Saturday, July 2, 2016

Cloned cattle combine meat quality and carcass yield

It’s possible to both improve meat quality and carcass yield, genetic traits that rarely show up together, say scientists at West Texas A&M University.

They did it by cloning genes from cattle that had been slaughtered.

“This outcome indicates that the antagonistic relationship between beef carcass quality and yield can be overcome by crossing rarely occurring animals,” said Ty Lawrence, professor of meat science and lead researcher on the project.

In 2012, WTAMU successfully cloned a bull from the carcass of a steer that graded Prime, Yield Grade 1—the best combination of quality grade and yield grade in the USDA’s beef evaluation system.

Such a rating is only achieved by about .03 percent of all beef carcasses. Three heifers—Gammas 1, 2 and 3—were cloned from another Prime, Yield Grade 1 carcass.

While not clones themselves, the 13 calves of Alpha (the bull cloned in 2012) and the Gammas were the first bovine offspring ever produced from two cloned carcasses. 

Last month, seven of them were harvested. The seven steer carcasses were evaluated by a third-party USDA beef-grading supervisor and graded significantly above the industry average. 

One of the seven achieved the Prime grade, three graded High Choice, and three were Average Choice. The industry average is Low Choice. 

Industry-wide, less than five percent of all beef—fewer than one in 20 carcasses—grades Prime.

All seven of WTAMU’s steers produced a yield grade of 1 or 2. The industry average is a 3. 

Compared to the average animal reported in the 2011 National Beef Quality Audit, the offspring of Alpha and the Gammas have 16 percent less trim fat, nine percent more ribeye and 45 percent more marbling.

“By finding, cloning, and crossing these rare genetics, we have demonstrated the ability to create exactly what the market desires: high quality taste fat without unnecessary waste fat,” Lawrence said.

The findings have been five years in the making, and the ongoing project has included numerous partners. 

The offspring “were raised by their mothers while grazing our native pastures, in the herd with our other commercial cattle,” said David Lust, a research team member and associate professor of animal science.
“They were weaned at a normal time and then fed at the WTAMU Research Feedlot for 185 days on a typical feedlot diet. They have been treated just like commercial cattle throughout the industry.”

The research team is encouraged that the data so far points toward a new way to improve beef production efficiency.

Following these initial results, the team plans to conduct a commercial scale trial with future Alpha-Gamma calves that are cattle bred, born, raised, fed and harvested outside the controlled University research environment. 

Additional trials will also proceed with Alpha alone; they want to know how he compares to top sires of multiple breeds selected through traditional ways. 

They also plan to continue to find and clone exceptional carcasses.