How much calcium is just right for transition cows?
Conflicting recommendations and a growing trend towards the extreme have left nutritionists and producers questioning the best approach to feeding dietary calcium to prefresh cows fed a negative DCAD diet.
Last month the SoyChlor team addressed common questions during an exclusive webinar by turning to the research for answers.
Q: What is driving the recent trend toward more extreme dietary calcium recommendations?
A: This recent trend toward the extreme may be due to a misinterpretation of the research. Research on metabolically alkalotic cows has heavily skewed the recommendations for feeding calcium to metabolically acidotic cows, but it is crucial to distinguish between metabolically acidified cows and metabolically alkalotic cows when reviewing the research. Although research has not yet definitively determined the ideal amount of calcium in negative DCAD diets for prepartum dairy cows, several trials suggest that a moderate amount is enough.
Q: Does the source of calcium impact DCAD status?
A: Absolutely. Both calcium chloride and calcium sulfate will contribute their soluble chloride and sulfate anions, making DCAD lower than would a similar amount of calcium coming from calcium carbonate. There is some question whether the carbonate from calcium carbonate might act as a metabolic buffer.
Q: How much dietary calcium does SoyChlor recommend?
A: Currently, there is no scientific justification for feeding high amounts of calcium to metabolically acidified dry cows. Some studies even show that diets with more than 1.5 percent calcium can reduce feed intake and reduce colostrum quality. In successful DCAD programs, the amount of dietary calcium is one of the least important factors. The SoyChlor team recommends a moderate amount of calcium; start with around 100 grams Ca per cow per day. Half of that can come from feeds, and the other half supplemental.
Get more answers to your dietary calcium questions by watching the full webinar here.