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Trace minerals directly affect unborn calves

If the cow isn’t getting sufficient minerals calf development and strength suffers

Not all minerals are created equal. Buy a proper blend for the third trimester period.

Within the next few months, there will be a lot of newborn calves on the ground. Fair- to good-quality forage is quite plentiful this year and grain is a reasonable price, so most of the cow herds I have seen across Western Canada this winter are in good body condition for calving. But one area I always feel that we should focus more on is to maintain or elevate their plane of trace-mineral status.

The developing calf fetus is totally reliant upon the supply of maternal trace minerals like copper, zinc, manganese and selenium, which are drawn through the placenta from the dam’s blood. Second, their own undeveloped trace mineral status takes precedent over their mum’s during the waning months of pregnancy. By providing a well-balanced mineral feeding program to beef cows during the last trimester of gestation, we can successfully get their newborn calves off to a healthy start.

Unfortunately, each winter I come across one or two cow herds that are within weeks of calving and I suspect are so trace-mineral depleted that they are too-far gone as good mothers. As a result, their newborn calves are often severely trace-mineral deficient at birth. Such poor trace mineral carryover from the mothers makes these baby calves highly susceptible to a long list of immediate- and long-term problems. These health and growing disabilities include immune dysfunction, abnormalities in bone and muscle development and digestive disorders, all of which are enveloped by general poor growth and high mortality.

Such poor “doers” are also likely to be fed poor-quality colostrum within hours after birth. It’s a similar case that it originates from fresh cows with poor trace mineral status and have poor pre-partum transfer of essential trace minerals as well as poor enrichment of immunoglobulins. Although it has been shown that feeding organic seleno-yeasts to post-partum cows increases colostrum selenium concentrations to healthy levels, dietary post-partum supplementation of copper, zinc, and manganese fail to work in the same way.

As a case in point, I have witnessed first-hand that when beef cows are in poor copper status, they calve out copper-deficient nursing calves. These newborn calves seem to have inadequate immune protection, because they tend to scour within days of birth to about three weeks of age. Many of these sick calves suffer from severe dehydration and perish. I find many of their owners tend to spend lots of money on sulfa pills and other scour treatments.

Fortunately, I find that more beef producers recognize the importance of a well-balanced good mineral and vitamin feeding program for late-gestating beef cows.

One of the best illustrations of good pre-calving trace mineral status and its value in beef cows was executed in a recent field study at Oregon State University (2016). These researchers sorted out 84 pre-calving beef cows with adequate trace mineral status into three treatment groups; no trace mineral supplementation, an inorganic supplement group and a group fed more bioavailable “chelated/organic” copper manganese, zinc and cobalt. These three experimental diets were fed through the third trimester until calving.

The best points of this trial demonstrated that the latter two trace-mineral supplemental groups improved the respective status of the late-trimester cows, while placental samples of the organic treatment had elevated levels of all four-tested trace-minerals. Saleable weaning weights averaged 519 pounds for calves from cows receiving the organic minerals versus 491 pounds for those from the group receiving the inorganic minerals.

I advise that beef producers feed a more fortified commercial mineral with more biologically available organic copper, zinc, manganese and seleno-yeast to gestating beef cows during the last trimester, during calving and even beyond to the breeding season. I would also target a daily consumption of 50-100 grams. If the cow herd is not eating enough or too much, add a one-third portion salt to the mineral mixture. Occasionally calculate the average mineral intake of the herd, and make the necessary adjustment for adequate and consistent mineral consumption.

By switching to such a commonly referred “beef breeder” mineral, some people are shocked at the $45 per 25-kg bag price tag compared to a “regular” cattle mineral that was costing them all winter, about $30 per 25-kg bag. I assure them that this premium is a nominal $3-$4 per head fed 90 days prior to calving.

Rather than consider it as an expense, always think of feeding the best mineral as a good investment. Its purpose is to build and assure good trace-mineral status in last trimester cows until calving, so it helps them calve out without many problems as well as produce calves with great newborn vitality.

About the author


Peter Vitti is an independent livestock nutritionist and consultant based in Winnipeg. To reach him call 204-254-7497 or by email at [email protected]



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