The purpose of present study is to compare the erythrocyte and leukocyte profile in white-eggshell and blue-eggshell of brown Tsaiya duck at growing period. Sixty 1-weeks-old white-eggshell and blue-eggshell female brown Tsaiya ducks were each divided into 2 groups. Ten birds of each strain were kept in one floor pen with 6 replicates in each group and feed and water were supplied ad libutum. At 10, 12 and 14 weeks of age, ducks were sampled from each strain for measurements of blood pictures. The results showed that blue-eggshell duck had higher red blood cell(RBC) and packed cell volume than white-eggshell duck at 10 wks of age (P ＜ 0.05); Nevertheless, there are higher level in mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration of white-eggshell duck than that of blue-eggshell duck (P ＜ 0.05). There were no significant differences in erythrocyte profile between both strains of Tsaiya ducks at 12 and 14 wks of age. The values of RBC number in both strain of ducks increased as age advanced during the whole experimental period (P ＜ 0.05). There were no significant differences in the percentage of monocytes, basophils and eosinophils between white-eggshell duck and blue-eggshell duck. The percentage of heterophils is higher in blue-eggshell strain of duck than that of white-eggshell duck and the percentage of lymphocytes is lower in blue-eggshell strain duck than that of white-eggshell duck (P ＜ 0.05) at 10 and 12 wks of age. Based on the viewpoint that H/L ratios represent animal stress indicator, it is suggested that the blue-eggshell duck is more stressful than white-eggshell duck; moreover, the rapid increase of H/L ratio in both strains of duck at 14 weeks-old indicating ducks may suffer greater physiological stress while ducks go into the egg-laying period.
