Optimització de l'alimentació nitrogenada en l'enceball intensiu de vedelles

The response to protein supplementation in rumiants rely on the effect of basal diet and protein supplement characteristics on the supply of microbial and undegrated dietary protein to the duodenum. The contribution of both protein fractions is related to the extent and rate of fermentation of both carbohydrates and protein sources. These effects have been scarcely studied on the conditions imposed by intensive beef cattle rearing systems. The proposed research aims to study the effect of coupling the rate of degradation of carbohydrate and protein sources on rumen metabolism and intestinal flow of protein by means of "in vitro" continuous fermentation studies and "in vivo" trials using rumen and duodenum canulated steers. Nutrient combinations expected to maximise performance reponses will be verified in conventional intensive feeding trials. The knowledge gained, together with the char