Timothy silage with low dietary cation-anion difference fed to nonlactating cows

Decreasing the dietary cation-anion difference (DCAD) by using anion sources before calving reduces hypocalcemia in cows at calving. Reduced DCAD from CaCl2-fertilized timothy hay achieves similar results, but the effects of feeding low-DCAD forage as silage have not been determined. The objective of this study was to evaluate the effect of low-DCAD timothy silage on dry cows. Six nonlactating and nonpregnant Holstein cows were used in a replicated 3 × 3 Latin square. Treatments were 1) control diet (DCAD=232mEq/kg of dry matter, DM); 2) low-DCAD diet using a low-DCAD timothy silage (LDTS; DCAD=−21mEq/kg of DM); and 3) low-DCAD diet using a fermentation by-product (LDBP; DCAD=−32mEq/kg of DM). Differences between dietary treatments were considered statistically significant at P≤0.05 and tendencies were noted when 0.05