UTP University of Science and Technology, Department of Cattle Breeding, Mazowiecka 28, 85-084 Bydgoszcz, Poland
Abstract. Analyses were performed based on records from the SYMLEK database. Data on milk performance of 20 068 Polish Holstein-Friesian cows were accounted for. Productive and functional traits were analysed alongside culling reasons. The cows first calved at an average age of 807 days and primiparous milk yield averaged 6513 kg. The lifespan of cows ranged from 1830 to 3156 days depending on reasons for culling. Cows removed from the herd for old age had the longest lifespan, whereas the least productive animals sold for further breeding had the shortest lifespan. Cows with the longest productive life had an average lifetime yield of 40 000 kg milk. The coefficients of correlation between primiparous milk production and lifespan ranged from 0.30 (cows culled for old age, low milk production, and culled for sale) to 0.08 (cows culled for other reasons). The analysed population was characterized by high positive coefficients of correlation between first lactation yield and lifetime yield (0.34–0.64). In all the classes of cows accounting for culling reasons, positive correlations were estimated between primiparous milk yield and milk production per day of age and day of productive life.
Keywords: cows, longevity, culling, milk yield
Bogucki, M. (2017). Association between primiparous and lifetime performance of cows. Acta Sci. Pol. Zootechnica, 16(2), 19–26. DOI:10.21005/asp.2017.16.2.03.