article · British Poultry Science
Research evaluated how dietary probiotic supplementation and stocking density affect growth performance and immune responses in broiler chickens reared in hot climate conditions. A trial of 1,800 day-old chicks tested three concentrations of a Bacillus subtilis probiotic alongside two stocking densities of 12 and 18 birds per square metre. Neither probiotic inclusion nor stocking density caused significant alterations in live body weight, feed consumption, or feed conversion ratio. Probiotic supplementation did, however, significantly enhance serum immunoglobulin M concentrations and cell-mediated immunity by six weeks of age. While levels of immunoglobulin A and immunoglobulin Y also increased, these improvements were not statistically significant, and organ weights for the spleen and bursa of Fabricius remained unaffected. Overall, the feed additive strengthened specific immune responses without penalising broiler growth under elevated temperatures.
Poultry raised in high-temperature environments often face physiological stress that can impair immune competence. Demonstrating that dietary Bacillus subtilis enhances cellular and humoral immune parameters without hindering feed conversion or growth rates provides valuable insight into nutritional management. This helps producers support bird health and resilience under heat stress without compromising standard production yields.
The findings are relevant to poultry feed manufacturers and broiler producers seeking functional additives to support flock immunity in hot climates. Because the trial tested direct dietary inclusion of a Bacillus subtilis strain at practical stocking densities, the research represents an applied and tested intervention. Adoption would focus on integrating the supplement into commercial broiler diets to maintain immune health without disrupting feed efficiency.
AI-generated from the published abstract. Always read the original work before citing.
1. The objective of the study was to evaluate the potential effects of dietary probiotic supplementation and stocking density and their interaction on growth performance, humoral and cellular immune responses of broiler chickens raised under hot climate conditions. 2. A total of 1800 1-d-old unsexed broiler chicks (Ross 308) were allocated in a completely randomised 3 × 2 factorial design, with three concentrations of dietary probiotic (0, 200 and 400 mg/kg) containing 4 × 10<sup>9</sup> cfu/g of Bacillus subtilis and two stocking densities (12 or 18 birds/m<sup>2</sup>) in a total of 6 treatment subgroups. 3. Dietary probiotic and stocking density had no significant effect on live body weight, feed consumption and feed conversion ratio. 4. Dietary probiotic supplementation had a positive effect on serum immunoglobulin M (IgM) and cell-mediated immunity when compared to the control at 6 weeks of age, whereas serum immunoglobulin A (IgA) and immunoglobulin Y (IgY) were improved, but not significantly so. Dietary probiotic and stocking density had no effect on relative weights of the bursa of Fabricius and spleen. 5. Dietary probiotic supplementation had a positive significant effect on serum IgM concentration and cell-mediated immunity without penalising growth performance in broilers raised under high ambient temperature.
This page summarises published work. The authoritative version sits with the publisher.
DOI: 10.1080/00071668.2017.1332405
Is something wrong with this record? Report it or request removal.
Discussion
Have you built on this work, tried to replicate it, or seen it applied in practice? Share what you know. Verified researchers and MARATTO™ domain experts can open a discussion, and any member can reply. Contributions are reviewed before they appear.
No discussion yet. Open the first thread.
New to MARATTO™? Create a free account.
