Subclinical necrotic enteritis (NE) is primarily caused by the gram-positive bacterium, Clostridium perfringens (Cp). The trend towards removal of in

Necrotic enteritis (NE) remains a major challenge in broiler production following the withdrawal of antibiotic growth promoters. In response, phytogenic feed additives (PFA) have emerged as promising alternatives. This study investigated the efficacy of a phytogenic blend (PHB) containing thymol, oleic acid, capric acid, and refined sunflower fat in mitigating NE-associated compromise in performance, gut health, liveability, oxidative stress, and excreta biomarkers of intestinal inflammation in broilers. A total of 450 Cobb 500 D-old chicks were randomly allocated to three dietary groups: NC (non-challenged control), CC (NE-challenged control), and PHB (NE-challenged birds fed 0.01% phytogenic blend), with 10 replicates of 15 birds each. Birds in the CC and PHB groups were orally inoculated with Eimeria spp. on d9 and Clostridium perfringens at d14 to induce NE. Birds were fed starter (d0-10), grower (d10-24), and finisher (d24-35) diets. During the starter phase (d0-10), birds fed PHB had significantly lower body weight gain (BWG) (P < 0.05) and higher FCR (P < 0.05) compared to the controls. NE challenge significantly (P < 0.05) reduced BWG, feed intake (FI), and increased FCR during d10-24, d10-35, and d0-35. During d10-35, PHB supplementation significantly improved BWG and FI and reduced FCR (P < 0.05) compared with the CC group. While NE challenge impaired gut morphology by reducing villus height (VH), VH/crypt depth (CD), and increasing intestinal lesion scores (P < 0.05), birds in the PHB group showed reduced duodenal lesions and increased VH/CD (P < 0.05) compared to CC birds. Furthermore, NE-related mortality and inflammation markers in excreta, such as calprotectin, fibronectin, and lipocalin-2, were significantly higher (P < 0.05) in NE-challenged birds compared to the NC group. Supplementation with PHB shifted liveability, and excreta calprotectin and fibronectin values towards the NC group (P > 0.05). These findings suggest that PHB supplementation improves intestinal histomorphology and liveability, reduces NE-related mortality, and alleviates inflammation, which together may contribute to the enhanced performance of the PHB-supplemented birds.

Organic acids are well known for their antibacterial and antifungal effects, but their potential efficacy against coccidian parasites remains underexplored. The aim of the study was to evaluate the effects of a butyric and valeric glyceride blend (BVg) in mitigating the adverse impacts of coccidiosis in broiler chickens. A total of 960 mixed-sex d-old Cobb 500 chicks were randomly allocated to five treatments with 12 replicates, each containing 16 birds. The five treatments were: non-challenged control (NC); coccidiosis challenged control (CC); CC+ BVg (BV; 500, 500, and 250 g/ton in the starter, grower and finisher phases, respectively); CC + anticoccidial salinomycin, 60 g/t (AntS); and CC + salinomycin + BVg (ABV). Coccidiosis challenge was induced on d9 via oral gavage with Eimeria spp. Performance parameters were determined on days 8, 19, 28 and 35. Lesion scoring and ileal digesta sampling was performed on d16 and excreta samples were collected on d20 for oocyst enumeration. One-way ANOVA followed by Tukey's test to separate means was applied to normally distributed data, while the Kruskal-Wallis test was used for data that did not meet the normality assumption. The results showed that BVg supplementation significantly improved feed conversion ratio (FCR) during starter (d0-8), grower (d8-19) and overall study (d0-35) periods compared to the CC group (P < 0.05). BVg supplementation also numerically improved flock uniformity and significantly reduced oocyst counts (P < 0.05) and duodenal lesions (P < 0.05) compared to the CC group. Additionally, BVg inclusion shifted hock burn lesions and tibia length values from the CC group towards the NC and ABV groups, respectively. These findings suggest that BVg may offer a promising nutritional strategy to mitigate the adverse effects of coccidiosis, reducing oocyst loads and gut lesions, while supporting the feed efficiency and hock burn lesions of broiler chickens.

Necrotic enteritis (NE) is a major poultry disease affecting profitability. Managing NE has become harder due to restrictions on in-feed antibiotics, which traditionally support gut health and production in broilers. To address this, a study was conducted to evaluate the effect of xylanase (Xy) and Bacillus subtilis (Pb) supplementation in a corn-soybean-based diet on the intestinal health of broiler chickens under NE challenge. A total of 630-d-old mixed-sex Cobb 500 broiler chicks were assigned to a 2 × 2 + 1 factorial design, giving five treatments: NE challenge without additives (CC); NE challenge with Xy (0.03%) (Xy); NE challenge with Pb (0.05%) (Pb); NE challenge with Xy (0.03%) and Pb (0.05%) (Xy+Pb); and non-challenge birds without additives (NC). NE challenge significantly increased serum fluorescein isothiocyanate dextran (FITC-d; P < 0.05), as well as ileal lactate, succinate, and total short-chain fatty acids (SCFA) concentrations (P < 0.05), while downregulating immunoglobulin A (IgA) and mucin 2 (MUC2) (P < 0.05). Pairwise permutational multivariate analysis of variance (PERMANOVA) showed distinct microbial profiles between the NC and CC groups (P < 0.05; unweighted and weighted UniFrac). Supplementation of Pb altered beta diversity compared with the CC, showing greater distances (weighted UniFrac; P < 0.05). It also shifted the relative abundances of Ruminococcaceae and Faecalibacterium towards NC levels, with no significant differences from either CC or NC groups (P > 0.05). Dietary Pb increased (P < 0.05) ileal lactate and total SCFA concentrations, irrespective of NE challenge. Dietary Xy significantly reduced Lachnospiraceae UCG 010 relative to CC birds (P < 0.05). It also showed tendencies towards lowering caecal propionate, iso-butyrate, and iso-valeric concentrations, and decreasing interferon gamma (IFN-γ) gene expression (P < 0.1). Overall, these results indicate that both Xy and Pb may help mitigate the adverse effects of NE by modulating gut microbiota and, thus, gut health. However, Pb showed greater and more consistent effects on SCFA production, microbiota diversity, and beneficial bacteria populations, highlighting its greater efficacy under NE challenge.