An ounce of prevention is worth a pound of cure.
That’s certainly the case when it comes to fresh-cow health problems. In fact, an on-farm trial conducted by Mark Kinsel, consulting veterinarian in Nampa, Idaho, found that it really does pay to prevent fresh-cow disorders.
The 2,500-cow dairy used two treatment protocols — one for “problem” cows, those with a difficult birth, milk fever, twin births, and one for “normal cows” — to manage the fresh cows. In addition, daily temperatures were taken and any cows with a fever greater than 103 F received prompt treatment. The result: cows that received treatment after fever detection produced the same amount of milk as herdmates that did not develop a fever. In addition, at 125 days in milk, all cows enrolled in the monitoring program had a 1,700-pound milk production advantage, on a mature equivalent basis, compared to herd performance in previous control periods. And to top it off, the dairy also saw a four-fold increase in its pregnancy rate.
Although the dairy started the program to help reduce the incidence of metritis and improve pregnancy rates, the monitoring program helped them get cows through the first 100 days of lactation with minimal fresh-cow problems.
Fresh-cow health problems — milk fever, displaced abomasum, retained placenta, ketosis and metritis — negatively impact your fresh cows’ performance. In a 100-cow herd, they can steal a combined total of about $383 worth of milk during the first 30 days of lactation. However, the losses don’t stop there. Decreased reproductive performance and increased risk of culling weigh on a cow’s profitability also.
In many cases, you may not notice the negative impact of a fresh-cow disorder until it becomes a big problem or clinical case. However, losses begin when a fresh cow develops a subclinical problem — a problem that’s not immediately obvious to an observer.
For example, research reported in the January 1997 Journal of Dairy Science shows that 30 percent of the total milk production losses from a displaced abomasum occur before the cow is diagnosed with the problem, says Yrjo Grohn, veterinarian at Cornell University. In the study, clinical diagnosis generally occurred at about 20 days in milk. However, milk losses during those first 20 days averaged 368 pounds of milk per cow.
When a subclinical problem persists, it often escalates into a clinical case and the negative impact on cow health and milk production continues to escalate.
To prove that point, researchers at Cornell University conducted another study to analyze monthly milk yields to determine the effect of ketosis on milk production at different stages of lactation. The study, which was published in the March 29, 1999 Preventive Veterinary Medicine, utilized 2,604 Holstein cows and showed that ketotic cows produced about 19.8 pounds less milk per day during the seven days after diagnosis than non-ketotic cows.
To complicate matters, “Research has shown that these disorders seem to be interrelated,” says Carlos Risco, veterinarian at the University of Florida. Because of this, one fresh-cow disorder can easily spin-off into another. For instance, cows which develop milk fever are almost six times more likely to develop ketosis, which limits milk production even further.
Even after clinical signs fade and milk production recovers, problems that occurred at freshening continue to hamper a cow’s performance — and increase her chances of being culled.
A study reported in the April 1998 Journal of Dairy Science examined the effect of seven common diseases on culling. The researchers found that during the first 30 days of lactation, cows that developed a displaced abomasum were 2.3 times more likely to be culled than non-affected herdmates and that cows with ketosis were 1.9 times more likely to be culled than their herdmates.
The table above shows the increased risk of culling due to three metabolic problems researched in the study.
In addition to the in-creased culling risk, fresh-cow problems also negatively impact cows’ reproductive performance. The result: an increase in days open and lower conception rates.
For example, a 1990 study, published in the Journal of Veterinary Medicine, found that ketotic cows averaged 100 days open and had a first-service conception rate of 40 percent. Their non-ketotic herdmates however, averaged just 80 days open and had a 75 percent first-service conception rate. Economic research shows the sooner you get cows bred after calving, the greater lifetime profitability they will have.
Another study, published in the February 1996 Journal of Dairy Science, looked at the change in conception rate. Cows with retained placentas had a 14 percent lower conception rate than cows that did not retain, and cows with metritis had a 15 percent lower conception rate than non-affected cows.
Losses add up
The National Animal Health Monitoring System (NAHMS) Dairy ‘96 Study found that on U.S. dairies, milk fever occurred at the rate of 5.9 percent. This same study found that displaced abomasums plagued 2.8 percent of U.S. dairy cows, and retained placentas affected 7.8 percent of dairy cows. Furthermore, an August 1995 Journal of Dairy Science study found that the incidence of metritis averaged 7.6 percent in New York Holsteins, while the incidence of ketosis averaged 4.6 percent.
Milk production losses in early lactation add up quickly. For example, in a 100-cow herd with a 22,000-pound rolling herd average, each cow that develops milk fever produces 4.7 percent less milk per day than her herdmates during the first 30 days of lactation. That means a fresh cow giving 72 pounds of milk per day would produce 101.5 pounds less milk in the first 30 days. Add in the 6 percent incidence rate for milk fever, and that brings total milk losses up to 609 pounds of milk if six out of 100 cows suffer from the disorder. With milk priced at $10 per hundredweight, the loss amounts to $60.90 during the first 30 days of lactation. Combine that with the milk production losses that occur from four other common disorders, and the total loss adds up to $383.30 for every 100 cows in your herd. (Please see, “The high price of fresh-cow disorders” above.)
And, that’s just the tip of the iceberg. These figures do not include the cost of treatment, and the losses from reduced reproductive performance and increased culling.
An ounce of prevention is worth a pound of cure.