Dairy cow livability measure added to genetic evaluations

The Council on Dairy Cattle Breeding (CDCB) announced today it was adding a new genetic evaluation tool—Predicted Transmitting Ability for Cow LIV

(LIV)—for all breeds for the August 2016 sire runs.

The new trait predicts the cow's ability to remain alive in the herd. Productive Life estimates survivability, but does not differentiate between culling and dying. LIV measures culling only.

"When a cow is sold for dairy or beef, the sale income is returned to the owner," says Duane Norman, CDCB technical advisor. "In contrast, if a cow dies or is euthanized, the cow produces no income."

"Populating U.S. dairy herds with cows capable of longer productive life gives producers more opportunity for voluntary culling," he says.

Deaths claim about 20% of U.S. cows. The lost disposal income of these animals equate to about $800 million annually. So reducing these losses can dramatically increase income opportunities.

The good new is that the LIV trait is also heritable and highly reliable. Even for young, genomic tested bulls, the reliability is 56%.

LIV values will range from -5 to +5, and are placed on a lifetime scale. Since the average LIV is 80%, the LIV ratings will be added or subtracted from this mean. For example, if a bull's daughters have a LIV of +2.1, his LIV rating is 82.5. Conversely, a bull with daughters with -0.5 LIV will have a rating of 79.5.

This 2.6 percent difference in an average, 200-cow herd, with cull cows valued at $1,200 per head, translates into $6,240 in additional income.

In the future, LIV will be incorporated into all four lifetime merit indexes. "Having Cow LIV is one more step toward adding value to the genetic information that will improve dairy producers' profitability," says Paul VanRaden, who along with Janice Wright, developed the rating at USDA's Animal Improvement Programs Laboratory. "Producers participating in DHIA can help to improve the reliability of this trait by accurately reporting the reasons why cows leave their herds."