The digestive capacity of the caecum-colon and the value of the nitrogen absorbed from the hind gut for protein synthesis in pigs

Abstract

1. The aim of the investigation was to study the effects of lysine, methionine, crude protein, a complete balanced diet, maize starch and potato starch infused continuously into the caecum on the digestibility of the nutrients, urinary nitrogen excretion and N balance in the presence of a normal or a depressed (modified) microflora. 2. The effects of the the infused nutrients on digestibility differed when diets supplemented with antibiotics were compared with unsupplemented diets. 3. Infused lysine improved the digestibility of crude protein (0.004/g lysine), crude fibre (0.01/g lysine), gross energy (0.003/g lysine) and lysine (0.03/g lysine) when the diets were not supplemented with antibiotics. 4. Infused lysine, methionine and crude protein seemed to be of very little value for protein synthesis in the pigs, as the effects on N balance, although positive, were very small. 5. Despite the fact that a part of the infused lysine passed through the caecum-colon and into the faeces intact, the effect of N balance was negligible, indicating that the ability to absorb amino acids through the gut wall in the caecum-colon was very poor. 6. Crude protein, a complete balanced diet, maize starch and potato starch infused into the caecum were digested almost as well as if they had been given orally, thus demonstrating the large digestive capacity of the caecum-colon.

Effect of Salinomycin on Nutrient Absorption and Retention by Growing Pigs Fed Corn-Soybean Meal Diets With or Without Oat Hulls or Wheat Bran

“…1984 Dietary antibiotics have been shown to increase the apparent absorption of N from the small intestine (Just et al 1981;Eggum et al 1982), and although the present data suggest that SM may alter fermentation in the gastrointestinal tract of the pig, the site of this action is not known. The …”

Digestibilities of nitrogen and amino acids in soya-bean, sunflower, meat and rapeseed meals measured with pigs and poultry

“…The soya beans, which had been body metabolism of essential amino acids grown in Brazil, were partially dehulled (Zebrowska, 1973;Gargallo and Zimmerman, during the manufacturing process. The two 1981; Just, J0rgensen and Fernandez, 1981; sunflower meals were made from the same Wiinsche, Hennig, Meinl, Kreienbring and batch of sunflower seeds which had been Bock, 1982;Just, J0rgensen and Fernandez, harvested in France. The manufacturing 1985).…”

Lysine synthesized by the gastrointestinal microflora of pigs is absorbed, mostly in the small intestine

“…This assumption is supported by the observation that the largest microbial population is concentrated in the large intestine, whereas the small intestine is the primary site of amino acid absorption. Although several authors have described the ability of the large intestinal mucosa to absorb amino acids (5,6,8), it appears to be of little or no nutritional significance (3,10,(14)(15)(16). There is, however, increasing evidence for a substantial and highly active microbial population in the upper segments of the gastrointestinal tract of pigs (1, 2, 7).…”