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The effect of nutrition on testicular growth in the merino ram

Murray, Peter John (1988) The effect of nutrition on testicular growth in the merino ram. Masters by Research thesis, Murdoch University.

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The effect of nutrition on testicular growth was examined in Merino rams. Rams were individually fed diets specifically formulated to provide a range in the ratio of protein:digestible energy. Measurements of testicular size, wool growth and liveweight change were made on rams fed on different diets and at different times of the year. This design also facilitated a study on the relative importance of photoperiod in determining testicular growth.

The digestibilities of dry matter, organic matter and gross energy were measured for a pelleted maintenance ration, this ration supplemented with lupin seed (750 g/d) and for animals receiving an intra-abomasal infusion of casein (200 g/d). Nitrogen and apparent water balances for these diets were calculated.

Testicular growth was highly correlated with change in liveweight in a curvilinear relationship. Change in liveweight and respiration rate were highly correlated with digestible energy intake. Crude protein intake and nitrogen balance were highly correlated with wool growth, with digestible energy intake having only a marginal influence. There was also a high correlation between digestible energy intake and testicular growth, with dietary protein having only a marginal influence. Combination of these results with published data on testicular growth in rams confirmed these relationships. Photoperiod was shown to affect the rate of change of testicular growth and also testicular size.

Item Type: Thesis (Masters by Research)
Murdoch Affiliation(s): School of Veterinary Studies
Notes: Note to the author: If you would like to make your thesis openly available on Murdoch University Library's Research Repository, please contact: Thank you.
Supervisor(s): Pethick, David and Rowe, J.
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