Diurnal and seasonal fluctuations in cloacal temperature in helmeted guinea-fowl (Numida meleagris) and the effect of ascorbic acid.

The study evaluated ascorbic acid (AA) effects on diurnal fluctuations in cloacal temperature (CT) in guinea-fowls. Twenty guinea-fowls were each assigned to two groups: Group I was administered with distilled water and Group II was treated daily with AA (50 mg/kg) orally. Measurements of dry-bulb temperature (DBT) and relative humidity (RH), to obtain temperature-humidity index (THI), and CT of each guinea-fowl were taken concurrently in the pen thrice a day for 3 days, 1 week apart, during the rainy, cold-dry (harmattan) and hot-dry seasons. Values of THI during the rainy (26.16 ± 0.36) and hot-dry (28.50 ± 1.11) seasons were above the thermoneutral zone for avian species (21), indicating that the guinea-fowls were exposed to heat stress in the seasons. Values of CT were higher (P < 0.05) in controls than experimental guinea-fowls (rainy, 42.17 ± 0.06 vs 42.04 ± 0.08; hot-dry, 42.78 ± 0.11 vs 42.52 ± 0.04°C) and were outside the normal range for avian species. Administration of AA modulated CT fluctuations by decreasing the values in hot-dry season. In conclusion, the hot-dry season was the most stressful for guinea-fowls, and AA modulated considerably CT fluctuations during the season. [ABSTRACT FROM AUTHOR]