Blood biochemistry and haematology values of juvenile Eurasian cranes (Grus grus) raised in captivity for reintroduction

The Eurasian crane ( Grus grus ) is currently held in over 50 zoological collections worldwide and present in the wild in a number of countries across Europe and Asia. Normal ranges have not previously been published for a number of haematological and biochemical parameters in the species and this study is the first to provide biochemical parameters in captive individuals of this species. Blood samples were collected from 90 juvenile Eurasian cranes with an average age of 70 days, across five consecutive years (2010-14), as part of health screening prior to reintroduction in the south-western UK. Haematology and biochemistry values were determined for 40 parameters. Statistical analyses were carried out to determine the effect of age, sex and year on these values. Mean values of many haematological and biochemical parameters differed between years: haemoglobin, mean corpuscular haemoglobin concentration, white blood cell count, heterophil percentage and number, lymphocyte percentage and number, monocyte percentage and number, eosinophil percentage and number, basophil percentage, total protein, albumin, globulin, albumin/globulin ratio, sodium, potassium, total calcium, ionised calcium, phosphorous, calcium/phosphorous ratio, alkaline phosphatase, aspartate aminotransferase, gamma-glutamyl transferase, bile acids, creatinine kinase, cholesterol, and sodium/potassium ratio. Calcium/phosphorous ratio, uric acid, bile acids, creatinine kinase, cholesterol and triglycerides decreased with age, while red blood cell count, haemoglobin, haematocrit, basophil number, potassium, total calcium and phosphorus increased with age. Females had higher values of red blood cell count, haemoglobin, lymphocyte number, basophil number, total protein, albumin, alkaline phosphatase, and creatinine kinase than males. A comparison with previously published values of captive and wild cranes is presented: the young age of the birds in our study was likely to have led to some of the observed differences to previous studies.