03/15/1993

AAES Using Ultrasound to Enhance Ribeye Steak Production

CAMDEN, Ala. - Auburn University scientists are using ultrasound equipment to help produce cattle with more ribeye muscle in a study at Camden's Lower Coastal Plain Substation, a unit of the Alabama Agricultural Experiment Station (AAES).

About 40 cattle producers and high school agriculture students were briefed on this and other current AAES research at a recent Livestock Field Day held at the substation.

"We are investigating the use of ultrasound for selecting the elite cattle that excel in ribeye muscling," said graduate student Craig Hays, who works with AU animal scientist Wendell McElhenney in the study.

Hays and McElhenney use these elite cattle in a selective breeding program and examine the resulting offspring to determine whether ultrasound made accurate predictions of the animals' ribeye-producing ability. Preliminary results show promise that ultrasound can be used to select cattle that are genetically prone to have larger ribeyes, Hays said.

Ultrasound, used in medical applications for years, uses sound waves to produce electronic images of internal structures. In this case, an ultrasound device is placed on an animal's back to measure the amount of ribeye muscle and backfat.

"Hopefully, in the future we will be able to make recommendations on the usefulness of ultrasound in predicting and altering carcass value," Hays said.

Also at the field day, AU entomologist Gene Strother told producers that insecticidal ear tags are "still the best and easiest and the best bargain" for controlling horn flies in cattle, but the type of tags used must be rotated to avoid a buildup of flies resistant to the tags. Strother said large numbers of the parasitic flies, which feed on blood, can cause a calf to lose 35-40 pounds by the time it is weaned. The insects also can cause a 30-40 percent decrease in milk production.

AU animal scientist Diego Gimenez advised that with today's changing market, producers will benefit by finding out if they are breeding the kind of beef processors and consumers want. Packers and processors look for quality grade, cutability, smaller size and higher dressing percentage. Consumers want leanness, good taste, quality, and convenience. An educational program known as "Alabama from Pasture to Rail" is available to help producers determine whether their product matches today's market, he said. Interested producers should call Gimenez at 844-1520 for more information.

Other AU animal scientists presented information valuable to swine breeders. Daryl Kuhlers and Steve Jungst compared two systems for crossbreeding pigs. Crossbreeding is important because hybrid pigs have positive traits, such as increased litter size and survivability, that neither purebred parent has.

In "three-breed terminal" crossbreeding, a sow that is a cross between two breeds is mated to a purebred boar of a third breed, Kuhlers said. The same breed of boar is used each year.

In "three-breed rotational" crossbreeding, a sow that is a cross between three breeds is mated to a purebred boar of one of the same breeds, he explained. A different breed of boar is alternated in each of three years with the goal of mating the sow to a male that is the most different genetically. For example, if a sow is 57 percent Duroc, 29 percent Yorkshire and 14 percent Landrace, then it would be mated to a purebred Landrace. The resulting offspring would be 57 percent Landrace, 29 percent Duroc and 14 percent Yorkshire. Sows of this mix would be mated to a Yorkshire boar.

The three-breed terminal system is easier to manage, but replacement sows must be bought each year, Kuhlers said. The lower the cost of replacement sows and the higher the market price for pork, the better it is to use this system of crossbreeding.

The three-breed rotational system is less expensive because replacement sows are produced on the farm, but producers must strictly manage the breeding program to maximize the benefits of crossbreeding, Jungst said. If the proper crosses are not made, producers could lose up to half of the genetic benefits of crossbreeding. About 45 percent of swine producers use the rotational system, usually on farms with 500 or fewer sows.

At the Lower Coastal Plain Substation, color-coded ear tags are used to identify the lineage of sows in rotational breeding programs, Jungst said.

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Office of Ag Communications & Marketing

Auburn University College of Agriculture
Alabama Agricultural Experiment Station
3 Comer Hall, Auburn University
Auburn, AL 36849
334-844-4877 (PHONE) 334-844-5892 (FAX)

Contact Jamie Creamer, 334-844-2783 or jcreamer@auburn.edu
by Robyn Hearn

April 15, 1993