Effect of Age and Bulls on Fresh Semen Quality and Frozen Semen Production of Holstein Bulls in Indonesia

Abstract
Artificial Insemination is a compatible method of reproduction in an effort to increase dairy productivity. Artificial Insemination Center as a producer of frozen semen was required to maximize bulls in producing high quality frozen semen optimally. The purpose of this research was to determine effect of age and bulls on fresh semen quality and frozen semen production of Holstein bulls in Indonesia. The research was conducted at Lembang and Singosari AI Centers. The material used were 24.634 data of qualified fresh semen and frozen semen production from 81 Holstein Bulls aged 1-9 years that used as frozen semen producer in period of 2008 to 2016. The variables observed in this research were data of age of bulls, fresh semen volume (mL); sperm motility (%); mass movement; concentrations (million/mL) and frozen semen doses at each production at age of bulls. Nested design was applied to obtain and analyze data. Results showed that Age and bulls have significant effect (P<0,01) to volume, mass, motility, concentration and frozen semen production. Increasing the age of bulls resulted in increase semen volume until 7-year-old, while semen concentration decreased from 3 years old with increasing age. Frozen semen production, mass movement and motility shown the same relative value on 3-9 years old except on 1 to 2 years old had increase. Bulls would produce frozen semen optimally on 3-9 years old. Indeed, with knowledge of this factor, AI Centre might adapt management of AI bulls to improve semen production.