Selenium review puts antioxidant nutrition back in focus

A new review in Animals pulls together the evidence on selenium’s role in antioxidant defense across cattle, pigs, and small ruminants, arguing that the trace mineral remains central to immune function, reproduction, growth, and resilience during periods of metabolic or environmental stress. The authors describe selenium’s biological role through selenoproteins such as glutathione peroxidases and thioredoxin reductases, and they highlight a practical challenge for veterinarians and nutrition teams: selenium intake depends heavily on regional soil and forage levels, the chemical form used in feed, and a narrow margin between deficiency and excess. In the US, FDA regulations generally cap selenium in complete feed for cattle, sheep, swine, chickens, turkeys, and ducks at 0.3 ppm. (law.cornell.edu)

Why it matters: For veterinary professionals, the review is a reminder that selenium status still deserves attention in herd and flock health plans, especially around calving, lambing, kidding, weaning, heat stress, and other high-demand periods when oxidative stress can undermine fertility, immune performance, and productivity. Background literature and veterinary references tie selenium deficiency to white muscle disease and other production and reproductive problems, while also showing that response to supplementation varies by species and by selenium source, with organic forms often discussed as more bioavailable than inorganic forms in some settings. A second MDPI paper, in poultry rather than ruminants or pigs, adds to the broader selenium literature by reporting dose-dependent effects of selenomethionine on rooster semen quality during short-term liquid storage, reinforcing selenium’s relevance to reproductive oxidative stress research. (merckvetmanual.com)

What to watch: Expect more discussion around species-specific supplementation strategies, source selection, and monitoring protocols as researchers try to define when selenium support improves performance without pushing animals toward toxicity. (extension.oregonstate.edu)