Heat Stress Management

By: S.D. Lukefahr, J.C. Paschal, and J.E. Ford

Particularly true of commercial bred stock, there are many management measures that can be followed to maintain normal fertility levels. The buck is more sensitive to infertility problems in the summer, more so than the doe. Buck fertility may decline when temperatures are above 85 F for several consecutive days, which actually represents several months out of the year in south Texas. Young bucks (6 to 9 months-old) have higher fertility and sex drive (libido) than older bucks and can be mated to does during the summer season to have good reproduction success.

In further coping with heat stress conditions, one strategy is to ensure that the inside temperature where the rabbits are housed is at least 10 degrees cooler than the outside temperature. Thermometers can be placed both inside and outside of the shed or other building as a check. A well ventilated shed or even shade trees will often meet this objective. During the heat of the day, sprinkler hoses may be placed on top of the roof of the shed and turned on, as well as manually wetting the grounds below cages with a garden hose to promote evaporative cooling. Water directly reduces the surrounding temperature, and when water comes in contact with prevailing breezes, this effectively cools the stock. In particularly adverse situations, large fans or commercial fog mist systems may be justified.

If necessary, additional measures include taking plastic soft drink bottles filled with water and freezing these overnight, or water-soaked burlap sacks or towels, that can be placed inside cages to keep rabbits cool. Needless to say, proper timing and consistency in implementing these heat stress management interventions is vital to the comfort, productivity and even survival of the stock.