Evaluation of a calcium based buffer for lactating dairy cows

Summary

Two formulations of a calcium buffer were evaluated to determine their effectiveness as a rumen buffer in diets fed to early lactation dairy cows. Dry matter intake was slightly lower for the diets containing the calcium based buffers compared with sodium bocarbonate, but milk yield and composition were similar for all treatments. The results of this trial indicate that these buffers are as effective as traditional buffers and can potentially be used as a substitute for sodium bicarbonate.

Situation

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. CalMin or CalMin16 are calcium based buffers (Celtic Sea Minerals) which have been demonstrated to work effectively as a buffer in situ, but data are limited related to their effectiveness in diets typically fed in the US.

Response

Forty-eight Holstein cows were enrolled in a 12 week randomized block trial beginning at 21 days in milk.. Cows were fed one of four diets to provide a negative control (no supplemental buffer), buffered with sodium bicarbonate (positive control), Calmin or Calmin16. Diets were formulated to be isonigrogenous and isocaloric and were fed diets once daily.Cows were milked three times each day and yield recorded at each milking. Milk samples were collected from three consecutive milkings for analysis of components, and body weight was recorded at the beginning and end of the trial.

Impact

Cows fed the negative control had higher concentrations of milk protein and lower concentrations of milk urea nitrogen than cows fed buffered diets. The trial was conducted during the winter, so these cows were not challenged with heat stress and were able to maintain a more desirable buffer status than expected although plasma creatine kinase concentrations were higher which suggest some degree of metabolic stress. Compared with cows fed the diet buffered with sodium bicarbonate, cows fed diets with either CalMin or CalMin16 has 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.

State Issue

Agricultural Profitability and Sustainability

Details

• Year: 2012
• Geographic Scope: International
• County: Tift
• Program Areas:
  • Agriculture & Natural Resources