Abstract

This study aimed to examine the effects of supplementation with the microalgae Arthrospira (Spirulina) platensis and Haematococcus pluvialis on the production and quality of eggs from Hy-Line Brown laying hens under heat stress conditions. The research was conducted at the Canchones campus of Arturo Prat University, located in the Atacama Desert, Chile. A total of 125 hens aged 22 to 36 weeks were used in an experimental design with five treatments: a) a control group without microalgae, b) groups with 1% spirulina and 20, 40, or 60 ppm of natural astaxanthin from Haematococcus pluvialis, and c) a group with 1% spirulina. The results showed that microalgae supplementation significantly improved egg production and live weight gain in the laying hens, particularly under heat stress conditions. Higher levels of dietary antioxidants correlated with better performance, surpassing the control group and industry benchmarks. Yolk color, which was strongly correlated with carotenoid content, increased significantly with higher levels of microalgae supplementation. The group with the highest concentrations of spirulina and astaxanthin produced the most intense yolk color and the highest carotenoid content. This study highlights the potential of microalgae supplementation to improve egg production and quality in cage-free laying hens, especially in environments with heat stress.