Physiological and meat quality responses to phased and continuous hydrolyzed yeast (<i>Saccharomyces cerevisiae</i>) supplementation in densely stocked broiler chickens.
Hydrolyzed yeast supplementation affects physiological outcomes in broilers but does not enhance growth performance compared to antibiotics.
Where it sits
this study against the rest of the thymulin (facteur thymique serique) corpusSummary and findings
This study assessed the effects of phased versus continuous hydrolyzed yeast supplementation on broiler chickens. It measured growth performance, physiological indices, and meat quality. Continuous antibiotic growth promoter supplementation showed superior growth metrics compared to hydrolyzed yeast strategies.
Abstract
The transition toward antibiotic-free broiler production has intensified interest in precision nutritional strategies that enhance bird resilience under intensive rearing conditions. Hydrolyzed yeast (HY, <i>Saccharomyces cerevisiae</i>) delivers a complex array of bioactive compounds that support gut function and immune regulation; however, the benefits of HY are likely growth-stage dependent, and continuous supplementation may be economically inefficient. This study evaluated the physiological, gut microbial, and meat quality responses of densely stocked Ross 308 broilers to phase-targeted HY feeding strategies: continuous HY supplementation and HY supplementation restricted to the starter, grower, or finisher phase. Growth performance, haemobiochemical indices, carcass and meat quality, and caecal microbiota composition were assessed. Continuous AGP supplementation yielded the highest (P < 0.05) feed intake, body weight gain, and feed efficiency. In comparison, HY feeding strategies did not improve growth performance (P > 0.05) relative to antibiotics, but did influence physiological and meat quality outcomes when applied continuously or in a phased manner. Phase-specific HY supplementation induced distinct physiological responses (P < 0.05), including changes in nitrogen-related and liver-associated blood indices, with negative impacts on carcass or meat quality. Caecal microbial alpha diversity remained unchanged across treatments (P > 0.05), though selective shifts in microbial composition occurred. Overall, few significant differences were detected between phased and continuous HY supplementation across the measured outcomes, suggesting that phased HY supplementation warrants further investigation as a practical nutritional strategy for antibiotic-free intensive broiler production.
Background
The study investigates nutritional strategies to enhance resilience in broiler chickens under intensive rearing, particularly as antibiotic-free production becomes more prevalent. Hydrolyzed yeast is considered for its potential benefits on gut function and immune regulation, but its effectiveness may vary with growth stages. Understanding the optimal supplementation strategy could inform economically viable practices.
Methods
The study involved densely stocked Ross 308 broilers and compared continuous versus phased hydrolyzed yeast supplementation. Outcomes measured included growth performance, haemobiochemical indices, carcass and meat quality, and caecal microbiota composition. The study also compared these strategies to continuous antibiotic growth promoter supplementation.
Results
Continuous antibiotic growth promoter supplementation resulted in the highest feed intake, body weight gain, and feed efficiency (P < 0.05). Hydrolyzed yeast strategies did not significantly improve growth performance compared to antibiotics (P > 0.05), but phase-specific supplementation induced distinct physiological responses (P < 0.05). Caecal microbial alpha diversity was unchanged, though selective microbial shifts were noted.
Interpretation
The findings suggest that while hydrolyzed yeast supplementation influences physiological and microbial outcomes, it does not match the growth performance benefits of antibiotics. The lack of significant differences between phased and continuous yeast supplementation indicates potential for phased strategies, but further research is needed to establish economic and practical viability.
Key findings
- Continuous AGP supplementation yielded the highest feed intake, body weight gain, and feed efficiency (P < 0.05).
- HY feeding strategies did not improve growth performance relative to antibiotics (P > 0.05).
- Phase-specific HY supplementation induced distinct physiological responses (P < 0.05).
- Caecal microbial alpha diversity remained unchanged across treatments (P > 0.05).
- Selective shifts in microbial composition occurred with HY supplementation.
Limitations
- Study conducted on broiler chickens only.
- Economic efficiency of supplementation strategies not fully addressed.
- No direct human applicability.
- Short-term study duration.