Dry cow protocols have largely been standardized throughout the last few decades. Traditionally, the dry period lasts about 60 days as cows are dried off by expected calving dates using blanket dry cow therapy. Recent research has been putting these standards to the test, though, with data showing that a gradual dry-off period, a shorter dry period, and selective treatment may result in more milk yield and lower somatic cell counts (SCC). Virginia Tech master’s student Holly Parks, along with associate professor of nutritional physiology, Ben Corl, highlighted dry cow protocols that have been challenged by research in a Virginia Dairy Pipeline article.
The dry period allows the cow to prepare for the calf prior to its arrival and allows time for the mammary gland to rejuvenate. As cows are treated and moved to a separate dry cow area, research has shown that additional care could be helpful for a more productive upcoming lactation. “Dry cow management by means of milk cessation methods, changes to dry cow therapy, and a reduction in dry period length are additional practices that may enhance the likelihood of a productive subsequent lactation,” noted the researchers.
Dry-off length and time
After cows are given treatment, the mammary gland goes through a process of involution. The mammary gland will still produce milk until 36 hours without milking when the udder reaches full capacity. Alveolar cells that are responsible for milk production will then slowly start to die and be reabsorbed by Day 11 after dry-off, reducing pressure. This has sparked new research as to whether abrupt dry-off or gradual dry-off methods are more helpful to the cow.
Abrupt dry-off occurs when the farm continues to milk cows regularly until the day of dry-off, while gradual dry-off slowly reduces the amount of milking events until the day of dry-off. “Research regarding gradual cessation has found that udder health is improved in relation to fewer clinical mastitis cases during the dry period at calving,” referenced Corl and Parks. The same study also showed that cows giving more than 35 pounds of milk per day at the time of dry-off had higher SCC scores in the next lactation.
Compared to the standard dry-off procedures at 60 days, there is also some research that showcases the benefits of an earlier dry-off. One study showed that implementing a shorter length (40 days) can reduce mastitis and transition issues. It also showed boost in milk yield and improvements in reproduction and energy balance, with no negative effect on colostrum production, said the researchers.
To treat or not to treat?
While these results are farm-specific, consider how you can improve your dry-off protocols. As blanket treatment treats all quarters with intramammary antibiotics, selective treatment focuses primarily on infected quarters. Parks and Corl also wrote, “Research has shown that using selective treatment has no negative effect on somatic cell count or milk yield in the following lactation. Utilizing selective treatment gives farms the ability to decrease antibiotic usage and cost in dry cows without affecting the health of the cow and milk production in a subsequent lactation.”
As studies evaluate how dry-off practices affect milk yields and mastitis, it is important to remember each management decision must focus on what works best for your operation. Consult with your veterinarian and nutrition experts on how to dial in on your current dry cow program.
