Two experiments were conducted to assess the effects of dietary supplementation of an exogenous multi-enzyme (EME) preparation to 35- to 65-d-old piglets on apparent total tract digestibility (ATTD), growth performance, digestive enzyme activities, and selected microbial populations in feces. In Exp.1, twenty eight 35-d-old piglets were randomly assigned to 7 dietary treatments (corn-soybean based diet supplemented with 0, 100, 150, 200, 250, 300, or 350 mg EME/kg) in a 14-d digestibility study. Piglets fed the diets supplemented with EME had greater ATTD of DM, CP, and GE (P = 0.001, 0.005, and 0.009, respectively) than those fed the diet without EME supplementation, and those ATTD values increased linearly and quadratically (P < 0.001) as the levels of supplemented EME increased. In Exp. 2, two hundred 35-d-old weanling piglets were randomly allocated to 20 pens. The pens were then randomly assigned to 5 dietary treatments (corn-soybean based diet supplemented with 0, 100, 150, 250, or 350 mg EME/kg) with 4 pens per treatment in a 30-d feeding experiment. Piglets has ad libitum access to diets and water, and they were weighed at the beginning (35-d-old), middle (50-d-old), and end (65-d-old) of the experiment. Fecal samples were grabbed directly from the rectum and digesta samples from duodenum, jejunum, and ileum were taken at the end of the experiment for the analysis of selected bacteria populations and digestive-enzyme activities. The ADG and ADFI tended to be greater with the increasing levels of supplemented EME in both periods, whereas G:F was improved (P = 0.012 and 0.017) by EME in the period of 35 to 50 d of age and during the overall experimental period. Furthermore, inclusion of EME in diet increased the counts of Lactobacilli spp. and Bacillus subtilis spp., but reduced the populations of Salmonella spp. and Escherichia coli spp. in the feces. The EME supplementation also enhanced (P < 0.05) the activities of amylase, lipase, and protease in the small intestine. The growth performance-enhancing effects of EME appeared to be mediated by the age of the piglet and the dose of EME used. Supplementation of corn-soybean meal diets for 35- to 65-d-old piglets with EME has a potential to enhance gut health condition, increase nutrient digestion, and increase growth performance.

To explore the effects of supplementing a basal diet with green sweet sorghum stalks on the gut microbiota in geese, one hundred and twenty 28 day old geese were divided into two groups. Group 1 was fed a basal diet and group 2 was fed 92% of the same basal diet with green sweet sorghum stalks ad libitum for 42 days. Three male geese from each group were killed at 70 days old, four gastrointestinal tract segments (duodenum, jejunum, ileum, and caecum) were collected, and the hypervariable V4 region of the bacterial 16S rRNA gene was sequenced. There were obvious changes of microbiome in the caecum compared with the other three intestinal segments after green sweet sorghum stalks were added to the diet. Group 2 had significantly higher alpha diversity in the caecum compared with group 1 (P <0.05). The phyla of bacterial communities in the caecum differed. Group 2 had more abundant Bacteroidetes and Firmicutes, but Proteobacteria were more abundant in group 1. At genus level, Bacteroides was more prevalent in group 2, as were Prevotella and YRC22 (P <0.05). Functional analysis revealed that the carbohydrate metabolism, membrane transport, endocrine system and digestive system metabolic pathways were overrepresented in group 2. In conclusion, caecal microbes might play an important role in digesting green sweet sorghum stalks in geese.Keywords: caecum, goose, microbiome, microbial diversity