Effects of single or combined supplementation of probiotics and prebiotics on ruminal fermentation, ruminal bacteria and total tract digestion in lambs

Abstract

Probiotics (beneficial living microorganisms) and prebiotics (fiber, cell wall material, mannan polysaccharides derived through hydrolysis of yeast cell walls) are feed additives that may have beneficial extra-nutritional pharmaceutical and/or metabolic effects on livestock health and growth performance. Due to differences in modes of action, their combination may have additive effects on digestion and fermentation in ruminants. For this reason, four male lambs (Dorper; 45.1 ± 2.7 kg initial weight) with “T” cannulas in the rumen were used in a 4 × 4 Latin square experiment to evaluate the effects of single or combined supplementation of probiotics and prebiotics on ruminal fermentation and total tract digestion. Dietary treatments consisted of a cracked corn-based basal finishing diet supplemented with: 1) no eubiotics (Control); 2) 3 g of live saccharomyces cerevisiae /lamb/day (2 × 1010 cfu/g, SC), 3) 3 g of mannan oligosaccharide (30 % w/w) plus b-glucans (20 % w/w) /lamb/day (MOS), and 4) combination of 1.5 g/day SC and 1.5 g/day MOS (SCMOS). Compared to controls, SC supplementation tended (P = 0.09) to increase total tract digestion of DM and OM, and increased (P < 0.05) total tract digestion of N, starch, and digestible energy (DE). Compared with Control, MOS increased total tract NDF (7.9 %, P < 0.01) and starch digestion, and tended to improve total tract digestion of (P = 0.09), N (P = 0.07), and DE diet (P = 0.07). Compared to Control, SCMOS increased (P ≤ 0.03) total tract digestion of all fractions evaluated, including a 4.2 % (P < 0.01) increase in DE. Although lambs fed MOS had greater (6.7 %, P = 0.02) NDF digestion than those fed SC, differences in total tract digestion of DM, OM, N, starch and DE diet were not appreciable (P ≥ 0.24). Compared with SC and MOS fed separately, SCMOS increased (P < 0.05) total tract digestion of N and NDF. Supplemental MOS and SCMOS tended (P = 0.09) to promote greater ruminal pH than the Control. Combining supplementation decreased (P ≤ 0.03) the molar proportion of butyrate and ruminal ammonia, consistent with decreased of ruminal concentration of C. aminophilum. Probiotic/prebiotic supplementation of high-energy lamb finishing diets enhances total tract digestion and digestible energy. Reduction hyper-ammonia producing ruminal bacteria with the combination probiotic plus prebiotic may contribute to improved dietary N economy. The combination of probiotics with prebiotics potentiate positive effects on digestion and ruminal fermentation in lambs fed a high-energy diets.