Many producers look at the incidence of left displaced abomasum or retained placentas to judge program success.
While these are good measures, experts would like you to place emphasis on four other parameters. Recently, these four parameters have been incorporated into a new Fresh Cow Summary from the
Here’s why you should consider looking at these four parameters in assessing the success of your transition or fresh-cow programs.
1. First-test milk production
“I look at first-test milk as an early indication of how fresh cows are doing,” says Mike Overton, dairy production medicine specialist at the
That is one of the reasons why the Transition Cow Index (
“We take a history of an individual cow and use that to project how she is going to perform at her first test,” says Ken Nordlund, professor of veterinary medicine at the
To make that projection, developers use a patented formula that includes the age of the animal, lactation number, milk production in the previous lactation, BST usage, number of times the cow is milked per day, somatic cell count in the previous lactation and other variables. The formula is used to project a 305-day lactation curve for the animal. Her projected lactation curve is then compared to her actual first-test reading to see if she is on track.
When an animal does better than expected, it means she is off to a healthy start. If she does worse than expected — and a negative deviation occurs -— it is a sign that she is experiencing problems.
“The beauty of the test is that it is the one and only test that can be taken and compared between farms,” says Nigel Cook, associate professor of veterinary medicine at the
Minnesota DHIA also plots “milk deviation”, but bases it exclusively on the animal’s first test compared to her second test in the current lactation. Therefore, Minnesota DHIA does not factor in the same variables that
Overton cautions against over-interpreting the results for individual animals. A cow can have a bad first test, owing to individual circumstances. Maybe the cow got pushed into the parlor by an agressive cow pusher, got scared and didn’t milk as well. Or, maybe the milking unit came off and didn’t get re-attached. For an individual cow, testing error or variation can occur. Yet, when viewed over all of the animals in the herd, significant trends can be established.
And, it is best to combine the first-test reading with other data to make a meaningful diagnosis.
2. Fat/protein ratio on first test
Yet, an “inversion” can occur when the butterfat percentage drops below the protein percentage. Hutjens says there may be signs of acidosis in the herd if 10 percent or more of the herd has butterfat readings that are 0.2 percentage points or less than the protein readings; for instance, 2.8 percent butterfat and 3 percent protein.
Meanwhile, a situation can occur on the other end when the butterfat percentage is significantly higher than the protein percentage. In this case, the cow may be mobilizing extra body fat and spilling non-esterified fatty acids into the blood, putting her at risk for ketosis.
If more than 40 percent of the herd is above the 1.4 line (meaning the butterfat percentage is more than 1.4 times the protein percentage on first test), it may be indicative of a ketosis problem, according to Todd Duffield, associate professor of veterinary medicine at the University of Guelph in Ontario, Canada.
When this occurs, ask yourself what is happening in the transition-cow program that puts the cows not only at risk for ketosis, but DAs and fatty-liver disease. Look at your close-up dry-cow management. Do the cows have enough bunk space? Are the heifers and mature cows segregated?
3. Percentage of cows freshening with mastitis
This is a direct mirror back to the dry-cow program. If 15 percent or more of the cows in a herd have somatic cell counts of 200,000 or greater at first test in a lactation, it indicates a problem in dry-cow management. Did the cows receive dry-cow antibiotic therapy, a teat sealant, or both at dry off? Was proper hygiene observed?
Veterinarians at the
According to Cook, a 6-percentage-point improvement has occurred among mature cows in 268 of the Wisconsin DHIA-recorded herds since 2001, and use of internal teat sealants at dry-off is one of the possible contributing factors.
Yet, 16.8 percent of the cows in these herds still freshen with somatic cell counts greater than 200,000. Experts would like to see that number fall to 10 percent or less.
4. Percentage of cows removed from herd in first 30 days in milk and first 60 days in milk
Let’s say you have a 100-cow herd, and your goal is to bring in 35 new heifers a year. Ideally, you will choose which 35 cows will leave to make room for the heifers. Perhaps they’re the cows that milk the least.
But, it doesn’t always work that way. Many times, you have no choice but to cull a cow because of a metabolic disorder or disease that she incurred during early lactation.
Cows removed from the herd in the first 30 days in milk usually represent fresh-cow disease problems, Cook says.
In one of the
When expanded to the first 60 days of lactation, the cull rate in those 79 herds grows to 9.7 percent, on average. Experts would like that number to fall to 6 percent or less.
You don’t want the 60-day cull rate to exceed the 30-day cull rate by more than two percentage points, says Mark Kirkpatrick, technical services veterinarian with Pfizer Animal Health.
Kirkpatrick says computer programs, such as Pfizer’s 100-Day Contract, can help producers zero in on the causes of high cull rates in their herds. For instance, a producer can select the cows that calved the week of Dec. 22 and see how they did in their lactation. If the cull rate is high among those animals, perhaps it was because the herdsman was on vacation that week for Christmas.
It’s truly amazing what you can learn from these programs. When used correctly, they can help you monitor the success of your fresh-cow program.