Effects of genes on beef tenderness

Previous research has shown two enzymes are responsible for postmortem beef tenderness: calpain promotes tenderness, while calpastatin is a calpain inhibitor.

Previous research has shown two enzymes are responsible for postmortem beef tenderness: calpain promotes tenderness, while calpastatin is a calpain inhibitor.

U.S. Meat Animal Research scientists evaluated the association of different genotypes of these enzymes with tenderness, juiciness and flavor. Three populations of cattle were used — Bos taurus (BT), Bos taurus with Bos indicus influence (BT/BI), and purebred (BI).

Those animals in the BT and BT/BI group that inherited CC and CT genotypes of the calpastatin gene produced tougher meat than those inheriting the TT genotype. Also, animals inheriting the CC genotype produced blander steaks than those inheriting the CT and TT genotypes. There was no significant sensory association of the calpastatin gene with the BI population.

Animals in the BT and BT/BI groups that inherited the CC and CT genotypes of the calpain gene produced significantly more tender meat than those inheriting the TT genotype. Again, there was no real effect on the BI population.

According to the researchers, the results indicate that selection for favorable alleles of the calpastatin and calpain genes will improve tenderness from the BT and BT/BI cattle populations (Casas et al., 2006 J. Anim. Sci. 84:520).
Michigan State University Beef Cattle Research Update, Summer 2006

Frost-seeding red clover into wheat can improve forage and soil quality by providing nitrogen, manure nutrient recycling and decreased risk of manure runoff.

Frost-seeding red clover into wheat offers several advantages — especially if you plan to spread manure on wheat stubble. Farmers who spread manure onto only wheat stubble can find the ground hard, cracked and vulnerable to liquid manure draining through tiles.

Using red clover as a cover crop has multiple benefits and minimum cost. Broadcast it onto wheat fields before spring thaw and the clover will be spindly at wheat harvest, but will fill in gaps after the wheat is taken off the fields, says Natalie Rector, Michigan State University (MSU) Extension nutrient management field specialist.

Clover utilizes the manure's nutrients as it grows, and the plants' taproots improve soil structure as they grow. Clover also provides erosion control after it's established, and fixes nitrogen.

“We've found red clover can offer as much as 100 lbs. of nitrogen credit in the spring,” says Dale Mutch, MSU Extension specialist. “The later the clover is allowed to grow in spring, the more nitrogen potential. That makes this cover crop especially attractive ahead of corn or other crops that are heavy nitrogen users.”

Applying the clover is simple. Three methods have been found to not affect wheat yields: Using an electric spinner seeder mounted on the back of an ATV, blending red clover seed with urea and broadcasting onto frozen soil, and drilling the seed as early as possible to drive over wheat in the spring.

Rector recommends 10-15 lbs. seed/acre to provide consistent stands. For more information visit www.rootzone.msu.edu.
MSU Communications and Technology Services

Rumen protozoa have been linked to antibiotic resistance.

Ag Research Service (ARS) scientists have discovered that protozoa — single-celled predatory organisms — found in the gastrointestinal (GI) tract of cattle can facilitate the transfer of antibiotic resistance from resistant bacteria to susceptible types.

Veterinary medical officer Steven Carlson, at the National Animal Disease Center in Ames, IA, is the first scientist to document rumen protozoa's role in transferring resistance within cattle.

Rumen protozoa engulf and destroy most bacteria. But Carlson and colleagues have ID'd and described the transfer of resistance to ceftriaxone, an antibiotic used to treat pneumonia, from GI tract bacteria known as Klebsiella to rumen-dwelling Salmonella sensitive to the antibiotic.

Last year, Carlson teamed with former ARS microbiologist Mark Rasmussen in a study revealing that disease-causing bacteria can strengthen from interaction with protozoa that are naturally found in animals. In that work, an antibiotic-resistant strain of Salmonella became especially virulent when tucked within rumen protozoa. The discovery suggests naturally occurring digestive-tract protozoa may be a place where dangerous bacteria can lurk and develop. To read more, visit www.ars.usda.gov/is/pr/2006/061003.htm.