TESTICULAR MORPHOMETRY OF CROSSBRED YOUNG BULLS SUBMITTED TO DIFFERENT STRATEGIES OF ENERGETIC SUPPLEMENTATION OF Brachiaria brizantha PASTURE

Abstract

The objective of this study was to correlate the testicular measurements and weight gain, as well as the possible influence of the feeding level on the morphometry of the testicles of 32 crossbred Holstein/Zebu, in sexual development process, kept in Brachiaria brizantha pasture submitted to two levels of energy supplementation (0.5% and 1.0% of LW, TM and TH) during the second half of the rainy season. In vivo growth of scrotal perimeter and the final measures of the glandular portion of the testicles according to the perimeter, length, width, volume, weight and shape were evaluated. The correlation coefficients between the testicular measures and weight gain were moderately positive, ranging between 0.12 and 0.32. The frequency analysis showed that long testicles of long prevailed in both treatments, with respectively 65% and 54% for TM and TH. There was a significant effect (p <0.05) of the feed system on the in vivo gain of scrotal perimeter in favor of the high level of supplementation (TH), which gained 5.93 cm versus 3.71 cm of the TM group. There was no significant effect (p> 0.05) of the feeding level on the testicles glandular measures. It was concluded that these characteristics are determined by the stage of sexual development and not by the feeding level and the testicular measures should not be used alone as a criterion for assessing the performance of crossbreed young bulls.

KEYWORDS: Performance, scrotal perimeter, testicular perimeter, testosterone.