- Influence of endogenous testicular androgens on the untilization of dietary components endocrine activity and productivity of male merino hogets
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INFLUENCE OF ENDOGENOUS TESTICULAR ANDROGENS ON THE UTILIZATION OF DIETARY COMPONENTS, ENDOCRINE ACTIVITY AND PRODUCTIVITY OF MALE MERINO HOGGETS
J. G. CLOETE. J. H. DREYER, A. M. MULDER and J.W. ROSSOUW. Agricultural Research Institute for the Karoo Region,
Middelburg, Cape Province
Testicular androgens were found to be necessary for maintaining a constant rate of growth until a live weight of at least 80 lb was reached. In the case of the castrate the daily rate of gain was reduced from 0.46 ± 0.06 to 0.32 ± 0.04 lb per day after a live weight of approximately 50 lb was reached. Intact males required 23 days less to reach a slaughtering weight of 80 lb than wethers. Rams exhibited a highly significant superior overall efficiency of feed conversion and also utilized dietary protein, calcium and phosphorus significantly better than wethers. Although not significant, the pituitary and thyroid glands tended to be heavier in the case of rams. Similarly histological examination of the thyroid glands of rams revealed that the height of the acinar cells tended to exceed that of wethers, but again not significantly. The carcasses of wethers were found to be of a superior grade to those of rams. No significant differences were noted in clean yield, staple length, crimps per inch, spinning count, fibre thickness and daily growth rate of the respective fleeces.