Studies on the intestinal digestion of nitrogen by sheep fed formalin-treated casein diets

J.C. MacRae

Applied Biochemistry Division, DSIR, Palmerston North

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Proceedings of the New Zealand Society of Animal Production. 1970, 30: 218-226

The treatment of casein with the formalin resulted in all the supplementary N reaching the duodenum. The abomasal (gastric) juices destroyed the formalin protection and 65% of the treated casein-N was subsequently digested within the small intestine; a further 22% disappeared between the ileum and the faeces. With the untreated casein, only half of the supplementary-N reached the duodenum in an undegraded form, 30% of the untreated casein-N disappeared within the small intestine and a further 14% disappeared beyond the ileum.

A substantial amount of the supplementary-N from each form of casein appeared in the urine; however, net retention of treated casein supplementary-N was 36% of that administered in the diet. Net retention of untreated casein nitrogen was only 17%.

Data are also presented which show substantial increases in the quantities of "essential amino acids" absorbed from the small intestine when the treated casein was fed.

Keywords: NZSAPAB;