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Supplement programs are built on availability of major and trace nutrients

by Wyoming Livestock Roundup

When considering a supplement program for livestock, Veterinarian Jessica Blake from Lander Valley Hospital suggests focusing on macronutrients first.

“We need to focus on the right amount of protein and energy, as well as the important vitamins and minerals, first,” she says.

Calcium, phosphorus, magnesium and potassium, for example, should be adequate in a cow’s diet before producers spend time and money implementing a trace-mineral program.

“Important vitamins include vitamin A and vitamin E,” she notes.

Vitamin E deficiencies can result from hay that has been harvested improperly or stored for too long.

“That can cause white muscle disease in cattle,” she explains.

Deficiencies in vitamin A can cause difficulty in fetal eye development.

Being prepared

“Do the hard legwork up front,” encourages Blake. “Get a feed analysis and mineral analysis.”

Liver samples or blood samples can be used to determine mineral levels that animals obtain from their diets, providing a baseline to work from.

“Producers can also get soil profiles,” notes Blake, although she adds that it can involve expensive testing.

“From a veterinarian’s standpoint, we also look at herd health,” she adds.

High rates of certain illnesses or diseases within a herd may indicate deficiencies in specific dietary nutrients.

Supplement plans

“We sit down and look at the total digestible nutrients (TDN). Then we look at protein. We have to have adequate levels of those before we go any further,” Blake explains.

Deficiencies in nutrition vary depending on the environment.

“It is very location specific. Ranchers have to know their area,” comments Blake.

If it is determined that a supplement plan is advantageous, supplements can be administered orally or by injection.

“The most common supplements are in feed as loose mineral, blocks or tubs,” says Blake.

These methods assume that cattle will ingest necessary amounts of supplement.

“The animal has to actually eat it,” she notes.

Supplement options

When determining which form of supplement is best, producers should consider the type of deficiency they are working with.

“How well those vitamins or minerals are absorbed by the animal’s body should be factored in,” she explains.

Because of the variability in oral supplements, some producers use an injectable form.

“Some people have great success with injectable supplements, because they are putting it directly into the animal’s body. They know exactly how much the animal is receiving,” she comments.


Injectable supplements are given at strategic times of the year, to enhance animal performance when it is most advantageous.

“Right before calving is one of those strategic times,” notes Blake.

Before a calf is born, the mother cow is mobilizing stored nutrients out of her liver to provide nutrition for the growing fetus.

“The cow can deplete her own nutrition, so we give her enough mineral to provide for the fetus and to maintain herself so she can get pregnant again,” she continues.

During early pregnancy when fetal programming or significant development of the fetus is taking place, 30 days before calving, during calving and when the cow needs to breed back are all key times for mineral supplement in cows.

“Anything that causes stress can affect nutrition,” she adds.

Extreme weather conditions, calving, transportation and other stressors can affect levels of protein, energy and other nutrients in cattle.

Assessing nutrient problems

“Work with a nutritionist,” suggests Blake.

In Wyoming, there are areas with selenium-rich soils, which can be toxic to cattle in highly concentrated amounts.

“For ranches in a high selenium area, certain products may not be something producers want to use without someone knowledgeable helping out,” she says.

Veterinarians can be a great resource to help determine the best supplement program.

“Most vets are trained in nutrition,” she comments.

Blake also notes that if a local vet doesn’t know the answers, they are part of a great network of professionals who can be contacted for information and advice.

“We are not just here for C-sections and sick animals,” she says. “Most of us enjoy talking about nutrition and would happy to discuss it.”

Sheep nutrition concerns

“Sheep are very sensitive to copper levels,” notes Veterinarian Jessica Blake.

Sheep should not be given supplements intended for cattle because they often contain much higher levels of copper that can be toxic.

“There is research coming out that there are great variances between sheep and goats, which have been considered very similar in the past,” she notes.

It is important to build supplement programs around specific operations and to keep in mind that different species have different nutritional requirements.

Compared to cattle, Blake comments, “Sheep have a whole different set of problems.”


Natasha Wheeler is editor of the Wyoming Livestock Roundup and can be contacted at

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