Efficacy of a novel multi-enzyme feed additive on growth performance, nutrient digestibility, and gut microbiome of weanling pigs fed corn-wheat or wheat-barley-based diet

Abstract

One-hundred-and-ninety-two weanling pigs (6.7 kg body weight) were used to evaluate the impact of a carbohydrases-protease enzyme complex (CPEC) on growth performance, nutrient digestibility, and gut microbiome. Pigs were assigned to one of the four dietary treatments for 42 d according to a 2 × 2 factorial arrangement of diet type (low fiber [LF] or high fiber [HF]) and CPEC supplementation (0 or 170 mg/kg diet). The LF diet was prepared as corn-wheat-based diet while the HF diet was wheat-barley-based and contained wheat middlings and canola meal. Each dietary treatment consisted of 12 replicate pens (six replicates per gender) and four pigs per replicate pen. Over the 42-d period, there was no interaction between diet type and CPEC supplementation on growth performance indices of pigs. Dietary addition of CPEC improved (P < 0.05) the body weight of pigs at days 28 and 42 and the gain-to-feed ratio of pigs from days 0 to 14. During the entire experimental period, dietary CPEC supplementation improved (P < 0.05) the average daily gain and gain-to-feed ratio of pigs. There were interactions between diet type and CPEC supplementation on apparent total tract digestibility (ATTD) of dry matter (DM; P < 0.01), gross energy (GE; P < 0.01), and neutral detergent fiber (NDF; P < 0.05) at d 42. Dietary CPEC addition improved (P < 0.05) ATTD of DM, GE, and NDF in the HF diets. At day 43, dietary CPEC addition resulted in improved (P < 0.05) apparent ileal digestibility (AID) of NDF and interactions (P < 0.05) between diet type and CPEC supplementation on AID of DM and crude fiber. Alpha diversity indices including phylogenetic diversity and observed amplicon sequence variants of fecal microbiome increased (P < 0.05) by the addition of CPEC to the HF diets on day 42. An interaction (P < 0.05) between diet type and CPEC addition on Bray-Curtis dissimilarity index and Unweighted UniFrac distances was observed on day 42. In conclusion, CPEC improved weanling pig performance and feed efficiency, especially in wheat-barley diets, while dietary fiber composition had a more significant impact on fecal microbial communities than CPEC administration. The results of this study underscores carbohydrase's potential to boost pig performance without major microbiome changes.

Keywords: carbohydrase; fiber; growth performance; gut microbiome; weanling pigs.

Figure 1.

Alpha diversity indices of microbiome in feces from weanling pigs at day 28: Shannon index (A); evenness index (B); phylogenetic diversity (C); observed amplicon sequence variant (ASV; D). Dietary treatment consisted of two diet types (low fiber [LF] and high fiber [HF]) without or with the addition of carbohydrase-protease enzyme complex (CPEC) at 170 mg/kg of diet (n = 12; ***P < 0.001; **P < 0.01; *P < 0.05; †P < 0.10).

Figure 2.

Alpha diversity indices of microbiome in feces from weanling pigs at day 42: Shannon index (A); evenness index (B); phylogenetic diversity (C); observed amplicon sequence variant (ASV; D). Dietary treatment consisted of two diet types [low fiber (LF) and high fiber (HF)] without or with the addition of carbohydrase-protease enzyme complex (CPEC) at 170 mg/kg of diet (n = 12; ***P < 0.001; **P < 0.01; *P < 0.05; †P < 0.10).

Figure 3.

Principal coordinates (PC) plots for beta diversity of microbiome in feces from weanling pigs at day 14: Bray-Curtis dissimilarity index (A); unweighted UniFrac distances (B); weighted UniFrac distances (C). Dietary treatments consisted of two diet types (low fiber [LF] and high fiber [HF]) with the addition of carbohydrase-protease enzyme complex at 0 g/kg (LF—and HF −) or 170 mg/kg (LF + and HF +) to the diets (n = 12).

Figure 4.

Principal coordinates (PC) plots for beta diversity of microbiome in feces from weanling pigs at day 28: Bray-Curtis dissimilarity index (A); unweighted UniFrac distances (B); weighted UniFrac distances (C). Dietary treatments consisted of two diet types (low fiber [LF] and high fiber [HF]) with the addition of carbohydrase-protease enzyme complex at 0 g/kg (LF—and HF −) or 170 mg/kg (LF + and HF +) to the diets (n = 12).

Figure 5.

Principal coordinates (PC) plots for beta diversity of microbiome in feces from weanling pigs at day 42: Bray-Curtis dissimilarity index (A); unweighted UniFrac distances (B); weighted UniFrac distances (C). Dietary treatments consisted of two diet types (low fiber [LF] and high fiber [HF]) with the addition of carbohydrase-protease enzyme complex at 0 g/kg (LF—and HF -) or 170 mg/kg (LF + and HF +) to the diets (n = 12).