Bio-functional and nutritional effects of Spirulina algae in commercial laying hens.

SUMMARY: Spirulina platensis (SP) has been identified as a 'functional food' in nutrition research. This review evaluates the potential of SP as a feed ingredient for laying hens, and to determine whether it can be classified as a functional food. We conducted a review study to assess the impact of Spirulina inclusion on the production of laying hens and the quality of eggs. Literatures have been shown improvement in performance and egg production along with immunomodulating, hepatoprotective and antioxidant effects of SP in laying hens. Additionally, it exhibits significant hypocholesterolemic activity and can enhance egg quality and egg yolk pigmentation. The studies explored a range of Spirulina inclusion levels, from 0.1% to 15%. Incorporating 1–3% SP in laying hens' diet can improve productive performance and internal egg quality parameters across published research. However, since the results were conflicting, we conducted a meta-analysis review using statistical data from various studies. This meta-analysis aims to assess the impact of Spirulina inclusion on laying hens production, and yolk colour. The Scopus, PubMed, Web of Science, and Google Scholar databases were searched from 1990 to 2024. The results showed that the use of Spirulina significantly reduced egg weight (standard difference in means (SDM): 0.223; I2: 92.073; 95% CI: −0.429, −0.018; P: 0.033) and yolk colour (SDM: −0.574; I2: 86.987; 95% CI: −0.930, −0.218; P: 0.002) in the control groups compared to the Spirulina-fed birds. However, egg mass (SDM: −0.345; I2: 88.094; 95% CI: −0.692, −0.002; P: 0.051), feed intake (SDM: −0.153; I2: 94.165; 95% CI: −0.475, 0.169; P: 0.352), and feed conversion ratio (FCR) (SDM: 0.106; I2: 86.604; 95% CI: −0.089, −0.302; P: 0.287) were not significantly affected by dietary Spirulina. Therefore, this meta-analysis concludes that Spirulina inclusion, at the doses tested, does not affect the main production performance parameters of laying hens. [ABSTRACT FROM AUTHOR]