Wpływ rasy i wieku buhajów na ilość i jakość ich nasienia

The investigations were carried out on seventy five bulls of Black and White Breed and forty six bulls of Red and White Breed used for procreation in the years 1977-1985 in the Animal Breeding and Insemination Centre in Karczów. All ejaculates produced by individual bulls during the first three years were examined. There were 33103 ejaculate features of both bull breeds analysed. The following features were examined: total quantity of semen, number of ejaculates, mean volume of ejaculate, spermatozoon concentration, their survival rate and translatory motion. On the basi s of the investigations it wae stated that the kind of breed had no effect on either quality or quantity of the semen. However, lower values of analysed features were observed in bulls of Black and White Breed. On the other hand the number of ejaculates, total quantity of semen and volume of ejaculate increased from year to year in bulls of both breeds. In the third year of using the bulls for procreation increase of the following was stated: spermatozoon concentration, percentage of sperm in translatory motion and their survival rate. However, this increase was not statistically significant.