Genetic parameters from both single-trait and bivariate analyses for prolificacy, weight and wool traits were estimated using REML with animal models for Columbia sheep from data collected from 1950 to 1998 at the U.S. Sheep Experiment Station (USSES), Dubois, ID. Breeding values from both single-trait and seven-trait analyses calculated using the parameters estimated from the single-trait and ...

Indonesian thin tail (ITT) sheep have a major prolificacy gene (FecJ(F)), the frequency of which is higher in the new born lambs, than in the remainder of the flock when mating is random, because carrier ewes produce more progeny than do non carriers. The frequency of the gene may vary between flocks, but remains relatively stable in flocks with established husbandry procedures. The countermand...

The clock gene Period 1 (Per1) may be a prolificacy gene, because it localized to the mouse oocyte and Per1-null drosophila shed fewer eggs. Because Per1 mapped to a region of mouse chromosome 11 syntenic to bovine chromosome 19 where a quantitative trait loci (QTL) for ovulation rate existed, we hypothesized that Per1 influenced folliculogenesis and ovulation rate in ruminants. Ovarian cortex ...

Breeding objectives were developed for Targhee sheep under rangeland production conditions. Traits considered were those for which EPD were available from the US National Sheep Improvement Program and included direct and maternal effects on 120-d weaning weight (WW and MM, respectively); yearling weight (YW); yearling fleece weight, fiber diameter, and staple length; and percent lamb crop (PLC)...

This study approaches the interrelation patterns between composition of milk and whey, curd yield, chromaticity, syneresis, technological quality Manchega sheep using multivariate factor analysis. In addition, effect main husbandry components (flock, prolificacy, season year, stage lactation, parity) on common latent factors that define pattern variation was assessed. For this purpose, 1,200 in...

The objective of this study was to characterize the litter sizes in Huanghuai goats with high prolificacy (HP, five or more kids born per litter on at least one occasion), and to compare their peripheral blood concentrations of progesterone and estradiol with those of goats with poor prolificacy (PP, up to three kids born per litter on any occasion). The circulating concentrations of progestero...

The aim of this study was to investigate the metabolic and biochemical changes in plasma that occur in the reproductive rabbit doe close to the parturition, as well as if the number of offspring affects the metabolism and the health status of the doe. At -3, 4 and 12 days from parturition (-D3, D4, and D12, respectively) nine rabbit does at their third parity from a commercial hybrid line (HYPL...

A 3-yr study was conducted to comprehensively evaluate Columbia, Suffolk, USMARC-Composite (Composite), and Texel breeds as terminal sires in an extensive rangeland production system. The objective was to estimate breed-of-ram effects on ewe fertility, prolificacy, and dystocia, and sire breed effects on lamb survival and growth until weaning at approximately 132 d of age. Data were from 22 Col...