Abstract:
EFFECTS OF BENTONITE AND MAIZE SUPPLEMENTS ON PRODUCTION OF WOOL IN SHEEP R.J. Forster * and R.A. Leng* The use of bentonite to increase wool growth in sheep was first reported by Leng (1983). Further studies,have demonstrated that the supplementation of bentonite to sheep in their drinking water increased wool growth by 1.7% in ce ,.aunated sheep grazing good quality pasture (I?enn and Leng, 1988). However, recent research in Western Australia did not find increases in wool growth when bentorLfte was included in a good quality pelleted diet or when added to a chaffed wheat straw diet (5.13. Rowe. pers. comm.). The present study was designed to determint: :Jx-? effect of bentonite and maize supplementation of straw based diets. Sheep were assigned to a diet consisting of 84% wheat straw (C) or 54% wheat straw and 30% cracked maize (M). Each diet was supplemented with 10% cottonseed meal and 6% urea/mineral mix (2.5% dried molasses, 1.5% urea, 2% minerals/vitamins). Bentonite ('Trufeed MW',Cudgen RZ Pty. Ltd., Brisbane) was supplemented to half the sheep in the drinking water at a rate of 15g/l. TABLE 1. The effects of bentorlite and/or maize supplements on wool growth Supplementation with bentonite tended to increase wool growth on the basal diet (pxO.1) and significantly increased wool growth on the maize supplemented diet (p<O.O3). Increases ;:; xool growth attained were between 24 and 30%. Bentonite did not affect liveweight gain on the maize supplemented diet bu' Lended to increase growth when the basal diet was fed (pcO.1). PreLl feeding levels of rumen NIIS were not different, however 4 h after feeding the level of NH3 on the basal diet was significantly decreased when bentonite was supplemented. These results indicate that bentonite has the potential to increase the growth of wool on supplemented straw diets. FENN,P.D. and LENG, R.A. (1988) In 'The Roles of Protozoa and Fungi in Ruminant Digestion', editors, J.V.Kolan,R.A.Leng, and D.I.Deneyer, (Penambul Books: Armidale, NSW). LENG, R.A. (1983). In 'Recent Advances in Animal &cuition in Australia 1983', p.`?A, editors '-+ D.J.Parrell and P.Vohra. (t'niv.New England Pub! ishing Unit: Armidale, NSW). . . . . ..H11.............-............-...........................................- *Department of Biochemistry,Microbiology and Nu*-' ~&on, University of New England, Armidale, NSW, 235 1, Australia 26A