Performance, Nutrient Utilization and Intestinal Environment of Weaned Rabbits Fed Diets Supplemented with Organic Acids in the Humid Tropics

Abstract

The performance, nutrient utilization and intestinal environment of weaned rabbits fed diets supplemented with organic acids (acetic acid, citric acid and formic acid) were investigated with 24 (6-week old) rabbits in a completely randomized design. The control diet was not supplemented while others were supplemented with 0.5% of each of the organic acids. Measurements were live weight, live weight gain, feed intake, carcass and organ characteristics, feed cost, nutrient digestibility, gut pH and intestinal microbial population. Organic acids had no significant (P>0.05) effect on the performance of the rabbits except mortality. Formic acid supplemented diet produced the highest values for shank (2.18%), back-cut (13.47%) and intestine (5.60%). Mortality was significantly (P<0.05) reduced with use of acetic acid diet (16.67%) against 50% for the control diet. Organic acid supplemented diets did not significantly (P>0.05) affect nutrient digestibility coefficients and feed cost indices. Rather, acetic and formic acids significantly (P<0.05) reduced the pH of the small and large intestine digesta compared to the control diet while organic acids had no significant (P>0.05) effect on the pH of caecum digesta. There were no significant (P>0.05) differences in the microbial population in the small intestine, large intestine and caecum. It was concluded that supplementation of rabbit diets with acetic or formic acid have some beneficial effect on rabbit production, significantly reduced mortality and intestinal pH but had no significant effect on feed cost, apparent nutrient digestibility, carcass and organ characteristics, and bacteria (Salmonella spp. and Escherichia coli) population in the intestine.