A microbial muramidase improves growth performance and reduces inflammatory cell infiltration in the intestine of broilers chickens under Eimeria and Clostridium perfringens challenge.

The objective of the present studies was to evaluate muramidase (MUR) supplementation in broilers under Eimeria and/or Clostridium perfringens challenge. For this, 2 experiments were conducted. Experiment 1. A total of 256 one-day old male Cobb 500 chicks were placed in battery cages in a completely randomized design, with 5 treatment groups, 7 replicate cages per treatment and 8 birds per cage. The treatments were: nonchallenged control (NC), challenged control (CC), CC + MUR at 25,000 or 35,000 LSU(F)/kg, and CC + Enramycin at 10 ppm (positive control-PC). Challenge consisted of 15× the recommended dose of coccidiosis vaccine at placement, and Clostridium perfringens (108 CFU/bird) inoculation at 10, 11, and 12 d. Macro and microscopic evaluation, immunohistochemistry, and gene expression were evaluated at 7, 14, 21, and 28 d of age. Experiment 2. A total of 1,120 one-day old male Cobb 500 chicks were placed in floor pens with fresh litter in a completely randomized design, with 4 treatment groups, 8 replicate pens per treatment, and 35 birds per pen. The treatments were: Control, supplementation of MUR at 25,000 or 45,000 LSU(F)/kg, and a positive control (basal diet plus Enramycin). At 10, 11, and 12 d of the experiment all the birds were inoculated by oral gavage with a fresh broth culture of a field isolate Clostridium perfringens (0.5 mL containing 106 CFU/bird). It was observed that in Experiment 1 MUR supplementation reduced the infiltration of macrophages and CD8+ lymphocytes in the liver and ileum of infected birds, downregulated IL-8 and upregulated IL-10 expression. In Experiment 2, MUR linearly improved the growth performance of the birds, increased breast meat yield, and improved absorption capacity. MUR supplementation elicited an anti-inflammatory response in birds undergoing a NE challenge model that may explain the improved growth performance of supplemented birds.

Effect of microbial muramidase supplementation in diets formulated with different fiber profiles for broiler chickens raised under various coccidiosis management programs.

The objective of the present study was to determine the effects of muramidase (MUR) supplemented to diets formulated with different fiber sources (inert or fermentable) on the growth performance and intestinal parameters of broiler chickens raised under different coccidiosis management programs. A total of 2,208 male Ross 308 broilers were housed in 96 floor pens and distributed into a 2 × 3 × 2 factorial arrangement in a completely randomized block design with 2 sources of fiber (inert or fermentable fiber), 3 coccidiosis management programs (none, vaccine, or Salinomycin), and with or without supplementation of MUR at 35,000 LSU(F)/kg of diet. Body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were calculated for each feeding phase (d 0-14, d 14-28, d 28-36) and from d 0 to 36. On d 17 and d 31, samples were taken to analyze several parameters. The experimental data were analyzed with 3-way ANOVA considering the main effect of fiber source, coccidiosis program, inclusion of MUR, and their interactions using JMP 16.2. 16S rDNA sequencing of the ileal and cecal content was carried out to analyze the diversity, composition, and predictive function of the microbiota. From d 0 to 36, BWG increased (P = 0.05) by 2.5% in birds supplemented with Salinomycin (P = 0.04), and by 2.2% with MUR supplementation (P = 0.02). Salinomycin and MUR improved FCR (P < 0.0001) when compared to nonsupplemented birds. The supplementation of MUR, regardless of the coccidiosis management program, reduced the intestinal viscosity (P = 0.03). On d 31, the highest blood concentration of carotenoids was observed in chickens fed diets supplemented with Salinomycin. MUR led to significant changes in the diversity, composition, and predictive function of the ileal microbiota, mainly on d 31. The results observed herein further explain the positive effects of MUR on the growth performance of broiler chickens.

Effect of dietary crude protein level on growth performance, blood characteristics, and indicators of intestinal health in weanling pigs.

An experiment was conducted to test the hypothesis that reducing crude protein (CP) in starter diets for pigs reduces post-weaning diarrhea and improves intestinal health. In total, 180 weanling pigs were allotted to 3 diets containing 22, 19, or 16% CP. Fecal scores were visually assessed every other day. Blood samples were collected from 1 pig per pen on days 1, 6, 13, 20, and 27, and 1 pig per pen was euthanized on day 12. Results indicated that reducing dietary CP reduced (P < 0.01) overall average daily gain, gain to feed ratio, final body weight, and fecal scores of pigs. Pigs fed the 16% CP diet had reduced (P < 0.01) serum albumin compared with pigs fed other diets. Blood urea nitrogen, haptoglobin, interleukin-1ß, and interleukin-6 concentrations in serum were greatest (P < 0.01) on day 13, whereas tumor necrosis factor-α and interleukin-10 concentrations were greatest (P < 0.01) on day 6. Villus height in the jejunum increased (P < 0.05) and crypt depth in the ileum was reduced (P < 0.01) if the 19% CP diet was fed to pigs compared with the 22% CP diet. A reduction (P < 0.05) in mRNA abundance of interferon-γ, chemokine ligand 10, occludin, trefoil factor-2, trefoil factor-3, and mucin 2 was observed when pigs were fed diets with 16% CP. In conclusion, reducing CP in diets for weanling pigs reduces fecal score and expression of genes associated with inflammation.

Evaluation of dietary supplementation of a novel microbial muramidase on gastrointestinal functionality and growth performance in broiler chickens.

This study was conducted to assess the effect of dietary supplementation of Muramidase 007 to broiler chickens on gastrointestinal functionality, evaluating growth performance, apparent ileal digestibility, intestinal histomorphology, vitamin A in plasma and cecal microbiota. A total of 480 one-day male chicks (Ross 308) were distributed in 16 pens allocated in 2 experimental diets: the control diet (CTR) without feed enzymes, coccidiostat or growth promoters, and the experimental diet (MUR): CTR supplemented with 35,000 units (LSU(F))/kg of the Muramidase 007. Digesta and tissue samples were obtained on days 9 and 36 of the study. A lower feed conversion ratio was observed in the MUR treatment. Apparent ileal digestibility of DM, organic matter and energy were improved by Muramidase 007. It was also observed that MUR improved digestibility of total fatty acids, mono-unsaturated fatty acids and poly-unsaturated fatty acids, and content of vitamin A in plasma at day 9 (P < 0.05). Histomorphological analysis of jejunum samples revealed no differences in the villus height or crypt depth; but a higher number of goblet cells and intraepithelial lymphocytes at day 36 with MUR. No differences were observed in plate counts of enterobacteria or Lactobacillus along the gastrointestinal tract, neither on the cecal short-chain fatty acids. An statistical trend was observed for reduction of cecal clostridia at day 9 for MUR. Analysis of cecal microbiota structure by 16S rRNA gene sequencing revealed relevant changes correlated to age. At day 9, broilers receiving MUR showed decreased alpha diversity compared to CTR that was not detected at day 36. Changes in specific taxonomic groups with an increase in Lactobacillus genus were identified. In conclusion, evaluation of the variables in this study indicates that dietary Muramidase 007 contributes to improve feed conversation ratio and gastrointestinal function in broiler chickens. Effects could have been mediated by slight shifts observed in the intestinal microbiota. More studies are guaranteed to fully understand the mechanisms involved.