Genetic correlations for litter weight weaned with growth, prolificacy, and wool traits in Columbia, Polypay, Rambouillet, and Targhee sheep.

نویسندگان

  • C M Bromley
  • L D Van Vleck
  • G D Snowder
چکیده

Total litter weight weaned at 120 d postpartum per ewe lambing is often believed to be a measure of range ewe productivity. Genetic correlations for litter weight weaned at 120 d with prolificacy, growth, and wool traits for Columbia, Polypay, Rambouillet, and Targhee sheep were estimated using REML with animal models. Observations per breed ranged from 5,140 to 7,083 for litter weight weaned, from 5,140 to 7,095 for prolificacy traits, from 7,750 to 9,530 for growth traits, and from 4,603 to 18,443 for wool traits. Heritability estimates for litter weight weaned were low and ranged from 0.02 to 0.11. Fraction of variance due to permanent environmental effects averaged 0.05 and, due to effects of mates, averaged 0.01. Estimates of genetic correlations with litter weight weaned varied from breed to breed. The ranges were as follows: 0.42 to 0.65 with litter size born, 0.80 to 0.99 with litter size weaned, -0.22 to 0.28 with birth weight, -0.07 to 0.23 with average daily gain to weaning, -0.56 to 0.19 with fleece weight, -0.15 to 0.02 with fleece grade, and -0.11 to 0.08 with staple length. Results suggest that, if selection were practiced on litter weight weaned, the average correlated responses would be expected to be favorable or neutral for prolificacy, growth, and wool traits although responses might vary from breed to breed.

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منابع مشابه

Genetic correlations for litter weight weaned with growth, prolificacy, and wool traits in Columbia, Polypay, Rambouillet, and Targhee sheep1

Total litter weight weaned at 120 d postpartum per ewe lambing is often believed to be a measure of range ewe productivity. Genetic correlations for litter weight weaned at 120 d with prolificacy, growth, and wool traits for Columbia, Polypay, Rambouillet, and Targhee sheep were estimated using REML with animal models. Observations per breed ranged from 5,140 to 7,083 for litter weight weaned, ...

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Genetic parameters among weight, prolificacy, and wool traits of Columbia, Polypay, Rambouillet, and Targhee sheep.

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,...

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عنوان ژورنال:
  • Journal of animal science

دوره 79 2  شماره 

صفحات  -

تاریخ انتشار 2001