Seasonal variation of bovine anti-J in the tropics

Summary Close to the Equator at an altitude of 1750 m above sea level a total of 27 cows of various breeds have been studied with regard to the fluctuation of their anti-J naturally occurring antibodies. Over 16 consecutive months the average total score of anti-J varied from a minimum of 20 in October to a maximum of 37 at. the end of December. Practically all the sera had the lowest level of anti-J in October. This is about two months after the lowest yearly maximum temperature. It is concluded that gradual changes in temperature can cause variation in anti-J titer, and that the magnitude of the seasonal temperature changes influences the fluctuation of the natural anti-J.