SCROTAL CIRCUMFERENCE AND ITS RELATIONSHIP WITH TESTICULAR GROWTH, AGE AND BODY WEIGHT IN INDIGENOUS BULLS

Abstract

The relationship among the scrotal circumference and testicular parameters with body weight and age were investigated in indigenous bulls. Data from thirty six indigenous bulls were recorded and classified into four age groups namely, Group I (15-18 months, n=7 animals), Group II (19-22 months, n=8 animals), Group III (23-26 months n=12 animals) and Group IV (27 months and above, n=9 animals). Age of the bulls were determined using their dental formula. Live weight body weight of each bull was calculated according to Shaeffer’s formula. Scrotal circumference were measured with a cloth tape and testicular parameters and were measured with a caliper. Body weight, scrotal circumference and testicular parameters were varied in different age groups even in left and right testes of the same animal. The results of different testicular parameters, scrotal circumference, and body weight at different age of Indigenous bulls were significantly (<0.05) different among the age groups. These parameters were increased by the advancement of age. The body weight was lowest in case of age group I (98.14±11.87 kg) and was highest in age group IV (214.22±33.27 kg). The scrotal circumference was lowest in case of age group I (17.14±.63 cm) and was highest in age group IV (24.33±1.31 cm). The average estimated testicular weight was lowest in age group I (86.38±12.18 gm) and was highest in age group IV (214.03±22.93 gm). Various measurements of the testes were highly correlated with each other (< 0.01). Body weight was more highly correlated with the various testicular measurements than age. Moreover age, testis weight, and body weight of Indigenous bulls were highly correlated with scrotal circumference. Scrotal circumference was highly correlated with other testicular measurements as well as testicular volume. Correlation coefficient R2 between scrotal circumference and age in indigenous bulls was 0.599 and between scrotal circumference and body weight was 0.785 which indicates a strong positive relationship among the parameters. Finally from the present study it could be concluded that scrotal circumference is a useful indicator and is an important selection criterion to determine the testicular development and breeding soundness in young bulls.