How does selenium benefit animal performance?

Agricultural species are subject to challenging conditions, from a variety of stressors and as such selenium is essential to maintain performance. Providing organic selenium helps building reserves, important in the effective fight against oxidative stress. Supplementation helps to ensure the efficacy of the antioxidant system, as well as improving gut health and immunity.
In poultry production, a combination of these effects means that selenium improves both growth rate and feed conversion (FCR). Organic Se supplementation increases Se levels in chicken muscle, increasing antioxidant status. When chicken meat is stored drip loss and lipid peroxidation are reduced, improving quality and increasing yield.
A reduction in mortality is also observed, explained in part by enhanced immunocompetence. Supplementation with organic selenium has also been shown to have an anti-viral effect, as well as protecting against damage to the intestine by pathogens. By increasing resistance to disease, energy for the immune system is spared – also improving FCR.
Through its implication in antioxidant processes, selenium is involved in various aspects of broiler breeder effi cacy, from male fertility to hatchability, embryogenesis, and chick early performance. As Se is transferred from breeders to offspring, day-old-chicks which parents are fed organic selenium benefit higher Se availability, superior antioxidant capacities and thus exhibit a better start.
In layers organic selenium has been shown to maintain egg production during the peak period. Also decreasing feed consumption, increasing egg weight: including shell, white and yolk. The quality of both table and hatching eggs are enhanced by dietary selenium supplementation. The increase in Haugh units has been shown to help maintain albumin quality/freshness during storage.
Source: eBook on Selenium supported by Adisseo