Feeding unborn calf affects carcass grade

Producing high-quality choice and prime beef carcasses starts earlier than most producers realize. The days in a feedlot at the end of finishing are important; however, the number of muscle cells and fat cells are determined before the calf is born.

Poor cow nutrition during pregnancy affects profit premiums on the finished calf.

“Most producers are surprised when they hear this,” says Justin Sexten, University of Missouri beef nutritionist. Sexten wants cow-calf producers to know the importance of winter feeding for the spring-calving cow herd. Poor nutrition for the mother cow, especially in the last trimester of pregnancy, cuts the number of cells that turn into marbling late in the calf’s life.

Key Points

• Studies prove that poor cow nutrition affects the beef quality of a calf.

• MU beef nutritionist explains the importance of fetal feeding.

• Spring-calving cows should be kept on a good winter feed ration.


It’s not just feeding for 150 days, but for 500 days that counts, Sexten says. During the feedlot phase, pouring on the corn can only fill the available fat cells dispersed in the muscle tissue. Feeding doesn’t increase the number of cells, fat or muscle.

Cow nutritionists now apply what was learned long ago in human nutrition. The mother’s diet during pregnancy causes long-term impact on the offspring’s development. The study of children born to women during famine found lifelong health problems. Starved mothers produced babies that had diabetes, heart, lung and many other problems.

Recent studies in Nebraska, Ohio and North Dakota show how calf performance through life, particularly in the feedlot, can be traced back to cow nutrition.

We’ve long known the bad management in the old farmer’s myth that you can starve birth weight out of calves to improve calving ease. Withholding feed for cows before calving also starves out marbling. Science shows that the number of potential fat cells to create marbling is laid down in months seven to nine of gestation. Marbling helps set the quality grade of a calf at harvest. Without marbling fat, the carcass won’t grade Choice or Prime, the grades bringing premiums on the market grid.

Quality feed for quality calves

Increasingly, the Missouri niche of producing high-quality beef depends on good winter feeding of cows, as well as genetics. “This changes the idea that we can get by with just any least-cost rations for cows,” Sexten says. Cows carrying calves need quality feed in December and January — up to calving time. That means high-quality hay with an energy supplement.

Now we know that a hard winter for cows can affect calf feedlot performance, Sexten says. “We’ve seen years when calves do very well in the feedlot. They next year, calves with the same genetics from the same herd don’t grade well. That can be traced back to the cow’s winter feed.”

Winter cow care becomes more important as more Missouri farmers retain ownership through the feedlot stage. That is where the grid premiums are paid on better-quality grades.

We can do something about that, Sexten says. Fetal feeding is one area we can control, and potentially make a difference.

Healthy cow ups colostrum quality

Cow-calf producers who think that they won’t benefit from better cow nutrition miss the point of calf survival and health after calving.

The most immediate payback for proper diet during pregnancy comes from better-quality calving. A cow in poor body condition is more likely to give up in a difficult birth. A weak cow isn’t a strong mother. The cow’s diet prepares the calf for survival.

“A cow starved before calving won’t produce high-quality colostrum,” says Justin Sexten, MU beef nutritionist. Rich colostrum, the first milk containing antibodies and beneficial bacteria, is essential for a calf to get up and get going. A calf that doesn’t get good colostrum becomes challenged from the beginning — if it survives.

Reduced calf-death loss and health problems depend on the quality of the colostrum.

Nutrition at breeding

New emphasis on late-gestation diets should not take away from attention to pre-breeding diets.

Field trials in the University of Missouri’s timed artificial insemination program showed lower conception rates on cows with poor body-condition scores. Cows being bred in fall-calving herds that have lush, stockpiled pastures from plentiful rain should be on that needed rising plane of nutrition. Cows in drought areas may need extra ration assistance at pre-breeding.

MU beef nutritionist Justin Sexten says the first step will be to test forage quality. You must know hay quality to calculate how much supplement to add. “If 3 pounds worked last year, 3 pounds may not be enough this year. There was a lot more poor-quality hay baled for winter feeding.”

Regional MU Extension livestock specialists have software for ration calculations and can lend a hay-testing corer.


This article published in the November, 2010 edition of MISSOURI RURALIST.

All rights reserved. Copyright Farm Progress Cos. 2010.