Factors affecting ewe prolificacy (number of lambs born per ewe lambing) were evaluated using records on 9705 Targhee, 12,721 Suffolk, and 7231 Polypay lambings from flocks participating in the US National Sheep Improvement Program. Factors considered were ewe age and season of lambing. Prolificacy was affected by age of the ewe (P<0.001) and was highest for ewes lambing between 4 and either 7 ...

Genetic parameters for Columbia, Polypay, Rambouillet, and Targhee sheep were estimated using REML with animal models for prolificacy, weight, and wool traits. All bivariate analyses included a covariance between additive genetic effects for the two traits plus appropriate additional covariances. Number of observations by breed ranged from 5,140 to 7,095 for prolificacy traits, from 7,750 to 9,...

The objective of this study was to estimate direct and indirect selection potential for length of productive life and lifetime prolificacy in Finnish Large White and Landrace swine populations. To study the direct selection potential, the heritabilities of these traits were estimated. The genetic correlations of length of productive life and lifetime prolificacy with prolificacy traits and over...

An evaluation of a new maternal line (LP) of rabbits was carried out. This new line was founded following a scheme similar to that applied in the selection for hyperprolificacy in rabbits or pigs. In this case, the selection criteria were hyperlongevity and an independent culling level near the average for prolificacy. Evaluation was carried out by comparison of the reproductive and longevity p...

Prolificacy is a desirable trait for genetic improvement of sheep flocks, since it holds the potential to improve productivity. Animals carrying single-nucleotide polymorphisms (SNPs) in genes associated with this trait can be identified and employed to increase prolificacy in flocks. In this study, we report a diagnostic method based on quantitative PCR and high-resolution melting curves to de...

Bone morphogenetic protein 15 (BMP15) is a member of the transforming growth factor beta superfamily, is specifically expressed in oocytes and is essential for sheep prolificacy. Reported mutations in this gene cause increased ovulation rate and infertility in a dosage-sensitive manner. In this work, a new naturally occurring mutation in the BMP15 gene from the ovine Rasa Aragonesa breed is des...

The Finnish Landrace (Finnsheep) is a well known high-prolificacy sheep breed and has been used in many countries as a source of genetic material to increase fecundity of local breeds. Analyses to date have indicated that mutations with a large effect on ovulation rate are not responsible for the exceptional prolificacy of Finnsheep. The objectives of this study were to ascertain if: 1) any of ...

The Garole is the only known prolific sheep breed in India and is a native of Sunderban, the swampy delta region of West Bengal [1]. Malpura is a popular mutton-type breed of semi-arid tropical region of India. These sheep are known for their hardiness and adaptability to the local environment but prolificacy is low with ewes usually producing single lambs. Increasing prolificacy of the Malpura...

Introduction Profitability in the swine industry is based on prolificacy. One measurement of prolificacy is the number of piglets produced per year. To optimize prolificacy and profits it is essential that sows are re-bred as soon as possible after weaning. An extended post-weaning anestrus decreases overall productivity and increases costs of production. A large number of sows undergo prolonge...

The Booroola fecundity gene (FecB) and growth differentiation factor 9 (GDF9) gene belong to the transforming growth factor β (TGF-β) superfamily. The mutations of these genes have additive effects on the prolificacy in sheep. The aim of the present study was to determine the possible mutations of FecB and FecG(H) genes in Lory sheep breed of the Lorestan province, Iran. Sixty blood samples wer...