It's occurred despite heavier harvest and carcass weights, and increased days on feed, Anderson says. “During this time, the percentage of carcasses receiving USDA Yield Grades of 4 or 5 has increased. All indications are that carcasses are heavier and fatter than a decade ago, yet USDA Quality Grade hasn't increased,” he says.

Anderson and Justin Gleghorn, also of VetLife, examined that company's database for non-genetic reasons that might explain the dearth of Choice progress. They looked at placement factors such as cattle age, sex and weight going on feed and seasonality. They examined cattle health, nutrition and management ahead of the feedyard, everything from the impact of photoperiod and the vitamin A of pasture forage. They looked at feedlot nutrition, health and management, everything from limit-feeding implications to the differences grain processing makes in energy availability.

They looked at the use of implants in steers and heifers and the impact of feeding heifers MGA (it increases grade, actually). Finally they looked at the relationship between using more corn co-products and differences in end-point selection.

Nothing suggested there should be a significant increase or decrease in quality grade, which leaves drought as the most likely environmental reason.

“Any nutritional insult impairs the ability to marble,” says Anderson, noting the drought still gripping wide sections of the nation has affected every section of cow country over the past five years.

“Since marbling deposition is a lifetime event, all segments of the industry will have to focus on quality in order to make significant progress,” Anderson says. “Research shows that early weaning and diets high in concentrates will increase marbling. The health status of cattle, especially early in the feeding period, appears to have an effect on performance and carcass characteristics. Growth promotants can affect marbling, but the effects are dependent upon sex and dosage of the product. End-point selection influences quality grade, yield grade and other economically important carcass traits.”

“The complexity of marbling allows some opportunity,” Anderson says. “While traditional wisdom states that marbling can be reduced by negative lifetime events, but not increased, recent research indicates that opportunity exists to increase marbling.”