Heat stress round table Feb 2012 Fabio de Rensis & M.A. Driancourt

2 Backbone of our discussion How do you know that heat stress is starting? Is over? Which changes in your management do you implement to minimize the consequences of heat stress on reproduction? Do you implement a specific strategy during the carry over period? What is, from your point of view, the main limiting factor to improve conception rate during the heat stress period?

How do you know that heat stress is starting? Is over?

External temperature and humidity Rectal temperature or breathing rate of a selected group of animals Drop in food intake Drop in milk production

Which changes in your management do you implement to minimize the consequences of heat stress on reproduction? Do you implement a specific strategy during the carry over period?

Decreased GnRH & LH Reduced feed intake Negative energy balance Infertility Estradiol Poor Estrus expression Poor quality oocytes-CL Compromised uterine environment Embryo losses Thermal stress increased cortisol,PRL De Rensis et al., Theriogenology 2003 Thermal stress 16 progesterone Poor Estrus expression Poor quality oocytes-CL

Which changes in your management do you implement to minimize the consequences of heat stress on reproduction? Do you implement a specific strategy during the carry over period? Cooling strategies Estrus synchronization treatments GnRH administration at AI or hCG during the luteal phase Embryo transfer

What is, from your point of view, the main factor limiting reproductive efficiency during the heat stress period?