Schizochytrium sp. Dietary supplementation modify Toll-like receptor 4 (TLR4) transcriptional regulation in monocytes and neutrophils of dairy goats.

Abstract

Animals protect themselves against pathogens or abiotic factors by innate or adaptive mechanisms. Long-chain polyunsaturated fatty acids (ω3) of microalgae modify both human and mice' immune systems resulting in a beneficial balance between pro-inflammatory and anti-inflammatory pathways. However, scarce information exists on their impact on lactating animals' immunity. The objective of this study was to investigate the impact of dietary inclusion of Schizochytrium sp. (rich in docosapentaenoic and docosahexaenoic acid), on the expression of several genes involved in the innate immunity of goats. Twenty-four dairy goats were divided into four homogeneous sub-groups (n=6). All goats were fed individually with alfalfa hay and concentrate. The concentrate of the control group (CON) had no microalgae while those of the treated groups were supplemented daily with 20 (ALG20), 40 (ALG40), and 60 (ALG60) g Schizochytrium sp. Monocytes and neutrophils were isolated from goats' blood in the 20th, 40th, and 60th days from the beginning of the experimental period. The relative transcript levels of TLR4, MYD88, MAPK, IRF3, IFNG, and pro-inflammatory cytokines (IL1B, IL2, IL8, TNF), and chemokines (CCL5 and CXCL16) were decreased in monocytes of microalgae treated goats compared to the CON. In contrast, MAPK and IL1B relative transcript levels were increased in neutrophils of ALG40 and ALG60 groups. In conclusion, the supplementation of goats' diet with 20g Schizochytrium sp. resulted in a downregulation of the pro-inflammatory transcriptions, and following further research could be considered as a sustainable alternative strategy to improve immune function.