By Dr. Neil Michael
Managing fresh cow performance is a challenge. When ketosis becomes an issue, cows start slowly and you can expect significant losses due to direct treatment costs and lost future income. Contributing factors
Much of the variation in how well cows go through transition can be explained by changes in cows, feedstuffs and the cow environment. Cow factors, such as long previous days in milk (DIM) and days dry, excessive body condition, and older age, all raise the risk of metabolic disease and culling. Likewise, cow environment factors like overstocking, pen changes near calving, heat stress and inadequate cow comfort also raise the risk of poor fresh cow performance. Lastly, common nutritional factors that contribute to fresh cow problems include poor bunk management, sorting, poor dry matter intakes and forages with elevated levels of butyric acid. All cows experience some degree of negative energy balance after calving due to a combination of lowered intakes and greater energy demands. The liver produces ketones as it converts body fat to provide energy during the transition period. The major ketones produced are acetate, acetoacetate, and beta-hydroxybutyrate (BHBA). Although cows can use ketones as a source of energy for many body functions (not milk production), ketosis occurs when excessive amounts of ketones build up within the bloodstream. Ketosis and animal health
Herd prevalence of ketosis has been reported to be 30 to 50 percent based on work by multiple researchers in recent years. Cows experiencing ketosis eat less, resulting in additional body condition loss and lowered milk production. Clinically, cows are often off-feed and may have an acetone smell on their breath. Most importantly, cows experiencing ketosis are at greater risk for other problems, including metritis, mastitis, and displaced abomasum (DA). That’s in addition to reduced milk production and fertility. Monitoring ketone levels
The gold standard for measuring ketone levels is blood BHBA testing. Recently, some nutritionists, veterinarians and herd managers have started taking advantage of a new technology that allows them to test blood BHBA at a fraction of prior costs using a small handheld meter originally targeted for human diabetics (Precision Xtra™). The tool can be used to evaluate metabolic risk of the herd and detection of ketosis on individual cows. To monitor metabolic risk in groups of fresh cows, individually test a target group of 12 cows that are 2 to 15 DIM using the blood BHBA meter. If two or more cows have BHBA results of 1.2 mmol/L or greater, your herd metabolic risk is high and you should investigate possible influencers. If fewer than two cows hit that level, you are doing a good job with your transition cow health. Changes in treatment
Many people have elected to use blood BHBA meters to test individual cows at 4 and 11 days in milk instead of routine urine and milk tests. Because the BHBA tests enable you to accurately detect very low levels of ketones, we suggest ketosis protocols be thoroughly reviewed and separated into progressive levels (from conservative to aggressive treatment). Progressive protocols have the advantage of avoiding overtreatment and limiting the number of cows that go off-feed. One of the biggest benefits of progressive protocols has been reduced use of dextrose IV. In the past, this treatment was regularly used to treat ketosis and prevent DAs. However, new research indicates that the high dosage of dextrose IV may actually cause DAs. Preventative care
Regularly testing BHBA levels on a herd basis also has improved preventative care. Herdsmen will sample 12 to 15 cows every other week to identify trends in metabolic risk. By keeping accurate records over time, they are able to link subclinical ketosis with factors such as previous DIM, days dry, and days in the close-up pen. This helps you better manage transition cows and solve the roots of ketosis rather than treating the symptoms. About the author: Dr. Neil Michael previously worked as the Vita Plus director of dairy initiatives. He grew up on a dairy and swine farm in northeast Indiana and attended Purdue University, where he earned a bachelor’s degree in food science, his DVM degree from the School of Veterinary Medicine and his MBA from the Kranert Business School. Michael joined the Vita Plus team in 2010 with a special interest in helping producers with transition cow health and economics, reproductive management, and data management related to animal performance and employees.