Estimation of heritabilities and genetic correlations for lifetime production and first lactation traits of Holstein cows in Japan
2002
Hagiya, K. (Iwate Univ., Morioka (Japan)) | Suzuki, M. | Kawahara, T. | Pereira, J.A.C. | Domon, Y. | Tsuruta, S. | Misztal, I.
Heritabilities for lifetime production and first lactation traits and genetic correlations among these traits were estimated using an animal model. Data consisted of 58,352 lifetime records of Holstein cows reported from 1975 to 1999 in the Hokkaido Dairy Cattle Milk Recording and Testing Association. Type traits and pedigree information of 132,096 animals were obtained from The Holstein Cattle Association of Japan. Herd life and productive life for 48- and 84-mo after the first calving were defined as longevity traits. Milk, fat, SNF, and protein yields in the productive life were defined as lifetime production traits. For the first lactation, these production traits and 17 type traits were analyzed. A total of 33 traits were simultaneously estimated with the multiple-trait EM-REML method. Heritability estimates of lifetime production ranged from 0.1 5 to 0.1 6. Genetic correlations between production traits for the 84-mo lifetime and for the first lactation ranged from 0.53 for milk and SNF yields to 0.61 for fat yields. Genetic correlations between fore attachment or udder depth and milk production for the first lactation were negative (-0.03 and -0.21, respectively). However, genetic correlations between these traits and 84-mo milk production were positive (0.22 and 0.20, respectively).
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