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.
奶牛存活率的值处于-5 到 5之间, 并且终生在这个范围内波动。奶牛的平均存活率是80%,存活率评级将从平均值中添加或减去。例如,如果一头公牛的女儿存活率+ 2.1,那么她的存活率等级为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.”
在未来,存活率将被纳入所有四个终身价值指标。Paul VanRaden说“拥有奶牛存活率是一个更一步增加价值的基因信息,提高牧场主的盈利能力”,他和Janice Wright美国农业部动物改进项目实验室一起研发出评级标准。“生产者参与DHIA可以通过准确牛离群的原因的报告来帮助改善这一性状的可靠性。”