Better management means better outcomes for dairy breeding outcomes. Julio Giordano, director of the Dairy Cattle Biology & Management Laboratory at Cornell University and an associate director of the Cornell Institute for Digital Agriculture, presented “Integrating Precision Technologies for Improving Management and Health of Dairy Cattle” as a recent webinar through the Dairy Cattle Welfare Council.

“Most farms will manage all cows the same,” Giordano said. “We tend to implement the same reproductive program for all calves; however, everyone must be aware that not all cows are the same. It’s not that we just have cows of different colors.”

He added that the biology, physiology and potential of cows varies among individuals in a herd. Putting cows in the same “bucket” or category means that they’re bred the same way. It’s convenient. It’s easy. But it’s not as effective long-term as precision management.

“There may be metrics of performance or areas of dairy herd management we can improve when we go from putting all the cows in the same bucket to putting cows in different buckets,” Giordano said. “More and more farms are … putting cows in different buckets.”

His research indicates that targeted reproductive management (TRM) targets cows for greater gains in herd performance or management when managed as a single group.

“We are just seeing just the surface, but there’s a whole lot of stuff underneath,” Giordano said.

The “buckets” for TRM are estrus during the voluntary waiting period (VWP); estrus during synch (promoting heat expression during synch protocols); ovarian status – what producers find at the first check; estrus/heat as a predictor of reproductive potential of cows and as a way to increase fertility; and heat buckets – whether or not they show heat during a certain time during lactation.

Giordano said that 40% to 50% have automated estrus alerts during the VWP.

“The sooner cows start cycling after calving, the more heats they’ll have and the better they’ll do,” Giordano said. “Today we have technology that can detect heat. We’ll use this to put cows in a heat group and a non-heat group.”

This is important because the heat during the VWP is associated with better reproductive performance.

“That’s pretty significant,” Giordano said. “Forty percent more of the cows showed a heat within three weeks.” That can justify separating cows based on heat vs. no heat in the VWP.

Giordano also said that cows not bred while in heat in those 28 – 34 days have to be enrolled in a synch program. Some cows weren’t detected by 50 days only because they lagged a bit. But allowing them a little more time allowed them to be bred while in heat.

“By 90 days, the heat cows and 76 of the no-heat cows have been bred at least once,” Giordano said.

He called targeting the heat cows and no-heat cows with different strategies as the “gold standard” for farms, along with synching every single cow for their first breeding.

“It is very good to optimize first service conception,” Giordano said. Although the first service conception rate is nearly always lower, “that’s not the most important metric,” he added.

In addition to pregnancy rate, how long it takes, survival and more are also important. Giordano said that these programs work well for farms that have heat detection technology.

“When cows show heat the end of synch protocols, they do better,” Giordano said.

He has a working hypothesis that if farmers have a way to make cows show heat at the end of a synch protocol, they can identify high fertility cows. This strategy can help save on semen costs.

“We have typically 56 hours from the time of the first treatment until the last GnRH (gonadotropin-releasing hormone),” Giordano said. “We want all cows on timed breeding. When you do that, you don’t let cows show heat. GnRH blocks heat expression and doesn’t let the cow show heat.”

To allow cows to show more heat, he advised delaying the last GnRH and timing the first service by increasing the proportion of cows that express estrus before insemination.

“We want cows to show heat, not just breed them in heat,” Giordano said. “Showing heat improves fertility.”

Delaying timed AI by just a day increased the percent of cows bred.

“Targeted repro management works,” Giordano said. “It can improve performance, management or both. We have some good predictors to use for TRM: estrus during VWP, estrus during synch, ovarian status, health, season, et cetera. A significant amount of work remains to create new TRM programs and demonstrate value to farms.”

by Deborah Jeanne Sergeant