Comparative study on the nutrient digestibility of diets containing brewer’s yeast products processed by different techniques fed to T-cannulated growing pigs

Abstract

To investigate the effect of processing techniques on the nutrient digestibility of diets containing whole brewer’s yeast products, i.e., directly dried (BDY); thermal-induced autolyzed (AYC); and fine-ground yeast (GDY) prepared from the same yeast filter mud, 3 diets, each contains one of the 3 products with similar energy and protein concentration, were formulated, respectively. Six growing pigs (bodyweight = 25.1 ± 2.0 kg) fitted with T-cannula at terminal ileum were allotted to a replicated 3 × 3 Latin square with 3 diets and 3 periods. The ileal digesta and feces were collected in each period and the digestibility coefficients were calculated using the concentration of nutrients and marker (Cr2O3) in tested diet, ileal digesta and feces. The results indicated that the processing methods significantly affect the digestion of most of diet nutrients especially in the foregut of pigs. Compared with BDY diet, the digestion of DM, CP, energy, Ca, total non-starch polysaccharides (TNSP), insoluble non-starch polysaccharides (INSP), total and insoluble mannose, insoluble glucose, and total and 12 individual amino acids was significantly increased in GDY diet in the foregut of pigs (P < 0.05). The AYC diet exhibited higher (P < 0.05) digestibility coefficients of CP, energy, INSP, total and insoluble mannose, and total and 15 individual amino acids than that of BDY diet in the foregut of pigs. The effect of processing methods on nutrient digestion in the hindgut of pigs was diminished with increased (P < 0.05) the digestion of OM, energy, TNSP and INSP in GDY diet and energy, TNSP, INSP and insoluble mannose in AYC diet. After properly processed, products prepared from whole yeast cells exhibited high potential in pig feeding as a major protein ingredient.