Vital Vitamin E
Vitamin E and its teammate selenium work to protect cell membranes
from destruction.
When a newborn calf has trouble standing to nurse and, if it walks at all, it does so with a stiff or crooked gait, the first culprit that comes to mind is typically white-muscle disease. Bob Larson, veterinarian and professor of production medicine at Kansas State University (K-State), says the effects of white-muscle disease are seen primarily in skeletal and heart muscle tissue.
Once diagnosed, recovery is unlikely.
“Calves with white-muscle disease can be treated with injectable vitamin E and selenium, but many calves showing symptoms of white-muscle disease do not recover,” says Larson.
For producers, one of the most frustrating aspects of white-muscle disease is that it could have been prevented. In his August 1998 Vet Call column in the Angus Journal, Larson explains, “White-muscle disease can be prevented by ensuring pregnant cows are consuming a diet that results in an adequate level of vitamin E.”
According to the article, vitamin E is an essential fat-soluble vitamin that aids in the proper function of the reproductive, muscular, circulatory, nervous and immune systems. Probably, the job it is most well-known for is as an antioxidant. In that role, vitamin E protects cell membranes from oxidative damage.
The article explains that oxidative damage is caused by free radicals, which are created naturally when cells work; thus, heart and skeletal cells are unintentional factories of free radicals. Stressed animals produce compounds like cortisol and epinephrine, which also give off free radicals.
Larson explains, “Typically, [free radicals] are rapidly removed by antioxidants such as vitamin E and selenium, but if they are allowed to build up, they can damage any tissue they are near.”
“Vitamin E is plentiful in green forage and grain, but is low in dormant or drought-stricken forages,” says Larson, “so supplementation is most important when cattle are grazing dormant forages or eating hays that have been stored for prolonged periods or stored under conditions that subject the hay to the effects of weathering.”
There is very little transfer of vitamin E to the calf during pregnancy and, “because the calf depends on vitamin E found in the colostrum, ensuring that cows are eating forages, feeds or supplements with adequate vitamin E during the last month or two of pregnancy is necessary, so that calves consume the level of vitamin E that they need early in life,” advises Larson.
In some areas of the country, both vitamin E and selenium deficiencies must be addressed every year. “Ranches that frequently deal with this problem often use a combination of feed-delivered vitamin E and injectable products,” notes Larson.
Supplementation by itself does not ensure adequate absorption of vitamin E. Because vitamin E is a fat-soluble vitamin, Larson explains that, “rancid fats in the diet, as well as high-moisture storage of corn will reduce the vitamin E content of feeds. But, a surprising problem can occur in areas of the country with high levels of selenium in the soil, in that excessive vitamin E can actually make the selenium toxicity a greater problem.”
Make prevention a priority before calving season this year — include vitamin E in the ration.
Editor’s Note: Paige Nelson is a cattlewoman and freelance writer from Rigby, Idaho.