Mineral for the Cow, Weight on the Calf: What Pregnancy Feeding Can Do

Most of us feed the cow and look at the calf. The idea behind fetal programming says to look the other way around: feed the cow with the calf in mind, because what she gets in pregnancy helps build the calf. A lot of mineral companies sell on that idea, and some of them put pounds on it. This is what is reported, what is not proven, and what I would do about it on a working ranch.

The basic idea

During pregnancy the calf's organs and muscle form. If the cow is short on key nutrients, the calf may start behind. A Purina nutritionist quoted in High Plains Journal said poor nutrition during that time can permanently alter the offspring's metabolism and physiology. That lines up with what many cattlemen see: poor-doing cows raise poor-doing calves.

What was reported

The High Plains Journal described a North Dakota State trial, passed along by the nutritionist. Heifers bred to have heifer calves were split into two groups. One got a commercial mineral at 4 ounces a head a day. The other got none. Same silage, hay and distillers grains, and the article says the diet was not short of minerals on paper. The reported results:

• About 50 percent more colostrum from the mineral cows.
• Calves got about 1.5 times more trace minerals through colostrum.
• Bigger ribeye and body measurements at weaning.
• Weaning weights 36 pounds higher, with the edge still there at 15 months.

Keep in mind the article was sponsored by a feed company and does not cite a paper, sample sizes or statistics. I would not bank 36 pounds on one report. I would take it as a reason to look at my own mineral program and measure the results.

Early pregnancy counts too

One more thing to keep straight. Another article, from Beef Magazine and also sponsored by a supplement company, says feeding minerals only in the last trimester may be too late if the calf was short earlier. It describes University of Wyoming work where range cows were held to 60 to 70 percent of requirements in early gestation and calves had fewer muscle fibers. So treat it as a whole-year program, not a last-90-days fix.

What I would do

1. Pull a forage test and talk to the vet. Know what your grass and hay are short on before you buy mineral.
2. Buy a mineral built for your area. Read the tag: key trace minerals, feeding rate.
3. Check what the cows actually eat. If the feeder runs empty in a week or sits full for a month, the program is not working.
4. Start before breeding and run it through calving. Do not turn it on in November and call it good.
5. Keep score: colostrum, calf vigor, treatment rates, weaning weights.

How to test it on your own place

If you run enough cows, split them. Half on the new program, half on the old, same pasture, same bull battery, same calving window. Weigh the calves at weaning and sort by sex and age before comparing. If the difference is a few pounds, it is noise. If it is thirty pounds at today's calf price, you will pay for the mineral and then some. Do the dollars before you decide.

What to watch for when you buy

Price per bag tells you nothing. Price per head per day at actual intake does. Some products use organic trace minerals and some use inorganic, and each company says theirs is best. Ask for university data that is not paid for by the seller. Our guide to hay math is worth reading alongside it, since forage is the other half of the cow's diet.

Where it can go wrong

• Over-feeding minerals wastes money, and some elements can harm cattle if overdone. Follow the label rate.
• Soil and water differ by region, so a program that works in one place may not work in another.
• A weak forage base is a bigger problem than any mineral can fix. If cows are thin, feed energy first.

Colostrum is where the trouble shows first

If you want one place to watch, watch the first 24 hours. A calf that gets enough good colostrum starts with antibodies and trace minerals on board. Thin or mineral-short cows can come up light on both. That is why the reported colostrum numbers caught my eye more than the weaning weights did. A calf that stands and nurses fast, and stays healthy through the first month, has already saved you money before the scale ever enters the picture. Our guide on newborn calf care covers what to do when the calf hits the ground.

Bottom line

Feeding the cow is feeding the calf. A proper mineral program is cheap compared with a lost calf crop, and it is worth running. Do not sign up for a promised number of pounds. Run it, record it, and decide with your own scale. More on feeding programs at farm.fm's page on optimizing feed formulation, with checkoff research at beefresearch.org, and local resources through agriculture.directory. Check current extension advice, because the research keeps moving.