Comparison of systemic and intramammary dry cow treatments Comparación de terapias sistémicas e intramamarias para el periodo seco en vacas lecheras

Objective. To compare four different dry cow treatments (DCT) and establish their effectiveness in reducing intramammary infections (IIM). Materials and methods. DCTs included systemic tylosin (12g) alone or accompanied by cefapirine intramammary infusions and or an internal teat sealant. A total number of 278 cows at the end of lactation period were randomly assigned to one of 4 dry cow treatment groups: CESE Group (n=89), intramammary cephapirin and teat sealant. TYCESE Group (n=84), intramammary cephapirin, tylosin 12 g intramuscular and teat sealant. TYSE Group (n=86), 12 g intramuscular tylosin and teat sealant; TY Group (n=76) 12 g intramuscular tylosin only. Milk samples for culture were collected at dry-off and 1 and 2 weeks after calving. Somatic cell counts (SCC) were taken from Dairy Herd Improvement Association (DHI) tests at dry-off, and the first two test days after calving. Results. Bacteria cure rate for Gram-positive intramammary infections (IMI) for TYCESE group was 93.6%, CESE group 78.9%, TYSE group 88.2%, and TY group 78.1%. All four groups showed a decrease in the SCC upon the first and second test after calving. Conclusions. The use of systemic tylosin in combination with intramammary antibiotics increased DCT effectiveness improving the Gram-positive cure rate IMI. Furthermore, systemic tylosin alone plus teat sealant is as effective as cephapirin plus teat sealant when used as DCT.