Abstract
Was evaluated the influence of alternative methods of detoxification of castor cake on nitrogen balance and ruminal evaluation in sheep fed isocaloric and isonitrogenous experimental diets. Twenty sheep (ten males and ten females) were used in five treatments (castor cake untreated, treated with limestone, treated with urea, treated with phosphate monodicalcium and autoclaved) and four repetitions. For nitrogen balance we used a randomized block design, with the blocks according to the sex and the variables pH and ammonia nitrogen (NH3-N) in the experimental design was split plot, with plots in the diets subplots and the collection times (0, 2, 5 and 8 hours postprandial). The treatments did not influence N intake, N urinary, urea and N-urea concentration in plasma. The Urinary N was higher in diet containing castor cake treated with phosphate monodicalcium (FOS) when compared with those containing castor cake treated by autoclave (ACL). Already the nitrogen balance (BN) was higher in diet ACL when compared to FOS diet. The pH and N-NH3 were within the normal range of sheep, being little affected by diet. Diets with methods of detoxification of castor cake promoted moderate changes in nitrogen balance with emphasis on the castor cake autoclaved and treated with limestone. The males sheep showed higher nitrogen balance than females.