Researcher Wants To See Teeth
Used In Beef Quality Grading

By David Bowser

CANYON, Texas — It's been 75 years since USDA first established the standards for grading beef, in a 1924 publication that determined the age of a carcass by the color and hardness of its bones.

Now a meat scientist at West Texas A&M University here thinks it may be time to take another look at the relationship between the maturity of a carcass and the

tenderness of the meat, as well as how maturity is measured.

Dr. Ted H. Montgomery first became interested in that relationship and the use of teeth to determine age while

traveling in South Africa.

"South Africa uses it pretty exclusively," Montgomery says. "Australia has a real interesting situation because they have a lot of little different systems. They have a new system called "leading quality standards," that I

understand a small portion of their cattle are being classified on."

South Africa uses dentition, the teeth, to determine the age of an animal. In the South African system, Category A cattle have no permanent incisors, Category B cattle will have from two to six permanent incisors, and Category C

cattle will have eight permanent incisors.

"I have to tell you, having been over there three times, I've gotten some pretty tender meat," Montgomery says, "and it's pretty consistent in terms of its tenderness."

That was one of the things that piqued his imagination while he was there. He says he didn't have a tough steak the whole time he was in South Africa.

"I can't always say that here in the United States," Montgomery notes.

He began exploring the relationship between muscle tenderness and using teeth to determine maturity.

In looking at the literature on this subject, Montgomery and his research staff found that the first pair of incisors break around 24 months, the second pair around 30 months, the third pair at 36 months, and the fourth pair at 44 months.

"You'll see some variation," he says, "but basically, these age differences hold pretty well."

He admits that while it may be difficult to get dental records on individual carcasses in high volume packing plants, it can be done.

"The plants I've been in South Africa, you can get that information," Montgomery says. "We get kill floor information taken through the cooler in terms of hot carcass weights."

Programs such as the Certified Angus Beef program can collect such information, Montgomery says, and it could be relayed to the graders on the grading chain.

"It's just a matter of getting it done and deciding that it might be important," he contends.

A great deal more research on using teeth to determine maturity has been done in countries such as South Africa than here at home.

"We've done very little work here in the United States relative to dentition," Montgomery says. "One of the reasons is that we don't use it in our system, so there's no compelling reason to for a meat scientist to go out there and look at dentition, because it's not applicable."

In South Africa, recent data indicates a relationship between age and tenderness, in that Class A carcasses were more tender than carcasses in age classes B or C.

"They look at straight dentition there," Montgomery says. It is maturity comparison versus chronological age.

"In our maturity values in our grading systems, we have an A-0 to A-100," Montgomery continues. "This is our youngest classification. Then we have a B category, B-0 to B-100. These two are eligible for Choice grade. Keep that in mind. The C, D and E categories are our older cattle. These are not eligible for Choice grade."

In terms of age in months, the common thinking is that an A maturity animal must be between nine and 30 months of age.

"That's not necessarily true," Montgomery counters.

But generally accepted guidelines indicate that B maturity is from 30 to 42 months, C maturity is 42 to 60 months, and D is from 60 to 90 months. "Greater than 90 would be your E maturity cattle," Montgomery says. "I don't know who

came up with this. Sometimes, I wish it had never been published."

From a grading standpoint, Montgomery says he could take a birth certificate into the packing plant validating the age of a certain animal and the grader would laugh at him.

"It doesn't really make any difference," Montgomery says. "If it doesn't show those characteristics as far as ossification (bone characteristics) is concerned, that animal is going to be classified the way that bone looks. It doesn't really make any difference what the chronological age is."

He says he conducted a study about a year ago concerning the age and tenderness relationship, basing his age data on dentition rather than ossification.

"We were curious about what happens when you have a relatively young animal as evidenced by dentition," Montgomery says. "I think dentition and probably ossification, because they're both physiological indicators of age, are still a pretty good indication of age."

But while ossification tends to be the judgment of a grader as a carcass goes by on the chain, Montgomery thinks dentition is a more objective method of determining maturity.

Last year Montgomery and his researchers found some cattle in a Panhandle feedyard that came from Mexico.

"We felt they would have some age on them," Montgomery says. "There were going to be enough older animals in that particular group that we could study."

Along with a research team of Ty E. Lawrence, Dr. Louis J. Perino and John D. Whatley, they got together and came up with a way to classify these animals according to dentition. They were surprised by what they found.

To get the ossification side of it, Montgomery brought in two of the grading supervisors out of the Amarillo office.

"These aren't line graders," Montgomery says. "These are supervisors. These are the guys who supervise the actual graders."

These particular supervisors were involved in the B-maturity audit for the NCBA.

After a 48-hour chill, the cattle were evaluated by the two grading supervisors for both skeletal and lean maturity.

"These cattle did have some age on them," Montgomery says. "They didn't have as much as we would have liked, but we did see some interesting things.

Among the cattle that scored zero on their dentition scores, those that had no permanent incisors, 91.53 percent were A-maturity and 8.47 percent were B-maturity.

"In other words, from a grading standpoint, these cattle would have to have a modest amount of marbling to

grade Choice," he says.

Dentition group four had 82.24 percent A-maturity, 9.78 percent B-maturity and 7.98 percent C-maturity.

In the group of cattle that had a dentition score of six, or three pairs of permanent incisors, 62.5 percent were A-maturity.

"This was really startling to me," Montgomery says. "If the dentition means anything, these cattle are 36 months of age. We say that A-maturity cattle go from nine months to 30 months. These cattle are over the line.

"What this means is that we're putting into our mix a lot of cattle that are very old, and we're still classifying them as A-maturity. This has to add a lot of

variability to the mix as far as those cattle are concerned."

Overall, Montgomery says, there was a decline in A-maturity cattle and an increase in C-maturity cattle.

"It falls in step with exactly what we're doing," he says, "but what happened is we have creeping into this mix some cattle that maybe ought to be looked at more critically. The carcasses that were classified as having C-maturity with two and four pairs of permanent incisors could be a problem."

Many of these cattle were not eligible for Choice Grade, yet they were probably under 36 months of age.

"It can be argued that physiologically they are showing those indications," Montgomery says. "I'm not going to argue with that. That's exactly right. The problem we have here are the cattle from the six pairs of permanent incisors that are 62.5 percent A-maturity carcasses."

Those cattle were clearly older than the intended maximum for Choice and add variability to population, he says.

Whatever the results, one thing was clear. As the current system is constructed, ossification falls through the cracks.

"We've made A-maturity a threshold figure," Montgomery says. "I know when we report carcass data, we just report A-maturity. We don't break it down. In fact, it would be very difficult to back off that now because of the chain

speeds."

The results of Montgomery's study indicate that using ossification, lean texture and color alone may affect accuracy in determining carcass maturity. The inclusion of dentition in maturity determination may improve accuracy and repeatability, he contends.