Study shows that additional methionine improves efficiency in heifers

July 9, 2012 By Evelyn Boswell

An extra dose of certain amino acids can help cows better use dietary protein or the nutrients they consume, according to a new study published by Agricultural Research Service scientists at the Fort Keogh Livestock and Range Research Laboratory (LARRL) in Miles City.

Amino acids -- the building blocks of proteins -- are essential, especially those that are "limiting," to cattle that graze on poor-quality forage, the scientists said in the article they published in the online edition of the international journal Amino Acids. Methionine is considered a limiting amino acid because if a diet is deficient in it, the usefulness of other limiting amino acids is restricted, thus preventing the formation of body protein.

In cows, in the rumen -- the first of their four stomach chambers -- are the first to use , which is then incorporated into microbial protein and provides to the animal.

Lead author Richard Waterman and his coauthors at LARRL - Mark Petersen and former intern Valerie Ujazdowski -- conducted their research from Jan. 13 through Feb. 26, 2010. They added methionine to the diets of 24 pregnant heifers, mostly Angus, that had been artificially inseminated. A large percentage of the methionine bypassed the rumen and went directly to the animal, resulting in an increase and more of amino acids, the researchers said. Results suggested that animals retained more of the nitrogen provided in the protein from dietary and microbial origin and excreted less back into the environment.

In the current study, heifers were given supplements 56 days before they had their calves. One group was given a wheat middling-based that contained urea, which provided adequate nitrogen to the of the rumen. Another group of heifers was fed the same amount of nitrogen, but a portion was replaced with a form of methionine with a protective coating to limit the ability of microbes in the rumen to use the methionine.

After 44 days, blood plasma amino acid concentrations were evaluated in response to dietary supplements. Methionine levels were higher in cows that received the extra amino acid, indicating that methionine bypassed the rumen and entered the animals' bodies. Even though the methionine had a protective coating, the small amount released in the rumen benefited both the rumen microbes and the animal itself.

The scientists said they also saw a decrease in other plasma amino acids, which suggested that providing additional methionine enhanced the ability of animals to more efficiently use other for growth and reproduction.

The research was conducted under a cooperative agreement between the USDA Agricultural Research Service and the Montana State University Montana Agricultural Experiment Station.

Explore further: Cells defend themselves from viruses, bacteria with armor of protein errors

Related Stories

Hops helps reduce ammonia produced by cattle

April 20, 2010

An Agricultural Research Service (ARS) scientist may have found a way to cut the amount of ammonia produced by cattle. To do it, he's using a key ingredient of the brewer's art: hops.

Recommended for you

Study finds 'rudimentary' empathy in macaques

December 1, 2015

(—A pair of researchers with Centre National de la Recherche Scientifique and Université Lyon, in France has conducted a study that has shown that macaques have at least some degree of empathy towards their fellow ...

Scientists overcome key CRISPR-Cas9 genome editing hurdle

December 1, 2015

Researchers at the Broad Institute of MIT and Harvard and the McGovern Institute for Brain Research at MIT have engineered changes to the revolutionary CRISPR-Cas9 genome editing system that significantly cut down on "off-target" ...

Trap-jaw ants exhibit previously unseen jumping behavior

December 1, 2015

A species of trap-jaw ant has been found to exhibit a previously unseen jumping behavior, using its legs rather than its powerful jaws. The discovery makes this species, Odontomachus rixosus, the only species of ant that ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.