Mannanoligosaccharides in diets for nursery pigs

Kansas State University Swine Research. A total of 168 pigs (average initial BW of 13.2 lb and avg initial age of 21 d) was used in a 35-d experiment to determine the effects of mannanoligosaccharides on growth performance of nursery pigs fed diets without antibiotics. Treatments were: 1) a positive control with carbadox added at 50 g/ton of diet, 2) a negative control without antibiotic, 3) the negative control with mannanoligosaccharides from dried Saccharomyces cerevisiae fermentation solubles (Bio-Mos added at 0.2% of the diet), and 4) the negative control diet with mannanoligosaccharides from the cell walls of yeast (Safmannan added at 0.1% of the diet). For d 0 to 7, ADG and F/G was no better (P>0.36) for pigs fed the diet with antibiotic than the other treatments. However, this lack of difference was the result of good growth performance among pigs fed the diets with mannanoligosaccharides vs the negative control (i.e., P<0.07 for ADG and P<0.02 for F/G). For d 0 to 21 and overall (d 0 to 35), ADG was greater (P<0.02) for pigs fed diets with antibiotic vs the other treatments and for pigs fed mannanoligosaccharides vs the negative control (P<0.04). However, there were no differences in ADG, ADFI, or F/G among pigs fed diets with the two different sources of mannanoligosaccharides (P>0.49). Analyses of fecal samples indicated no effect of any treatment on fecal concentrations of total coliforms and E. coli (P>0.54). In conclusion, we did observe a positive effect of the mannanoligosaccharides on growth performance of weanling pigs that was intermediate to the nonmedicated and medicated control diets. Those effects were not associated with changes in coliform concentrations in the feces and were most likely caused by other physiological effects.