Feeding trial in pigs with a diet containing sodium n-butyrate.

Pigs weighing 7 to 102 kg were fed a diet containing 0.17% sodium n-butyrate. The diet increased the average daily body mass gain of pigs by 23.5%. Due to its dietetic effect, feed consumption increased by 8.9%. However, owing to the higher feed conversion, specific feed utilization was reduced by 11.8%. The experimental diet markedly reduced the percentile proportion of coliform bacteria in the ileum as compared to Lactobacillus ssp.: it decreased the coliform count and increased the counts of Lactobacillus spp. The diet increased the length of ileal microvilli and the depth of caecal crypts. It raised the concentration of immunoreactive insulin in the blood plasma. The feed supplemented with sodium butyrate did not alter adversely the clinical indices tested. It reduced feed costs by 9% and increased the returns from sales by 13%. As the additive is normally produced by microbial fermentation in the large intestine, it is not alien to the body. Sodium butyrate exerted its favourable effect in 3.6- to 24.2-fold lower concentrations than the organic acids (citric acid, fumaric acid, propionic acid) used earlier. With respect to its favourable biological and economic effect, sodium n-butyrate can be recommended for use in pig feeding as a growth promoter.