The effect of a mixed-management system on the release of oxytocin, prolactin, and cortisol in ewes during suckling and machine milking

Reprod Nutr Dev. 2000 May-Jun;40(3):271-81. doi: 10.1051/rnd:2000131.

Abstract

Milk yield and plasma oxytocin (OT), prolactin (PRL), and cortisol (CORT) during suckling and machine milking were measured in multiparous ewes subjected to a mixed management system of 3 sucklings and two daily milkings. Peak hormones were significantly increased and were similar during suckling and milking for PRL (181 vs. 163.3 ng x mL(-1)) and CORT (12.5 vs. 11.5 ng x mL(-1)). During the period of exclusive suckling, OT was always significantly released (90.3 pg x mL(-1)); however, during the period of mixed management, OT concentrations only increased during suckling compared to milking (91.7 vs. 13.1 pg x mL(-1)). The mean volume of milk obtained during suckling (632 mL) was significantly higher than during milking (255 mL). Thus, during a mixed management system, oxytocin and prolactin releases are not under similar central regulation. A mixed system, without OT release during milking, does not contribute to accelerate the conditioning of ewes for machine milking.

MeSH terms

  • Animals
  • Animals, Suckling
  • Dairying / methods*
  • Female
  • Hydrocortisone / blood*
  • Lactation*
  • Oxytocin / blood*
  • Prolactin / blood*
  • Sheep*
  • Time Factors

Substances

  • Oxytocin
  • Prolactin
  • Hydrocortisone