Alfalfa hay and dehydrated alfalfa included in winter rations can help keep mature hogs warm during winter's chill. That's because pigs produce more body heat when they consume and digest alfalfa vs. corn.
Grow/finish diets can contain at least 10 percent alfalfa, say Duane Reese and Murray Danielson, with the University of Nebraska Extension Service. This could be particularly helpful for pigs raised in hoop structures.
If nutritional scours are a problem or edema disease exists, the animal scientists say you can incorporate 10 percent alfalfa hay in starter diets. Beyond that use, alfalfa products' fiber content and low metabolic energy does not fit well with young pigs' needs.
For lactating sows, alfalfa should be limited to 10 percent of the ration. In gestation, "alfalfa haylage can represent up to 40 percent of a sow's diet, on a 100 percent dry matter basis, without affecting reproductive performance," says Danielson.
"Because of the wide calcium-to-phosphorous ratio in alfalfa (6:1), you must be careful when formulating these diets," says Reese. "You can not substitute alfalfa for grain on a pound-for-pound basis."
Only use high quality alfalfa – harvested in the pre-bloom or early bloom stage. It will have a higher crude protein and lower fiber content than more mature alfalfa, Danielson notes.