Journal articles: 'Sheep Fertility'

1

Raoof, Salim Omar. "Role of Sex Chromatin on performance in the Arabi sheep." Iraqi Journal of Veterinary Medicine 41, no. 1 (June 5, 2017): 145–50. http://dx.doi.org/10.30539/iraqijvm.v41i1.97.

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This study was conducted on 122 Arabi sheep belonged to private flock in Erbil plain Kurdistan region- Iraq, from July/ 2014 to August/ 2015 for studying the role of sex chromatin on daily milk production, total milk production, lactation period, fertility rate, prolificacy, birth weight and fertilizes estrous sequences. The repeatability for the studied traits were estimated. The ratio of sex chromatin shapes drum stick, sessile nodule, tear drop and small club were 23.37%, 60.22%, 8.54% and 7.87% respectively.The overall means of daily milk production, total milk production, lactation period, birth weight, fertilize estrous sequences, fertility rate, and Prolificacy were 814.65 g 81.49 kg 103.53 day, 78.10%, 1.60, 3.84 kg and 1.50 respectively. Sex chromatin shapes had significant (P<0.05) effect on all traits studied. The results revealed that the estimation of the Repeatability coefficient for daily milk production was 0.42. It was concluded from this study that production traits (milk production and birth weight) and reproduction (fertility rate, prolificacy and fertilize estrous sequences) performance of Arabi sheep were significantly affected by the shapes and percentage of sex chromatin distribution and measurements. The sex chromatin shapes could be used as a tool for early selection of the elite individuals.

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Petrovic, Milan, V. Caro-Petrovic, D. Ruzic-Muslic, N. Maksimovic, Z. Ilic, B. Milosevic, and J. Stojkovic. "Some important factors affecting fertility in sheep." Biotehnologija u stocarstvu 28, no. 3 (2012): 517–28. http://dx.doi.org/10.2298/bah1203517p.

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Efficiency of sheep production is conditioned by fertility. According to some authors number of offspring obtained per lambing is more important than gain of weight. Genetic relationships involving reproductive traits were seldom studied. Reproductive traits have low heritabilities, a discrete phenotypic expression, and are expressed only in sexually mature ewes leading to low selection intensities and long generation intervals. Documentation of realized selection response is also often complicated by the low heritabilities of fertility traits. Existence of a major gene affecting prolificacy had been suggested and at that time there were many sceptics who strongly doubted that a trait as complex as reproduction could be profoundly influenced by a single gene. Major genes affecting prolificacy in sheep was founded. A mutation in the bone morphogenetic protein 15 gene (BMP15, also known as GDF9B) responsible for high prolificacy in Inverdale sheep had been discovered and evidence of segregating major genes was being reported from flocks around the world. Development of gene mapping techniques, and locating alleles that are responsible for the fertility of sheep began a new chapter in predicting and controlling the fertility of sheep. The beneficial effects of nutrition on reproduction in sheep are well known. This procedure is known as flushing. The effect of Body Condition Score (BCS), before mating, during mating and after mating period, on reproductive efficiency of different breeds of sheep in the different rearing systems were studied. The farm manager has the ability to control or at least to manipulate the factors that have an impact on fertility.

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PAPADOPOULOS (Σ. ΠΑΠΑΔΟΠΟΥΛΟΣ), S., E. THEODOSIADOU (Α. ΘΕΟΔΟΣΙΑΔΟΥ), D. KANTAS (Δ. ΚΑΝΤΑΣ), and E. VALASI (Ε. ΒΑΛΑΣΗ). "The application of in vitro fertilization techniques for the evaluation of ram fertility." Journal of the Hellenic Veterinary Medical Society 66, no. 2 (January 31, 2018): 63. http://dx.doi.org/10.12681/jhvms.15588.

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The prediction of field fertility of a given ram by using in vitro tests would be of great importance for the reproductive management in sheep flocks. There are many in vitro procedures available for evaluating semen quality and fertilizing ability, and the method chosen depends on the objective of evaluating the sperm and the available resources. The in vitro evaluation of semen fertilizing ability was firstly developed for the artificial insemination (AI) purposes and secondly for the application of in vitro fertilization (IVF) technique. The IVF techniques allow the assessment of fertility in terms of ability to penetrate and fertilize in vitro mature oocytes and ultimately to yield component embryos following IVF and culture. In this review are briefly presented in vitro studies performed in an attempt to establish an accurate laboratory test for the evaluation and, even more, the prediction of field fertility in sheep.

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4

Vlasenko, S., O. Zhulinska, and O. Yeroshenko. "Clinical and laboratory prognostic indicators for fertility in sheep." Naukovij vìsnik veterinarnoï medicini, no. 1(149) (May 30, 2019): 6–14. http://dx.doi.org/10.33245/2310-4902-2019-149-1-6-14.

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With the use of technology of artificial insemination in sheep farms are not yet defined criteria for assessing the full value of the preparation of females for insemination, and hence – the possibility of prediction and correction of their fertilization, which prevents the rational use of cryopreserved semen and ensuring the maximum reception of the offspring. We have proved the prognostic importance of fertilization of the morphofunctional state of the vulva and the vagina and the quality of mucus in sheep breeds during estrus. The material of the study was 327 sheep of ascanian breeding, which during the sexual intercourse before insemination examined the vulva, vagina and evaluated the estrus slime (number, color, consistency, presence of impurities, elasticity, electrical resistance, type of crystallization, protein content). The results of ultrasound diagnosis of pregnancy were determined by the fertility of sheep with different integral compositions of clinical and laboratory parameters. It has been established that in sheep, in which fertility in the first sexual cycle reached 65.1%, most often found a pink, moderately edematous vulva with clear mucus. In females with pale mucous membrane and insignificant amount of mucus, the effectiveness of inseminates declined to 53.3-58.0%. In a significant amount of estral mucus, the proportion of infertile animals increased twofold. At the same time, the selection of liquid, but cloudy, or thick mucus is a sign of an unfavorable prognosis, in which fertility decreases by 1.8-2.1 times (p <0.001). Dense, white, paste-like isolates were observed in a small number of sheep, mostly bright at the beginning of the anestral season. Low fertility in the first sexual hunting (35.5%) and a high multiplicity of repeated inseminations (29.0%) indicate that sheep with thick estral slime are only beginning to enter the sexual season, and this quality of secrecy indicates an inadequate estrogenization of the body. It was also found that in the infertile sheep during sexual hunting, the protein content of cervical mucus was 4.8 times higher, and the elasticity of mucus was reduced by 2.9 times. The most prevalent was the prognosis of average fertilization (53.3-58.0%), which was recorded in 62.9% of experimental sheep. The prognosis of high fertilization, which resulted in 62.5-65.1% of oseminins, was found in 27.8% of females. At the same time, the number of females with a fertility forecast at 40% was only 3.1%, and the prevalence of an unfavorable prognosis, in which fertility was the smallest (30.0-35.5%), reached 6.2%. Key words: sheep, askanian breeding, estrus, fertility prognosis, estral mucus, vulva, vagina, artificial insemination.

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5

Scaramuzzi, RJ, JA Downing, BK Campbell, and Y. Cognie. "Control of Fertility and Fecundity of Sheep by Means of Hormonal Manipulation." Australian Journal of Biological Sciences 41, no. 1 (1988): 37. http://dx.doi.org/10.1071/bi9880037.

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The results of four experiments are presented in summary form. The data are considered in relationship to the improvement of the fecundity and fertility of the Australian ewe breeding flock. In the first, three commonly used methods of oestrous synchronization were examined and showed differences that are attributed to the different patterns of hormonal changes associated with the methods demonstrated. The second experiment looked at the use of active immunization against testosterone and concluded that this method can improve fecundity but not fertility. The third experiment, a group of five trials, studied the use of progestagen sponges and PMSG in anoestrous ewes as a means of inducing normal fertility. The extensive data produced in this experiment allowed the relationships between ovulation rate and fertility and between fertility and prolificacy (fecundity) to be examined. Fertility appeared greatest when the mean flock ovulation rate was about 2�5. At this ovulation rate prolificacy was also improved and a high proportion of twins were produced. We concluded that high fertility and low prolificacy (i.e. of 1�00) are an unlikely combination. In the final experiment the effect of post-mating hormonal supplementation on fertility was examined and a number of earlier reports were confirmed by showing that fertility can be improved with supplementary progesterone between days 10 and 25 post-mating. The effect appears to be modified by hormonal and nutritional factors.

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Maxwell, W. M. C., and H. R. Wilson. "Fertility of fresh, chilled and frozen merino sheep embryos." Theriogenology 41, no. 1 (January 1994): 251. http://dx.doi.org/10.1016/s0093-691x(05)80161-x.

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7

Evans, A. C. O. "Ovarian follicle growth and consequences for fertility in sheep." Animal Reproduction Science 78, no. 3-4 (October 2003): 289–306. http://dx.doi.org/10.1016/s0378-4320(03)00096-4.

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8

David, Ingrid, Philippa Kohnke, Gilles Lagriffoul, Olivier Praud, Franck Plouarboué, Pierre Degond, and Xavier Druart. "Mass sperm motility is associated with fertility in sheep." Animal Reproduction Science 161 (October 2015): 75–81. http://dx.doi.org/10.1016/j.anireprosci.2015.08.006.

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9

Boland, M. P., and T. F. Crosby. "Fecundin: An immunological approach to enhance fertility in sheep." Animal Reproduction Science 33, no. 1-4 (October 1993): 143–58. http://dx.doi.org/10.1016/0378-4320(93)90112-5.

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10

Bortoletti, G., F. Gabriele, V. Seu, and C. Palmas. "Epidemiology of hydatid disease in Sardinia: a study of fertility of cysts in sheep." Journal of Helminthology 64, no. 3 (September 1990): 212–16. http://dx.doi.org/10.1017/s0022149x00012189.

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ABSTRACTHydatidosis, caused by Echinococcus granulosus, is a cyclozoonotic disease of economic significance in Sardinia. The life-cycle involves stray and sheep dogs as definitive hosts and sheep, pigs, goats and cattle as intermediate hosts. The most important intermediate host is sheep, due to home slaughtering with ready access of the viscera to dogs. This survey was undertaken in 1987 to ascertain the epidemiological significance of sheep in maintaining the life-cycle. A total of 700 (91·3%) of 767 sheep harboured hydatid cysts. The frequency distribution of the number of hydatid cysts was over-dispersed. Of 497 infected sheep, 7·6% had fertile cysts, 75·7% sterile cysts and 16·7% fertile + sterile cysts.

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11

Vazic, Bozo, Biljana Rogic, Milanka Drinic, and Novo Przulj. "Relationship between the genetic hemoglobin polymorphism, morphometry and fertility of Pramenka sheep breed from Central Bosnia." Genetika 49, no. 1 (2017): 151–60. http://dx.doi.org/10.2298/gensr1701151v.

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The characteristics of these sheep are highlighted depth measures of external appearance with modest width measures. Another weaker feature of Pramenka sheep is poor fertility. Despite the mentioned disadvantages, Pramenka sheep is the most grown sheep in Central Bosnia and sheep production is based on it. Methodical selection to improve the characteristics of Pramenka sheep has not applied. However, sheep breeders tend to improve the qualitative and quantitative characteristics of sheep, and that means more intensive work on the selection. In this sense, genetic markers are used to carry out the selection lately. Three types of hemoglobin, HbAA, Hband HbBB of Pramenka sheep population (at 189 male and female animals) in Central Bosnia were segregated by the method of electrophoresis. The following genotype frequencies are determined: HbAA 0.11; Hb0.41; and HbBB 0.48. Allele frequencies, HbA and HbB for Pramenka sheep breed (estimate based on genotype frequencies) were 0.315 and 0.685. It was found that the population of sheep was in the equilibrium of the frequency of hemoglobin genotypes. Sheep with HbAA genotype had lower morphometric measures in relation to the other two genotypes. The statistically significant difference between sheep with Hbgenotype and HbAA genotype was recorded only for the shin perimeter. The ewes that lambed one lamb have the following frequency of HbAA, Hband HbBB genotypes: 0.13; 0.40 and 0.47, and the ewes with twins: 0.02; 0.40 and 0.58. Fertility, as important quantitative characteristic of sheep, was more emphasized in genotype HbBB, than in HbAA genotype. This was confirmed by the statistical analysis.

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12

Ceyhan, Ayhan, Ahmet Şekeroğlu, and Mustafa Duman. "Niğde İlinde Yetiştirilen Akkaraman Irkı Koyunların Bazı Döl Verim Özellikleri ve Kuzuların Büyüme Performansı." Turkish Journal of Agriculture - Food Science and Technology 7, no. 10 (October 12, 2019): 1509. http://dx.doi.org/10.24925/turjaf.v7i10.1509-1514.2249.

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In this study, growth performance of Akkaraman lambs and some fertility parameters of Akkaraman sheep raised in semi extensive farm conditions were investigated. A total of 6300 heads Akkaraman ewes (6000 ewes and 300 rams) housed in 34 farms located in central villages of Niğde province were evaluated between 2012 and 2016. The data of birth weight of 30161 lambs, body weight of 29517 lambs aged 90 days old and some fertility parameters of 30000 heads ewes were used. The average lambing rate of ewes was found 90.1%. The twining rate of ewes was 20.8%; the average litter size was 1.12 lambs. Birth weights of Akkaraman sheep lambs was 4.23 kg, average 90th day live weights were 23.05 kg. Effects of year, birth type, dam age, and sex were found statistically significant on birth and 90-day live weights of the Akkaraman lambs. As a result, it was concluded that the fertility of Akkaraman sheep and growth characteristics of lambs raised by public under semi-extensive conditions could be improved and the economic situation of sheep farms could be better by the implementation such improvement project.

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13

Genkovski, D. "Productive indices of sheep breeds and varieties reared in the conditions of Central Balkan mountains." Biotehnologija u stocarstvu 22, no. 3-4 (2006): 55–64. http://dx.doi.org/10.2298/bah0604055g.

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Main productive indicators (live weight, wool-yield, wool length, economic fertility, biological fertility) at different ages of sheep from Karakachanska breed and Local Sredno Staroplaninsko and Tetevensko varieties were examined. The results showed that the sheep from Tetevensko variety indicated the highest values of live weight from the birth to 3.5 years of age, and the lowest - those from Karakachanska breed. The highest value of mean daily growth was examined from the birth to 3-months age in all groups of the study. It was highest for Tetevensko variety - 0.240 kg and for Karakachanska breed - the lowest, 0.217 kg, respectively. The highest wool-yield in all groups was at 18-months age - Karakachanska breed - 3.65 kg, Sredno Staroplaninsko variety - 3.42 kg, Tetevensko variety - 3.75 kg and with age it decreased. The sheep from Karakachanska breed at 18-months age were with the longest wool - 28.15 cm, and with the shortest one from Tetevensko variety at 4.5-years of age- 13.03 cm. With age it decreased insignificantly in all groups. The sheep from Tetevensko variety, followed by those from Local Sredno Staroplaninsko variety, indicated the highest values of economic and biological fertility.

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14

Hama, Abdulla Ahmed, Fatimah Mohammed Ali, Wijdan M. S. Mero, and Kalil Hassan. "Biochemical markers and fertility rate of hydatid cyst isolated from human and animal in Sulaimani province." Kurdistan Journal of Applied Research 2, no. 2 (July 30, 2017): 1–5. http://dx.doi.org/10.24017/science.2017.2.2.

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Hydatid disease is a helminthic infection, caused by the metacestode stage of cestode belonging to the Echinococcus grnulosus (dog tapeworm). The species and strain identification of Echinococcus are of medical importance for strategic control measuring. The present study achieved to determine and compare fertility and biochemical profiles of hydatid cyst fluid isolated from human, cattle, sheep and goat. The human originated cyst has been found to be more fertile (88%), followed by sheep-originated cyst (85%). The high rate of fertility was found in the liver followed by lungs in all intermediate hosts. However, the statistically significant differences of a biochemical test of cyst fluid among intermediate host were observed just in the uric acid, while the result of biochemical tests Hydatid cyst fluid isolated from liver significantly was higher than that of the lung for the most biochemical tests. The fertility and biochemical parameters value differences directly have related to the location of cyst and strains of E. granulosus. This finding concluded the sheep strain is a predominant strain and responsible for human and animal echinococcosis and sheep is the main intermediate host responsible for the perpetuation of the life cycle of E. granulosus in Sulaimani.

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15

Petrovic, M. P., D. Ruzic-Muslic, M. Zujovic, and C. Mekic. "Genetic improvement of fertility in sheep by selection according to physiological parameters." Biotehnologija u stocarstvu 23, no. 5-6-1 (2007): 311–21. http://dx.doi.org/10.2298/bah0701311p.

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In this paper, fertility parameters of sheep are discussed and principles analyzed in order to obtain the optimal methods for their evaluation. Mathematical procedures for evaluation of genetic and phenotypic parameters and anticipation of genetic values, today, are mainly based on different linear and non-linear concepts, therefore it is necessary to accept the reality that there is no absolute accuracy. Special emphasis is on the possibility of use of physiological quantitative fertility indicators in sheep selection, considering that there is correlation between them and fertility traits. In this regard, the degree of response to direct and indirect selection within population is analyzed in order to established the nature of parameters necessary for evaluation of data and determine the relative degree of such response.

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Dolebo, Asrat Tera, Negar Khayatzadeh, Aberra Melesse, David Wragg, Mourad Rekik, Aynalem Haile, Barbara Rischkowsky, Max F. Rothschild, and Joram M. Mwacharo. "Genome-wide scans identify known and novel regions associated with prolificacy and reproduction traits in a sub-Saharan African indigenous sheep (Ovis aries)." Mammalian Genome 30, no. 11-12 (November 22, 2019): 339–52. http://dx.doi.org/10.1007/s00335-019-09820-5.

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Abstract Maximizing the number of offspring born per female is a key functionality trait in commercial- and/or subsistence-oriented livestock enterprises. Although the number of offspring born is closely associated with female fertility and reproductive success, the genetic control of these traits remains poorly understood in sub-Saharan Africa livestock. Using selection signature analysis performed on Ovine HD BeadChip data from the prolific Bonga sheep in Ethiopia, 41 candidate regions under selection were identified. The analysis revealed one strong selection signature on a candidate region on chromosome X spanning BMP15, suggesting this to be the primary candidate prolificacy gene in the breed. The analysis also identified several candidate regions spanning genes not reported before in prolific sheep but underlying fertility and reproduction in other species. The genes associated with female reproduction traits included SPOCK1 (age at first oestrus), GPR173 (mediator of ovarian cyclicity), HB-EGF (signalling early pregnancy success) and SMARCAL1 and HMGN3a (regulate gene expression during embryogenesis). The genes involved in male reproduction were FOXJ1 (sperm function and successful fertilization) and NME5 (spermatogenesis). We also observed genes such as PKD2L2, MAGED1 and KDM3B, which have been associated with diverse fertility traits in both sexes of other species. The results confirm the complexity of the genetic mechanisms underlying reproduction while suggesting that prolificacy in the Bonga sheep, and possibly African indigenous sheep is partly under the control of BMP15 while other genes that enhance male and female fertility are essential for reproductive fitness.

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Barry, T. N. "The role of condensed tannins in the nutritional value of Lotus pedunculatus for sheep." British Journal of Nutrition 54, no. 1 (July 1985): 211–17. http://dx.doi.org/10.1079/bjn19850106.

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1. Lotus pedunculatus (cv. Grasslands Maku) grown on acid low-fertility soil and containing high concentrations of condensed tannin (76–90 g/kg dry matter (DM)) was grazed by growing sheep for 31–42 d periods in three experiments. In Expt 2 an additional group of lambs grazed areas oversown with white clover (Trifolium repens) and red clover (Trifolium pratense). Lambs were transferred from grazing ryegrass (Lolium perenne) – white clover straight on to lotus in all experiments (unconditioned sheep). In Expt 3 a second group was included which had grazed high-tannin lotus for a pre-experimental period of 8 weeks (conditioned sheep).2. Effects of condensed tannin on body and wool growth were assessed by studying responses to daily oral administration of polyethylene glycol (PEG; molecular weight 3350, 75–100 g/d). PEG forms a complex with condensed tannin, which is assumed to be inert in its passage through the digestive system, and so effectively reduces the nutritional effects attributable to high condensed-tannin concentrations.3. Live-weight gain (LWG) in the absence of PEG was low (27–125 g/d) for sheep grazing high-tannin lotus, and PEG administration increased LWG by 41–61 g/d and increased wool growth. In Expt 3, responses to PEG supplementation tended to be less with conditioned than with unconditioned sheep, indicating that conditioned sheep had partially adapted to the high-tannin diet.4. PEG supplementation had no effect on either LWG or wool growth of sheep grazing areas oversown with mixed clovers, confirming its effects as specific to forages containing condensed tannins. These experiments therefore conclusively show that high concentrations of condensed tannin induced by growing Lotus pedunculatus under low soil fertility conditions prevent maximum expression of LWG and wool growth in grazing sheep. These results contrast with high LWG (153–315 g/d) observed in growing sheep grazing the same lotus cultivar grown in high fertility soil and containing 20 g condensed tannin/kg DM, a level considered to be nutritionally beneficial.

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JEWELL, P. A. "Factors that affect fertility in a feral population of sheep." Zoological Journal of the Linnean Society 95, no. 2 (February 1989): 163–74. http://dx.doi.org/10.1111/j.1096-3642.1989.tb02310.x.

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19

Mir, M. R., and H. Geldermann. "Variant Molecular Marker in MHC Effect Fertility Trait in Sheep." Biotechnology(Faisalabad) 7, no. 4 (September 15, 2008): 787–92. http://dx.doi.org/10.3923/biotech.2008.787.792.

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Yamagami, Takuji, Rika Yoshimatsu, Tomohiro Matsumoto, Hiroshi Anzai, Masahiro Yoshizawa, Yutaka Fukui, and Tsunehiko Nishimura. "Fertility After Uterine Artery Embolization: Investigation Using a Sheep Model." Reproductive Sciences 17, no. 4 (November 30, 2009): 350–57. http://dx.doi.org/10.1177/1933719109353455.

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21

Laurent, Alexandre, Jean-Pierre Pelage, Michel Wassef, and Jacques Martal. "Fertility after bilateral uterine artery embolization in a sheep model." Fertility and Sterility 89, no. 5 (May 2008): 1371–83. http://dx.doi.org/10.1016/j.fertnstert.2007.03.058.

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Ferri, N., S. Ulisse, F. Aghini-Lombardi, F. M. Graziano, T. Di Mattia, F. P. Russo, M. Arizzi, et al. "Iodine supplementation restores fertility of sheep exposed to iodine deficiency." Journal of Endocrinological Investigation 26, no. 11 (November 2003): 1081–87. http://dx.doi.org/10.1007/bf03345254.

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Ajam, Ismael K., Thamer R. S. . Al-Jubouri, and Qayssar H. Ghayyib. "TGF-B Super Family Correlation with the Fertility of Iraqi Awassi Ewes." Basrah Journal of Agricultural Sciences 32 (September 4, 2019): 26–32. http://dx.doi.org/10.37077/25200860.2019.137.

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This study was conducted in Barakat Abu al Fadhl Al- Abbas station (AS) for raising sheep/a subsidiary of Al- Kafeel Company for General Investment and livestock services in Holy Karbala province and Babylon Province It was undertaken on Awassi sheep for between October, 2013 to May, 2014 to investigate the polymorphism of TGF-B gene and its association with reproductive traits of Awassi sheep. Blood samples were collected from (80) ewes included 35 samples of Awassi ewes producing twins (pure breed), 21 samples of Awassi ewes producing twins lambs (hybrid breed), also 25 samples of Awassi ewes producing single lambs (pure breed), with age (2 .5- 5) years. DNA samples were extracted from each blood sample of sheep. Reference PCR primers were utilized to amplify segments in TGF-B Super Family gene. Then, AFLP technique was performed for each PCR fragment. The results indicated that two genotypes for each of the fragments of TGF-B Super Family gene (AF and FF) were identified. TGF-B Super Family gene revealed two fragments (156 and 245 bp) for FF genotypes and three fragments (156, 254 and 410 bp) for AF genotypes. PCR- AFLP methods detected two genotypes (AF and FF) with predominant of AF genotype in Awassi ewes producing twin, and this study refers to utilizing TGF-B gene as good genetic markers and their correlation with high fertility and twins producing Awassi sheep.

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Mekic, Civijan, Predrag Perisic, Zorica Novakovic, Milan Petrovic, and Radomir Vujic. "Sheep fertility during induction and estrus synchronisation in the anoestrus season depending of the body weight of tested eves." Veterinarski glasnik 68, no. 5-6 (2014): 323–30. http://dx.doi.org/10.2298/vetgl1406323m.

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The aim of this research was to determine if there are differences in sexual reaction of the grown sheep II de frans breed depending on the body weight of treated eves during induction and synchronization of estrus with fluorogestonacetate (FGA) + PMSG in anoestrus season. Total number of 262 eves was treated and they were divided in to three groups. The first group consisted of the sheep whose body weight was from 40 to 50kg, the second group of the sheep whose weight was from 50-60kg and the third group of the sheep whose weight was above 60kg. Each group received sponges of FGA. After removal of the sponges all sheep received intramuscular injection of 500 i.u of PMSG. The "Sugonal" prepared by Veterinary institute Subotica was used. After two days the insemination was conducted. The results show that from first group 43.78% sheep lambed, from second group 46.66% and from third group 59.32%. Average sheep fertility after treatments was for the first group 113.28%, 118.37% for the second group and 137.14% for the third group. The ratio of singles, twins and triplets was for the first group 72:28:0 %, for the second group 70.69:24.14:5.17%, and for the third group 47.92:45.83:6.25%. Determined differences between number of lambed sheep and treated sheep, fertility and number of twins, as well as between investigated groups were statistically significant (P<0,05). Conclusion is that sheep of body weight above 60kg have had significantly better reaction to the treatment.

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Yildiz, K., and S. Gurcan. "Prevalence of hydatidosis and fertility of hydatid cysts in sheep in Kirikkale, Turkey." Acta Veterinaria Hungarica 51, no. 2 (March 1, 2003): 181–87. http://dx.doi.org/10.1556/avet.51.2003.2.6.

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This study was conducted in order to determine the prevalence and fertility of hydatid cysts in sheep in Kirikkale, Turkey. A total of 3.2% of 553 lambs and 50.9% of 1320 adults were found to be infected with hydatid cysts. The most common locations of cysts were in the liver and lung. Liver cysts tended to be more fertile than lung cysts (81.53% v. 76.47%), though the difference was not significant. The mean number of viable protoscoleces in the liver and lung cysts were 12,400 and 5,800, respectively. In general, 1-10 cysts were found in liver (51.8%) and lung (64.7%). The findings of this study indicate that hydatid cysts are common in sheep and the fertility rate of cysts is quite high. Sheep play an important role in the life cycle of Echinococcus granulosus in this region.

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Brash, LD, NM Fogarty, and AR Gilmour. "Reproductive performance and genetic parameters for Australian Dorset Sheep." Australian Journal of Agricultural Research 45, no. 2 (1994): 427. http://dx.doi.org/10.1071/ar9940427.

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Reproductive performance of ewes in a large Dorset stud flock is reported. The data included 2488 ewes with 10016 joining records over 25 years. Average performance for reproductive traits were: fertility 92%, litter size 1.31, neonatal lamb survival 91%, lamb survival to weaning 85%, with overall lambs born 1.20 and lambs weaned 1.02 per ewe joined. Differences between breeds (Poll Dorset and Dorset Horn), season of birth (spring and autumn) and season of joining (spring and autumn) were significant for most reproduction traits. Linear and quadratic regressions for age of ewe at joining were highly significant for all traits (P < 0.001) with maximum performance between three and six years of age. Estimates of heritability for ewe reproductive traits were: 0.062 � 0-02 for number of lambs born and 0.04 � 0.01 for number of lambs weaned per ewe joined, and component traits, 0.02 �0 -01 for fertility, 0 08 � 0 -02 for litter size and 0.00 � 0.01 for lamb survival. Estimates of repeatability were less than 0.14 for all the reproduction traits, which resulted in substantially higher predicted heritabilities when repeated records were used. Heritability estimates for average ewe lifetime performance, with approximately four records, were 0.08 � 0 06 for lambs born, 0.12 � 0.05 for lambs weaned, 0.08 � 0.04 for fertility, 0.l9 � 0 -04 for litter size and zero for lamb survival. The genetic correlations between litter size and lambs born and weaned were close to unity, whereas those for fertility were lower and declined from lambs born (0.6l � 0.22) to lambs weaned (0-45 � 0.30). The estimated heritability for ewe longevity, defined as the number of years the ewe remained in the breeding flock, was 0.00 � 0.03. The potential for genetic improvement in reproductive rate is discussed in relation to other reports in the literature and in the context of the roles of the Dorset breed in the Australian lamb industry. Increased reproductive rate in Dorset flocks impacts on stud profitability and the rate of genetic improvement from selection for other traits such as liveweight. The parameter estimates derived will be used in compiling breed-specific parameter sets for genetic evaluation in LAMBPLAN.

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Awad, Nabil S., Mohamed M. Soliman, Alaa A. Mohamed, Ayman M. Sabry, Ahmad F. Shahaby, and Adel E. El-Tarras. "Effect of altitude on some male fertility related traits in Saudi ovine and caprine species." Annals of Animal Science 15, no. 3 (July 1, 2015): 641–53. http://dx.doi.org/10.1515/aoas-2015-0007.

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Abstract This study aimed to evaluate the effect of altitude on some male fertility related traits in Saudi sheep and goats. Testicular tissues were collected from a slaughterhouse in Taif governorate (1800 m above sea level) and Makkah governorate (sea level). Sperm characteristics (1 - individual motility, 2 - percent live sperm 3 - percent abnormal sperm) were examined. Semi-quantitative RT -PCR assay was used to evaluate the expression of IGF-II, StAR, LDLr and CYP11A genes. No significant effect of altitude on tested sperm parameters was revealed. Expression of IGF-II gene in both sheep and goats was significantly (P<0.05) higher at sea level compared to high altitude. A similar effect of altitude on StAR gene expression was only observed in goats, while in sheep the level of effect did not reach the significance threshold. Moreover, LDLr gene expression was significantly (P<0.05) higher for both sheep and goats at high altitude than at sea level. The CYP11A gene expression was significantly (P<0.05) higher in high altitude sheep than in those raised at sea level, while the opposite trend was observed for goats. In conclusion, high altitude had an effect on the expression of some studied male fertility related genes, but sperm parameters were not significantly affected.

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Stankov, K. "Economic efficiency of Bulgarian dairy synthetic population and Assaf sheep breeds." Agricultural Science and Technology 12, no. 1 (March 2020): 42–46. http://dx.doi.org/10.15547/ast.2020.01.008.

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Abstract. The economic efficiency of ewes from the Bulgarian dairy synthetic population (BDSP) and Assaf sheep breeds, reared in three production systems, e.g. grazing on pasture, stall-pasture rearing and stall rearing was studied. The results from the study showed that BDSP ewes in the stall-pasture rearing system had a relatively low milk yield for a specialised dairy sheep breed – 80L for the lactation period. In this system, without the subsidy, the profit and cost efficiency were negative, while with subsidy, minimum positive results were achieved. For BDSP ewes reared in a stall-pasture rearing system with stall feeding during the grazing period and grazing on improved pastures, the obtained milk yield was by 33% higher. The subsidy resulted in satisfactory profit and cost efficiency, while without the subsidy, the farm ended in loss. BDSP and Assaf ewes reared in stalls, demonstrated substantially higher milk yield and productivity. They realised a profit and good cost efficiency. The milk yield of BSDP sheep reared in stalls was 200L per lactation, and fertility – 140%. The Assaf breed in which a high level of selection and regulated reproduction cycle was achieved, had 250L milk per lactation and 140% fertility. The profit with subsidy was 128.85 BGN (1Lev=0.975€) and without the subsidy: 48.85 BGN, with relatively high cost efficiency. An introduction of traits for higher milk yield, polyestrus and fertility from Assaf into BSDP sheep is necessary.

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Newton, J. E., D. J. Brown, S. Dominik, and J. H. J. van der Werf. "Impact of young ewe fertility rate on risk and genetic gain in sheep-breeding programs using genomic selection." Animal Production Science 57, no. 8 (2017): 1653. http://dx.doi.org/10.1071/an15321.

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Genomic selection could be useful in sheep-breeding programs, especially if rams and ewes are first mated at an earlier age than is the current industry practice. However, young-ewe (1 year old) fertility rates are known to be lower and more variable than those of mature ewes. The aim of the present study was to evaluate how young-ewe fertility rate affects risk and expected genetic gain in Australian sheep-breeding programs that use genomic information and select ewes and rams at different ages. The study used stochastic simulation to model different flock age structures and young-ewe fertility levels with and without genomic information for Merino and maternal sheep-breeding programs. The results from 10 years of selection were used to compare breeding programs on the basis of the mean and variation in genetic gain. Ram and ewe age, availability of genomic information on males and young-ewe fertility level all significantly (P < 0.05) affected expected genetic gain. Higher young-ewe fertility rates significantly increased expected genetic gain. Low fertility rate of young ewes (10%) resulted in net genetic gain similar to not selecting ewes until they were 19 months old and did not increase breeding-program risk, as the likelihood of genetic gain being lower than the range of possible solutions from a breeding program with late selection of both sexes was zero. Genomic information was of significantly (P < 0.05) more value for 1-year-old rams than for 2-year-old rams. Unless genomic information was available, early mating of rams offered no greater gain in Merino breeding programs and increased breeding-program risk. It is concluded that genomic information decreases the risk associated with selecting replacements at 7 months of age. Genetic progress is unlikely to be adversely affected if fertility levels above 10% can be achieved. Whether the joining of young ewes is a viable management decision for a breeder will depend on the fertility level that can be achieved in their young ewes and on other costs associated with the early mating of ewes.

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OLIVEIRA, Marilza Assunção de, Roseane Pinto Martins de OLIVEIRA, Ana Rita de LIMA, Edmar Vaz de ANDRADE, Jan Sidarta Lima de ABREU, and Franklyn Ferreira de OLIVEIRA. "Physical evaluation, morphological and identification of seminal proteins in Santa Ines sheep." Revista Brasileira de Saúde e Produção Animal 18, no. 1 (March 2017): 211–20. http://dx.doi.org/10.1590/s1519-99402017000100020.

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SUMMARY This study aimed to identify proteins in the seminal plasma associated with fertility in sheep of Santa Inês in Manaus, AM, using twodimensional electrophoresis techniques associated with mass spectrometry. Semen samples from eight adult sheep were collected by removing an aliquot for the physical and morphological assessments of semen and seminal plasma was subjected to SDS-PAGE profile and two-dimensional electrophoresis. Gels were stained with colloidal Coomassie, scanned and analyzed using ImageMaster 2D Platinum software, version 6.0. The selected individual spots were cut from the master gel, digested with trypsin and subjected to identification by mass spectrometry (MALDITof / Tof). Of the 108 spots detected in the gel, it selected 10 differential spots (based on the distribution thereof in the bidimensional gel and pre-analysis of the 2D ImageMaster Platinum Software) identifying 03 proteins: clusterin, a protein 14-3-3 zeta chain and Ram Seminal versicles 22kDa Protein. The identity of these proteins implies that the components of seminal plasma participate in physiological processes involved in sperm protection, motility and sperm capacitation, all associated with fertility. These proteins need to be better studied to see whether the same could be used as molecular markers of fertility as they were also found in other studies conducted with sheep Santa Ines.

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Quereda, Juan J., Empar García-Roselló, Marta Barba, María L. Mocé, Jesús Gomis, Estrella Jiménez-Trigos, Esther Bataller, Rebeca Martínez-Boví, Ángel García-Muñoz, and Ángel Gómez-Martín. "Use of Probiotics in Intravaginal Sponges in Sheep: A Pilot Study." Animals 10, no. 4 (April 20, 2020): 719. http://dx.doi.org/10.3390/ani10040719.

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Sheep estrous synchronization is mainly based on progestagen-impregnated sponges which could cause vaginitis. Several species of Lactobacillus used as probiotics are commonly used in the treatment or prevention of urogenital infections in humans. However, no studies have been performed to analyze the potential use of probiotics to prevent urogenital infections in sheep. A randomized controlled clinical trial was conducted with 21 one-year-old ewes to develop a model of probiotic infusion in vaginal sponges in order to study their influence in ewe’s vaginal microbiota, general health status, fertility and prolificity. Synchronization of estrus was based on intravaginal sponges for 14 days. Bacterial communities (Enterobacteriaceae and lactic acid bacteria) were highly fluctuating over time and between animals. The safety of probiotic infusion (mix of Lactobacillus spp. 60% L. crispatus, 20% L. brevis and 20% L. gasseri) in the vagina of healthy ewes was firstly confirmed. Neutrophils were observed in 80% (8/10) of the control ewes compared to 36% (4/11) of the ewes in the probiotic group 2 days after sponge removal (p = 0.056). Fertility in the control and probiotic groups was 60% (6/10) and 91% (10/11), respectively p = 0.097. These results suggest that Lactobacillus spp. infusion in the ewe’s vagina does not affect general health status or fertility.

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al-Shorepy, S. A., and D. R. Notter. "Response to selection for fertility in a fall-lambing sheep flock." Journal of Animal Science 75, no. 8 (1997): 2033. http://dx.doi.org/10.2527/1997.7582033x.

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David, I., J. M. Astruc, G. Lagriffoul, E. Manfredi, C. Robert-Granié, and L. Bodin. "Genetic Correlation Between Female Fertility and Milk Yield in Lacaune Sheep." Journal of Dairy Science 91, no. 10 (October 2008): 4047–52. http://dx.doi.org/10.3168/jds.2008-1113.

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Nagy, By I., J. S, olkner, I. Komlosi, and L. Safar. "Genetic parameters of production and fertility traits in Hungarian Merino sheep." Journal of Animal Breeding and Genetics 116, no. 5 (October 1999): 399–413. http://dx.doi.org/10.1046/j.1439-0388.1999.00204.x.

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Nichols, J. E. "SOME OBSERVATIONS ON THE PROBLEM OF FERTILITY AND FECUNDITY IN SHEEP." Zeitschrift für Tierzüchtung und Züchtungsbiologie einschließlich Tierernährung 10, no. 2 (April 26, 2010): 225–334. http://dx.doi.org/10.1111/j.1439-0388.1927.tb00143.x.

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Pereira, R. M., P. Mesquita, M. Batista, M. C. Baptista, J. P. Barbas, J. Pimenta, I. C. Santos, et al. "Doppel gene polymorphisms in Portuguese sheep breeds: Insights on ram fertility." Animal Reproduction Science 114, no. 1-3 (August 2009): 157–66. http://dx.doi.org/10.1016/j.anireprosci.2008.10.003.

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Babochkin, Peter Sergeevich, and Margarita Vasilyevna Zabelina. "Features of formation of the lethal qualities of the young sheep edilbaevskoy depending on the milk yield of their mothers." Agrarian Scientific Journal, no. 6 (June 18, 2019): 43–45. http://dx.doi.org/10.28983/asj.y2019i6pp43-45.

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The article presents the fertility of the Queens, the safety of young animals, slaughter indicators of young sheep of the edilbaev breed, obtained from ewes with different levels of productivity.

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Ghoreishi, Hourad, Sadegh Fathi-Yosefabad, Jalal Shayegh, and Abolfazl Barzegari. "Identification of mutations in <i>BMP15</i> and <i>GDF9</i> genes associated with prolificacy of Markhoz goats." Archives Animal Breeding 62, no. 2 (October 14, 2019): 565–70. http://dx.doi.org/10.5194/aab-62-565-2019.

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Abstract. The Markhoz is a local goat breed in the Kurdistan region of Iran. The mohair obtained from these animals plays an important cultural role and is used for making local clothes in the Kurdistan region. This breed is a low-fecundity local goat, and searching for genes associated with fertility of these goats is important for their breeding. Moreover, this research is complementary to prior studies of candidate genes associated with fertility. The growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are attractive candidates expressed by the oocyte and are associated with increased ovulation rate in sheep. However, there are no reports on single nucleotide polymorphisms associated with fertility of Markhoz goats. Hence, we studied these candidate genes and found two novel mutations (g.233C>A and g.755T>G) in GDF9 exon I and in BMP15 exon II, respectively. Furthermore, we investigated their association with prolificacy. These nucleotide changes are detectable with the PCR-RFLP method and can be used in the screening for highly fecund goats. Both of the mutations significantly increased litter size in heterozygote form for BMP15 and homozygote form for GDF9 in this goat breed. Homozygote females for the BMP15 mutation were not identified in the Markhoz breed, which is similar to the situation found in Belclare sheep, small-tailed Han sheep, and Jining Grey goats.

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Abdel-Rahman, Salah, Yehia Mustafa, Hagar Errasool, Hanim Heikal, and Ayaat Elmaghraby. "FSHR (exon 10) gene polymorphisms and its association with fertility trait in Egyptian Ossimi sheep." Biotehnologija u stocarstvu 35, no. 2 (2019): 127–40. http://dx.doi.org/10.2298/bah1902127a.

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For the association between of Follicle stimulating hormone receptor (FSHR) gene (partial part of exon 10) polymorphisms and litter size trait in Egyptian Ossimi sheep, polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) and DNA sequencing techniques were developed. Fifty female Ossimi sheep reared under Egyptian conditions were selected according to their litter size. DNA from blood samples of these animals was isolated to amplify 250-bp of the FSHR gene influencing litter size production trait in sheep. Based on litter size, 50 animals were selected from the highest to the lowest litter size productivity during three seasons. PCR-SSCP analysis of the FSHR gene (250-bp) showed two various genotypes AA and with frequencies 0.64 and 0.36, respectively. The frequencies of the A and B alleles were 0.82 and 0.18, respectively. PCR fragment of FSHR gene (191-bp) was sequenced only in the high and low litter size productivity animals (GenBank accession numbers from MG973191 to MG973207, sequentially). The result indicated that 6SNPs (G/71, G/72, G/77, A/110, A/111, A/191) in high fertile animals, while, 10 SNPs (T/1, C/2, T/14, A/69, A/70, A/71, A/74, G/74, A/75, A/136) have found in low fertile animals. Statistically, AA and genotypes have no significant differences (p> 0.05) on litter size trait in Ossimi sheep. FSHR (exon 10) locus was moderate polymorphic (PIC= 0.25) and it can be used for high litter size productivity in Ossimi sheep as a marker-assisted selection (MAS).

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Waghorn, G. C., I. D. Shelton, and W. C. McNabb. "Effects of condensed tannins in Lotus pedunculatus on its nutritive value for sheep. 1. Non-nitrogenous aspects." Journal of Agricultural Science 123, no. 1 (August 1994): 99–107. http://dx.doi.org/10.1017/s0021859600067824.

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SummaryLotus pedunculatus was grown under high fertility conditions and its nutritive value was determined in a feeding trial with sheep at Palmerston North, New Zealand in 1989. The condensed tannins (CT) accounted for 5·5 % of lotus dry matter (DM) and its effect on digestion was evaluated by giving an intraruminal infusion of polyethylene glycol (PEG) to six of the sheep (PEG group). PEG preferentially binds with CT so that the lotus becomes essentially CT-free.The experiment was carried out with 14 sheep (six PEG and eight ‘Tannin’) held in metabolism crates indoors and given freshly cut lotus hourly, for 32 days. This paper presents data relating to carbohydrate and mineral digestion, together with aspects of rumen function.Digestibility of lotus DM was 68%, and the digestibility of fibre was not affected by CT. Infusion of PEG increased rumen concentrations of NH3 and volatile fatty acids (P < 0·001) but effects on molar ratios of VFA were inconsistent with time. CT reduced rumen degradation and absorption of sulphur and increased net absorption of both phosphorus and zinc, but other effects on mineral digestion were small.Although the lotus was offered at c. 90% of ad libitum, intakes of the tannin sheep began to decline after c. 15 days of feeding and were c. 12% lower than those of the PEG sheep at the end of the trial (P < 0·05). At slaughter, rumen pool sizes were similar for the two treatments but the Tannin sheep had a lower fractional outflow rate, which suggests a slower rate of digestion in the rumen. Growth rate and wool production were similar for sheep on both treatments. It is concluded that the CT in Lotus pedunculatus grown under high fertility conditions had little effect on fibre and mineral digestion but the depression in DM intake reduced its nutritive value for sheep.

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Z, Hernández-Russo. "Effect of Gastrointestinal Nematodes on Reproduction and Lamb Growth in Australian Merino Sheep." Open Access Journal of Veterinary Science & Research 5, no. 2 (2020): 1–5. http://dx.doi.org/10.23880/oajvsr-16000204.

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Environmental conditions in Uruguay favour the development of gastrointestinal nematodes (GIN) throughout the year, with clinical or subclinical manifestations that cause significant economic losses. The aim of this study was to evaluate the effect of the GIN on fertility, fecundity, reproductive rate and lamb growth in Australian Merino sheep grazing on basalt fields. The study was carried out in a farm located in north of Uruguay. Sixty-eight Merino ewes facing a natural parasite challenge were divided into two groups. Control group was doused with active anthelmintic that have proven efficacy to minimize the effects of parasitic and the parasitized group that did not receive anthelmintic, except rescue dosages. Stool sample of each sheep was collected monthly for egg counts (EPG) of GIN using McMaster technique and nematode genders were identified from infective larvae obtained in cultures by Roberts O’ Sullivan technique. Artificial insemination and ewes were mated for new service, and pregnancy condition was diagnosed by ultrasound. Lambing control was made and lambs were weighed at birth and marking. The evolution of EPG values showed significant differences between groups at the end of gestation and lactation. Haemonchus spp. was the main gender of nematodes found, followed by Trichostrongylus spp. Fertility was 95 % versus 90 %; fecundity 87 % versus 63 % and reproductive rate 73 % versus 47 % for the control group and the parasitized one respectively. No significant differences were recorded in birth-weight. However market-weight and lamb daily gain were lower in the parasitized group. The effect of natural infection GIN was evident in lower reproductive performance of Australian Merino sheep.

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Al-Mutar, H., L. Younis, and H. Khawla. "Effect of the Point Mutation in Growth Differentiation Factor 9 Gene in Awassi Sheep Oocytes on Sterility and Fertility." Journal of Pure and Applied Microbiology 12, no. 4 (December 30, 2018): 2095–102. http://dx.doi.org/10.22207/jpam.12.4.46.

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David, I., P. Kohnke, J. Fehrenbach, A. R. Lopes Simoes, E. Debreuve, X. Descombes, F. Plouraboue, P. Degond, and X. Druart. "New objective measurements of semen wave motion are associated with fertility in sheep." Reproduction, Fertility and Development 30, no. 6 (2018): 889. http://dx.doi.org/10.1071/rd17472.

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In sheep, wave motion in semen is currently used by AI centres to select ejaculates for insemination. Despite its low cost, convenience and established ability to predict fertility, the subjectivity of this assessment is a limiting factor for its applicability. The aims of the present study were to establish an objective method for the analysis of wave motion and to assess the associations of objective parameters with fertility after cervical insemination. Collective sperm motion in undiluted semen was observed by phase contrast microscopy at low magnification in a 100-µm deep glass chamber. Images of moving dark waves over a grey background were recorded and analysed by the optic flow method, producing several velocity-related parameters. Turbulence was assessed from the motion of fluorescent polystyrene beads. Among objective parameters, optical flow entropy and the average speed of beads were both able to discriminate ejaculates suitable for insemination. Two synthetic variables of optic flow and bead motion and a global objective variable were computed from linear combinations of individual parameters and compared with the subjective motion score for their predictive value. These were as efficient as the wave motion score for assessing fertility and can be proposed for the assessment of ram semen in routine AI procedures.

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Kulikova, A. Ya. "Genetic potential of the gene pool of sheep of the Kuban breeding type of the Lincoln breed and methods of its conservation." Veterinariya, Zootekhniya i Biotekhnologiya 1, no. 8 (2020): 18–25. http://dx.doi.org/10.36871/vet.zoo.bio.202008003.

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The use of a rotational scheme for sheep selection in purebred breeding in a closed population ensured the maintenance of a high level of productivity of long-wooled sheep and their advantage in live weight by 24,0–27,0%, fertility by 20,8%, and maturation from 15,1 to 18,3%, wool productivity – up to 36%, compared with the requirements for the breed, as well as flock replacement due to its own reproduction without expensive import of paternal breeds.

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Constantinou, A. "RUMINANT LIVESTOCK GENETIC RESOURCES IN CYPRUS." Animal Genetic Resources Information 4 (April 1985): 1–8. http://dx.doi.org/10.1017/s1014233900000134.

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SUMMARYFriesian cattle, Chios sheep and Damascus goats have become dominant livestock breeds in Cyprus. Chios sheep were found to be superior to the indigenous Cyprus FatTailed and the imported Awassi with respect to precocity, fertility and prolificacy. Awassi performed very well with regard to milk yield and lamb viability. Crossbreds were more or less intermediate. Crosses of Chios with Cyprus Fat-Tailed have contributed substantially to the improvement of milk and meat production from sheep in the country.Damascus goats are very good in litter size and milk yield; a specific strain of the indigenous goat also appears to be a valuable genotype.

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Nemati, Z., and A. Barzegari. "Study of the bone morphogenetic protein 15 (BMp15) mutation in Moghani sheep using RFLP method." Proceedings of the British Society of Animal Science 2009 (April 2009): 181. http://dx.doi.org/10.1017/s1752756200030209.

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The Moghani is the main fat-tailed type of sheep in north-west of Iran and north-east of Turkey, where it is raised for meat, milk and carpet wool. In sheep, a wide range in litter size has been observed among different breeds and within breeds. Several genes have been recently identified that affect female fecundity in domesticated sheep such as BMP15 gene which encodes bone morphogenic protein 15 (Davis 2005 and Hanrahan et al,. 2004) and is a member of the transforming growth factor b (TGFb) super family (Galloway et al, 2000). The identification of the BMP15 mutation is important for the sheep industry and those involved in the study of mammalian fertility. In this study we investigated mutation of BMP15 gene in Moghani sheep in Iran.

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Silva, Reanne Moraes Meira da, Juliana Targino Silva Almeida e Macêdo, and Pedro Miguel Ocampos Pedroso. "Uterine segmental aplasia in sheep." Acta Veterinaria Brasilica 15, no. 2 (July 6, 2021): 93–95. http://dx.doi.org/10.21708/avb.2021.15.2.9376.

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The complete absence of one of the uterine horns, named segmental uterine aplasia or unicorn uterus, occurs due to deficiency in the development of segments of the paramesonephric or Mullerian ducts. It is a congenital or hereditary anomaly of the female reproductive tract caused by recessive genes, which occurrence is unusual. In cows, this malformation was initially called “white heifer disease”, comprising an alteration in the Mullerian ducts in association with the white skin gene that causes aplasia of the uterus, cervix and vagina. Two pieces of sheep reproductive system from a slaughterhouse under federal inspection in the state of Bahia, Brazil, were received for pathological diagnosis. The collection, dissection and macroscopic analysis were carried out. In the macroscopic evaluation, uterine segmental aplasia was identified in both cases, with complete absence of the left uterine horns. Both had agenesis of the uterine tubes associated with the absence of internal bifurcation of the uterine horns. Animals that have a unicorn uterus often have reduced fertility which consequently leads to losses to sheep farming.

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Mossa, F., F. Jimenez-Krassel, D. Scheetz, M. Weber-Nielsen, A. C. O. Evans, and J. J. Ireland. "Anti-Müllerian Hormone (AMH) and fertility management in agricultural species." Reproduction 154, no. 1 (July 2017): R1—R11. http://dx.doi.org/10.1530/rep-17-0104.

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A reliable, easy to assess marker for fertility in agricultural species would be highly desirable and Anti-Müllerian Hormone (AMH) is a promising candidate. This review summarizes recent findings concerning AMH and its role in fertility management, mainly in cattle. It focuses on (1) alterations in circulating AMH concentrations from birth to puberty and during estrous cycles; (2) correlation of circulating AMH concentrations with ovarian follicle numbers and ovarian reserve; (3) factors that impact circulating AMH concentrations; (4) use of AMH as a predictor of fertility. Circulating AMH concentrations can be easily and reliably measured with a single blood sample in adult cattle because AMH varies minimally during the estrous cycle and is repeatable across multiple cycles. Circulating AMH concentrations are positively associated with several measures of fertility. Dairy heifers with low compared with higher AMH concentrations subsequently had lower pregnancy rates, higher probability of being culled after birth of their first calf and shorter herd longevity. Also, AMH is predictive of response to superovulation in cattle and sheep. Several factors contribute to the variability in AMH concentrations among individuals; for example, beef cattle have higher AMH than dairy cattle. Nutritional imbalances, disease and endocrine disruptors during fetal life may negatively program the size of the ovarian reserve and consequently serum AMH concentrations and potential fertility in adulthood. We conclude that AMH may be a predictor of fertility and herd longevity in cattle, whereas in sheep and other farm species, the potential association between AMH and reproductive performance remains largely unexplored. Free Italian abstract: An Italian translation of this abstract is freely available at http://www.reproduction-online.org/content/154/1/R1/suppl/DC1

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BOJAR, WIKTOR, ANDRZEJ JUNKUSZEW, and MONIKA OLECH. "Influence of SRLV infections in sheep flocks on growth and reproductive performance." Medycyna Weterynaryjna 74, no. 8 (2018): 540–43. http://dx.doi.org/10.21521/mw.6098.

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The aim of the study was to determine the influence of the occurrence of SRLV infections on lamb growth and reproductive performance of sheep. The study was carried out on 98 sheep flocks from mid-Eastern Poland, covering the area of Lubelskie, Świętokrzyskie and Podkarpackie provinces. The study included 6,470 mother ewes. Flocks with at least one detected case of SRLV-positive serological test were considered infected. All flocks included in the experiment were subjected to the analysis of lamb growth on the basis of their body weight achieved on the 56th day of life. Moreover, traits related to reproductive performance, such as fertility, lamb/ewe rate and lamb weaning rate, as well as the reproductive performance itself were evaluated. The observations showed that both ewes (18.98 kg) and rams (19.70 kg) achieved higher body weights in the flocks where SRLV had not been detected. In the flocks in which the presence of SRLV was detected the achieved body weight was lower by 0.93 kg and 1.26 kg, respectively. The sheep in the SRLV-infected flocks were characterized by a significantly lower fertility and higher lamb/ewe rate in comparison to other flocks. The analysis conducted for the purpose of the study showed that the presence of SRLV in a flock resulted in a worse lamb weaning rate by about 6.69 percentage points. To sum up, the flocks with detected presence of SRLV were characterized by a significantly lower fertility and greater lamb mortality rate. The presence of SLRV also had a detrimental effect on the body weight obtained on the 56th day of life, both in rams and ewes. The results of the study clearly indicate the negative influence of SRLV on the reproductive performance of sheep..

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Stankov, K. "Еconomic efficiency of local, merino and meat-type sheep breeds raised in Bulgaria without milking." Agricultural Science and Technology 12, no. 1 (March 2020): 37–41. http://dx.doi.org/10.15547/ast.2020.01.007.

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Abstract. The goal of the present study is to perform an economic assessment of the local (autochthonic), merino and meat-type sheep breeds raised in Bulgaria without milking and under the conditions of a market economy and free commerce. We studied sheep from three herds, of the Srednostaroplaninska breed, Northeast Bulgarian Merino breed (NEBM) and the Île-de-France breed. The sheep from all three herds were under selection control. The results of the study indicated low economic effects for all three herds. Without subsidies, the local and merino breeds finished with negative values for profits and cost-efficiency of the income and expenses, and zero for the meat-types. The subsidy for the sheep of the Srednostaroplaninska breed made up 37.9% of the income, whereas the sold lambs and sheep culled for meat made up 60.7%. This indicated that the local mountain sheep cannot provide the necessary income for a farm’s normal function without milking and without subsidies, under the present market situation. The efforts in this field should be directed towards organic production of meat and dairy products and a closed production cycle. The income from sold lambs and sheep culled for meat from the NEBM breed made up 66.8% of the total income, whereas wool accounted for merely 4.6%. The subsidy provided 28.5% of the farm’s funds. Accomplishing an economic effect in merino breeds is possible only if prices for buying off wool were normalized, and the fertility of the ewes was increased. For the meat-type sheep of the Île-de-France breed, the income from selling meat and breeder lambs, as well as sold culled sheep made up 75.6%, and the subsidy – 22.7%. A higher economic effect for this breed could be achieved through selection towards fertility and more frequent births, i.e. 3 litters in 2 years. A significant productive and economic effect in the meat-type breeds could be achieved from ram breeding and conducting industrial crossbreeding in the stock part of the breeds.

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Journal articles on the topic 'Sheep Fertility'

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