New research looks at selenium supplementation before calving and its effect on early-lactation udder health of pastured dairy heifers.

The study involved a group of 140 Holstein-Friesian heifers in Chile. One month before calving, heifers were assigned to one of three groups. One group received no selenium supplementation. Heifers in a second group received a single, subcutaneous injection of barium selenate (1 mg/kg of live weight). A third group was fed selenium yeast (3 mg/heifer/day) until calving.

According to the results, both sources of supplementation tended to reduce the incidence of intramammary infection and the prevalence of quarters with high somatic cell count at calving. However, pre-calving supplementation did not reduce the incidence of new infections or clinical mastitis cases during the remainder of the first 30 days of lactation. It also did not decrease somatic cell count during this time.

When the researchers injected heifers with barium selenate before calving, and fed them diets containing selenium before and after calving, they saw no clinical mastitis cases during the first month of lactation.

The researchers reported their results in the October 2010 issue of the Journal of Dairy Science.

Be sure to attend Dr. Pamela Ruegg's presentation, "Heifer Mastitis - How to Help Heifers Calve Clean," at the 2011 Dairy Calf & Heifer Conference, April 5-6, in Lake Geneva, Wis., to learn more about heifer mastitis prevention.