Puzzling calf deaths due to vitamin E deficiency

It took 50 hours of detective work before veterinarians could figure out what was killing newborn calves at an east-central Alberta farm.

The probable diagnosis was a rare condition called hypovitaminosis E, a severe deficiency in vitamin E.

The case started last year when a farm at Irma reported a number of unexplained calf deaths to the practitioners at the Viking Veterinarian Clinic.

The farm had 200 cows, 30 home raised heifers and 40 purchased females. The feed program was normal and the vaccination program was well rounded.

The home-raised heifers’ calves started to die shortly after birth. Forty calves died by the time it was all over.

Post mortems done at the clinic when the first calves died resulted in an initial diagnosis of selenium deficiency leading to white muscle disease, veterinarian Lacey Fowler told the University of Calgary’s annual beef conference held June 19-20.

However, that diagnosis was eventually ruled out, and samples from organs were sent to a laboratory, which resulted in no definitive answers.

“We were frustrated,” Fowler said.

The next group of post mortems went to the diagnostic lab at the University of Saskatchewan.

“A mineral panel on liver tissue was done and there it found exceedingly low levels of vitamin E,” she said.

A serum panel measured levels of magnesium, manganese, iron, cobalt, copper, zinc, selenium, moly-bdenum and vitamin E.

There was no selenium deficiency in conjunction with the low levels of vitamin E.

The treatment involved working with the producers to create a balanced diet with oral supplements. The heifers were injected with a selenium and vitamin E product as well as vitamins A and D.

All calves received a prophylactic shot of Nuflor to control respiratory disease.

Vitamins A, D and E are readily available in fresh green grass, but it does not over-winter well in stored feed. The best way to meet a herd’s vitamin requirements is to force feed with top dressed grain or a total mixed ration. Producers need to consult with a nutritionist.

John McKinnon, beef industry chair at the University of Saskatchewan, said producers often ask which mineral package is best for their operations.

“When you are considering which mineral program to go with, you have to consider the uniqueness of your operation, the area that you live in and some of the factors that influence mineral availability,” he said.

Soil type and water quality influence the availability and concentration of minerals.

Supplements also need to be adjusted to the time of year and life stage of the cattle.

“There are critical components of nutrition for both minerals as well as energy and protein that we have to recognize for fetal development in the last 60 days prior to calving,” McKinnon said.

A cow’s energy, mineral and vitamin reserves are drawn down during pregnancy and can affect calf health and the ability to rebreed.

Calcium and phosphorous are among the most important macro minerals.

Calcium requirements change throughout the stages of pregnancy.

Twenty grams per day are needed if a cow eats two percent of body weight on a dry matter basis and should increase to 32 grams per day during the second trimester. Up to 40 grams per day may be required after calving.

A deficiency could cause milk fever, decreased milk production or bone abnormalities.

Cows need 14 grams of phosphorus during the second trimester and 27 grams after calving.

Phosphorus deficiencies could be linked with poor fertility.

Legumes and grass-legume forage in Western Canada are high in calcium but low in phosphorus. Grass hay is more intermediate in calcium and low in phosphorus. Cereal greenfeed is low in calcium and phosphorus.

Magnesium and potassium deficiencies are not common in Western Canada. A lactating cow needs .2 percent of magnesium on a dry matter basis and .5 percent of potassium.

It is more common to have too much potassium in forages because there is a high level in the soil.

High potassium levels can accumulate in plants and alter the mineral balance with other minerals such as magnesium.

“When this ratio gets out of whack, you will start to see grass tetany in cattle out on pasture,” McKinnon said. “Ruminants can tolerate high levels of potassium, but it can interfere with magnesium absorption and interfere with this tetany ratio.”

Manure has a high level of potassium, which will accumulate in the soil. The levels can go up in drought periods and lead to milk fever or tetany.

Cattle also need trace minerals. The actual amount per day may be no bigger than the head of a pin, but a deficiency can lead to big problems, he said.

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