Body condition score as early indicator of days open using random regression analysis [electronic resource].

Includes reference.

The objective of the present study was to evaluate genetic variability in body condition score (Bcs) along with its relationship with reproductive performance (Do: days open) for Hungarian Holstein Friesian cows. Body condition score' records were available from calving to end of lactation of the first three parities. Data consisted of 162,792 test-day observations on 4,215 cows daughters of 1,410 dams and 132 sires recorded between the years 1998 and 2001. Polynomial random regression of the third order was applied to explain variation in body condition score and days open. Heritabilities, additive and permanent environmental correlations were estimated using random regression animal model. Heritability of body condition score was estimated as 0.17± 0.08 on average, ranging from 0.01 for the first parity during early lactation to 0.26 for the second and the third parities during mid lactation. Heritability estimate of days open was 0.20 on average, ranging from 0.19 to 0.23 during late and early production life, respectively.

Summary in Arabic.

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