Buffer for lactating dairy cows

Lactating dairy cows require dietary buffers to neutralize the large quantities of acids produced during ruminal fermentation to prevent sub-clinical ruminal acidosis. Traditionally sodium bicarbonate has been used as the primary buffer. UGA animal and dairy scientists fed 48 Holstein cows one of four diets to provide a negative control (no supplemental buffer), buffered with sodium bicarbonate (positive control), Calmin or Calmin16. Cows fed the negative control had higher concentrations of milk protein and lower concentrations of milk urea nitrogen than cows fed buffered diets. Compared with cows fed the diet buffered with sodium bicarbonate, cows fed diets with either CalMin or CalMin16 had lower dry matter intake but there were no differences in milk yield or concentrations of milk fat, protein, lactose, or solids-not-fat. The CalMin16 had higher concentration of magnesium which effectively maintain plasma magnesium compared with the other diets which were supplemented with magnesium oxide.