GONADAL AND EXTRAGONADAL SPERM RESERVES AND TESTICULAR HISTOMETRY OF POST PUBERTAL MUTURU BULLS.

Testes and epididymides were obtained from three pubertial Muturu bulls aged 11 months and 12 post pubertal bulls aged between 13 and 17 months and weighed between 91 and 148kg. Samples of each testis and epididymal segments namely, caput, corpus and cauda, were processed for histology while samples for gonadal and extragonadal sperm reserves were processed using the homogenisation technique. Paired testes weight increased from 78.99+8.74g at 11months of age to 90.10+10.86g. 110.30+5.67g and 106.34-6.52g at 13, 15 and 17 months of age, respectively. Paired testes sperm numbers were 3.00+1.50 X 10', 5.25 0.51 x 10', 10.44+2.55 x 10° and 9.14+3.08 x 10°, during the corresponding periods. Similarly, daily sperm production (DSP) increased by 77%, 250% and 207% at 13, 15 and 17 months of age, respectively. There was a 22% increase in the seminiferous tubule diameter from the time of puberty at 11 months to the time bulls were 15 months old, but the histological characteristics of the different epididymal segments did not follow any definite trend during these periods. Correlations between paired testes weight and other testicular and epididymal parameters were positive and significant (P<0.01). These results suggest that Muturu bulls may be used for breeding from the age of 15 months.