Recent research reinforced what was already known about lowering DCAD levels in prefresh diets, but also added some practical applications to producers’ toolboxes.
By Dr. Elliot Block, Research Fellow, Arm & Hammer Animal Nutrition
Lowering prepartum dietary cation-anion difference (DCAD) in the three weeks prior to calving to reduce postpartum metabolic disease is a tried and true strategy to help dairy cows successfully navigate the transition period.
Over and over, this nutritional solution has been shown to reduce incidence of retained placenta and hypocalcemia. These health challenges negatively impact postpartum feed intake and energy balance, and are two causes of expensive and significant reductions in reproduction and milk production when they occur.
However, in order to reduce social and nutrition stress from multiple pen moves and ration changes, some dairies need to lower DCAD levels longer than the traditional 21 days to take advantage of this nutritional management strategy. In addition, some dairies are unable to create multiple prefresh groups because of facility limitations, which can make a 21-day lower DCAD diet difficult to implement.
Positive Results
Research1 from the University of Minnesota published in the September Journal of Dairy Science shows that feeding lower DCAD diets for as long as 42 days has a positive effect on blood calcium status and milk production.
In the study, cows were fed one of three diets:
• A negative DCAD (−16 mEq/100 g of dry matter) for 21 days before calving
• A negative DCAD (−16 mEq/100 g of dry matter) for 42 days before calving
• A positive DCAD (+12 mEq/100 g of dry matter) for 42 days before calving
Results indicated:
• Overall, cows in both groups fed the negative DCAD diet tended to have greater postpartum total blood calcium compared with cows fed the positive DCAD diet
• Cows fed negative DCAD for 42 days prepartum tended to have greater postpartum total blood calcium than cows fed negative DCAD for 21 days prepartum
• Feeding a negative DCAD diet for 21 days prepartum resulted in higher milk yield during the first 56 days of lactation compared with cows fed a positive DCAD diet prepartum
• Milk production for cows fed negative DCAD prepartum diets for 42 days was similar to the 21-day treatment
Practical Applications
The research reinforced what was already known about lowering DCAD levels in prefresh diets, but also added some practical applications to producers’ toolboxes:
• The confirmation that cows can receive negative DCAD diets longer than 21 days can mean fewer pen moves for large herds because they don’t need to split prefresh groups.
• Results also mean producers who do not have facilities that allow multiple prefresh groups can more easily adopt this nutritional management strategy for improved transition cow health and performance.
Click here to access the abstract and learn more about the study.
1 Weich W, Block E , Litherland N. Extended negative dietary cation-anion difference feeding does not negatively affect postpartum performance of multiparous dairy cows. J Dairy Sci 2013;96:5780-5792.
