Feed pigs less fat, more fiber to slow growth

As work at meat processing plants slows during COVID-19, hog producers may want to feed pigs cheaper diets and hold them longer.

University of Missouri Extension swine nutritionist Marcia Shannon says producers can feed more fiber and less fat to slow growth.

“This is a good time to move to feeding low-energy, high-fiber diets with an adjusted lysine-to-calorie ratio and remove any growth-promoting technologies,” Shannon says.

Fiber, a poor source of energy, is cheap and fills pigs up. Pigs might eat more, but the feed is cheaper than traditional mixes, she says. Fiber is the carbohydrate part of the diet that can’t be digested by enzymes secreted in the pig’s intestinal tract.

Shannon suggests replacing all protein and fat sources with soy hulls, wheat middling, wheat bran, corn gluten or sugar beet pulp, but probably not distillers grains because those sources are drying up as well due to lower gas prices and reduced ethanol production. Currently, most other fiber sources are easy to find in Missouri.

One drawback is that confinement pits will fill with more manure when feeding high-fiber diets. “This means confinement producers will need to monitor their manure management more closely,” she says.

The goal is to increase the neutral detergent fiber (NDF) content of the diet to 20%. Pigs fed NDF content of 10-15% will eat more to meet their daily energy requirement. As NDF nears 20%, pigs get too full to eat, Shannon says.

Also, remove additives such as copper sulfate and extra protein packs that raise the cost of the diet. “Don’t add any extra fat. Cheapen those diets up,” she says.

Doing this will increase time in the finisher by as much as four to seven days. If producers remove growth promoters, they might be able to add two or three days more on top of that. The younger the pigs are, the easier it is to slow growth.

Show-pig producers have used this growth technique successfully for many years to continue to show in certain weight classes at fairs, she says.

Shannon says she does not recall anything that has closed processing plants for this length of time. Even a day’s closing for an ice storm can cause a backlog in the food supply chain.

“If some of these meat processing plants stay closed for an extended period, we’ll see a backlog. Some estimates are four days of backlog for every day the plant is closed,” she says.

Two years ago, pork producers dealt with piglet losses from porcine epidemic diarrhea virus, another coronavirus. Unlike COVID-19, PEDV does not affect humans. However, both will have huge impacts on the swine industry through disruptions in the food supply chain.

Shannon recommends related resources at pork.org/public-health/what-you-need-to-know-about-covid-19(opens in new window). MU Extension also lists numerous COVID-19 resources at extension2.missouri.edu/covid-19-resources-public.