THE EFFECT OF GROWTH RATE IN PURE-BRED AND CROSS-BRED BOARS ON THEIR SEMEN CHARACTERISTICS

摘要

The aim of the study was to examine the effect of daily growth rate on the semen characteristics of purebred boars (Polish Large White and Polish Landrace) and crossbred boars (Duroc x Pietrain and Pietrain x Duroc). The research was carried out on 29purebred boars (2024 ejaculates) and 22 crossbred boars (1156 ejaculates). The following characteristics were analysed: ejaculate volume, sperm concentration, percentage and number of live spermatozoa, and number of insemination doses obtained per ejaculate. A high rate of growth in the boars was found to have no negative effect on the quality of their ejaculates. In both purebred and crossbred boars, the largest ejaculate volume, the highest percentage of live sperm and the most insemination doses perejaculate were obtained for the boars with the highest daily weight gain (over 851 g).The semen of crossbred boars with the same intensity of growth as purebred boars (801-850 g and > 851 g) was characterized by significantly greater ejaculate volume, a higher sperm concentration, a higher live sperm count in the ejaculate, and a higher average number of insemination doses prepared from one ejaculate. The results indicate that the level of the selection index currently used in the breeding of boars has no negative impact on the characteristics of their ejaculates.