Effect of chronic heat load during pregnancy on birth weight, behaviour and body composition of Australian feral goat kids.

Six feral does maintained at elevated ambient temperatures (27.2 degrees - 34.8 degrees) for the last half of pregnancy had rectal temperatures (Tr) elevated by 0.4 degrees above 10 unstressed does. Heat-stressed twin-bearers were 0.15 degrees hotter than single-bearers and bore lighter kids (1.70 kg), than unstressed does (2.24 kg) while singles were less affected (2.22 kg versus 2.28 kg). Birth weight was more highly correlated (P less than 0.001) with the daily minimum Tr of the dam than with the mean or maximum Tr. Kids from heated does stood and began sucking as quickly as control kids but during the first six hours scored significantly (P less than 0.01) lower on a scale of general activity. There were no significant differences in body content of nitrogen, fat and ash or, when birth weight was considered, weight of hide, CNS and liver.