engleski

Estimation of genetic parameters for longevity in Slovenian dairy cattle

Genetic parameters for longevity in Slovenian Holstein (H), Simmental (S) and Brown Swiss (B) cattle were estimated with sire_mgs (maternal grandsire) model using survival analysis, applaing a proportional hazard function following a Weibull distribution. Longevity was described as length of productiove life (LPL), that is as number of days from first calving to the culling or to the moment of data collection (cmpleted - uncensored and censored records) Truncation date was January 1, 1991 while August 1, 2008 was date of data collection. Estimated sire variances were 0.050 (H), 0.021 (S) and 0.034 (B). Herd variances were 0.191 (H), 0.299 (S) and 0.318 (B). Heritabilities estimates were 0.161 (H), 0.064 (S) and 0.101 (B).

longevity ; genetic parameters ; proportional hazards model ; dairy cattle

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