Researchers study cattle eyes for a more accurate age verifier


MANHATTAN, Kan. – There is nothing cuter than the big brown eyes of a calf, but Kansas State University researchers are interested in Betsy’s eyes for another reason.
They are looking at the eye lenses of cattle in hopes of developing a new age verification method, said Michael Dikeman, a professor in the department of animal sciences and industry.
Correlation. Scientists believe that the weight of a lens and its nitrogen content may correlate with chronological age in cattle.
Researchers have found that there is a relationship between the amount of nitrogen in the eye and the chronological age of pigs, Dikeman said.
Kansas researchers are looking to see whether the same is true in cattle.
Why it matters. Some beef importers, including key buyer Japan, have said they will only accept beef from cattle that are 20 months of age or younger.
Japan halted imports of U.S. beef 19 months ago after a cow in Washington state was confirmed to have bovine spongiform encephalopathy.
BSE does not appear to affect younger cattle and has not been found in animals under 20 months of age.
Until Japan imposed the ban, it had been a primary buyer of U.S. beef. Negotiations between the United States and Japan focused on the resumption of U.S. beef sales to Japan have been ongoing.
Nine months ago Japan agreed that it would resume purchases as long as the beef was from cattle 20 months of age or younger.
So far, however, no purchases have occurred.
New method. The USDA has proposed to use a method of evaluating carcasses known as “A40 carcass maturity” to assure Japan and others that cattle are 20 months or younger.
That method, however, has some flaws, scientists said.
“Under this standard (A40 carcass maturity), approximately 90 percent of cattle which are actually 20 months or younger would be excluded,” said Chris Raines, a Kansas graduate student who is working on the eye study.
“This is because the carcass maturity assessment is not as accurate as the beef industry would like.”
Graders. Beef carcass maturity is evaluated by USDA graders to determine whether the animal was 20 months or younger at the time of slaughter.
But Dikeman said that the actual age of a steer or heifer and the age that it appears to be can vary greatly from animal to animal.
Kansas State, in the study funded by the Kansas Beef Council, is looking for a more accurate method of determining age in hopes that a higher percentage of beef will be eligible for export.
“If the eye lens method is more accurate in determining the age of cattle, then both beef processors and cattle producers could benefit because a higher percentage of cattle would be eligible for export,” Dikeman said.
Current progress. The procedures of the study include collecting eyes from 500 head of cattle with known ages ranging from 14 to 36 months at commercial processing plants.
After collection, the lens of each eye will be separated out, weighed and then tested for total nitrogen content, Dikeman said.
These findings, correlated with the chronological age of each animal, will be used to develop an age-prediction equation with a high enough confidence level to meet Japanese standards.
Raines said that the biggest challenge with the study so far is trying to find cattle over 20 months with known ages.
Results from the research are expected to be available by next spring.

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