Relationships among body condition score, milk yield and sires' breeding value for beef production efficiency in Czech Fleckvieh cattle

Abstract

The objective of this study was to analyze the relationships among cows’ body condition score before calving, subsequent BCS changes, milk yield, lactation characteristics and their sires’ relative breeding value for net daily gain. Increasing the relative breeding value of net daily gain in the sires was associated with increased BCS in their daughters. The differences ranged between 0.02 and 0.18 points in the particular lactation periods, but they were not statistically significant. The group of cows with the highest BCS before calving showed the highest BCS decrease (–0.25 points) after calving (<I>P</I> < 0.01); the BCS loss lasted for 3 months. The analysis of the relationship between the relative breeding value of sires for net daily gain and milk yield of their daughters showed a negative effect of RBV NG ≤ 89 on the daughters’ milk yield (<I>P</I> < 0.05), while the negative differences were up to – 279.12 kg of fat-protein corrected milk. The effect of this trait on the lactation curve was also analyzed.