Heat production, body temperature, and body posture in west African dwarf goats infected with Trypanosoma vivax.

The relationships between heat production, body temperature, and body posture (standing/lying) were studied in goats suffering from trypanosomiasis. Sixteen goats were selected and infected with 1 x 10(6) Trypanosoma vivax parasites and 8 goats served as controls. In week 2, 4, and 6 after infection heat production, body posture, and body temperature were measured at 15-minute intervals. Heat production was higher (P < 0.01) in infected animals compared with control animals (342, respectively 306 kJ.kg- 0.75.d-1), body temperature was also higher (P < 0.001) in infected goats (39.78 degrees C, respectively 38.51 degrees C). The standing related energy costs per day were lower in infected animals (27 respectively 36 kJ.kg-0.75.d-1). Infected animals, therefore, masked part of the energy costs of infection by reducing the standing time. The heat production of infected animals was increased by 21 kJ.kg-0.75.d-1 per 1 degree C fever (7% increase). During periods of standing, body temperature increased with time, whereas during lying periods, it decreased. The number of standing periods was increased in infected animals. It was discussed whether postural behaviour is influenced by thermoregulatory mechanisms.