Garfield County Cooperative Extension

As the Cow Eats, So Grows the Calf

Rick Nelson Extension Educator, Ag/4-H & CED

Your cowherd checklist might look pretty sparse after the calves are weaned and pregnancy is confirmed. Maybe the cows have regained some condition and are coasting now on crop residue or dry native pastures. Next consideration might be calving?

More properly, the next item would be nutrition during late gestation. Research from University of Nebraska say cow nutrition in the months prior to calving can determine their calves’ future production.

This is called fetal programming.

This research also demonstrated that there is a positive effect on heifer fertility, which is important to beef producers for sure, and then there was also a benefit to weaning weights that was pointed out in this three multi-year of studies on the topic.

When researchers followed steer calves through the feedlot, another result became apparent.

The greatest impact was on quality grade, and a greater share of that was on the upper two-thirds of the Choice grade. That is the marbling mark at which cattle need to be accepted into the Certified Angus Beef ® (CAB ®) brand, a gateway to more quality premiums.

The majority of this work focused on protein supplementation during the final trimester of gestation.

This is the traditionally when producers would supplement cows, in that dormant grazing period. Other fetal programming work has looked at early- to mid-gestation nutrition, but this research showed that this rarely a period for concern. Unless experiencing drought, this is really a non-issue in beef production in spring-calving herds.

The study divided cows into four groups. For three consecutive years cows were either grazing native pasture or corn stalks, and then they were split again with half receiving supplement and half not.

Both of the groups fed a daily pound of 28% crude protein supplement showed calf benefits, but the effects were more apparent for those on winter range. That is probably because they were the most nutrient deficient, thus the results were magnified. Although the supplemented cows went into calving in better body condition, all had similar pregnancy rates in the next breeding season.

In all three years of study, supplementation almost never had an impact on birth weights, but it apparently impacts a metabolic system that provides a different gain and type of deposition. The steers whose mothers were supplemented on range had a 48-pound (lb.) advantage in weaning weight, and they maintained that edge through harvest. Their carcasses were nearly 42 lb. heavier. For beef producers who own the cattle through harvest, the real payout comes in the form of greater carcass quality grade and carcass weights. Offspring of the supplemented cows graded 86% Choice, compared to 71% in the non-supplemented group. However, the premium Choice percentage dropped 18 points without the added protein, 39% vs. 21%. Yield was virtually the same. The increase in percent Choice, without an increase in yield grade, translated to a $47 advantage in carcass value.

Cells are already differentiated into muscle, fat, organs or bone by late gestation, so it might just be an overall programming of nutrient utilization. The perceived lower plane of nutrition from those fetuses in the non-supplemented group might be programming the way they use nutrients after birth.

The reproduction benefit to heifer calves might come from the fact that certain nutrients can alter blood flow to the fetus and those same nutrients could affect hormone secretion.

The important practical note in all of this is that it is more about keeping cows in good body condition than anything else.


Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Oklahoma Cooperative Extension Service is implied.


Oklahoma State University, U. S. Department of Agriculture, State and Local governments cooperating.  Oklahoma State University in compliance with Title VI and VII of the Civil Rights Act of 1964, Executive Order 11246 as amended, Title IX of the Education Amendments of 1972, Americans with Disabilities Act of 1990, and other federal and state laws and regulations, does not discriminate on the basis of race, color, national origin, gender, age, religion, disability, or status as a veteran in any of its policies, practices, or procedures."




Document Actions