Antibiotic treatment may be an economical practice for reducing the rate of intramammary infections in pre-fresh heifers, according to research conducted at the University of Tennessee.

During two studies, researchers infused all four quarters of 111 Jersey heifers with lactating cow antibiotic formulations one or two weeks prior to freshening. They did not infuse quarters of the 82 Jersey heifers in the control group.

The heifers treated with an antibiotic seven or 14 days prior to expected calving produced an average of 12,597 pounds of milk — 1,168 pounds more milk — during their first lactations than did heifers not treated with antibiotic infusions. The researchers calculated the net revenue from antibiotic treatment to be about $175 per heifer, at a milk price of $15.80 per hundredweight and after subtracting treatment cost and the cost for an antibiotic residue test.

The researchers concluded that it can be profitable to treat heifers for mastitis with antibiotics before calving. They recommend treating heifers 14 days before calving.

However, consult your veterinarian before implementing this practice to determine which antibiotic to use for your particular situation. And, be prepared to test the milk from all treated heifers — especially those which calve sooner than expected — for antibiotic residues before putting the milk into the bulk tank.