Adding amino acids to dairy rations improves performance

FREEPORT, Ill. — Many factors impact fertility and reproduction of dairy cows, including the nutrition of their rations.

“After the cow is pregnant, whatever she eats during the dry period is fed to the calf through the placenta,” said Phil Cardoso, an associate professor of animal sciences at the University of Illinois.

In California, researchers palpated cows around 30 days and again at 45 days.

“The embryo loss was from 10% to 20%,” said Cardoso during a presentation at the Illinois Dairy Summit hosted by the Illinois Milk Producers Association and U of I Extension. “For every early pregnancy you lose, that costs from $150 to $300.”

There are several factors that can be tracked which impact pregnancy rates, including body condition score, quality of the follicle and size of the embryo.

“From 14 to 18 days after a cow is bred, the embryo will send a signal to the cow that she is pregnant and don’t come into heat or if the embryo is not large enough she may come back into heat,” the university professor said.

Cardoso focused his discussion on the importance of the nutrition during the transition period, which includes three weeks before and after calving.

Sometimes, dairymen formulate diets on crude protein and expect that to be associated with how much milk the cow will produce.

“But you’re going to be frustrated because that association is not there,” Cardoso said.

“Dairymen should be looking at amino acids,” he said. “Small increments can add up to results.”

Methionine and lysine, Cardoso said, should be included in the ration based on the energy that is fed to the cows.

“For this research project, the cows were fed two levels of energy — a diet with straw and a diet without straw,” he said. “The ratio of energy to amino acids is consistent.”

The researchers ultrasounded the cows to evaluate the muscle and fat and how it changed from minus 28 to 70 days in milk.

“The cows that were not fed amino acids lost more muscle and fat than the cows on a control energy diet with ammo acids,” Cardoso said.

Fifteen to 16 days after calving, a cow should be ovulating.

“We checked the fluid in the follicle and the cows fed the methionine have more methionine in the follicle,” Cardoso said.

For a research project at the University of Wisconsin, methionine was fed to cows from 20 to 150 days and the researchers checked for pregnancy at 28 and 61 days.

“There was no difference in first lactation cows in pregnancy loss,” Cardoso said.

“For the multipara cows, the control cows that were not fed amino acids had 19% pregnancy loss and that loss was reduced by 6% for the cows that received methionine which fed the embryo so it could survive,” he said.

Cardoso talked about 10 years of milk sample data from the U of I dairy herd.

“The protein has been increasing. However, it is not a straight line. It goes up and down,” Cardoso said.

“We feed for amino acids, so the protein for our herd during the summer months doesn’t go as low as other farms,” he said. “This is going to depend on how much it costs to add amino acids, so you have to work with your nutritionist, but it could be a meaningful way of improving income.”

In Australia, research shows cows that have more milk protein also have higher conception rates and they stay pregnant, Cardoso said.

The impact on reproduction can be significant. For example, Cardoso said, with a 5,000-cow herd, if the service rate goes from 65% to 75%, with a 25% pregnancy rate and the abortions go from 10% to 7%, at $200 per pregnancy, that’s $169,000.

“I’m getting that back with those changes, so don’t only think about milk components — there are other things impacted,” he said.