Impact of Chlorella vulgaris Intake Levels on Performance Parameters and Blood Health Markers in Broiler Chickens

This systematic review examines the effects of cumulative Chlorella vulgaris intake levels on broiler chickens, focusing on growth performance and systemic health markers. The review establishes a clear relationship between cumulative C. vulgaris intake and significant outcomes in poultry nutrition and health through a detailed analysis of various studies. The correlation analysis revealed that cumulative C. vulgaris intake levels ranging from 0.8 to 718 g/bird influenced growth rates and feed efficiency, following sigmoid models. Specifically, intakes of approximately 20 g/bird maximized final body weight (R-2 = 0.616, p < 0.001), cumulative body weight gain (R-2 = 0.627, p < 0.001) and daily weight gain (R-2 = 0.639, p < 0.001). The feed conversion ratio also improved with increasing C. vulgaris intakes up to this level, although this was non-significant (R-2 = 0.289, p = 0.117). In addition, similar cumulative C. vulgaris intake levels impacted plasma health markers in broilers, leading to reductions in triacylglycerols and cholesterol and improvements in immunoglobulin levels. These findings underscore the importance of carefully calibrated C. vulgaris supplementation strategies to optimise poultry growth and health without adverse effects. Future research should focus on refining C. vulgaris dosing guidelines and further exploring its long-term effects and mechanisms of action to enhance poultry health and production sustainability.