Avilamycin B

This study was designed to study the effect of diet supplementation with an organic acids-based formulation (OABF) on luminal- and mucosa-associated bacteria, concentration of volatile fatty acids (VFA), microbial glycolytic enzyme activity and expression of mucin 2 (MUC2), immunoglobulin A (IgA) and tight junction protein, i.e., zonula occludens-1 (ZO1), zonula occludens-2 (ZO2), claudin-1 (CLDN1), claudin-5 (CLDN5) and occludin (OCLN), genes at the ileal and cecal level. A 2 × 2 factorial design was used having OABF inclusion and avilamycin as main factors. Subsequently, 544 day-old male Cobb broilers were allocated in the following 4 treatments, each with 8 replicates: no additions (CON), 1 g OABF/kg diet (OA), 2.5 mg avilamycin/kg diet (AV) and combination of OA and AV (OAAV). The trial lasted for 42 days. In the ileum, OAAV resulted in lower mucosa-associated total bacteria levels (P O × A = 0.028) compared with AV. In addition, ileal digesta levels of Clostridium perfringens subgroup were decreased by avilamycin (P A = 0.045). Inclusion of OABF stimulated the activity of microbial glycolytic enzymes, whereas avilamycin resulted in lower acetate (P A = 0.021) and higher butyrate (P A = 0.010) molar ratios. Expression of ZO1 and CLDN5 was down-regulated by both OABF (P O = 0.016 and P O = 0.003, respectively) and avilamycin (P A = 0.016 and P A = 0.001, respectively). In addition, CLDN1 was down-regulated in AV compared with CON (P O × A = 0.012). Furthermore, OABF down-regulated MUC2 (P O = 0.027), whereas avilamycin down-regulated nuclear factor kappa B subunit 1 (NFKB1) (P A = 0.024), toll-like receptor 2 family member B (TLR2B) (P A = 0.011) and toll-like receptor 4 (TLR4) (P A = 0.014) expression. In the ceca, OABF inclusion increased digesta levels of Clostridium coccoides (P O = 0.018) and Clostridium leptum (P O = 0.040) subgroups, while it up-regulated MUC2 expression (P O = 0.014). Avilamycin (P A = 0.044) and interaction (P O × A < 0.001) effects for IgA expression were noted, with CON having higher IgA expression compared with AV. In conclusion, new findings regarding OABF inclusion effects on an array of relevant biomarkers for broiler gut ecology have been reported and discussed in parallel with avilamycin effects used as a positive control. This new knowledge is expected to provide a response baseline for follow up trials under various stress and challenge conditions.

1. This study aimed to determine the effect of avilamycin (AGP) and a multi-strain Bacillus probiotic (DFM) on the performance, gut histology and microbiology of broilers fed on a mixed grain diet. 2. A total of 800 chicks were allocated to four treatments: a control diet, control+AGP, control+DFM, or control+AGP+DFM. Bodyweight, feed intake and FCR were measured at d 0, 21 and 42. Samples were taken at d42 to determine villus height (VH), crypt depth (CD) and ratio (VH:CD). Mucosal E. coli and Lactobacilli counts were measured at d42. 3. At d42, DFM and AGP+DFM significantly increased weight over the control, with AGP returning an intermediate value. FCR followed a similar pattern. DFM and AGP+DFM significantly increased VH and CD in all gut sections compared to the control. 4. DFM and AGP+DFM reduced E. coli counts compared to control, with AGP reducing caecal counts only, while Lactobacilli counts were increased. 5. Divergent histology and microbiology between treatments highlight the different modes of action of AGP and DFM for improving broiler growth and feed efficiency.

An experiment was conducted to investigate the supplementation of two commercially available multistrain probiotics as an alternative to antibiotics on growth performance, intestinal morphology, lipid oxidation and ileal microflora in broiler chickens. A total of 280-day-old ROSS 308 mixed-sex broiler chickens with an average initial body weight of 42 ± 0.5 g were randomly divided into four treatments with five replicate cages of 14 birds each cage in a completely randomized design and fed with the following diets for 42 day: (a) control (CON) (antibiotic-free diet), (b) antibiotic (ANT) (CON + Avilamycin 150 g/ton feed), (c) probiotic A (CON + Protexin® 150 g/ton feed) and (d) probiotic B (CON + Bio-Poul® 200 g/ton feed). The results showed the broilers fed the ANT diet had greater average daily gain than broilers fed the CON diet during day 1-14 (p < 0.05). At day 42, two birds were randomly selected per replicate for evaluation intestinal morphology, lipid oxidation and ileal microflora. birds fed diet supplemented with probiotic A and probiotic B increased villus height and goblet cells numbers in the jejunum and villus height to crypt depth ratio and villus height in the ileum as compared to birds fed CON diet (p < 0.05). The malondialdehyde value was reduced (p < 0.05) in the ANT, probiotic B and probiotic A groups compared with the CON group. The Lactobacillus population was increased and Clostridium spp. population decreased in the ileum of broilers fed diets containing the probiotic B and probiotic A compared with those fed CON diet (p < 0.05). The results from this study indicate that the probiotic A (Protexin® ) and probiotic B (Bio-Poul® ) used in this trial may serve as alternatives to ANT.