Original scientific paper

LIFETIME PRODUCTION PERFORMANCE OF HOLSTEIN-FRIESIAN COWS

Sonja Jovanovac ; Agricultural University Osijek, Republic of Croatia
Olga Čiča ; Agricultural University Osijek, Republic of Croatia
Elizabeta Kurtek ; Belje, PIK Darda, Hrvatska
Savo Ristić ; Belje, PIK Darda, Hrvatska

Abstract

This study included 981 lactation records of 312 daughters of Holstein-Friesian sires from state farms of Slavonija and Baranja. The average age at first calving was 28'9 months and the age at culling was 76.3 months (6.27 years). The average length of production life, number of lactations, total milk yield and total fat yield were 3.89 years, 3.14 lactations,22,335 kg and 813 kg, respectively. The index of exploatation expressing the relative length of production life was 57.28.
The relations between the age at first calving and lifetime performances were negative and statistically insignificant, except for the index of exploatation (r= -0-198**). The correlations between milk production in the first lactation and total milk yield, milk per day of production life and per day of life were positive and significant (0.157*, 0,498**, 0,355**, respectively).
It was evident that with selection for high milk yield in the first lactation, more milk yield can be expected in later life, but not a longer production life.

Keywords

Hrčak ID:

162017

URI

https://hrcak.srce.hr/162017

Publication date:

22.9.1990.

Article data in other languages: croatian

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