Understanding and Managing Metabolic Diseases
Published on Tue, 12/01/2020 - 10:28am
Understanding and Managing Metabolic Diseases.
By Jaclyn Krymowski.
Despite years of learning and research, along with some good old-fashioned trial and error, metabolic diseases continue to be a crippling issue within the dairy industry There are certainly enough white papers, articles and research on this topic out there to make anyone’s eyes glaze over. While there is a lot we understand, metabolic issues are very tricky to target, in part because it doesn’t take much to start a cascade of issues at arguably the most delicate point in a cow’s lifestyle – the transition period.
Not only can metabolic-related diseases be life-threatening, they are costly to treat, impact production, detract from the animal’s welfare and subclinical cases can affect a cow without even being known. With pre- and post-fresh cows being extremely sensitive to management and change, there are a lot of boats for management to keep afloat.
What we know
According to A 100-Year Review: Metabolic health indicators and management of dairy cattle by Drs. Overton, McArt and Nydam published in the 2017 Journal of Dairy Science, we’ve only been using metabolic issues to manage and monitor diseases in dairy herds for the last 25 years. This is largely due to our relatively new-found scientific knowledge in this area. It was during the 1990s in which indicators of metabolic health and wellness were first utilized in observational studies. More extensive research swelled in the 2000s, giving us many of the early indicators we have today. Fortunately, this means we are usually able to catch and effectively treat clinical animals for everything from milk fever to ketosis to retained placentas before an animal has reached that tipping point of no return.
About three weeks before and after calving are what make up the transition period as we know it today. Not only does a dairy cow go through all the typical hormonal struggles that accompany parturition, her body must prepare to run the race of production-level lactation for the next several months. Going from the dry state and maintaining pregnancy to this stage requires a lot of rapid metabolic changes within the cow, and if her body and systems are unprepared, she can (and almost certainly will) crash very quickly.
According to Metabolic Disorders of Dairy Cattle, a white paper by Dr. Burim N. Ametaj from the University of Alberta, metabolism can be defined as “…the sum of all physical, chemical, and metabolic processes occurring in a living cell or organism related to absorbance, breakdown or synthesis of necessary organic molecules in the body.”
It is the interruption or dysfunction of any or multiple of these processes that result in what we commonly refer to as metabolic diseases. While milk fever (hypocalcemia), ketosis, acidosis and fatty liver come to mind, laminitis, displaced abomasums, metritis, liver abscesses and bloat all fall into this category.
One of the issues in the complexity of metabolic disease is many of these issues are inter-related and one thing can lead to another. For example, the relationship between displaced abomasums and ketosis is what’s commonly referred to as bi-directional, meaning one may lead to another according to Dr. Todd Duffield in his white paper Minimizing Subclinical Metabolic Diseases in Dairy Cows. Likewise, he notes while the numbers aren’t exactly known, there seems to be a high correlation between subclinical metabolic issues and culling – even if it is unknown that was the underlying issue an animal is being culled for.
Management and Treatment strategies
Due to the large role of diet in metabolic ailments, nutritionists are often on the of the first lines of defense preventing them in the first place. But even a well-balanced ration coupled with helpful feed additives and buffers are hardly sufficient on their own without proper management.
For example, Fat Cow Syndrome, a term used to describe a complex of issues that accompany overfed animals in late lactation, can happen even in properly rationed diets. In an issue titled Dairy Cow Health and Metabolic Disease Relative to Nutritional Factors from NebGuide, a bulletin from the University of Nebraska-Lincoln Extension, experts recommend feed strategy to restore lost body condition during late lactation before the dry period. Besides helping avoid overweight animals, this is also helpful because feed conversion into body tissue is more efficient in late lactation than the dry period. Specifically, a body condition score of 3.5 is recommended at the time of dry off and maintained through calving. If a manager is unable to walk the pens on a regular basis to keep an eye on bodyweight, make sure you have employees properly trained to determine body condition scores.
Likewise, it is important to be sure animals are not too thin which can contribute to issues like ketosis. Contributors to Dairy Cow Health and Metabolic Disease Relative also recommend increasing grain 10 to 15 days before calving by 1 pound a day before reaching 15 pounds. This not only keeps animals at an optimal weight, it also prepares the cow for her lactation diet. If possible, changing the ration should be kept as gradual as possible through the first six weeks of lactation.
While certain metabolic issues can be prevented and monitored on a group scale, especially when it comes to diseases that are directly nutrition and diet-related, many clinical and subclinical issues will creep up on individual animals. If employees are not trained to monitor cows properly, animals may not be able to receive individualized treatment until they are seriously ill.
To help prevent this, be sure you have designated employees to walk pre-fresh and fresh groups at least a couple times a day. They need not be able to identify all the specific metabolic-related diseases, but they should at least be able to pick out the common symptoms including lack of intake, abnormal gaits, depression, gastric discomfort and downers. Once these animals are identified, they can promptly be examined and treated if necessary, by the herd health team. Remember to keep your health records up to date and clearly mark them as being metabolic-related so you can monitor and improve the herd’s overall performance in the transition period.
Because they are so multi-factorial, preventing metabolic diseases is an effort requiring the cooperation of everyone involved in herd management. Keep open lines of discussion with your veterinarian and nutritionists as you monitor progress and identify recurring issues. At the same time, take the time to invest in and educate yourself on these issues by attending conferences, webinars and reading through the research on your own time. Don’t underestimate the contribution your other employees can make in this area to monitor and treat animals. Besides being costly to treat, metabolic diseases on any level can impact a cow’s milk production and reproductive health far beyond the fresh and post-fresh periods. It’s important to have as many sets of eyes and hands around to help in this ongoing effort.