Relationship of Scrotal Circumference with Spermatozoa Production in Various Breed of Indonesian Local Bulls

Bulls for artificial insemination must qualify as a superior bull that has good genetic quality and semen production. Therefore, the selection process for bulls must be carried out accurately. The study aims to determine the relationship between scrotal circumference with semen production in the Ongole crossbred, Bali, Madura and Brahman bulls. The research materials were four breeds of bull Ongole crossbred, Bali, Madura and Brahman, which are each breed consist of ten bulls. The research methods were measuring scrotal circumference volume, spermatozoa concentration and individual motility of spermatozoa, Total Spermatozoa per ejaculate (TS) and Total Motile Spermatozoa per ejaculate (TMS). The observations performed as much as ten replications for each bull. Data were analyzed descriptively and statistically by using Analysis of Variance (ANOVA) with randomized group design. Furthermore, the relationship between scrotal circumferences with semen production was analyzed by using Pearson correlation and the effect of the scrotal circumference with semen production was calculated by linear regression. The results showed the breed of cattle influences the production of spermatozoa in Ongole crossbred, Bali, Madura and Brahman bulls. The largest scrotal circumference was the highest semen production in Brahman bull, 3.682 Cm with total spermatozoa 8.000,24+2.289 million/ml and total motile spermatozoa 4,667.60+2,289 million/ml. Ongole crossbred bull have a scrotum circumference of 34.50±4.80 cm with total spermatozoa 6,192.55±2,102.88 million/ejaculate and total motile spermatozoa 4,225.75±1,465.56 million/ejaculate. Bali bull scrotum circumference 32.50±2.65 cm, total spermatozoa 7,033.19±2,024.98 million/ejaculate and 4,908.36±1,494.30 total motile spermatozoa 4,908.36±1,494.30 million/ejaculate. Madura bull have a scrotum circumference of 33.88±2.17 cm, 5,349.24±2,183.97 million/ejaculate and the total motile spermatozoa are 3,460.48±1,414.20 million/ejaculate. In conclusion, scrotal circumferences of the bull have a contribution to the production of spermatozoa, where the bulls with the largest of scrotal circumferences have the highest semen production. Moreover, there is no correlation between scrotum circumferences with spermatozoa production.