THERMOREGULATORY RESPONSE OF BROILER CHICKENS FED SUPPLEMENTAL BAOBAB (ADANSONIA DIGITATA L) LEAF MEAL UNDER HEAT STRESS
Keywords:
Thermoregulation, Corticosterone, Heat stress, Ambient temperature, Broiler chickensAbstract
The thermoregulatory response of broiler chickens fed Baobab (Adansonia digitata L) leaf meal supplementation was evaluated in a 7 weeks trial. Forty-five (45) Cobb 500 broiler chickens were used for the experiment. The birds were distributed into five (5) treatment diets in a completely randomized design and replicated three (3) times where three (3) chicks served as a replicate of each treatment diet. The five (5) dietary treatments were labelled T1 (0.00% BLM), T2 (supplemented with 0.025% BLM), T3 (supplemented with 0.05% BLM), T4 (supplemented with 0.075% BLM) and T5
(supplemented with 0.10% BLM). Data on ambient temperature, relative humidity, axillary and cloaca temperatures were taken, also faecal samples were collected for corticosterone analysis. Results showed significant differences (p<0.05) in the faecal corticosterone levels, birds on T5 (0.10% BLM) had the highest faecal corticosterone (1.094±0.041). The morning, afternoon and evening ambient temperature stood at 25.63±0.40°C, 33.38±0.40°C and 29.35±0.55°C respectively while the relative humidity was at 77.02±5.84%, 53.65±3.21% and 68.29±2.45% for these periods of the day. No statistical differences (P>0.05) were recorded for the axillary and rectal temperatures for different times of the day across the experimental groups, however, birds on T2 (0.025% BLM) had the lowest axillary (40.19±0.10°C), (40.27±0.01°C) and rectal temperature (40.47±0.11°C), (40.42±0.09°C) for morning and evening respectively and least rectal temperature (41.07±0.08°C) in the afternoon. The study thus concluded that supplementing baobab (Adansonia digitata) leaf meal in the diet of broiler chickens can help in ameliorating heat stress.