Is tenderness genetically heritable? A three-part checkoff-funded study hopes to validate the presence of specific gene markers in the offspring of selected bulls, proving that these qualities are heritable traits.

Four universities and 16 U.S. beef breed associations are cooperating on a 42-month study just underway to identify cattle genetics that enhance tenderness. When complete, each breed association will have a start on its own tenderness EPDs to be used for genetic selection.

The study will also estimate expected economic returns to producers for selecting cattle based on tenderness EPDs.

Breed associations involved include Angus, Beefmaster, Brahman, Braunvieh, Brangus, Charolais, Hereford, Gelbvieh, Limousin, Maine-Anjou, Red Angus, Shorthorn, Salers, Simmental, Simbrah and South Devon.

Ten sires within each breed will be designated as DNA sires from which 50 progeny are to be produced to validate ten genetic markers on DNA for tenderness. Carcass traits and Warner-Bratzler shear force will be obtained on all progeny for EPD development. First matings for part of the 11,000 cattle involved in the study took place in 1996. Tenderness tests on the progeny will be conducted at Kansas State University using the Warner-Bratzler shear test and a trained sensory panel. Texas A&M, Colorado State University and Cornell University scientists are also involved with the project.

For more information contact Ronnie D. Green, Colorado State University, at 970/491-2722 (rdggene@lamar. colostate.edu)

North Dakota beef cows do well on crambe meal, say researchers at North Dakota State University (NDSU). Crambe is an oilseed that's useful for producing plastics and industrial lubricants.

Research at NDSU shows that the meal left over after the oil is extracted makes an excellent protein feed for cattle.

In the NSDU research, crambe could be fed at rates of up to 10% of the dry matter intake of pregnant and lactating cows with no impact on performance. For steers, researchers boosted crambe levels to 15% of the diet with no problems. Researchers compared performance to cattle on diets containing sunflower or soybean meal as the protein source.

Previous research from the 1980s showed that crambe meal contained glucosinolates with a sharp flavor, causing reduced feed intake and disruption in the production of thyroid hormones. However, NDSU researchers saw none of those effects where crambe was fed in a mixed ration.

Based on that early research, current use of crambe meal in livestock diets is limited to 4% of the diet by the U.S. Food and Drug Administration (FDA).

NDSU researchers hope their current findings will support changes in those FDA restrictions. Last year, North Dakota producers raised 20,000 acres of crambe. The crop is useful in rotations for breaking disease and insect cycles.

For more information contact Vern Anderson, North Dakota State University, at 701/652-2951.

Adding legume forages to cornstalks can help cut feed costs for cow-calf producers, according to Iowa State University research.

Many cow-calf producers in the Corn Belt already graze cows on cornstalks in the winter to reduce stored feed costs, but cornstalks are deficient in protein, Vitamin A, phosphorus and other minerals.

Incorporating hay crop forages that are high in protein and energy into a winter-grazing system with cornstalks can reduce those deficiencies.

Over three winters, Iowa researchers used berseem clover as a crop rotation cover crop with corn. Three groups of crossbred cows in mid-gestation were assigned to one of the following treatments: control, fed alfalfa grass hay in a dry lot; treatment 1, grazed on cornstalks alone and treatment 2, grazed cornstalks and berseem clover. Alfalfa hay was fed to the grazing cows when needed as a supplement to maintain a body condition score of 5.

Overall performance didn't differ significantly among the three groups. Cows grazing berseem clover/cornstalks performed as well as those maintained on a dry lot for the first half of the winter season with little hay supplementation. However, the cows' performance declined the second half of winter because the berseem clover was more susceptible to weather damage than the cornstalks.

Cows grazing cornstalks or the berseem clover/cornstalks combination required less hay than those on the dry lot. However, the berseem clover/cornstalks system produced all of or more than the amount of hay used for supplementation from two cuttings of hay taken by early August.

The researchers concluded that berseem clover has high enough nutritive value to supplement cornstalks in late fall and early winter, but it loses its nutrient value in late winter. Producers should also be aware that it is susceptible to drought and can be difficult to grow.

For more information contact Jim Russel, Iowa State University, at 515/294-4631.

A microorganism from South America is the latest biological weapon against the red imported fire ant. ARS researchers are releasing fire ants infected with the pathogen T. solenopsae.

The pathogen infects ant colonies and chronically weakens them. Workers transmit the pathogen to the queen through food exchange. The disease slowly reduces her weight. She lays fewer and fewer eggs, all infected with the pathogen, further weakening the colony.

Scientists hope this biocontrol agent can reduce fire ant numbers. The ants now infest millions of acres across 11 southern states.

For more information contact David Williams, Imported Fire Ant and Household Insects Research Unit, at 352/374-5982 (dfw@nervm.nerdc.ufl. edu). l

"Research Roundup" is compiled by Kindra Gordon at 612/851-4671 or Kindra_Gordon@intertec.com