Piena produktivitāte un mūža garums dažādas izcelsmes vaislinieku meitām
2017
Cielava, L., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Agriculture
The potential lifespan of dairy cows is affected not only by eternal, but also by different genetic factors. The effect of used sires on their daughter longevity traits is widely studied in Europe. In many countries (Germany, France, Great Britain etc.) longevity as a trait is included in dairy cow breeding programs. The aim of our study was to determine the effect of sire and the origin country of sire on their daughter milk productivity and longevity traits. Data about daughters of 6 different sires – 3 sires of Latvian (LV) origin and 3 sires of German (DE) origin were included in the data base. Data were collected about 6,628 culled dairy cows that in timespan from year 2005 to year 2010 had at least three full lactations. 95.5% of daughters were Holstein Black and White breed from DE sires, but 68% of daughters were Latvian Brown breed cows from LV sires. To compare milk productivity, we calculated energy corrected milk (ECM). The daughters of LV origin sires were characterized by significantly lower (p0.05) milk productivity than daughters of DE sires. The average lifespan for daughters of LV sires were about 43.2 days longer than for daughters of DE sires, but daughters of DE sires were characterized by higher lifetime milk productivity (23492.8±248.13 kg ECM). Daughters of LV2 sire were characterized by the longest lifespan (2633.3 days) and highest lifetime milk productivity (25412.3 kg ECM). The highest average life day milk productivity (10.4 kg ECM) was obtained from daughters of sires with DE origin.
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