A preliminary study on the dynamics of serum color in perspective to hemoglobin and bilirubin in indigenous sheep of Pakistan

The present study is the first of its kind being reported for an indigenous sheep breed of Pakistan with objectives to (a) assess the diagnostic efficacy of a human-based "serum hemolysis reference palette" for sheep serum, (b) deduce normal reference intervals (RIs) for hemoglobin (Hb) and bilirubin, and (c) devise a novel serum color chart for on-field estimation of Hb and bilirubin through color matching of sheep serum. Apparently, healthy Sipli sheep (n = 130) were bled twice attaining whole blood and serum samples (n = 260). The study animals were grouped on the basis of gender, that is, males (n = 51) and females (n = 79) and age, that is, G1 (up till 1 year) (n = 41), G2 (from 1 to 2 years) (n = 46), and G3 (from 2 to 3 years) (n = 43). None of the 260 serum samples of the sheep matched the color given on the human-based "hemolysis reference palette." The G1 animals revealed marked variation in their serum color. Hence, on the basis of RIs, the serum samples (n = 178) of adult sheep (G2 and G3) showing three main color bands were used in devising a novel serum Hb and bilirubin estimation chart for adult sheep serum. In conclusion, the human-based serum hemolysis palette is not valid for sheep serum. The RIs attained in the study could provide a yardstick for assessment of health in indigenous sheep breeds whereas the serum color chart may be of value in estimating Hb and bilirubin in a quick, reliable, and cheaper way for the resource-poor settings of the world.