Editor’s note: The following case was handled by Bob Corbett, nutritionist and veterinarian with Dairy Health Consultation in Spring City, Utah.
A 5,000-cow dairy in Mexico had been experiencing a number of issues with metabolic disease and infectious disease in fresh cows and heifers.
Bob Corbett, a nutritionist and veterinarian from Spring City, Utah, was called in to see what he could do about it.
It became apparent that much of the problem had to do with the way the transition cows were being handled prior to calving. The farm had expanded and many of the close-up pens were filled to capacity. Cows that were over-conditioned going into calving were placed in a special pen. In that particular pen, and in some other pens, as well, the cows weren’t given the benefit of a close-up ration for a full three weeks.
This can happen on a lot of farms, Corbett points out. The farm may set its computer to flag cows at 259 or 260 days of a 280-day gestation period. But if the farm is only moving cows once a week, some of the cows that miss the cut may have to wait up to six more days before moving into the close-up pens.
In addition, up to 20 percent of the cows can calve 10 days early ― day 270 vs. day 280, Corbett says.
As a result, many cows aren’t getting the full benefit of a close-up ration, which is meant to prepare them for lactation. Indeed, it is probably the most critical ration on the farm, Corbett says.
At this dairy in Mexico, the managers decided that the over-conditioned cows should only be in the close-up pens for two weeks to try and prevent more weight gain. And, with the vagaries of moving them once a week, that meant some of the cows were only in there for a week or so. On top of that, they were fed a lower-quality ration than the other transition cows.
“That was probably the worst thing they could do,” Corbett says. It was important for the animals to maintain body condition going into lactation, but they were being slighted. Many of the animals ended up with serious energy-balance issues during early lactation, such as fatty liver syndrome and ketosis. There was also a high rate of retained placenta.
As a result of a high rate of metabolic disease, affected cows did not reach a high level of peak milk. Each pound of peak milk results in approximately 250 pounds more milk during lactation. The lower peak milk resulted in less milk produced during lactation. These cows then gained an excessive amount of weight before going dry, resulting in a significant number of animals that were over-conditioned in the dry pen. This can become a vicious cycle unless the transition period is managed properly.
To resolve this, Corbett changed the pre-set dates on the computer to flag cows at 252 to 254 days of gestation, adding almost a full week to what the previous settings had been. It was also important to have all of the animals moved at the same time, whether they were over-conditioned or not. The goal was to have all of the animals in the close-up pens for at least three weeks before calving. And, all of the cows were placed on a normal close-up ration.
The dietary cation-anion difference (DCAD) of the ration was adjusted to make it negative for the prepartum cows, which helped the cows mobilize calcium from their bones and their digestive tract to the bloodstream. Additional calcium was added to the mineral mix in order to maintain blood calcium levels during parturition.
These changes made a big difference. Metabolic problems cleared up and the cows had a much smoother transition period.
As for the farm owners, “they were very pleased,” Corbett says. “They had been fighting that problem for quite some time.”