Summarized state of art of animal housing in warm/hot climate : productive traits

Abstract

Since energy balance, thermoregulation and environmental aspects of "high producingdairy cows" were thoroughly studied (Brody, 1945; Flatt et al., 1969; Berman et al., 1985),the high producing dairy cow more than doubled production with a body weight increase of about 10-20% which imposed a three fold increase of heat increment (Kadzer et al., 2002).There is an apparent world wide lack of realization that changes in the physical and geneticconstitution of cows may have affected their thermoregulatory capability in hot climate forexample, blood plasma fluctuation in volume and constituents (Maltz et al, 1994); as wellas how they cope with heat stress (Kadzer et al., 2002). As a result, research inthermoregulation in relation to housing facilities and cooling management falls behind(except for few exceptions seen below) the aggressive selection for increased productionthat livestock undergoes as well as changes in technology and housing materials. Therefore,most of the improvements in this area are farmers and designers initiatives based oncommon sense and experience.