Effects of heat stress and a low energy diet on blood parameters and liver hsp70 and iNOS gene expressions in local chickens

Two experiments were conducted to compare effects of heat stress and its combination with low dietary energy on blood indices, liver hsp70 and iNOS gene expressions in three Tanzanian local chicken ecotypes. In experiment one, five weeks old Kuchi (K), Ching'wekwe (C) and Morogoro medium (M) were randomly allocated to separate pens in a 3 × 2 factorial design in two adjacent rooms with controlled temperature. The study had three replicates consisting of 39 chickens per room, 13 per ecotype per pen making a total of 234 chickens. In one room, temperature was maintained at 26.5 ± 0.5 °C while in another it was maintained at 32±1 °C for 7 days and thereafter 37±1 °C for 10 days. A similar design was used in experiment two except that chickens were fed 55% less energy. In experiment one, serum corticosterone levels increased (p