THE USE OF SWEET POTATO (Ipomoea batatas, (L) Lam) IN ANIMAL FEEDING II BEEF PRODUCTION

3.5 ha of sweet potato were used to feed 30 crossbred Brahman bulls with an average weight of 184 kg and approximately one year old in an experiment to study the use of sweet potato in beef production. The five treatments were allocated to the experimental units in an unrestricted randomized block design. Treatments contained 0:100, 25:75, 75:25, 50:50 ant 100:0 ratios of tubers to sweet potato forage (on a try matter basis) supplemented with urea to provide 0, 18, 35, 53,and 71% of total nitrogen respectively. An additional treatment of 38.6% molasses, 60.2 of the aerial parts of sweet potato and 1.2% urea was also used with. the aim of comparing its effect with the 100% tuber treatment under the same conditions of energy and protein. All the rations contained 11.25% of crude protein. Food intake did not vary averaging 2.37 and 0.29 kg/100g LW/d for dry matter and crude protein respectively. The mean energy intake was 5.57 Mcal metabolizable energy/100 kg LW/d and this increased as the proportion of tubers in the ration increased. In addition, dry matter digestibility increased from 62 -92% as the proportion of tubers increased, The molasses treatment resulted in slightly higher intakes (2.75 kg/100 kg LW) even though its in vitro digestibility was lower (56%). Liveweight gain did not differ significantly between treatments. The mean being 0.767 kg/animal/d. The mean feed conversion efficiency was 7.06kg DM/kg LW gain. In the molasses treatment liveweight gain and feed conversion efficiency were poorer compared to the 100% tuber treatment, the values obtained were 0.623 kg/animal/d and 9.0 kg intake/kg gain. Economic considerations revealed that 12% of the tubers had no commercial value. The use of this material together with the sweet potato forage for feeding to the cattle, could produce a profit of 38% thus providing a new' alternative for the livestock producer. From these results we can conclude that the forage and the tuber of sweet potato can be considered as a very useful feed for cattle; that the addition of tubers and urea to forage improves liveweight gain and feed conversion efficiency and that the we of forage and west. tubers of sweet potato as a feed for livestock has economic advantages for the small producer.