Deterioration of Frozen Semen of Bali Cattle after Cooling at 5°C

Frozen semen is produced through several stages, which deteriorate spermatozoa. This research aimed to evaluate the deterioration degree of frozen semen after 5 °C cooling and freezing of Bali cattle. The samples included 10 male Bali cattle with a body weight of 542-668 kg, from which semen was collected once a week for five weeks. The deterioration of each individual’s sperm was determined by observing two distinct straws. The parameters observed included viability, abnormalities, intact plasma membrane, and intact acrosome cap. Initial observations of the parameters were conducted following the addition of semen to diluent A1 (AD) as much as the volume of fresh semen. The semen in the AD group was not cooled and frozen. The A1 semen was then divided into two, namely, those with cooling at 5 °C for 4 hours (PT1) and at 5°C for 22 hours (PT2). The results showed that individual variations in Bali cattle caused significant differences in viability and intact plasma membrane of AD and PT1 groups, while PT2 did not differ in viability and intact plasma membrane spermatozoa. Abnormalities were significantly different between AD and PT2 groups, however PT1 did not differ in abnormalities spermatozoa. Intact acrosomal cap was significantly different in the AD, PT1, and PT2 groups. In conclusion, individual variations, including viability, abnormalities, intact plasma membrane, and acrosome cap of spermatozoa, were better at 4 hours compared to cooling at 5°C for 22 hours. A Cooling time of 4 hours at 5°C can be recommended for frozen semen processing.