Diet medication and beta-glucanase affect ileal digesta soluble beta-glucan molecular weight, carbohydrate fermentation, and performance of coccidiosis vaccinated broiler chickens given wheat-based diets

Exogenous enzymes as alternatives to feed antibiotics in poultry has become an emerging research area with the emergence of antibiotic resistance. The objective was to evaluate the effects of diet medication (antibiotics) and β-glucanase (BGase) on digesta soluble β-glucan depolymerization, carbohydrate fermentation, and performance of coccidiosis-vaccinated broiler chickens fed wheat-based diets. A total of 1,782 broilers were raised on litter floor pens, and each treatment was assigned to 1 pen in each of the 9 rooms. The 3 dietary treatments were based on wheat as the sole grain (control, control + medication and control + 0.1% BGase), and the birds were fed the respective treatments ad libitum from 0 to 33 d. Treatments were arranged in a randomized complete block design and analyzed as a one-way ANOVA. Beta-glucanase reduced the peak molecular weight, weight average molecular weight (Mw) and maximum molecular weight for the smallest 10% β-glucan molecules (MW-10%) in ileal digesta at d 11 and 33, whereas diet medication reduced Mw and MW-10% at d 33 compared to the control (P < 0.01). Beta-glucanase and medication reduced the ileal viscosity at d 11 compared to the control (P = 0.010). Ileal propionic acid concentration at d 11 and caecal total SCFA, acetic, and butyric acid concentrations at d 33 were lower in the BGase-supplemented diet than in the control (P < 0.05). The BGase-added diet had higher duodenal pH compared to the control at d 33 (P = 0.026). The effect of medication on carbohydrate fermentation was minimal. Diet medication increased weight gain after d 11, whereas BGase increased the gain for the total trial period compared to the control (P < 0.001). Feed intake was not affected by the dietary treatment. Medication and BGase improved feed efficiency after d 11 compared to the control (P < 0.001). The response to diet medication was larger than BGase, considering weight gain and feed efficiency after d 11 (P < 0.001). In conclusion, diet medication and BGase depolymerized high molecular weight ileal soluble β-glucan and increased overall bird performance. Dietary BGase may benefit bird health in broilers fed wheat-based diets without medication.

Hulless barley and beta-glucanase levels in the diet affect the performance of coccidiosis-challenged broiler chickens in an age-dependent manner

Diet β-glucanase (BGase) depolymerizes viscous β-glucan into lower molecular weight carbohydrates, which might act as a prebiotic in chickens exposed to enteric disease. Coccidiosis-challenged broiler chickens were fed graded levels of hulless barley (HB) and BGase to determine their effects on growth performance. Broilers were fed high β-glucan HB (CDC Fibar; 0, 30, and 60% replacing wheat) and BGase (Econase GT 200P; 0, 0.01, and 0.1%) in a 3 × 3 factorial arrangement. A total of 5,346 broilers were raised in litter floor pens and vaccinated for coccidiosis in feed and water on day 5. Each treatment was assigned to 1 pen (66 birds) in each of 9 rooms. Statistical significance was set at P ≤ 0.05. Overall, HB decreased body weight gain (BWG) and increased feed: gain ratio (F:G) of broilers. From day 0 to 11, BGase did not affect BWG and F:G, at the 0 and 30% HB. However, at 60% HB, the 0.01% BGase improved them, and the 0.1% BGase had no effect on BWG and increased F:G. For the day 22 to 32 and 0 to 32 periods, BGase did not affect BWG for 0 and 30% HB levels, but for the 60% HB, both BGase levels increased gain. The 0.1% level of BGase resulted in the lowest F:G for all HB levels, with the degree of response increasing with HB. No interaction was found for ileal digesta viscosity at day 11; the level of HB did not affect viscosity, but both levels of BGase decreased viscosity. At day 33, BGase did not affect viscosity at 0 and 30% HB levels, but viscosity was lowered for the 0.1% BGase treatment at the 60% HB level. In conclusion, HB reduced broiler performance, and BGase alleviated most but not all the effects. In young birds fed 60% HB, 0.1% BGase did not impact BWG and increased F:G.

Effect of live yeast Saccharomyces cerevisiae supplementation on the performance and cecum microbial profile of suckling piglets

One mechanism through which S. cerevisiae may improve the performance of pigs is by altering the composition of the gut microbiota, a response that may be enhanced by early postnatal supplementation of probiotics. To test this hypothesis, newborn piglets (16 piglets/group) were treated with either S. cerevisiae yeast (5 x 109 cfu/pig: Low) or (2.5 x 1010 cfu/piglet: High) or equivalent volume of sterile water (Control) by oral gavage every other day starting from day 1 of age until weaning (28±1 days of age). Piglet body weight was recorded on days 1, 3, 7, 10, 17, 24 and 28 and average daily gain (ADG) calculated for the total period. At weaning, piglets were euthanized to collect cecum content for microbial profiling by sequencing of the 16S rRNA gene. ADG was higher in both Low and High yeast groups than in Control group (P<0.05). Alpha diversity analyses indicated a more diverse microbiota in the Control group compared with Low yeast group; the High yeast being intermediate (P < 0.01). Similarly, Beta diversity analyses indicated differences among treatments (P = 0.03), mainly between Low yeast and Control groups (P = 0.02). The sparse Partial Least Squares Discriminant Analysis (sPLS-DA) indicated that Control group was discriminated by a higher abundance of Veillonella, Dorea, Oscillospira and Clostridium; Low yeast treated pigs by higher Blautia, Collinsella and Eubacterium; and High yeast treated pigs by higher Eubacterium, Anaerostipes, Parabacteroides, Mogibacterium and Phascolarctobacterium. Partial Least Squares (PLS) analysis showed that piglet ADG was positively correlated with genus Prevotella in High yeast group. Yeast supplementation significantly affected microbial diversity in cecal contents of suckling piglets associated with an improvement of short chain fatty acid producing bacteria in a dose-dependent manner. In conclusion, yeast treatment improved piglet performance and shaped the piglet cecum microbiota composition in a dose dependent way.

Effects of bacterial colonization on the porcine intestinal proteome

The gastrointestinal tract harbors a complex community of bacteria, of which many may be beneficial. Studies of germ-free animal models have shown that the gastrointestinal microbiota not only assists in making nutrients available for the host but also contributes to intestinal health and development. We studied small intestinal protein expression patterns in gnotobiotic pigs maintained germ-free, or monoassociated with either Lactobacillus fermentum or non-pathogenic Escherichia coli. A common reference design in combination with labeling with stable isobaric tags allowed the individual comparison of 12 animals. Our results showed that bacterial colonization differentially affected mechanisms such as proteolysis, epithelial proliferation, and lipid metabolism, which is in good agreement with previous studies of other germ-free animal models. We have also found that E. coli has a profound effect on actin remodeling and intestinal proliferation, which may be related to stimulated migration and turnover of enterocytes. Regulations related to L. fermentum colonization involved individual markers for immunoregulatory mechanisms.