Effects of Cow Nutrition on Progeny Carcass and Meat Characteristics
by Troy Smith, field editor, Angus Journal
RAPID CITY, S.D. (Dec. 3, 2013) — Fetal programming research has shown that a cow’s nutritional status during pregnancy can have far-reaching effects on her calf. Not only does it impact the calf’s health and performance, but evidence suggests it’s likely to influence the calf’s carcass characteristics. Learning more about those effects was the focus of research discussed by South Dakota State University meat scientist Amanda Blair during the Range Beef Cow Symposium (RBCS) Dec. 3-5, in Rapid City, S.D.
While a calf’s muscle-fiber numbers are set at birth, the second trimester is thought to be an important period of muscle and fat cell development, said Amanda Blair, SDSU meat scientist.
“As a meat scientist, I’m concerned with muscle and fat. Beef consumers are concerned with beef’s appearance, palatability (tenderness, juiciness, etc.) and cost, but all of those things come down to muscle and fat,” stated Blair. “So can we use our knowledge (of fetal programming) to manipulate development of muscle and fat?”
According to Blair, South Dakota researchers have been looking for answers by focusing particularly on the effects of cow nutrition during the second trimester. While a calf’s muscle-fiber numbers are set at birth, the second trimester is thought to be an important period of muscle and fat cell development.
Blair described a study involving two groups of cows whose respective diets were designed to maintain one group in adequate body condition [body condition score (BCS) 5-5.5] during a 98-day mid-gestation period, while the second group was allowed to lose about two-thirds of a condition score during that period. After completion of the 98-day period, the cows were commingled and managed as a common group through calving. After weaning, all calves received the same management during backgrounding and finishing periods.
Postharvest carcass evaluation showed that calves born to cows whose diets were energy-restricted during mid-gestation exhibited less backfat. Carcass yield grades were also lower than for calves born to cows whose diets were not energy-restricted. Researchers saw no significant differences in marbling scores but calves from dams on restricted diets produced carcasses with less subcutaneous fat. There were no differences in meat color or tenderness measured by shear force.
“Maternal energy status had no influence on the degree of muscling as measured by ribeye area, although alterations in maternal energy occurred during what has been suggested to be the period of maximal fetal muscle-fiber development,” reported Blair.
Differences in fat deposition led Blair to believe there may be opportunities to positively affect marbling and subcutaneous fat thickness relative to lean muscle during prenatal development.
Blair spoke Tuesday at RBCS XXIII. Visit the Newsroom at www.rangebeefcow.com/2013 to view her PowerPoint, read her proceedings paper or listen to her presentation.
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The RBCS is a biennial educational symposium offering practical production management information. It is sponsored by the Cooperative Extension Service and animal science departments of the University of Wyoming, South Dakota State University, Colorado State University and the University of Nebraska.
Comprehensive coverage of the symposium is available online at www.rangebeefcow.com. Compiled by the Angus Journal editorial team, the site is made possible through sponsorship of LiveAuctions.tv and the cooperation of the host committee.
Editor’s Note: This article was written under contract or by staff of the Angus Journal. To request reprint permission and guidelines, contact Shauna Rose Hermel, editor, at 816-383-5270.
