|WEISS, W - The Ohio State University|
|AZEM, E - Dsm Nutritional Products, Ltd|
|STEINBERG, W - Dsm Nutritional Products, Ltd|
Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2015
Publication Date: 6/4/2015
Publication URL: http://handle.nal.usda.gov/10113/61349
Citation: Weiss, W.P., Azem, E., Steinberg, W., Reinhardt, T.A. 2015. Effect of feeding 25-hydroxyvitamin D3 with a negative cation-anion difference diet on calcium and vitamin D status of periparturient cows and their calves. Journal of Dairy Science. 98(8):5588-5600. doi:10.3168/jds.2014-9188.
Interpretive Summary: Effect of Feeding 25-Hydroxyvitamin D3 with a Negative Cation-Anion Difference Diet on Calcium and Vitamin D Status of Periparturient Cows and Their Calves . Low blood calcium is a major health concern in transition dairy cows. Feeding anionic diets often reduces hypocalcemia but additional dietary strategies are needed. We hypothesized that feeding 25-(OH)D3 compared with vitamin D3 would increase the concentrations of the active form of vitamin D in serum and colostrum which would improve calcium status of the cow and vitamin D status of the calf. Supplementation of 25-(OH) D3 did increase vitamin D status of the cow and her calf. However, it did not enhance calcium status of the cow and prevalence of clinical and subclinical hypocalcemia were non-significantly increased.
Technical Abstract: Holstein cows (>1 gestation) were fed 1 of 3 diets during the last 13 d of gestation (ranged from 22 to 7 d). The Control diet was formulated to provide 18,000 IU/d of vitamin D3 and had a dietary cation-anion difference (DCAD) of 165 mEq/kg (DCAD = Na + K – Cl – S). The second diet (DCAD+D) provided the same amount of vitamin D but had a DCAD of -138 mEq/kg. The third diet (DCAD+25D) had no supplemental vitamin D3 but provided 6 mg/d of 25-OH vitamin D3 with a DCAD of -138 mEq/kg. Diets were fed until parturition and then all cows were fed a common lactation diet that contained vitamin D3. Negative DCAD diets reduced urine pH with the greatest decrease occurring with the DCAD+D treatment. Urinary Ca excretion was greatest for cows fed DCAD+25D followed by cows fed DCAD+D. Urinary pH was negatively correlated with urinary excretion of Ca for cows fed DCAD+D. No such correlation was observed with the DCAD+25D treatment because substantial excretion of urinary Ca occurred at moderate urinary pH values for that treatment. Cows fed DCAD+25D had greater serum concentrations of 25-OH vitamin D3 than other treatments from 5 d after supplementation started through 7 DIM. Concentrations of 1,25-(OH)2 D in serum were greatest in DCAD+25D cows starting at 2 d before calving and continued through 7 DIM. Serum Ca concentrations 5 d before calving were greatest for cows fed DCAD+25D, but at other time points before and after parturition, treatment did not affect serum Ca. Incidence of clinical hypocalcemia was not statistically different between treatments, but cows fed DCAD+25-D had the highest incidence rate (12.5, 0, and 20% for Control, DCAD, and DCAD+25D). Calves born from cows fed DCAD+25D had greater concentrations of 25-OH vitamin D in serum at birth than calves from other treatments (before colostrum consumption) but concentrations were similar by 3 d of age. Concentrations of 25-OH vitamin D in colostrum and transition milk were increased by feeding DCAD+25D but by 28 DIM, treatment effects no longer existed. Overall, feeding 25-OH vitamin D with a negative DCAD diet increased vitamin D status of the cow and her newborn calf but had minimal effects on calcium status and did not have positive effects on the incidence of hypocalcemia.