Exogenous and endogenous contributions to nitrogen fluxes in the digestive tract of pigs fed a casein diet. II. Ileal and faecal digestibilities and absorption of amino acids

Abstract

Summary ― The present work aimed at quantifying nitrogen (N) and amino acid (AA) fluxes in the digestive tract of growing pigs fed a casein diet. In this paper we report on digesta passage at the terminal ileum, on apparent balances at the ileal and faecal levels, and on nutrients appearance in the portal vein. Digesta flow-rate at the terminal ileum was maximum between 6 and 12 h after the meal. About 10% of N and 5% of total AA ingested were recovered within 24 h. AA absorption started 30 min after the meal, and was measurable until 13 to 14 h. The total AA absorbed in 24 h accounted for 128% of the AA ingested. The

Comparison of ileal apparent, standardized and true digestibilities of amino acids in pigs fed wheat and lupine seeds

“…The presented AD of AA for casein obtained with minipigs were equal with reported values obtained with Landrace pigs (Hennig et al, 2006) and with similar casein diets (Kies et al, 1986;Darcy-Vrillon et al, 1991;Moughan et al, 1996;Officer et al, 1998;Traylor et al, 2001). Nevertheless, all these experiments showed that the AD of casein AA cannot be assumed to be 100%.…”

Forty years of achievement in french research on digestive physiology in the pig

“…The ileal and faecal digestibilities of amino acids were revisited in pigs with ileocolic postvalve fistulation and fed a casein diet, taking into consideration the exogenous vs. endogenous origin of nitrogen. In these conditions, the reabsorption of endogenous nitrogen amounted to 79% up to the end of the small intestine and to 88% over the whole digestive tract [60,178]. Ileal endogenous losses of amino acids, which depend on the level of protein and the presence of ANFs, were then evaluated in piglets with ileorectal anastomosis in association -The large metabolic phenomena occurring in the digestive wall, resulting in the absorption of high amounts of lactic acid and the metabolisation of some non-essential amino acids e.g.…”

Exogenous and endogenous contributions to nitrogen fluxes in the digestive tract of pigs fed a casein diet. III. Recycling of endogenous nitrogen

“…The urea -present in the TCAsoluble plasma fraction -is also an important component of endogenous N secretion (Rérat et al, 1979). Rérat and Buraczewska (1986) (1985,1987 Recycling of endogenous N After our preliminary approach (Souffrant et al, 1986), the total daily endogenous Nsecretion and the reabsorption of endogenous N in the GIT were estimated again for the data published in our first and second reports (Corring et al, 1990;Darcy-Vrillon et al, 1991) The average amount of N ingested on the day of collection was 23.6 ± 2.1 g, whereas 2.2 ± 0.3 and 1.3 ± 0.1 g N were found in ileal digesta and faeces respectively. Using the blood flow method and measuring the porto-arterial concentration differences, a daily total N-absorption of 33.0 ± 2.1 g was found, representing 140% of N-intake.…”