Small but essential part of nutrition plan | A 1,400 pound beef cow requires 0.4 pounds of minerals per day
STRATHMORE, Alta. — Mineral supplements are a small part of a cow’s diet, but a deficiency may cause health problems that are difficult to diagnose.
“All forage rations will require supplementation with trace minerals at some point in the year,” says nutritionist Jamie McAllister of Champion Feed Services in Stony Plain, Alta.
“Don’t just feed mineral for the sake of feeding mineral.… More is not always better and more can create more problems than not supplementing at all.”
McAllister said a 1,400-pound beef cow requires 0.4 pounds of minerals per day, which is a small but essential part of a nutrition plan. Protein should make up 13 percent of the daily requirement and energy 84 percent. Producers need to consider the energy value of the feed rather than protein content.
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Macro nutrients are calcium, manganese, phosphorus, sulfur, potassium and sodium chloride.
Calcium is required for bone development, maintenance and muscle contractions. A deficiency might be to blame if a calving cow stops part way through labour.
Phosphorus affects energy metabolism and fertility.
Magnesium is needed to help the body use Vitamin D.
Sodium chloride, or salt, is the only mineral that cattle crave.
“Lots of producers would say, ‘my cow isn’t eating that mineral, so she mustn’t need it. She knows what she needs and she will eat it.’”
McAllister said this is not true, and cows could die from a deficiency.
“Lots of times in order to get a cow to eat minerals, you have to put salt in it.”
Potassium works with sodium to maintain osmotic balance within body organs and cells. Nerve functions needs sodium potassium to send messages to the brain.
Sulfur is the only mineral involved in protein metabolism.
Excess sulfur can be toxic and a high amount can interfere with the amount of selenium available to the animal. It can also interfere with vitamin B uptake.
Producers should get a forage analysis done to learn whether there is a deficiency or excess amount of minerals.
As well, the province has diverse conditions, so feed should be tested to properly balance mineral supplements rather than buying a generic mix.
Symptoms of mineral deficiencies may be milk fever, winter or grass tetany, goiter, white muscle disease, scours in calves, failure to get pregnant or poor productivity for no apparent reason.
Many common feeds lack certain macro minerals.
Grass hay is often short of calcium, phosphorus, magnesium and sodium, while alfalfa is deficient in phosphorus and sodium. However, alfalfa will always be higher in calcium than cereals.
Cereals may not have enough calcium, magnesium, sodium and potassium.
The mineral content increases in heavily fertilized fields, but soil pH can affect how minerals get into plants.
Quick growing plants that produce lush forage could lead to grass tetany, a magnesium deficiency.
Drought conditions affect plants’ mineral content.
Mineral content may increase in a crop in the rain, but the energy content would drop.
Minerals decline but fibre goes up as plants mature.
A cow’s mineral requirements vary throughout the year. Supplements may be needed during later gestation and lactation.
Poor forage may require added minerals. Mould will reduce the mineral content of forage.
Micro minerals in beef cattle diets may include supplementation of iron, manganese, copper, selenium, iodine, zinc, cobalt and molybdenum. These are also known as trace minerals.
Iron is not usually a big concern as a supplement in forages, but zinc may be deficient. Cobalt and iodine are not usually added to forage but can be delivered in a blue salt block. Cobalt works with B12 for fibre digestion.
Iodine contributes to goiter control and thyroid health.
Selenium levels can vary from very high to very low, depending on the region. Selenium is related to immunity. A deficiency may result in more retained placentas. It also works with Vitamin E.
Trace minerals can make a difference in hoof and hair coat health.
Zinc contributes to hard, strong hoofs.
“If you are short of zinc, sand cracks are a possibility,” McAllister said.
He theorizes that moving cows from a low energy wintering program to green grass may cause sand cracks, which are vertical lines in the hoof.
A copper shortage may be noticed as a lightening of hair colour.
Organic or chelated trace minerals attach to a protein chain or a single amino acid. Their bioavailability, which is the path by which they are absorbed into the body, is different than traditional minerals. They are also expensive.
All minerals are intake related.
Salt can be used to enhance intake or it may be used to discourage cattle from eating too much.
Do not provide additional salt sources unless suggested on the mineral tag.
Do not feed salt and mineral separately unless the mineral is being force fed.
If feeding grain or silage, mix in the mineral daily or every other day to ensure consistent and uniform intake. Some producers mix it with silage before calving.
If mineral intake is excessive, producers should add salt, move the mineral feeder away from the watering source or change brands.
If mineral intake is inadequate, they should add soybean meal, ground grain or dry molasses to encourage consumption.
“Free choice can be a problem,” McAllister said. “I can make the best ration in the world for you, but it has little value if the cows won’t eat it.”
