Seasonal effects on semen quality of ongole crossbred and simmental bulls used for artificial insemination

摘要

? 2019, Fundacion CIPAV. All rights reserved. ? 2019, Fundacion CIPAV. All rights reserved. This study evaluated the effects of rainy and dry seasons on semen quality of bulls at Ungaran artificial insemination center. The semen was collected twice a week from one Ongole crossbred and one Simmental bulls, both at 5 years old, totaling 198 semen collections (99 of each bull). The results showed that the sperm concentration of Ongole crossbred bull was higher in the rainy season, however, the sperm motility before-freezing was higher in the dry season. On the other hand, Simmental bull showed no seasonal variation on all semen quality traits. The comparison of semen quality between these two breeds showed that the Ongole crossbred bull had a higher semen volume, however, the sperm concentration, total sperm count, total motile sperm count, and frozen semen dose were higher in the Simmental bull. The approved fresh semen was tended to be higher in the Simmental bull than the Ongole crossbred bull (98% vs 90.9%), but the discarded frozen semen was relatively higher in the Simmental bull than Ongole crossbred bull (8.25% vs 4.44%). This study suggests that the semen collection of Ongole crossbred and Simmental bulls could be done both in the rainy and the dry seasons. Simmental bull has superior semen concentration and the number of approved fresh semen than Ongole crossbred bull. However, the susceptibility of Simmental bull to the tropical environment resulting in a lower semen freezability compared to Ongole crossbred bull. This study evaluated the effects of rainy and dry seasons on semen quality of bulls at Ungaran artificial insemination center. The semen was collected twice a week from one Ongole crossbred and one Simmental bulls, both at 5 years old, totaling 198 semen collections (99 of each bull). The results showed that the sperm concentration of Ongole crossbred bull was higher in the rainy season, however, the sperm motility before-freezing was higher in the dry season. On the other hand, Simmental bull showed no seasonal variation on all semen quality traits. The comparison of semen quality between these two breeds showed that the Ongole crossbred bull had a higher semen volume, however, the sperm concentration, total sperm count, total motile sperm count, and frozen semen dose were higher in the Simmental bull. The approved fresh semen was tended to be higher in the Simmental bull than the Ongole crossbred bull (98% vs 90.9%), but the discarded frozen semen was relatively higher in the Simmental bull than Ongole crossbred bull (8.25% vs 4.44%). This study suggests that the semen collection of Ongole crossbred and Simmental bulls could be done both in the rainy and the dry seasons. Simmental bull has superior semen concentration and the number of approved fresh semen than Ongole crossbred bull. However, the susceptibility of Simmental bull to the tropical environment resulting in a lower semen freezability compared to Ongole crossbred bull.