Short- and medium-chain fatty acids as a feed supplement for weaning and nursery pigs.

The effect of supplementing piglet diets with acidifiers containing the short-chain fatty acids - SCFA (propionic C3 and formic) together with medium-chain fatty acids -- MCFA (caprylic C8 and capric C10) on performance, nutrient apparent digestibility, intestinal microflora and small intestine structure was investigated. The study was performed on 326 piglets allocated to 5 experimental groups. They were fed a standard diet (Group I - control) or a standard diet supplemented with 0.5% propionic and formic acids (Group II - PF). Group III (PF + C8), group IV (PF + C10) and group V (PF + C8 + C10) received the same mixture as group II with a supplement of 0.2% of caprylic and/or capric acids, respectively. Apparent digestibility of nutrients and microbiological analyses were performed. The structure of jejunum mucosa was also examined. Piglets receiving capric acid (groups IV and V) had the highest body weight gains. Piglets receiving MCFA digested protein and fiber better (P < or = 0.05) than piglets receiving SCFA as acidifier. There was no difference in intestinal microflora except for Clostridium perfringens, the population of which was reduced by SCFA (group II). Villi of the mucosal epithelium were the highest (P < or = 0.05) in piglets receiving SCFA with capric acid (group IV). Under the conditions of this study a mixture of SCFA (propionic and formic) with capric acid significantly improves performance of piglets.