Influence of body structure types and pronouncement of meat forms of bulls on their sexual activity

Abstract

The relevance of the study is determined by the need to find ways to improve the attributes of the reproduction of bulls that affect the economic efficiency of their use. The purpose of the study was to identify the relationship between the features of the exterior of bulls and their sexual activity, other signs of reproduction. Bulls of the Ukrainian meat breed were divided into two groups using the size Index: large-sized and compact. The pronouncement of meat forms in bulls was determined at the age of 15 months on a 60-point scale. Sexual activity was characterised by the duration of the manifestation of sexual reflexes from bringing the animal to the mount to mounting it. In experimental bulls, the duration of the period of productive use, the number of deliveries to the mount and attempts of mounting it, and the number of ejaculates received and culled were recorded. It was found that the tendency to distribute active moderate and calm manifestations of sexual reflexes in bulls of different types of body structure and the development of meat forms are similar. Most of all, there was a proportion of moderate sexual activity, but specific trends were observed within the groups. The proportion of high sexual activity was higher in compact bulls compared to large-sized peers and animals with better pronounced meat forms. Further, large-sized bulls tend to increase the duration of productive use, predominate in the proportion of mounts made and are characterised by a decrease in the proportion of ejaculate culling. Bulls with more pronounced meat forms tend to increase the duration of productive use, which is due to their higher breeding value based on the characteristics of meat productivity. In terms of the proportion of mounts made and the percentage of ejaculates culled, there was no difference between animals with different meat forms. The results obtained prove that compact bulls are more suitable for intensive use at an early age, and large-sized producers are more effective in adulthood. The better development of meat forms somewhat reduces the sexual activity of young bulls. At a more mature age, meat forms practically do not affect the results of using bulls. The results obtained allow selecting the type of body structure of bulls that have the highest sexual activity