The study evaluated the influence of dietary supplementation with nano-encapsulated cumin oil, B. subtilis, or a combination of both to mitigate the impacts of heat stress on the performance and health of growing rabbits. In the feeding trial, a total of eighty-four growing New Zealand White (35 days, 781.3 ± 1.8 g average body weight) were randomly distributed in a completely randomized design into four groups; each had 21 rabbits arranged in 7 replicates (3 rabbits each). The experiment lasted 42 days (35 days to 77 days). Growing rabbits received a basal diet (first group, CON) without additives, while the other groups were supplemented with nano-encapsulated cumin oil (NECO, 200 mg/kg), B. subtilis (BS, 500 mg/kg), or both (BSNO, 500 mg BS plus 200 mg/kg NECO). Adding BSNO significantly enhanced body weight gain, carcass weight, and feed conversion ratio and reduced mortality rate (p < 0.05). Additionally, the BSNO enhanced digestive system performance by increasing the secretion of trypsin enzymes, as well as nutrient digestibility, especially for protein and fiber (p < 0.05). Supplementing BSNO enhanced oxidative stability and immunity via higher levels of superoxide dismutase (SOD), IgA, IgG, triiodothyronine (T3), thyroxine (T4) and lower malondialdehyde (MDA) levels (p < 0.05), indicating a better ability to adapt to stress. During the examination of gut health, pathogenic bacteria counts decreased, as well as down-regulation of interleukin-6 (IL-6) gene expression and up-regulation of cationic amino acid transporter-1 (CAT-1), interleukin-10 (IL-10), and mucin-2 (MUC-2) gene expression (p < 0.05), supporting gut integrity. This study highlights the potential of mixing nano-encapsulated cumin oil and B. subtilis in growing rabbits’ diets as an effective strategy to counteract the negative effects of heat stress caused by high ambient temperatures.

Heat stress in broilers disrupts vital functions, leading to decreased performance and overall health, as well as significant economic losses. To alleviate the negative influences of heat stress on broilers, several strategies have been employed, most notably dietary supplementation. The present study investigates the impact of supplementing nano-encapsulated probiotics and alpha-lipoic acid on growth performance, gut microbiota, immune response, and gene expression in heat-stressed broilers. A total of 360 one-day-old male Ross 308 broiler chicks were randomly assigned to four groups (6 replicate per group): a control group fed a basal corn-soybean diet (CON) and three treatment groups receiving the basal diet supplemented with nano-encapsulated probiotics (NC-P, 1 × 10⁶ CFU/g of diet), alpha-lipoic acid (ALA, 300 mg/kg), or their combination (CNPA). Supplementing the CNPA mixture significantly improved growth performance, as evidenced by enhanced feed conversion ratio, body weight gain, carcass traits, and up-regulated IGF-1 gene expression (P < 0.05). Moreover, the mixture decreases cholesterol, triglycerides, LDL-cholesterol, and uric acid levels (P < 0.05). CNPA mixture improves the ability to adjust heat stress by enhancing antioxidant status, via increased superoxide dismutase (SOD), and decreased malondialdehyde (MDA, P < 0.05). Furthermore, CNPA mixture reduces pathogenic bacteria and up-regulates the expression of cationic amino acid transporter-1 (CAT-1, P < 0.05) and mucin 2 (MUC-2) genes, enhancing intestinal health. Overall, the combination of nano-encapsulated probiotics with α-lipoic acid effectively mitigates heat stress impacts in broilers.

The purpose of this study was to evaluate the effect of early feeding with probiotic-fermented feed on growth performance, intestinal microbiota structure, immune responses, and gene expression. Two hundred and forty-one-day-old African ostrich chicks were randomly divided into three groups (eight replicates/group). The control group was fed a basal diet (CON), whereas the PELF3 and PELF6 groups were fed the probiotic-fermented feed for the first 3 or 6 days post-hatching, respectively, after which, all chicks were fed the basal diet for 56 days. The results showed that adding PELF3 or PELF6 significantly enhanced body weight gain and the feed conversion ratio. Chicks fed PELF had higher superoxide dismutase (SOD, p < 0.05), immunoglobulin A (IgA), and IL-10 levels and lower IL-6 and malondialdehyde (MDA, p < 0.05) levels than those fed CON. Plasma cholesterol, low-density lipoprotein (LDL), creatinine, uric acid, and alanine aminotransferase (ALT) levels decreased; however, high-density lipoprotein (HDL, p < 0.05) levels increased in the PELF groups. The addition of PELF reduced the pathogenic counts in the intestines of chicks (p < 0.05). Moreover, increased expression of IGF-1 and MUC-2 genes was observed in the PELF3 and PELF6 groups, whereas the expression of SLC15A1 increased in the PELF6 group. In conclusion, growth performance, immunity, gene expression, oxidative stability, and gut microbiota can all be significantly enhanced by early feeding with PELF. This study demonstrated an effective technique for applying early feeding of PELF in ostrich chicks.