Genetic trend of age at first mating in backfat selected gilts
1997
Nalinee Imboonta | Chancharat Reodecha | Ning, Wang (Chulalongkorn Univ., Bangkok (Thailand). Faculty of Veterinary Science. Dept. of Animal Husbandry)
Performance test and reproductive records of Landrace, Yorkshire and Duroc gilt from 4 commercial farms collected from 1992 to 1996 were used in this study. The number of gilt records after editing was 5,305. The breeding values was predicted by best linear unbiased prediction (BLUP). Genetic trend was predicted by regression of means calculated from prediction breeding values of animals from an animal model across years. Estimated annual genetic trends for age at first mating of Landrace, Yorkshire and Duroc were 0.18+-0.03, 1.63+-0.04 and -0.11+-0.06 days, respectively and for backfat thickness of these three breeds were -0.022+-0.001, -0.013+-0.01 and -0.034+-0.001 cm, respectively. The annual genetic trend observed indicated that selection against backfat thickness could result in increasing age at first mating of Landrace and Yorkshire but not Duroc gilts.
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