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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Genetics and Animal Breeding » Research » Publications at this Location » Publication #97450
Title: GENETIC PARAMETERS FOR AGE AT PUBERTY AND STAYABILITY IN CROSSBRED CATTLE

Author
item VEGA-MURILLO, V. - UNIV. OF NEBRASKA-LINCOLN
item Cundiff, Larry
item Van Vleck, Lloyd

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Heritabilities and genetic correlations for age at puberty and five measures of stayability of beef cows were estimated with linear mixed models. Data for animals born in years 1970-1972 were collected from Cycle I of the Germ Plasm Evaluation Program at the U.S. Meat Animal Research Center. The females were two-breed crosses representing seven breeds of sire. Records on a total of 788 females from 192 sires were used. The stayability traits considered were probabilities of a female having 2 (S(2/1)), 3 (S(3/1)), 4 (S(4/1)), 5 (S(5/1)) and 6 (S(6/1)) calves, given that she calved once. Stayability traits were coded as 1 if the cow had a calf at or after a given age, and 0 otherwise. Variance components were estimated using REML. A sire model with no relationships among the sires was assumed. Models included fixed effects of breed group, year of birth, and Julian birth date as a linear covariate. Estimates of heritability and genetic correlations were obtained from single- and two-trait analyses. Heritability estimates were 0.60 for age at puberty and 0.00, 0.00, 0.00, 0.02 and 0.01 for S(2/1), S(3/1), S(4/1), S(5/1) and S(6/1), respectively. Genetic correlations between age at puberty and stayability traits were 1.0, -1.0, -1.0, -0.6 and 0.2, although such estimates have little meaning when heritability is next to zero. The small estimates of heritability suggest that selection for stayability would be difficult.