15 September 2025

4 minute read

By: Sarah Mikesell

In swine production, oxidative stress may be an invisible challenge, but its effects are far from subtle. From decreased feed efficiency to suppressed growth rates, it quietly chips away at productivity.

Dr. Marlin Hoogland, veterinarian and Director of Innovation and Research at Feedworks, says producers and veterinarians alike should be on alert for this metabolic imbalance, especially during the most physiologically demanding times in a pig’s life.

What causes oxidative stress?

“The easiest way to think about oxidative stress is that there's an imbalance in what normally happens in the body through metabolism or immune functions,” said Hoogland. “You get the normal production of reactive oxygen species - those are oxidants. The body has a normal mechanism through vitamins and enzymes that counterbalances that and manages the oxidative stress - those oxidants - through antioxidants.”

Essentially, oxidative stress results when the body generates more oxidants than it can neutralize. The result? A systemic imbalance that can compromise productivity, reproductive performance and immune resilience.

“Oxidative stress can be damaging. Outwardly, a producer or veterinarian might notice it from loss of productivity, predominantly in the form of growth rates and feed efficiencies. When it gets to a point, you could have loss of total productivity in terms of animals,” he explained. “So we can see oxidative stress lead to fewer total born and/or born alive. When it gets to that level, it certainly impacts in the total throughput within a system.”

Major stress events ramp up oxidative stress

While oxidative stress can affect pigs at all life stages, there are particular windows of vulnerability where its effects are magnified.

“For the piglet side, there's significant oxidative stress as they go through different time periods in their life, particularly weaning is a major stressful event,” he said. “What we see later on in life is oxidative stress really ramps up in the later grow-finish when they're really putting on a lot of muscle tissue – a high growth rate.”

Sows aren’t immune either. In fact, oxidative stress often hits hardest during late gestation and lactation.

“If you look at the sow in particular, she's going to experience a lot of her oxidative stress more in late gestation and certainly into lactation. This is when she's going through big changes with a lot of embryo growth and a lot of tissue mass with the fetuses developing,” said Hoogland.

Environmental conditions and disease pressure can further tip the scales toward imbalance.

“During high physiological stress and environmental stress, we do see more oxidative stress,” Hoogland said. “This could be associated with disease. It’s another thing that's coming into their life that really can overwhelm the immune system.”

Seasonal factors play a role too, with summer heat amplifying oxidative stress in both sows and grow-finish pigs. However, Hoogland warns not to overlook wintertime risks.

“Certainly, we know with pigs, the two main things that drive some of that would be the heat itself. Sows in particular in the summer deal with more heat stress,” he said. “However, if you're looking at what we deal with in the swine industry with a lot of viruses, PRRS in particular has not gotten better. It seems to have gotten more challenging for veterinarians and producers.”

Once considered a seasonal threat, PRRS has evolved into a year-round concern, compounding oxidative stress with its immunosuppressive effects.

“Some of the breaks we're seeing June and July, they're happening in locations that haven't had viral breaks in 10 to 12 years,” said Hoogland. “So, it's very frustrating that we're seeing this virus continue to push the way it has. And not only in grow-finish where it's been a significant challenge but on sow farms for sure.”

Nutritional strategies to mitigate oxidative stress

To mitigate oxidative stress, nutritional strategies have become a cornerstone of Feedworks’ approach. Among them is the use of polyphenol-based products that support antioxidant function at the cellular level.

“From the standpoint of what we're looking at with oxidative stress, we're focused on some of the antioxidant measures that we can take,” he said. “There's a group of polyphenols, Elife is the product that Feedworks has had the most success with, and it has worked really well with our customers.”

According to Hoogland, Elife’s effectiveness lies in its ability to restore the body’s own antioxidant reserves.

“What we're finding is that it has the ability to regenerate some of the vitamin E within the pig and vitamin E is a key part of the vitamin systems that fight with antioxidants,” he said. “So using things like these polyphenols and looking at levels of other things in the diet, like the vitamin E already in the diet and vitamin A, we are looking at where some of the antioxidants are at – this is important with what we're learning about oxidative stress.”

In the ever-complex landscape of modern swine production, oxidative stress is an often-overlooked threat that demands attention. As Hoogland explains, the solution starts with awareness—and continues with strategic nutrition that supports pigs during their most stressful moments.