In this study, the potential association of PrP genotypes with ewe reproductive traits and lamb growth traits was investigated. Data were included on ewes and lambs of the INRA 401 breed from the Bourges-La Sapinière INRA experimental farm. This breed was chosen because of good breeding (prolificacy and maternal abilities) and carcass qualities, and the large number of available animals with pe...

Female reproductive trait were studied in four pure breeds (the Finnsheep, Suffolk, Targhee and Minnesota 100), the F1 crosses between Finnsheep rams and females of the other three breeds and F2 and backcross ewes. Precocity of sexual development, defined as the percentage of ewe lambs lambing at 12 months of age, was measured in 709 ewe lambs in 4 years. Lambing and weaning rates were measured...

Objectives were to estimate effects of sire breed (Dorset, Finnsheep, Romanov, Texel, and Montadale), dam breed (Composite III and northwestern whiteface), mating season (August, October, and December), ewe age (1, 2, and 3 yr), and their interactions on reproductive traits of F1 ewes. A total of 1,799 F1 ewes produced 3,849 litters from 4,804 exposures to Suffolk rams during 35-d mating season...

This study reports the phenotypic trends for wool, growth, and reproductive traits in mixed-age ewes after twenty years of genetic selection. Data were obtained from Merino nucleus flock Uruguay between 1999 2020. Overall, aim this selection was to reduce fiber diameter (FD) increase both clean fleece weight (CFW) live (LW). on ewe wool traits, LW, body condition score (BCS), total number lambs...

East Friesian-sired F1 ewe lambs (n = 27) and Lacaune-sired F1 ewe lambs (n = 31) born in 1999 were compared for lamb production, lactation performance, and udder morphology traits in a dairy sheep production environment in 2000. The ewe lambs were the progeny of seven East Friesian and five Lacaune sires. A contemporary group of high percentage East Friesian ewe lambs (> 3/4 East Friesian, n =...

Breeding ewes to lamb at 1 yr of age can improve profitability for some production systems. The first objective of this study was to evaluate the effect of age and weight at breeding and total postweaning weight gain on reproductive performance of ewe lambs. The second objective was to compare the effects of weight and age variables in four major sheep breeds (Columbia, Polypay, Rambouillet, an...

Data were recorded for annual reproduction, wool traits and pre-joining live weight of between 992 (for staple strength) to approximately 1200 production records of Merino ewes over the period from 1997 to 2002. The resource population has been divergently selected from the same base since 1986, either for (H line) or against (L line) maternal multiple rearing ability. When expressed relative t...

Data of 3272 lambing records collected on 818 ewes born from 689 dams and sired by 371 rams were used in the evaluation of ewe lifetime productivity (total number born, number weaned and total weight weaned). These records were collected from ewes born from 1969 to 1994 and which gave birth during the period from 1971 to 1999. Year of birth of ewe and ewe two-tooth liveweight affected the ewe p...

Variation in ovulation rate of ewes was studied with particular reference to the heterosis effect in a 3-breed (Dorset Horn, South Australian Merino, Corriedale) experimental sheep population. For the population as a whole, heterosis effect on the young (1 1/2 year-old) ewes (+0.17 k 0.06** ova, or 14.5%) was similar to that on the mature (5 1/2 year-old) ewes (+0.19 f 0.06** ova, or 12.5%), in...

reproductive abnormalities cause major losses of sheep production. abattoir materials were used todetermine the extent of reproductive wastage. reproductive tracts were collected from 524 ewes slaughtered at urmia slaughter-house in urmia, northwest of iran, during a period of 12 months. overall, 30.10% of the ewes examined were pregnant. a total of 149 (28.44%) tracts developed acquired reprod...