Worapol Aengwanich and Orawan Chinrasri

pp. 183 - 189

Abstract

Laying Japanese quails (n = 60), 30 weeks of age reared at the experimental laboratory unit of the
Faculty of Technology, Maha Sarakham University, Maha Sarakham province, Thailand. Birds were in cages
with wire floors. Randomized Complete Block was the design of the experiment. During the first 4 days of
experimental period, quails were fed on a standard commercial diet with four treatments: supplemented
with dexamethasone at 4 levels namely 0 (control group), 1.25, 2.50 and 5.00 mg/kg diet. On days 1, 3, 7,
10 and 14 of the experimental period, percentage of heterophil, lymphocyte, monocyte, basophil, eosinophil, and heterophil/ lymphocyte ratio values of laying quails were examined. The results revealed that
percentage of heterophil of laying quail with added dexamethasone at 1.25 and 2.50 mg/kg in diets were
significantly higher than others (P<0.05). Percentage of lymphocyte of Japanese quails receiving dexamethasone at 1.25 and 2.50 mg/kg was significantly lower than birds receiving dexamethasone at 0 and 5.00
mg/kg (P<0.05). Heterophil: lymphocyte ratio of laying birds supplemented with dexamethasone at 1.25 and 2.50 mg/kg in diets was significantly higher than that of laying quail that added dexamethasone at 0 and
5.00 mg/kg in diets (P<0.05). The percentage of monocyte, basophil and eosinophil after receiving dexamethasone each levels were not significantly different (P>0.05). After discontinuing dexamethasone administration on day 4 of the experimental period, percentage of heterophil, lymphocyte and eosinophil, monocyte,
and heterophil: lymphocyte ratio, of quails recovered to normal within 10 days.

Keywords

• dexamethasone
• differential white blood cell counts
• heterophil / lymphocyte ratio
• Japanese quail (Coturnix coturnix japonica)