|Van Zyl, C. - UNIV. OF NEBRASKA-LINCOLN|
|Van Vleck, Lloyd|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: November 17, 1997
Publication Date: N/A
Technical Abstract: Genetic parameters for Columbia, Polypay, Rambouillet and Targee sheep were estimated using REML with animal models for fertility, growth and wool traits. Total litter weight weaned was included as a composite trait. Numbers of observations ranged from 5,140 to 7,095 for fertility, from 7,750 to 9,530 for growth, from 4,063 to 34,746 for wool, and from 4,609 to o6,469 for composite trait. Model 1 for fertility traits included genetic and permanent environmental effects of the ewe and residual effect. Model 2 for growth traits included genetic effect of animal and maternal genetic and permanent environmental effects of dam. Model 3 for wool traits in- cluded both genetic and permanent environmental effects of animal. Model 4 for composite trait same as Model 1 but with additional random effect of mating sire. Heritability ranged from .07 to .11 for litter size at birth and from .03 to .07 for litter survival to weaning. Heritability ranged from 0.16 to 0.22 for birth weight, from 0.09 to 0.20 for weaning weight and from 0.07 to 0.19 for average daily gain. Heritability ranged from .47 to .53 for fleece weight, from .25 to .49 for fleece grade and from .36 to .53 for staple length. Heritability ranged from .03 to .12 for litter weight weaned. Relative variances of permanent environmental and random effects of mating sire were small for fertility and moderate for growth, wool and composite traits. Variance of maternal genetic effects was small- er than for direct genetic effects for growth traits. Heritability for fleece traits indicates genetic progress could be expected from selection. Results indicate litter weight weaned can be used in selection.