A Practical Approach to Reducing the Incidence of Intramammary Infection in Heifers by Using Prepartum Systemic Tylosin Therapy

Abstract

While mastitis in heifers is recognized as a problem, most dairymen often view heifers at parturition as free of intramammary infections (IMI) For example, in a survey (Bormet al, 2006) that included farms in seven states and one province, as many as 63% of heifers and 34% of their quarters had a IMI at calving. IMI during lactogenesis can impair mammary development and cause a decrease in milk yield in the productive life at the animal level. At the herd level IMI could cause an increase in somatic cell counts (SCC) and clinical mastitis cases. To prevent and treat IMI in heifers, infusion of antibiotics in the mammary gland before calving was proposed. However, systemic administration of antimicrobials to heifers before calving could offer advantages related to its relative lower cost and easier administration when compared to intramammary infusion. Tylosin offers an excellent diffusion into the mammary gland related to its basic pK, which results in a very high milk to plasma concentration ratio.