Behavior of Simmental Heifers of Two Genotypes at the Age of Puberty and Mating.

A survey was performed to find out the methods for improving the Holtenized Simmental cattle through selective breeding with Montbeliarde bulls. The objective of the survey was to identify the behavior patterns for the key positions, including growth, development, conformation, and reproductive performance, in the heifers of two genotypes. The differences in the social behavior of heifers kept in separate group sections were revealed more in favor of the Montbeliarde bull daughters. At the age of heifers at mating, they were 66% more frequent than that in their peers with the high rates of consanguinity in Holsteins, which were more active and aggressive. Thus, the findings showed that the occurrence rates of the stereotypic behavior were 17–33% higher among the animals at the age of 10–11 months and 14–15 months, while the gender-related behavior was less frequently observed. In addition, the use of different fodder factors under the conditions of one of the sections resulted in that the Montbeliarde bull progeny consuming the dietary compound feed tended to adapt to any irritation quicker by 8.5%; the animals responding to the irritant were 7.3% less. The heifers of genotype 1/4Simmental ×1/4Holstein × 1/2Montbeliarde are more resistant to the irritant and capable of intensive development. The valid differences in the liveweight were 39.6 kg and 60 kg at the age of 10–11 months and 14–15 months, respectively. The Montbeliarde bull daughters at the ages of 10–11 months and 14–15 months were distinct in higher feed intake by 10 and 5.8%, respectively, when compared to their 3/4Holstein peers. The Montbeliarde bull offspring are earlier maturing, since the successful conception was registered 1.4 months earlier and their first-service pregnancy rate was 4% higher than that in the heifers of genotype 1/4Simmental × 3/4Holstein. [ABSTRACT FROM AUTHOR]