Authors: SERDAR KOÇAK, MUSTAFA TEKERLİ, CEYHAN ÖZBEYAZ, BANU YÜCEER
Abstract: This study was undertaken to investigate the effects of certain factors on birth weight and survival rate, utilizing the records of 8399 Holstein calves maintained at the Ceylanpınar State Farm in southeastern Anatolia. The data were collected from the calf barn sheets, including birth weight, pedigree details, and calf fate. The survival rate was scored as 1 (alive) or 0 (died) in accordance with the records. Analysis of variance indicated that the effects of year, season, parity, and calf sex on birth weight were significant (P < 0.01). Only calf sex had a significant (P < 0.01) influence on survival rate. The least squares means of birth weight for all calves averaged 38.79 ± 0.171 kg. The survival rates were 0.95 ± 0.004, 0.94 ± 0.004, and 0.92 ± 0.005 at 3, 6, and 12 months of life, respectively. Heritabilities were 0.115 ± 0.0023 for birth weight and 0.020 ± 0.009, 0.011 ± 0.008, and 0.011 ± 0.008 for 3-month, 6-month, and 12-month survival rates. Genetic correlations between birth weight and every rate of survival were estimated as -0.113, -0.012, and 0.106. The corresponding phenotypic correlations were 0.022, 0.014, and -0.013. It was concluded that the birth weight and survival rates of Holstein calves reared at Ceylanpınar State Farm were acceptable. However, further improvements can be accomplished by more effective feeding and management based on the low heritabilities.
Keywords: Birth weight, survival rate, heritability, Holstein
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