Apparent and true ileal digestibility of amino acids and nitrogen balance measured in pigs with ileo‐rectal anastomosis or T‐cannulas, given a diet containing peas

Abstract

Abstract The apparent ileal digestibility of the main constituents of a diet based on peas (Pisum sativum L) and of the amino acids of these peas was determined with three pigs which were surgically modified to create an ileo‐rectal anastomosis with complete isolation of the large intestine, and three pigs surgically fitted with a T‐cannula at the terminal ileum. The animals first received a diet containing ground peas as the sole protein source and then a protein‐free diet which permitted the estimation of the excretion of endogenous amino acids at the level of the ileum and the calculation of the true digestibility of pea amino acids. The apparent digestibility of organic matter, crude protein, cell walls, starch and energy was systematically higher in cannulated pigs, but the difference was only significant for cell walls ( P < 0.05). For the amino acids the difference was only significant for the apparent as well as the true digestibilities of methionine, proline and tryptophan. It seems that the observed difference originates from the collecting method for the cannulated pigs. The nitrogen balance has shown that with pigs an ileo‐rectal anastomosis emitted less urinary N and more faecal N ( P < 0.05) than cannulated pigs. On the other hand, the estimation of the biological value and of the net protein utilisation of pea proteins was the same for both kinds of pig ( P > 0.05).