New Monounsaturated Soybean Oil Works Well In Pig Diets

By Lauren Quinn

Adding a fat source to the traditional corn-soy swine diet is common practice, but the type of fat can make a difference both for growing pigs and carcass quality. Polyunsaturated fats, the primary type in distillers dried grains with solubles (DDGS), can reduce fat quality and complicate processing of pork bellies and bacon.

High oleic soybeans, high in monounsaturated fats, create a stable oil valued by the food industry and nutritionists concerned with heart health. And according to new University of Illinois research supported by the United Soybean Board, high oleic soybean oil performs well as a DDGS substitute both for growing pigs and pork processing characteristics.

The research team fed growing pigs a standard corn-soybean meal finishing diet, plus DDGS or high oleic soybean oil (HOSO) as a fat source. They included DDGS at 25% and the HOSO at 2%, 4%, or 6% of the complete diet.

"When we fed the high oleic soybean oil, we saw reduced average daily feed intake, which makes some sense because as we include more energy in diets, pigs will usually consume less. The pigs were more efficient in converting that diet into pounds of gain," says Bailey Harsh, assistant professor in the Department of Animal Sciences at Illinois and lead researcher on two new studies in the Journal of Animal Science.

In addition to growth performance, the first study focused on overall carcass characteristics.

"When we think about what is important to producers or to the standard commercial finisher, it's how those pigs perform and yield in terms of carcass weight and fat free lean. We wanted to make sure all of that was in one study so a producer could look at that and say, well, here's the impact on my bottom line," Harsh says.

The researchers found minimal differences in primal weights across the diets, but the overall trend showed greater fat thickness and reductions in fat-free lean as the HOSO percentage went up.

"As we added more fat to the diet, moving from 2% to 6%, the pigs grew more efficiently but were a little bit fatter and their carcass cutability dropped just a little bit, but not enough that we would be too concerned," Harsh says.

A second study focused solely on loin and belly quality, including palatability, from the same set of pigs. Drilling down allowed the researchers to evaluate whether the diets affected the highest-value primal cuts.