Negatieve effecten van antinutritionele factoren in diervoeders op de stikstofbelasting van het milieu en mogelijkheden tot reductie. Voedingsfysiologische effecten [Negative effects of anti-nutritional factors in animal feed on nitrogen burden of the environment and possibilities of its reduction. Nutritional physiology effects]

Antinutritional factors (ANFs) protect the seed against attacks of moulds, bacteria, insects and birds. The defensive effect of ANFs is apparently related to disturbances in digestive processes in insects and microorganisms. When animals consume seeds containing ANFs, the digestive processes and growth may be disturbed in a similar manner. In the present paper, the fact is discussed that all proteins passing undigested through the small intestine will be fermentatively digested in the large intestine. The final products of the protein digested in the large intestine are excreted in the faeces or urine. For investigations into the digestion of protein in pigs and the amounts of N excreted into the environment, it is of importance to measure the ileal digestibility of protein. Studies showed that ANFs such as trypsin inhibitors, lectins and tannins present in legume seeds reduce the ileal digestibility of protein. In the case of Phaseolus beans it was found that more protein passed through the terminal ileum than was ingested with the feed. With peas was shown that ANFs reduce the ileal digestibility of protein. The carbohydrates of peas did not affect the ileal digestibility of protein, although the ileal chyme was more loose. In the case of faba beans, negative correlation of tannins with ileal digestibility of protein was observed. Calculations showed that, when ANFs were removed from peas and faba beans a considerable reduction in excretion of N into the environment can be achieved. These calculations also showed important possibilities of reducing the secretion of N into the environment by elimination of ANFs. Chemicals/CAS: nitrogen, 7727-37-9; trypsin inhibitor, 9035-81-8; Biological Factors; Lectins; Nitrogen, 7727-37-9; Trypsin Inhibitors.