In this feeding trial, a total of 500 Cobb-500 broiler (day-old) chickens were randomly assigned to a control dietary treatment (basal diet only) or supplemented with crushed seeds of coriander (Coriandrum sativum L.), black cumin (Bunium persicum (Boiss.) B. Fedtsch) and ajwain (Carum copticum L.) (at 10 mg/kg each) and exogenous protease (30,000 IU/kg), respectively, in order to assess the effect of the diets on nutrient digestibility, bone strength and gut morphology. The results indicated that the digestibility coefficients of crude protein, crude fat, nitrogen-free extract, calcium and phosphorous were significantly (p < 0.05) higher in protease-treated birds compared to the control. The tibia bone weight was improved (p = 0.03) in Carum copticum, Coriandrum sativum and protease-supplemented birds. Bone length increased (p < 0.05) in protease and Carum copticum fed broilers, while the robusticity index decreased (p < 0.05) in all treatments. Villus length and width decreased (p < 0.05) in Carum copticum and Bunium persicum fed broilers. From findings, it was demonstrated that exogenous protease shows comparatively better results in improving bone quality, ileal digestibility and villus morphology in broilers.

The current study investigated the potential of selenium nanoparticles (SeNPs) and mannan-oligosaccharide (MOS) supplementation in ameliorating high stocking density (HSD) stress in broilers. A total of 392 day-old male chicks were divided into seven groups with eight replicates (n = 7): NSD [basal diet (BD) + normal stocking density: 10 bird/m²], HSD [BD + high stocking density: 16 bird/m²], Se–HSD [BD + Selenium (Se) 0.15 mg/kg], MOS–HSD (BD + MOS 5 gm/kg), Se–MOS–HSD (BD + Se 0.15 mg/kg and MOS 5 gm/kg), SeNPs–HSD (BD + SeNPs 0.15 mg/kg) and SeNPs–MOS–HSD (BD + SeNPs 0.15 mg/kg and MOS-5 gm/kg). HSD stress decreased (p < 0.05) weekly body weight and body weight gain and increased (p < 0.05) FCR compared to the NSD group. Supplementation with SeNPs and the SeNPs–MOS combination improved (p < 0.05) the weekly body weight and FCR in HSD-stressed broilers during the 5th and 6th weeks. On day 21, HSD stress decreased (p < 0.05) duodenal villus height (VH) and villus surface area (VSA) and increased (p < 0.05) serum corticosterone and cholesterol compared to the NSD group. Supplementation with the SeNPs–MOS combination increased (p < 0.05) duodenal VH and VH:CD, and jejunal total goblet cell (TGC) density and decreased (p < 0.05) serum corticosterone and cholesterol and ileal intra-epithelial lymphocyte (IEL) density in HSD-stressed broilers. On day 42, HSD stress decreased (p < 0.05) duodenal and jejunal VH, VSA, VH:CD, PCNA positive cell density and TGC density, Ileal VSA and TGC density, and increased (p < 0.05) serum cholesterol and ileal IEL density compared to the NSD group. Supplementation with the SeNPs–MOS combination increased (p < 0.05) spleen and bursa absolute weights, duodenal VH, VSA, VH:CD, PCNA positive cell density and jejunal VH, VH:CD, and decreased (p < 0.05) serum cholesterol and ileal IEL density in HSD-stressed broilers. Our findings signify that HSD is stressful for broilers particularly during the finishing phase. Supplementation with the SeNPs–MOS combination mitigated HSD stress by partially improving the gut microarchitecture, gut barrier function and performance indicators.

In this study, we investigated broiler growth traits, intestinal health and immune aggregates in response to supplementation of Origanum vulgare and Cinnamomum verum, citric acid and malic acid in drinking water at varying levels and durations on broiler. We randomly allocated 140 day-old broilers into four (4) groups, with each group having seven replicates (n = 5). A basal diet and water were provided to all the groups ad libitum in accordance with standard farming practices. Keeping group I as the control, group II was supplemented with 1 mL/3.3 L of water for 1–4 days, 1 mL/4 L from 15–18 days and 1 mL/4 L water from 26–29 days. Group III and IV were supplemented with 1 mL/4 L of water and 1 mL/6 L of water for 35 days, respectively. After the completion of the trial (day 35), two broilers per replicate (14 birds per group) were slaughtered to sample the visceral organs. The results demonstrated that the feed conversion ratio (FCR) and body weight gain improved (p ≤ 0.05) during the fourth and fifth week of the trial in group III in comparison to the control group. Although the small intestine villus height and villus-height-to-crypt-depth ratio improved (p ≤ 0.05) in group III, the muscularis externa thickness of the ileum was highest (p ≤ 0.05) in the control group. Similarly, the lymphatic follicular and nodular area of the immune organs improved (p ≤ 0.05) in group III. In all segments of the small intestine (duodenal, jejunal and ileal), the number of acidic and total goblet cells was highest (p ≤ 0.05) in group II. In conclusion, dietary Origanum vulgare, Cinnamomum verum, citric acid and malic acid at the dose of 1 mL/4 L of drinking water (group III) was the most effective in improving the growth performance, gut development and associated immune components in broilers.