Early pregnancy diagnosis of captive Amur tigers (Panthera tigris altaica)

Abstract

From January 2015 to February 2017, urine samples was collected from twelve captive female Amur tigers during both their mating (or receptive) periods and the first four weeks after mating at the Hengdaohezi Feline Breeding Center (FBC) in China. A radioimmunoassay was applied to determine the progesterone levels in the urine samples. The relationship between progesterone levels and pregnancy in Amur tigers was assessed according to whether the tigers gave birth in the end. Results showed that average progesterone levels increased significantly (P < .05) after mating for all female tigers having parturition. And the minimum value of progesterone levels of them during the fourth week after mating was consistently higher than 0.21 ng/mL, the maximum value in mating period of all female tigers. However, there were no significant differences in progesterone levels between mating period and the first four weeks after mating of the female tigers having no parturition. Therefore, early pregnancy in captive Amur tigers can be diagnosed when urine progesterone concentrations attain a level higher than 0.21 ng/mL for seven days in a row after mating.