Genetic Trend of Length of Productive Life in Holstein and Slovak Simmental Cattle in Slovakia

Abstract

National genetic evaluation of lengh of productive life in Slovakia was carry out from the year 2014 till 2018, three times per year (March, June and October). The survival analysis was performed using Weibull sire model. The heritability obtained from Weibull model was different between populations (0.13 in Holstein and 0.05 in Slovak Simmental, respectively). RBVs of Holstein sires born up to 1999 shows decreasing tendency in all five years. A desirable tendency started from the year 2000. Differences between RBV in particular years are due to descent censored records during the evaluated period. Similar trends showed in Slovak Simmental bulls RBVs. Culled cows reached average 305-day milk yield 6499 kg and 4645 kg in Holstein and Slovak Simmental breeds, respectively. The length of productive life there was 898 days in Holstein and 985 days in Slovak Simmental cows. Age at first calving reached 930 days in Slovak Simmental and 851 days in Holstein heifers. The progress of both traits in the years 2014–2018 was lower in Holstein population, +288 kg milk and +76 productive days than in Slovak Simmental cows.

Keywords

• length of productive life
• cattle
• genetic trends
• milk yield