Background Isoacids are the product of branched-chain amino acid fermentation and are naturally producedin the hindgut by microbial fermentation. In ruminants, supplementation of isoacids as a feed additive improvesfi...Background Isoacids are the product of branched-chain amino acid fermentation and are naturally producedin the hindgut by microbial fermentation. In ruminants, supplementation of isoacids as a feed additive improvesfiber utilization, with a positive impact on animal productivity. However, information on how isoacids impact nutrientdigestibility in swine is limited. The objective of this experiment was to determine the optimal inclusion levelof an isoacid blend product based on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD)of nutrients and fermentation products in the ileal digesta and feces of growing pigs fed a corn-soybean meal diet.Methods Twelve ileal cannulated pigs (20.9 ± 0.6 kg) were used in a 5-period crossover design with 6 diets and 2replicate pigs in each period. Dietary treatments consisted of increasing levels (0%, 0.5%, 0.75%, 1%, 1.25%, and 1.5%)of an isoacid blend (isobutyrate, isovalerate, and 2-methyl butyrate, 1:1:1) added to a corn-soybean meal basal diet.Each experimental period consisted of 14 d: 10 d for acclimatization to the diets, 2 d for fecal collection, and 2 dfor digesta collection.Results Isoacids supplementation quadratically improved the AID of hemicellulose (P < 0.05) and tended to improvethe AID of crude fiber (P < 0.1). The AID of most indispensable amino acids (except Met + Cys, Trp, and Val) as wellas the ATTD of crude protein, gross energy, neutral detergent fiber, and hemicellulose improved or tended to improvelinear or quadratically (P < 0.05 or P < 0.1). In addition, the ATTD values of Arg, His, Ile, Leu, Met + Cys, Phe, Thr, and Valincreased quadratically (P < 0.05). Collectively, 1% of isoacids inclusion resulted in the greatest response. Furthermore,isoacids supplementation tended to increase (P = 0.071, quadratically) the concentration of ammonia and decreased(P < 0.05) the concentrations of acetic acid and total volatile fatty acids with a tendency to decrease (P = 0.064) isovalericacid in the ileal digesta. In fecal samples, the proportion of acetic acid decreased (P < 0.05) quadratically, whereas the proportionsof propionic, valeric, and caproic acids tended to increase linearly and/or quadratically (P < 0.1).Conclusions Isoacids supplementation at 1% in swine diets can improve nutrient digestibility, particularly aminoacids and fiber at the ileal level and ATTD of crude protein, gross energy, and hemicellulose.展开更多
基金financially supported by Zinpro Corporation(grant number:SA2300029,2022–2025).
文摘Background Isoacids are the product of branched-chain amino acid fermentation and are naturally producedin the hindgut by microbial fermentation. In ruminants, supplementation of isoacids as a feed additive improvesfiber utilization, with a positive impact on animal productivity. However, information on how isoacids impact nutrientdigestibility in swine is limited. The objective of this experiment was to determine the optimal inclusion levelof an isoacid blend product based on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD)of nutrients and fermentation products in the ileal digesta and feces of growing pigs fed a corn-soybean meal diet.Methods Twelve ileal cannulated pigs (20.9 ± 0.6 kg) were used in a 5-period crossover design with 6 diets and 2replicate pigs in each period. Dietary treatments consisted of increasing levels (0%, 0.5%, 0.75%, 1%, 1.25%, and 1.5%)of an isoacid blend (isobutyrate, isovalerate, and 2-methyl butyrate, 1:1:1) added to a corn-soybean meal basal diet.Each experimental period consisted of 14 d: 10 d for acclimatization to the diets, 2 d for fecal collection, and 2 dfor digesta collection.Results Isoacids supplementation quadratically improved the AID of hemicellulose (P < 0.05) and tended to improvethe AID of crude fiber (P < 0.1). The AID of most indispensable amino acids (except Met + Cys, Trp, and Val) as wellas the ATTD of crude protein, gross energy, neutral detergent fiber, and hemicellulose improved or tended to improvelinear or quadratically (P < 0.05 or P < 0.1). In addition, the ATTD values of Arg, His, Ile, Leu, Met + Cys, Phe, Thr, and Valincreased quadratically (P < 0.05). Collectively, 1% of isoacids inclusion resulted in the greatest response. Furthermore,isoacids supplementation tended to increase (P = 0.071, quadratically) the concentration of ammonia and decreased(P < 0.05) the concentrations of acetic acid and total volatile fatty acids with a tendency to decrease (P = 0.064) isovalericacid in the ileal digesta. In fecal samples, the proportion of acetic acid decreased (P < 0.05) quadratically, whereas the proportionsof propionic, valeric, and caproic acids tended to increase linearly and/or quadratically (P < 0.1).Conclusions Isoacids supplementation at 1% in swine diets can improve nutrient digestibility, particularly aminoacids and fiber at the ileal level and ATTD of crude protein, gross energy, and hemicellulose.
