This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the October 2020 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
Cattle were ideally created (or evolved) to consume and digest high fiber diets. Whoever (or whatever) was responsible for designing the rumen so elegantly probably should have paid more attention to the respiratory tract.
The design of the bovine respiratory tract makes it easy for BRD bacteria like Mannheimia, Pasteurella, Histophilus and Mycoplasma to move deep into the lung and find places to hide and makes it hard for the animal’s immune system to counterattack them. The bovine lung is so susceptible to infection and damage that it has been used as an “animal model” of chronic obstructive pulmonary disease (COPD) in humans.
This is a problem because cattle need a lot of oxygen. Cattle need nearly three times as much oxygen as a similar-sized horse just to stay awake and lie around. But the horse has nearly three times more lung capacity than the steer. Lung damage is one of the reasons that BRD hits cattle so hard, so fast. Continue reading