| Abstract |
A total of 4,727 records of crossbred Holstein cow provided by the Chokchai Dairy Farm were used to: 1) investigate relationship between Holstein Genetic Fraction (HGF) versus Length of Productive Life (LPL), which HGF was the most risk to cull for Chokchai Dairy Farm, and 2) estimate genetic parameter of LPL for possibility to do selection base on genetic performance. The survival analysis using parametric Weibull Frailty Model (WFM) which was composed of two main components: a) fixed component, such as effects of HGF Group (HGFG), Year-Month of Calving interaction (YM), Lactation-Stage interaction (LS), Age at First-Calving (AFC), and 305-days milk yield of First-Lactation (1stM305), and b) random component were sire (usire) effect. The results showed that, HGFG2 had the most risk of culling from the herd (HGFG2 (>87.50 and ≤93.75%) = 1.647, HGFG3 (>93.75 and <100%) = 1.191, and HGFG1 (≤87.50%) = 1.000, respectively). It seems clear that selection base on genetic performance has possibility (sire variance = 0.029 and heritability = 0.089), however accuracy for single trait selection is quite low. Therefore, we suggest to integrating LPL with another economics traits to improve efficiency of LPL selection. |
Publication
Journal Publication
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