IMPROVEMENT IN NUTRIENT RETENTION AND CHANGES IN EXCRETA VISCOSITIES IN CHICKS FED RYE-CONTAINING DIETS SUPPLEMENTED WITH FUNGAL ENZYMES, SODIUM TAUROCHOLATE AND PENICILLIN

Abstract

Three feeding experiments were performed with chicks to study the effects of supplementing sodium taurocholate, penicillin and a crude fungal enzyme preparation, Trichoderma viride cellulase (T.v. cellulase), in rye- and wheat-based diets on the viscosity of water extracts of feed and excreta and on nutrient retention. Sodium taurocholate had no effect (P > 0.05) on the viscosity of extracts of the diet or excreta but slightly improved fat retention (P < 0.05) in chicks fed a rye-containing diet. Penicillin treatment had no direct effect on the viscous component in rye, but increased (P < 0.05) fecal viscosity and fat retention in chicks fed rye-containing diets. T.v. cellulase produced the most dramatic results among the treatments increasing (P < 0.05) fat and dry matter retention by 12 and 5 percentage units, respectively, in the rye-fed birds, but had no effect (P > 0.05) on these parameters when added to a wheat-based diet. Also, T.v. cellulase dramatically reduced excreta viscosity which was different to the effect of sodium taurocholate and opposite to the effect obtained with penicillin. An in vitro study also tested five crude enzyme preparations of widely diverse origin. T.v. cellulase was by far the most efficient viscosity-reducing enzyme and as a result was selected for the animal studies. In conclusion, penicillin, crude fungal enzyme, and sodium taurocholate additions to a rye-based diet increased, decreased or had no effect on excreta viscosities, respectively, but in all cases increased fat retention. They therefore probably have different mechanisms of action. Key words: Chicks, rye diet, nutrient retention, excreta viscosity, fungal enzyme, penicillin, sodium taurocholate.