Water turnover in adult local crossbred bulls with improved feeding

D. Mohamad Aziz and R. Abdullah Sani

Abstract

An experiment was conducted to study the effect of copra cake supplementation on the performance and thermoregulation of Local Indian Dairy x Australian Milking Zebu crossbred bulls
grazed on native pasture under coconut plantation. Two groups of five animals each, approximately two years of age and weighed about 260-330 kg, were randomly chosen from two groups of animals which had been raised with two different nutritional systems. One group was raised with copra cake supplementation (1.13-1.59 kg/animal/day) while another group was not supplemented. This nutritional system was further continued for another six months. The supplemented group was used as the treatment group and the non-supplemented group as a control. At the end of the trial period, tritiated water (3.7 m Bq/kg b.w.) was injected intramuscularly to every animal to determine the water metabolism. Blood samples were collected every two days for 15 consecutive days. The activity of tritium in the plasma samples was determined and the water turnover parameters were calculated. It was found that the body weight of the supplemented group (340 kg) was not significantly different (P<0.05) from the control group (328 kg) while the ADG for the control group (274 g) was higher than the treatment group (110 g). Body water space, total body water, half-life and water turnover rate of the treated group (80% b.w.,67% b.w.,4.05 days and 396 ml/kg ^0.82/day respectively) were not significantly different from the untreated group (78%, 66%, ,3.49 days and 446 ml/kg ^0.82/day respectively). The results indicated that quantity of copra cake supplementation in this experiment did not increase the ADG of the adult animals compared with the control. In contrary,
the local grass provided enough nutrients for these animals. Also, the copra cake supplementation did not give any effect on the heat balance. Further study should be carried out on stall-fed animals to determine the effect of grazing activity on the heat balance of the supplemented animals.

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