In the October 10, 2015 issue of Hoard's Dairyman (page 625), Dr. Michael Hutjens authored an article entitled "Fine-tune Your Feeding Knowledge." In that article, he reviewed 5 research reports that were presented at this year's annual American Dairy Science Association (ADSA) meetings in Orlando, FL.
One of those reports (Reducing DCAD in close-up cows), summarizes the research that was conducted by Dr. Tom Overton, investigating the effects of three levels of dietary DCAD pre-partum in which Animate® was used as the acidifying mineral supplement.
Experimental diets were analyzed with DCADs of, +18.3, +5.2 or -7.4 mEq/100g of dry matter with high dietary calcium (1.5% DM). Diets were fed beginning 24 days prior to expected calving date.
Results demonstrated:
- Cows fed the lowest DCAD diet (-7.4 mEq/ 100g of dry matter) had an average urine pH of 5.9 and had higher blood calcium concentrations (9.19 mg/dl) in the week post-partum compared to cows fed the medium DCAD or control diets.
- When comparing mature cows (> 3 lactation) vs. 2nd lactation animals, mature cows fed the lowest DCAD diet responded more favorably with significantly higher blood calcium concentrations than cows fed the medium DCAD or control diets.
Take-home message:
- Feeding a negative DCAD diet pre-partum, resulting in a urine pH below 6.0, is a useful strategy to help maintain optimal blood calcium levels post-partum.
- Urine pH monitoring is a useful tool to determine whether pre-partum negative DCAD diets are being optimally fed.
For more detail on the two abstracts presented at ADSA by Dr. Tom Overton, contact Dr. Overton at
11.5.2015