Dr. Ryan Pralle, a transition cow specialist with the University of Wisconsin – Platteville shared some of the latest research findings about transition cows in a recent episode of The Dairy Signal from the Professional Dairy Producers (PDPW). Separating facts from fiction, Pralle shared his thoughts on transition cows, ketosis, body condition scores (BCS) and reproduction management.
The transition period is critical to a successful production period. Body score, calving interval and managing high-energy feed intake are all keys to the transition from dry to milking to peak production to the dry period again.
Fact: Ketotic cows aren’t always an emergency. When testing for ketosis, a level of 1 or 2 can indicate ketosis but at a non-critical level and may not require treatment. A level any higher than that does need to be addressed. A key management action that may result in a low number spiking upwards is when moving from pen to pen as a cow transitions. Pen moves can be hard on a cow, and visual management as well as a ketone test after about 10 days in a new pen can quickly assess the health of a cow early in lactation. While a cow may look well and seem to be doing well, a keto monitor may ward off problems later. For example, when tested with the fresh cow group, a cow may be fine; 14 days in milk she may show increased ketones and a drop in production, so an additional test at 10 days post pen move could be very beneficial.
Fact: Keeping transition cows comfortable is a critical step often overlooked. Pralle reminded dairies to make sure they keep a low stocking density in transition and fresh cow pens. Proper ventilation in that area is a must, and deep bedding will go a long way to ensuring enough rest for the fresh cow. He recommended a urine test strip at least once when the cow is in these pens to test for metabolic health. It may also be a good idea to pull blood once to help with appetite management, testing the blood for beta-hydroxybutyrate acid (BHBA). Managing BHBA, which helps the liver as the body metabolizes backfat, is critical to transition cow management. Non-esterified fatty acids (NEFA) are the energy that mobilize backfat to milk through maintenance of the mammary gland, brain and elsewhere in the body. Testing for these two substances can give a good indication of the way a cow is headed as she moves through the transition stage.
Fiction: A high BHBA is always a bad thing. Depending on BCS, a high BHBA threshold can mean that a cow is working just as she should to produce milk efficiently. Careful monitoring is needed, however, to ensure that she has not gone too far the other way and begins to drop in milk.
Fiction: High production means all is well. Research has shown that the highest-producing cows often show signs of subclinical ketosis when tested with a blood pull. Two signs of subclinical ketosis are an unexpected drop in milk and cows not breeding back properly.
Fact: A key piece of transition cow management is a shift in perspective as far as calving interval, forced dry-off and lifetime milk production. When cows are bred back to calve with a 45-day dry period, several results occur. First, they are forced to be dried off while still eating a high-energy diet; thus a move to the dry cow pen avoids a long period of low production with high-energy feed intake. Second, taking her off high-energy feed late in lactation lowers the risk for a significant change in BCS. The lower the change in BCS, the better transition a cow will have.
Researchers are seeing that the best-managed herds are managing reproduction first and foremost to avoid that high-energy feed late in lactation and keeping days dry to a minimum, resulting in more lifetime milk and healthier cows through the transition and production periods.
A management practice change based on recent research may be to split the transition cow group into two. One group would be fed a low-energy feed and could be made up of those cows that are far off from calving. While this would be beneficial to manage ketosis and other metabolic problems later, it could see a result of lower milk production and lower fat test once she returns to the production herd. The key is to balance the pros and cons of adding this second group. Pralle said, don’t change just to change but pointed out that if BCS is well maintained with short dry periods, two groups will work well.
Two concluding management practices Pralle reiterated were to super-manage your reproduction program to shorten dry day numbers, avoiding time for a cow to add too much backfat. Second, while it may be labour intensive, training an employee to monitor BCS in the close-up pen and again eight to 14 days after calving can have significant benefits in a reduction in ketosis and displaced abomasum problems.
