Original scientific paper
Study on the reproductive capacity of bulls of the autochthonous Rhodope Shorthorn cattle breed
2015, 16 (2) p. 47-53
The sperm production of bulls from the autochthonous Rhodope Shorthorn cattle breed was studied. The breed is among the smallest in Europe, the average weight of the cows ranging from 200 to 250 kg, and of the bulls from 330 to 370 kg. It was found that during the first 6 months from the start of exploitation, at the age of the bulls from 18 to 24 months, AI bulls had high reproductive capacity. The ejaculate volume was 1,74±0,09 ml in average (LS), the percentage of motile spermatozoa was 74,3±3,48% and the concentration 1268±13,1 x 106/ml. It was established that the bull had a significant impact on the reproductive performance, but the individual differences in the main characteristics were not high – motility 71,8-77,0%, concentration – 1222-1324 х 106/ml. The season also had a significant effect on the percentage of motile spermatozoa. Within the period from January to June, the highest reproductive capacity of the bulls was observed from February to May and the lowest in June.