Effect of temperament on pregnancy and plasma progesterone andcortisol in cows receiving embryo transfers.

摘要

In cows, stress can inhibit feeding,growth and reproduction. However cows can exhibit calm and/or reactive demeanors.We report plasma cortisol, progesterone and reproductive performances in cowsexhibiting different temperaments. Hybrid cows (n=235) were synchronized by Fixed-Time Embryo Transfer (FTET) protocol later diagnosed as pregnant. Receptor cowsunderwent a behavioral assessment classified as having calm, slightly or veryaggressive behavior. We found that behavior did not affect the response to thehormonal protocols for synchronization of ovulation or plasma cortisol levels. Howeverwe did find that very aggressive cow temperament reduced (P <0.05) plasmaprogesterone and pregnancy rates.