PORCINE MASTITIS-METRITIS-AGALACTIA (MMA) SYNDROME - MAMMARY-GLAND RESPONSIVENESS TO OXYTOCIN GIVEN TO HEALTHY SOWS DURING LACTATION

  • 1 January 1979
    • journal article
    • research article
    • Vol. 40  (8) , 1104-1106
Abstract
Mammary gland responsiveness to exogenous oxytocin during lactation was assessed by measuring changes in intramammary pressure of healthy sows given (i.m. injection) synthetic oxytocin (40 units). Response to oxytocin was measured once a week for the 1st 8 wk of lactation. Pressure change recordings were expressed as mean area (cm2) under the trace at each 10-min interval over 30 min after oxytocin had been given. During the 2nd wk of lactation, there was a 55.3% increase (P < 0.05) in responsiveness to oxytocin (25.1 .+-. 4.2 cm2/10 min) as compared with the 1st wk (13.9 .+-. 2.2 cm2/10 min). Responsiveness decreased from the 2nd to the 8th wk. Since the incidence of mastitis-metritis-agalactia in sows is particularly high during the 1st wk of lactation, low responsiveness of the mammary gland to oxytocin may be a contributing factor.