Effects of the Gulf Coast Tick on Blood Composition and Weights of Drylot Hereford Steers12

Publisher Website
Google Scholar
Abstract
Light weight Hereford steers in a drylot situation when fed a standard ration were infested at 2 levels with Amblyomma maculatum Koch. The effects of high and low tick infestations on the blood composition and weights of the steers were compared with values measured in tick-free animals over a period of 7 weeks. Significant changes occurred in animal weights between treatment groups. High infested animals were 24 kg lighter than control animals at the end of the study whereas low infested animals were 14 kg lighter. Significant increases occurred in the blood parameters of total serum protein, serum globulin, the alpha, beta, and gamma globulin fractions, and plasma fibrinogen values over the course of the study in both infested groups of animals as compared with tick-free animals. Also, in high infested cattle, significant decreases occurred in the total leukocyte cell counts over the study as compared to the other 2 groups. In both groups of tick-infested cattle, decreases occurred over time in the numbers of ticks which attached. The possible causes for these reductions in tick numbers and the changes in animal weights and blood composition are discussed.