influence the early postpartum behaviour of ewes and lambs under extensive field conditions.
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Katz, M. E., and M. J. Hynes. "Characterization of the amdR-controlled lamA and lamB genes of Aspergillus nidulans." Genetics 122, no. 2 (June 1, 1989): 331–39. http://dx.doi.org/10.1093/genetics/122.2.331.
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Abstract Four Aspergillus nidulans genes are known to be under the control of the trans-acting regulatory gene amdR. We describe the isolation and initial characterization of one of these amdR-regulated genes, lamA. The lam locus, however, was found to consist of two divergently transcribed genes, the lamA gene, and a new gene, also under amdR control, which we have designated lamB. Using recombinant DNA techniques we have constructed a strain of A. nidulans lacking a functional lamB gene. Experiments conducted with this strain demonstrate that lamB, like lamA, is involved in utilization of 2-pyrrolidinone in A. nidulans. Metabolism of a related compound, gamma-amino butyric acid (GABA) is not affected. We also provide evidence that the conversion of exogenous 2-pyrrolidinone to endogenous GABA requires a functional lamB gene. The expression of both lamA and lamB is subject to carbon and nitrogen metabolite repression in addition to amdR-mediated induction by omega-amino acids.
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Campbell, Braden J., Jefferson S. McCutcheon, Francis L. Fluharty, and Anthony J. Parker. "PSIII-5 Delaying Weaning Age of Lambs Grazing Chicory (Cichorium Intybus) Increases Body Weight." Journal of Animal Science 99, Supplement_1 (May 1, 2021): 157. http://dx.doi.org/10.1093/jas/skab054.269.
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Abstract Two common challenges in forage-based lamb production systems is the restriction of net energy from grass-based pastures and the production losses associated with parasitic infection. The inclusion of nutrient rich forage in the diet and delaying lamb weaning age has shown to improve lamb growth rates in some systems. The objective of this experiment was to investigate the effects of grazing chicory (Cichorium intybus) and delayed weaning on the growth and health of young pasture-raised lambs. We hypothesized that improving the quality of available forage and delaying weaning would increase the body weight and parasite resilience of lambs. A total of 18 cross-bred ewes and 36 cross-bred lambs (25.2 ± 0.5 kg) were stratified by weight, sex, and randomly assigned to one of two weaning treatments: lambs weaned at 60 days of age (weaned) and lambs remained with their dam and weaned at 120 days of age (delayed weaned). Data were analyzed using PROC MIXED in SAS. Lamb body weight and indices of parasitism were measured every 14 days. There was a treatment × day effect for body weight as delayed weaned lambs were heavier on days 28, 42, and 56 compared with the body weight of weaned lambs (P < 0.02). In addition, there was a treatment × day effect for average daily gain (ADG) whereas delayed weaned lambs demonstrated greater ADG on days 14, 28, 42, and 56 compared with the ADG of weaned lambs (P < 0.02). In monitoring lamb health, there was a treatment × day effect as weaned lambs had a greater packed cell volume (PCV) on day 14 compared with the PCV of delayed weaned lambs (P < 0.03). Conversely, on day 56, weaned lambs had a lower PCV compared with the PCV of delayed wean lambs (P < 0.004). Delayed weaning has shown to be beneficial in improving lamb growth; however, in this instance, delayed weaning demonstrated variable responses in supporting lamb health while grazing on improved pastures.
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Pattinson, S. E., C. A. Williams, and M. W. Witt. "Evaluation of pressed sugar beet pulp ensiled with dried maize distillers grains as a feed for finishing lambs." Proceedings of the British Society of Animal Science 2001 (2001): 112. http://dx.doi.org/10.1017/s1752756200004944.
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Lamb concentrate costs account for around 30% of the variable costs of an early lambing system and can account for up to 33% of the variable costs for store lamb finishing (MLC, 2000). Over recent years the price for finished lambs has declined. It is against this background of declining lamb prices and reduced gross margins that cheaper alternatives to proprietary lamb concentrates are being sought. The aim of this work was to evaluate an ensiled mix of pressed sugar beet pulp and dried maize distillers dark grains (Praize, Trident Feeds Limited) for finishing lambs.
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El Fadili, M., C. Michaux, J. Detilleux, and P. L. Leroy. "Comparison of five crossbreeding types involving Timahdit, D’man and improved terminal sire breeds of sheep: ewe reproduction, lamb survival and growth performance." Animal Science 71, no. 3 (December 2000): 435–41. http://dx.doi.org/10.1017/s1357729800055351.
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AbstractA crossbreeding experiment involving Timahdit (T), D'man (D) and improved sire breeds (M) was conducted to compare lamb production in five crossbreeding types: D ✕ D, T ✕ T, D ✕ T (DT), M ✕ T, and M ✕ DT lambs. Reproductive and production traits were analysed in 1187 litters, 1586 lambs born and 1346 lambs weaned, progeny of 605 ewes. Effects of crossbreeding type, year of birth, sex of lamb, age of dam, and type of birth were significant on the majority of traits studied. The D ✕ D and M ✕ DT crossbreeding system showed the highest litter sizes at lambing and at weaning with respective values in D ✕ D (2·17, 1·34) and M ✕ DT (1·72, 1·39). Ewes bearing the M ✕ DT cross lambs showed the highest (P < 0·05) litter weight at weaning (28·28 kg) followed by those with M ✕ T (23·14 kg), and D ✕ D (22·53 kg) lambs. M ✕ DT and M ✕ T lambs were heavier and grew faster than the other lambs. On the other hand, lamb survival rates and growth traits were the lowest in D ✕ D but those in T ✕ T and D ✕ T genetic types of lamb were intermediate. Results showed that D as a dam breed had a favourable effect on litter size (P < 0·01) but unfavourable effect on lamb survival and birth weight. The reproductive performance of DT crossbred ewes, due to their high prolificacy and lamb survival, associated with the favourable effect of an improved terminal sire (M) for growth traits, indicated that the three breed cross (M ✕ DT) could enhance lamb production in Morocco.
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Fahmy, M. H., and S. Robert. "Ewe and lamb behaviour at parturition in prolific and non-prolific sheep." Canadian Journal of Animal Science 77, no. 1 (March 1, 1997): 9–15. http://dx.doi.org/10.4141/a96-014.
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This study was conducted to investigate ewe and lamb behaviour at parturition in prolific and non-prolific sheep. Observations were taken on 16 Romanov (R), 16 Finnsheep (F) and 13 Suffolk (S) ewes at their first and second parturitions. Time intervals between displaying first signs of uneasiness and first contraction, rupture of foetal membranes bag and first contraction, sighting the first lamb and expulsion of the last lamb, and contact time between ewes and their litters were assessed and correlated with litter size, and litter weight at birth and at weaning. Romanov ewes had the largest litters (3.02), took longer to deliver (120.7 min), and interacted more with their lambs (30.9 min) after lambing. F and S ewes were similar in many behavioural traits despite significant differences in number and weight of lambs delivered. Prolific R and F ewes lambing single and twin lambs delivered them faster than S ewes with similar litter sizes. Duration of lambing was significantly correlated with ewe–lamb contact but only for the two prolific breeds (r = 0.51 and 0.76 for R and F, respectively). Ewe-lamb contact was also correlated with litter size (r = 0.83), litter weight at birth (r = 0.72) and at weaning (r = 0.47) but only in F ewes. For R, F, and S ewes lambing litters of one and two lambs, the average intervals between first sight of a lamb and its expulsion were 9.2, 20.8, and 25.8 min, the intervals between expulsion and standing were 37.0, 18.6, and 19.6 min, and between standing and suckling, 24.2,20.4, and 27.2 min per lamb, respectively. The average contact time between a ewe and each of her lambs was 13.1, 8.8, and 11.0 min, respectively. The corresponding intervals for R and F ewes lambing up to four lambs were 10.3 and 11.1, 43.3 and 21.4, 35.7 and 25.6, and 8.8 and 7.8 min (P > 0.05) per lamb, respectively. The data showed several differences between prolific and non-prolific sheep in behavioural traits at birth. Key words: Maternal behaviour: Lamb behaviour, Romanov, Finnsheep, Prolific sheep
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Ridler, Anne L., Kate J. Flay, Paul R. Kenyon, Hugh T. Blair, Rene A. Corner-Thomas, and Emma J. Pettigrew. "Factors Associated with Mortality of Lambs Born to Ewe Hoggets." Animals 12, no. 3 (January 28, 2022): 319. http://dx.doi.org/10.3390/ani12030319.
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The reproductive performance of ewe hoggets is poorer than that of mature-age ewes due to production of fewer lambs with poorer survival. Scant data are available on the risk factors for, and causes of, the mortality for lambs born to ewe hoggets, the impact of ewe deaths on lamb loss, and the causes of death for lambs born to ewe hoggets vs. mature-age ewes lambing in the same circumstances. In this study, 297 lambs born to 1142 ewe hoggets were necropsied along with 273 lambs born to 1050 mature-age ewes. Low lamb birthweight, multiple litter size, and increasing ewe hogget average daily gain from breeding to late pregnancy were risk factors for lamb mortality. The most common cause of mortality for lambs born to ewe hoggets was stillbirth and the risk factors for stillbirth were similar to those for lamb mortality generally. Approximately 11% of ewe hoggets’ lamb deaths were due to the death of the dam. Causes of mortality differed between lambs born to ewe hoggets vs. those born to mature-age ewes. Management practices to increase ewe hogget lambs’ birthweights (particularly those from multiple litters) and supervision of ewe hoggets at lambing time are recommended.
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HEANEY, D. P., and J. N. B. SHRESTHA. "EFFECTS OF SOYFLOUR IN MILK REPLACER ON THE PERFORMANCE OF ARTIFICIALLY REARED LAMBS." Canadian Journal of Animal Science 67, no. 3 (September 1, 1987): 757–63. http://dx.doi.org/10.4141/cjas87-078.
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Two artificial rearing experiments were conducted to evaluate both preweaning and postweaning performance of artificially reared lambs, ad libitum fed a milk replacer having one-third of the milk protein replaced by soyflour protein (S) compared with those fed MR with all the protein provided by milk products (M). From weaning at 21 d of age to 91 d of age all the lambs were fed the same high-concentrate diet. In the first experiment there were no significant differences in lamb weights, daily gains, postweaning feed conversion or lamb survival. In the second experiment there were lower (P < 0.05) postweaning daily gains, lower (P < 0.05) 91-d weights and higher (P < 0.05) postweaning feed conversion (2.69 vs. 2.52 kg feed kg−1 gain) for S lambs compared with M lambs, although there were no significant differences due to MR treatment for weaning weights, preweaning daily gains or lamb survival. In both experiments the S lambs consumed slightly more MR than M lambs. Using prices prevailing at the time of the study the lower ingredient cost of the soyflour resulted in a saving in MR cost of $1.45 per lamb weaned. In the second experiment, the lower MR cost would have been partially offset by the approximately 1 kg extra liveweight per lamb at 91 d of age. It was concluded that soyflour could contribute one-third of the total protein in MR for ad libitum fed, artificially reared lambs with little, if any, reduction in lamb performance. However, savings in feed costs resulting from the cheaper ingredient cost might be partially offset by lower postweaning lamb gains. Key words: Lambs, artificial rearing, milk replacer, soy protein
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Johns, C., J. Johns, and D. R. Stevens. "Increasing lamb survival and lamb weaning weight through feeding high fecundity crossbred sheep." NZGA: Research and Practice Series 16 (January 1, 2016): 323–28. http://dx.doi.org/10.33584/rps.16.2016.3244.
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The monitoring of a high fecundity ewe flock in the Te Anau basin demonstrates the process of improved feeding to improve lamb survival and growth to weaning. Feed budgeting was changed from traditional to tailored feed requirements based on measured ewe liveweight with wastage of 15% factored in. Feed allocation was changed from monthly to weekly increases during late pregnancy, and set stocking was delayed until the planned start of lambing. This increased late pregnancy feed allocation from 99 kg DM/ewe to 128 and 144 kg DM/ewe for twin and triplet bearing ewes, respectively. Ewe body condition score was maintained at between 3 and 3.5, with condition score loss between scanning and lambing being reduced to zero. Lamb survival and lamb liveweight gain to weaning increased in both twin and triplet bearing ewes. Pregnancy scanning increased from 200 to 222 lambs per 100 ewes, between 2007 and 2012, while lambing percentage (lambs weaned/ ewe mated) rose from 132% to 165%, with more ewes rearing lambs and rearing multiples. Lamb wastage declined from 37% in 2007 and 2008, to 25% in 2011 and 2012, though scanning percentage rose by 20%. Lamb weights increased from 27.5 to 36 kg/lamb at 100 days of age. The increase in the liveweight of lambs and ewes at weaning reduced the calculated feed requirements over summer and autumn, potentially releasing 70 to 110 kg DM/ewe to provide feed to meet the extra winter feed requirements. Keywords: ewe body condition score, feed allocation, lamb survival, lamb weaning weight
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Lockwood, A., J. Trompf, L. Kubeil, A. Thompson, G. Refshauge, G. Kearney, and S. Hancock. "Decreasing the mob size but not stocking rate of ewes at lambing increases the survival of twin lambs born on farms across southern Australia." Animal Production Science 60, no. 16 (2020): 1949. http://dx.doi.org/10.1071/an19632.
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Context Data collected from producers in south-eastern Australia found that the survival of twin-born lambs decreased by 3.5% for each extra 100 ewes in the mob at lambing. Increasing stocking rate by 1 ewe/ha decreased lamb survival by a further 0.7%. These survey findings suggest that lamb survival could be improved by optimising the allocation of ewes to mobs and paddocks at lambing. Aim The present paper reports two experiments. Experiment 1 tested the hypotheses that (1) the survival of twin-born lambs would be greater when ewes lamb in smaller mobs and at lower stocking rates, and (2) the effects of mob size and stocking rate would be greater in Merinos than in non-Merino breeds. Experiment 2 tested the hypothesis that the survival of twin-born Merino lambs would be greater at lower mob sizes when ewes lambed at stocking rates <4 ewes/ha. Methods Experiment 1 investigated a 2 × 2 factorial combination of mob size (high or low) and stocking rate (high or low) on the survival of twin-born Merino and non-Merino lambs at 70 on-farm research sites across southern Australia. Experiment 2 investigated the effect of high or low mob size on the survival of twin-born Merino lambs when ewes lambed at stocking rates of <4 twin ewes/ha at 15 on-farm research sites. In both experiments, adult twin-bearing ewes were randomly allocated into a treatment and lambing paddock on Day 140 from the start of joining at each farm. Lamb survival in each mob was calculated based on lamb losses between pregnancy scanning and lamb marking. Key results In both experiments, the effect of mob size on lamb survival was found to be linear, with survival of twin-born lambs decreasing by between 1.9% and 2.5% per additional 100 ewes in the mob at lambing, regardless of breed (P < 0.001). In Experiment 1, there was no effect of stocking rate or mob size by stocking rate on lamb survival. Conclusions The present research demonstrated that reducing mob size but not stocking rate will improve the survival of twin-born lambs to marking for extensive enterprises in Australia where ewes lamb at stocking rates of up to 12 ewes/ha. Implications These findings will contribute to guidelines for optimising ewe nutrition and resource allocation to improve lamb survival.
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Kanyar I. M. and F. Karadaş. "EFFECT OF MELATONIN AND VITAMIN E AS ANTIOXIDANTS ON BODY WEIGHT, CARCASS TRAITS OF AWASSI LAMBS FED A HIGH-ENERGY AND NORMAL DIET." IRAQI JOURNAL OF AGRICULTURAL SCIENCES 54, no. 5 (October 29, 2023): 1339–50. http://dx.doi.org/10.36103/ijas.v54i5.1835.
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This experiment was carried out to evaluate the effects of vitamin E (Alpha tocopherol acetate) supplementation and melatonin implants on growth performance, and meat quality traits of Awassi male lambs fed by a high and normal energy concentrated diet in Iraq. Lambs were divided equally to two main groups to be fed either high or normal energy diet ,and each of them divided in to five treatment, the first as a control (T1,T6),two level of melatonin (18, 36mg/lamb) were applied to (T2,T3,T7,T8) and two level of vitamin E (200,400mg/lamb/day) to (T4,T5,T9,T10).All animals were slaughtered at the end of the fattening period. Lambs received 400 g/day vitamin E with high energy diet surpassed significantly other treatment in final weight gain, vitamin E 400 mg/lamb/day and melatonin 18-36 mg/lamb at day 14 of storage increased retail color stability. enhanced meat color parameters. Melatonin implantation 18 mg/lamb, 36 mg /lamb significantly at day 7 of storage reduced MDA value, but at day 14 of storage vitamin E 200 and 400 mg/day/lamb reduced significantly MDA value of the Muscle Longissimus dorsi (LD) during storage.
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Holst, PJ, DG Hall, and CJ Allan. "Ewe colostrum and subsequent lamb suckling behaviour." Australian Journal of Experimental Agriculture 36, no. 6 (1996): 637. http://dx.doi.org/10.1071/ea9960637.
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Behavioural and colostral data were obtained from 70 parous Border Leicester x Merino ewes (and their lambs) that lambed in 0.25 ha paddocks. Data collected included a colostral sample immediately postpartum, lamb weight and temperature, site of parturition and lamb sucking attempts to 48 h post-partum. Colostrum dry matter percentage was 56.5 for ewes with single lambs and 61.5 for ewes with twins (P<0.05). Colostrum colour and consistency score (1-7) of twin-bearing ewes was 5.5 compared with single-bearing ewes of 6.5 (nearer normal milk). Lamb sucking behaviour suggested the more viscous the colostrum, the more often the lamb attempts to suck (P<0.001) and for a longer period at each attempt (P<0.05). This effect diminished over time so that by 24-48 h there was no difference in behaviour expressed as duration x number of sucking bouts, when normal milk would be expected. Twin lambs had significantly more sucking bouts than single lambs up to 4 h post partum. The consequences of these observations would be more serious for twin lamb survival and may explain why some individual twin lambs often die from starvation.
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Lambe, N. R., M. J. Young, G. Simm, J. Conington, and S. Brotherstone. "Seasonal tissue changes in Scottish Blackface ewes over multiple production cycles." Proceedings of the British Society of Animal Science 2003 (2003): 4. http://dx.doi.org/10.1017/s1752756200011637.
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A previous study using X-ray computed tomography (CT) of Scottish Blackface hill ewes found that carcass fat, internal fat and muscle are depleted during pregnancy and early lactation and deposited during late lactation and the dry period. Relationships were also found between fat and muscle levels and lamb production traits (Lambe et al., 2002a). Changes in tissue levels over multiple production cycles of the hill ewe, and how these changes relate to lamb production are also of interest. The aims of this study were to model changes in carcass fat, internal fat and muscle through three production cycles and to compare patterns of tissue change in ewes producing different numbers of lambs.
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Freitas-de-Melo, A., F. Sales, R. Ungerfeld, and V. H. Parraguez. "Melatonin treatment during late gestation of undernourished ewes: lamb body temperature and mother–young behaviours after birth." Animal Production Science 62, no. 2 (2022): 131. http://dx.doi.org/10.1071/an21016.
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ContextIn extensive grazing sheep systems, pregnant ewes undergo periods of undernutrition because gestation coincides with winter when natural pasture is of lowest quantity and poorest quality. The lamb’s weight and thermoregulatory capacity, and the ewe–lamb bond at birth, may be compromised. Maternal melatonin treatment during gestation may reverse these effects.AimThe aim was to determine the effects of melatonin treatment of single-lambing, undernourished ewes during the last third of gestation on lamb birthweights and body temperatures, and on ewe–lamb interactive behaviour after birth.MethodsAt Day 100 of gestation, 39 single-bearing ewes received a subcutaneous melatonin implant, and 54 ewes served as controls with no implant. Throughout gestation, the ewes remained under extensive conditions grazing on natural pasture. Measurements were made of lamb birthweight, body temperatures (surface temperature by infrared thermography and rectal temperature), and ewe–lamb behaviours during a handling test at 6–17h after lambing.Key resultsThere was no effect of melatonin treatment on lamb birthweight or rectal temperature, or on ewe–lamb interaction behaviours. Hip minimum surface temperature was greater in lambs from melatonin-treated ewes than lambs from control ewes (21.2°C±0.9°C vs 18.8°C±0.8°C; P=0.05), and there was a similar trend for hip mean surface temperature (24.6°C±0.9°C vs 22.3°C±0.7°C; P=0.06). Rump surface temperatures were greater in male than female lambs: maximum (27.9°C±1.2°C vs 22.9°C±1.2°C; P=0.01), minimum (22.2°C±1.5°C vs 16.7°C±1.5°C; P=0.02) and mean (25.4°C±1.3°C vs 20.5°C±1.3°C; P=0.02).ConclusionMelatonin treatment during the last third of ewe pregnancy slightly enhanced the surface temperature of lambs at birth but did not influence ewe–lamb interaction behaviour after birth (i.e. after establishment of the ewe–lamb bond).ImplicationsFurther study in more depth is warranted into the possible effects of maternal supplementation with commercial melatonin implants on lamb development, thermoregulatory capacity, behaviour and survival rates in extensive grazing systems, including the effect on ewe–lamb behaviours immediately after birth for both singletons and twins.
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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.
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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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Haslin, Emmanuelle, Emma J. Pettigrew, Rebecca E. Hickson, Paul R. Kenyon, Kristene R. Gedye, Nicolas Lopez-Villalobos, J. M. D. R. Jayawardana, Stephen T. Morris, and Hugh T. Blair. "Genome-Wide Association Studies of Live Weight at First Breeding at Eight Months of Age and Pregnancy Status of Ewe Lambs." Genes 14, no. 4 (March 27, 2023): 805. http://dx.doi.org/10.3390/genes14040805.
Full textAbstract:
This study estimated genetic parameters and identified candidate genes associated with live weight, and the occurrence of pregnancy in 1327 Romney ewe lambs using genome-wide association studies. Phenotypic traits considered were the occurrence of pregnancy in ewe lambs and live weight at eight months of age. Genetic parameters were estimated, and genomic variation was assessed using 13,500 single-nucleotide polymorphic markers (SNPs). Ewe lamb live weight had medium genomic heritability and was positively genetically correlated with occurrence of pregnancy. This suggests that selection for heavier ewe lambs is possible and would likely improve the occurrence of pregnancy in ewe lambs. No SNPs were associated with the occurrence of pregnancy; however, three candidate genes were associated with ewe lamb live weight. Tenascin C (TNC), TNF superfamily member 8 (TNFSF8) and Collagen type XXVIII alpha 1 chain (COL28A1) are involved in extracellular matrix organization and regulation of cell fate in the immune system. TNC may be involved in ewe lamb growth, and therefore, could be of interest for selection of ewe lamb replacements. The association between ewe lamb live weight and TNFSF8 and COL28A1 is unclear. Further research is needed using a larger population to determine whether the genes identified can be used for genomic selection of replacement ewe lambs.
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Jordán, María J., Cristina Martínez-Conesa, Sancho Bañón, Julio Otal, María Quílez, Inmaculada García-Aledo, Pascual Romero-Espinar, and Pedro Sánchez-Gómez. "The Combined Effect of Mediterranean Shrubland Pasture and the Dietary Administration of Sage By-Products on the Antioxidant Status of Segureña Ewes and Lambs." Antioxidants 9, no. 10 (September 30, 2020): 938. http://dx.doi.org/10.3390/antiox9100938.
Full textAbstract:
The objective of this study was to determine if the combined effect of ewe grazing and the incorporation of sage by-products in the lamb feed enhances the Segureña ewe and lamb antioxidant status. For that, the endogenous (related to blood antioxidant enzymes) and exogenous (plasma antioxidant activity) antioxidant systems of ewes and lambs were studied at the physiological stages of lactation, after weaning and at the end of the fattening period. Major results indicated that grazing improved the enzymatic antioxidant defense of ewes during the stressful period of lamb weaning, and also, the antioxidant status of the ewe plasma at both physiological stages: lactation and after lamb weaning. With regards to the lambs, ewe grazing stimulated the antioxidant enzymatic defense during lactation, but not the antioxidant capacity of the plasma. At the end of the fattening period, the inclusion of sage by-products in the lamb diet (10% w/w) enhanced both the enzymatic cascade and antioxidant capacity of the lamb plasma. The antioxidant capacity of the lamb meat was also studied and the benefits of sage were detected in samples from the deltoideus muscle. Thus, Mediterranean grazing stimulated the antioxidant defense in ewes, while the inclusion of sage by-products in the lamb diets enhanced the antioxidant status of both blood and meat.
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Payne, Claire E., Liselotte Pannier, Fiona Anderson, David W. Pethick, and Graham E. Gardner. "Lamb Age has Little Impact on Eating Quality." Foods 9, no. 2 (February 13, 2020): 187. http://dx.doi.org/10.3390/foods9020187.
Full textAbstract:
There is an industry wide perception that new season lamb has better eating quality than old season lamb. This study aims to identify differences in consumer eating quality scores between two age classes in lamb. Consumer eating quality scores from eight cuts across the carcass were evaluated from new season (NS; n = 120; average age = 240 days) and old season lambs (OS; n = 121; average age = 328 days), sourced from four different flocks. Cuts were grilled (loin, topside, outside, knuckle and rump) or roasted (leg, shoulder, rack) and scored by untrained consumers for tenderness, juiciness, liking of flavour and overall liking. There was no difference in eating quality scores between the two age classes for the loin, leg, shoulder and rack. This was similarly shown in the topside with the exception of juiciness scores where NS lambs were higher than OS lambs. There was also a lack of age difference in the outside with the exception of flock 3 where NS lambs scored higher than OS lambs for all sensory traits. Across all sensory traits, OS lambs received on average 2.8 scores lower for the knuckle and 3.1 scores lower for the rump compared to NS lambs. These results show little difference in eating quality between NS and OS lamb, and highlight the potential to develop high quality OS or “autumn lamb” products, with a similar premium price at retail as NS lambs.
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Minter, C. M., G. Perrott, and E. Legendre. "The effect of feeding varying levels of barley and dried molassed sugar beet feed compared to a commercial creep on the performance of intensively reared Iambs." Proceedings of the British Society of Animal Science 1996 (March 1996): 164. http://dx.doi.org/10.1017/s1752756200593594.
Full textAbstract:
Feed is the major cost of indoor lamb production, it accounts for up to £12/lamb reared (MLC, 1994) which is equivalent to 23% of the output value. Most intensively produced lambs are fed expensive specially formulated lamb creep diets. The aim of this experiment was to evaluate the effect varying the proportions of the starch (barley, WB) and digestible fibre (dried molassed sugar beet feed; SBF) and a protein pellet compared to a commercial lamb creep (LC) on lamb physical and financial performance.180 early weaned lambs, (weaned at 6 weeks of age), weighing on average 17.5 kg liveweight were allocated to one of six treatments; 0% SBF, 20% SBF, 40% SBF, 60% SBF, 80% SBF and LC. Each diet contained 20% protein balancer pellets with the remainder being whole barley. The LC diet was offered alone.
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Minter, C. M., G. Perrott, and E. Legendre. "The effect of feeding varying levels of barley and dried molassed sugar beet feed compared to a commercial creep on the performance of intensively reared Iambs." Proceedings of the British Society of Animal Science 1996 (March 1996): 164. http://dx.doi.org/10.1017/s0308229600031305.
Full textAbstract:
Feed is the major cost of indoor lamb production, it accounts for up to £12/lamb reared (MLC, 1994) which is equivalent to 23% of the output value. Most intensively produced lambs are fed expensive specially formulated lamb creep diets. The aim of this experiment was to evaluate the effect varying the proportions of the starch (barley, WB) and digestible fibre (dried molassed sugar beet feed; SBF) and a protein pellet compared to a commercial lamb creep (LC) on lamb physical and financial performance.180 early weaned lambs, (weaned at 6 weeks of age), weighing on average 17.5 kg liveweight were allocated to one of six treatments; 0% SBF, 20% SBF, 40% SBF, 60% SBF, 80% SBF and LC. Each diet contained 20% protein balancer pellets with the remainder being whole barley. The LC diet was offered alone.
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Hass, Christine C. "Bighorn lamb mortality: predation, inbreeding, and population effects." Canadian Journal of Zoology 67, no. 3 (March 1, 1989): 699–705. http://dx.doi.org/10.1139/z89-101.
Full textAbstract:
Survival of lambs in the population of bighorn sheep (Ovis canadensis) on the National Bison Range, Montana, was less than 25% during 1983 and 1984. Sixty-seven percent of lamb mortality occurred within 3 days of birth; ewe behaviour and recovered remains indicated that coyotes likely accounted for most of the mortality. Herd history, calculated inbreeding coefficients, and the observation of several small, weak lambs implied that inbreeding depression, while probably not a major factor in lamb mortality, may have predisposed some lambs to predation. Lamb production was high (88–96%); in spite of high mortality, population numbers were stable.
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Dugan, M. E. R., V. Salazar, D. C. Rolland, P. Vahmani, J. L. Aalhus, Ó. López-Campos, N. Prieto, and M. Juárez. "Retail lamb fat composition in western Canada." Canadian Journal of Animal Science 99, no. 4 (December 1, 2019): 971–74. http://dx.doi.org/10.1139/cjas-2019-0003.
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The fatty acid composition of retail lamb backfat commonly available in Western Canada was analyzed, including 16 lambs collected from a slaughter plant in central Alberta, and backfat collected from racks and chops imported from Australia (n = 8) and New Zealand (n = 8). Lamb fat from New Zealand was the richest source of vaccenic and rumenic acids. Both New Zealand and Australian lamb were the richest source of n-3 fatty acids. North American lamb was richer in t10-18:1, but a subset had fatty acid compositions similar to New Zealand lamb.
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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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Hall, DG, NM Fogarty, and AR Gilmour. "Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 1. Lamb birth weight, survival and growth." Australian Journal of Experimental Agriculture 35, no. 8 (1995): 1069. http://dx.doi.org/10.1071/ea9951069.
Full textAbstract:
Merino rams of the Trangie Fertility and Booroola strains were joined to Poll Dorset ewes in single sire mating groups over 3 years. Forty sires produced a total of 1250 lambs in 885 litters from 451 ewes. Lamb birth weight averaged 4.1 kg, 80.8% of lambs survived to 3 days of age and growth rates to weaning (mean 93 days) averaged 289 g/day. Lambs with Trangie Fertility sires grew 15 g/day faster and were 1.3 kg heavier at weaning than those lambs with Booroola sires (P<0.001). There were no effects of sire strain on birth weight or lamb survival. Birth weight increased with dam liveweight in mid-pregnancy (P<0.001), and weaning weight and growth rate increased with dam liveweight at joining (P<0.001). Survival of lambs was predominantly a function of birth weight. Lambs weighing 4 kg at birth from primiparous dams had survival rates of 76% compared with 88% for lambs from multiparous dams (P<0.01). No lamb under 2.0 or over 6.3 kg survived, and 48% of deaths occurred within 1 day of birth. Dystocia, particularly of heavy, single-born lambs, caused 53% of observed lamb deaths. For the traits birth weight, lamb survival, weaning weight and growth rate, the direct heritabilities were 0.24 � 0.10, 0.05 � 0.05, 0.19 � 0.10 and 0.12 � 0.08 respectively; the corresponding maternal heritabilities were 0.08 � 0.05, 0.05 � 0.04, 0.05 � 0.05 and 0.07 � 0.05 respectively; and the common environmental effects among litter mates (c2) were 0.57 � 0.08, 0.47 � 0.08, 0.15 � 0.08 and 0.13 � 0.08 respectively.
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Pannier, L., E. N. Ponnampalam, G. E. Gardner, D. L. Hopkins, A. J. Ball, R. H. Jacob, K. L. Pearce, and D. W. Pethick. "Prime Australian lamb supplies key nutrients for human health." Animal Production Science 50, no. 12 (2010): 1115. http://dx.doi.org/10.1071/an10132.
Full textAbstract:
This study investigated genetic and non-genetic factors affecting the iron, zinc and omega-3 fatty acid levels of fresh lamb meat. Results from the 2007 progeny of the Australian Sheep Industry Cooperative Research Centre Information Nucleus flock, ~2000 lambs, are presented here. The average level of iron and zinc in lamb muscle was 2.05 and 2.31 mg/100 g, respectively. The iron level was 103% of that required to claim lamb as a ‘good source’ of iron for men of all ages and women older than 50 years, and the average level of zinc was 116% of that required to claim lamb as a ‘good source’ of zinc for women, but was insufficient for a ‘good source’ claim for men. The iron and zinc content of muscle were affected (P < 0.001) by age at slaughter, sex, site at which the lambs were reared, and sire (independent of breed). Lambs from all sites reached the ‘source’ claim for iron for all adults and lambs from all sites, expect lambs from the Cowra and Hamilton sites, had greater iron levels than that required for a ‘good source’ claim for men and women over 50 years old. For zinc, all sites reached the ‘source’ and ‘good source’ claim for men and women, respectively. The major sources of variation in omega-3 fatty acid levels were site and kill group within site (P < 0.001), most likely reflecting nutritional differences associated with the availability of green feed. The eicosapentaenoic acid + docosahexaenoic acid values for all sites indicated that lambs from the Cowra, Rutherglen and Struan sites had adequate levels for a ‘source’ claim of omega-3. The overall average level of eicosapentaenoic acid + docosahexaenoic acid in lamb meat was 23.5 mg/100 g, which is higher than the level required to claim lamb as a ‘source’ of omega-3. The effect of sire on omega-3 fatty acid level was small, but statistically significant (P < 0.001). These results confirm that lamb can represent a ‘source’ or ‘good source’ of these nutrients.
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McGrattan, P. D., and A. R. G. Wylie. "Influence of genotype and gender on receptor binding affinity (Kd) for insulin and insulin receptor concentration in skeletal muscle and adipose tissue of growing lambs." Animal Science 73, no. 1 (April 2001): 77–84. http://dx.doi.org/10.1017/s1357729800058070.
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AbstractDifferences in receptor binding affinity for insulin, and insulin receptor concentration, were found in skeletal muscle and adipose tissue of lambs differing in genotype and gender. The Rouge de l’Ouest lamb genotype had a lower receptor affinity for insulin in m. rectus capitis skeletal muscle compared with both Dutch Texel and Greyface lamb genotypes (P < 0·01). Insulin receptor concentration in m. longissimus dorsi skeletal muscle was greater in the Texel lamb genotype compared with both the Greyface (P < 0·001) and Rouge de l’Ouest (P < 0·05) lamb genotypes. Insulin receptor concentration in perirenal fat tissue was greater in the Rouge de l’Ouest lamb genotype compared with the Texel lamb genotype (P < 0·05).There were no differences in receptor affinity for insulin between individual tissues in male and female lambs. The concentration of insulin receptors in male lambs was greater in m. longissimus dorsi (P < 0·05), subcutaneous adipose tissue (P < 0·05) and perirenal fat (P < 0·001) compared with female lambs. Receptor affinity for insulin in individual tissue depots also demonstrated significant genotype ✕ gender interactions. M. longissimus dorsi had a lower receptor affinity for insulin in Texel male lambs compared with Greyface male lambs (P < 0·05). M. rectus capitis had a lower receptor affinity in Rouge de l’Ouest male lambs compared with Texel male lambs (P < 0·01). M. rectus capitis also had a lower receptor affinity for insulin in Rouge de l’Ouest female lambs compared with both Texel and Greyface female lambs (P < 0·01). Within individual genotypes, m. longissimus dorsi had a lower receptor affinity for insulin in Greyface female lambs compared with Greyface male lambs (P < 0·05) whereas m. rectus capitis had a lower receptor affinity for insulin in Texel female lambs compared with Texel male lambs (P < 0·05).Such differences in tissue receptor affinity for insulin and receptor concentration in lambs differing in genotype and gender could, through effects on tissue sensitivity and/or responsiveness to insulin, manipulate nutrient partitioning between skeletal muscle and fat tissue and hence control, at least in part, the efficiency of lean meat production.
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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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Keogh, T. P., S. R. McGrath, V. H. Oddy, M. Hernandez-Jover, H. Dickson, and M. B. Allworth. "Are there opportunities to improve lamb feedlot production efficiency? A cross-sectional survey." Animal Production Science 62, no. 4 (December 14, 2021): 381–91. http://dx.doi.org/10.1071/an21309.
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Context Feedlotting lambs has the potential to considerably increase the efficiency of lamb production in Australia. Many producers have turned to grain-finishing lambs to capitalise on high lamb prices and, due to the perceived profitability of this practice, further research to improve production has not been prioritised. Lambs are, however, difficult to adapt to a predominantly grain-based diet, often resulting in highly variable feed intake and growth rates. Aims The aim of this survey was to investigate the apparent growth rates and feed conversion ratios of lambs in current feedlotting enterprises. A secondary aim was to identify research priorities that could improve feedlot production efficiency. Methods A cross-sectional survey was conducted between February and May 2020 among Australian lamb producers, with the target population being lamb producers using feedlots to finish lambs. Producer responses from 59 current lamb feedlotters were collated and analysed. Key results The most frequently reported growth rates were between 300 and 350 g/day, and most respondents reported a feed conversion ratio of 5:1. The incidence of shy feeders was a median of 3.5% and mortality was a median of 1%, with acidosis reported as the major contributor to mortality. Conclusions The results of the current survey indicate that for the majority of responding producers, lamb growth rates and feed conversion ratios are consistent with those predicted by the nutrient requirements of domesticated ruminants (CSIRO 2007), and improvements in production are unlikely without significantly increasing nutrient intake. Shy feeders, acidosis and the intake of lowly digestible feeds are the clear limitations to production efficiency. Implications Research to improve productivity of lambs in feedlots needs to prioritise the implementation of feeding strategies that minimise social and nutritional issues, and promote maximum intake of nutrients.