Effect of behaviour of Holstein Friesian and Simmental bulls on semen quality

Abstract

The aim of the study was to determine the relationship between the behaviour of Holstein-Friesian and Simmental bulls and the quality of their semen. A total of 76 breeding bulls of the Holstein-Friesian and dual-purpose Simmental breeds were investigated. Analysis was made of the response of bulls to humans and other bulls, facial hair whorl position and length, scrotal circumference, and semen characteristics (mean ejaculate volume, mean sperm concentration, and sperm wave motion). The age and breed of the bulls had a statistically significant effect on semen quality, scrotal circumference and the animals response to an unfamiliar human (Plt,0.05, Plt,0.01). The coefficients of correlation between the bull s response to a handler and to other bulls averaged 0.73. In general, only weak correlations were found between behavioural traits of the bulls and quality of their semen. It is worth noting a good correlation (r=0.50; Plt;0.05) between hair whorl position and sperm concentration in Simmental bulls.

Keywords

• bulls
• behaviour
• semen quality