Determination of some blood parameters in the African lion (Panthera leo)

[摘要] The goal of this study was to generate a database of laboratory results for African lion (Panthera leo) blood to obtain reliable reference ranges to augment what is currently available in literature. Also to investigate the possibility of age and sex having an influence on these reference ranges. The specific objectives of this study were: o to determine reference values for haematological and biochemical blood variables for lions bred in captivity, as a function of age and sex; o to evaluate the Beckman Coulter Ac•T 5diff Haematology Analyzer for lion differential white blood cell analyses; o to determine morphometric measurements and establish reference growth curves (and range reference values) for lions bred and reared in captivity as a function of age and sex; o to determine reference values for some practical and meaningful body measurements and their correlations. This study was conducted on three lion ranches in the Free State province and at the Bloemfontein Zoological Gardens (Bloemfontein Zoo) with captive lions (Panthera leo) of both sexes and ages ranging from three months to nine years. Lions were divided into four age groups according to published literature. Animals were chemically immobilized (darted) with Zoletil® 100 at 4 to 5mg/kg in their holding camps and moved to a shaded place as soon as the drug had taken its full effect. Blood was collected into three different types of blood collection tubes and body measurements were taken. This was all done as fast as possible before the effect of the immobilizing drug could wear off. In some cases it was necessary to give an animal a top-up dose to prevent it from waking up too quickly. Animals were moved back to their holding camps to fully recover from the immobilization. Blood analyses done with the Ac•T 5diff Haematology Analyzer from Beckman Coulter® for haematological parameters was conducted within 30 minutes after blood collection. Blood for biochemistry parameters was centrifuged, serum collected and cryo preserved at -20°C until it could be taken to the laboratory for analyses. Blood smears were made on the lion ranches and Bloemfontein zoo immediately after the analysis with the Ac•T 5diff Haematology Analyzer, fixed and packed for transport to the laboratory. At the laboratory the serum was used for biochemistry analyses, using standard laboratory techniques. Blood smears were stained and examined under a light microscope for the differential white blood cell count by means of the manual-visual method. Results were statistically analyzed to determine reference ranges and the influence of age and sex on these reference range values for the different parameters, were considered. Body measurement were also statistically analyzed to determine correlations between body weight and different other measurements. These correlations were then used to determine if it will be possible in a field situation to use the age and sex of an animal together with a certain body measurement to estimate body weight accurately, if actual weighing was not possible. From these analyses it was concluded that age and sex do have an influence on blood analysis and blood reference ranges for the African lion (Panthera leo). Unfortunately, it differs between parameters and there is not one rule to apply. The conclusion could also be made that body weight could be determined by measuring the head length of an animal. More research is warranted to obtain more data set and establish range reference values that can be validated and used with a high degree of confidence in the lion breeding industry.

[发布机构] University of the Free State