In addition to the many visible signs associated with heat stress in beef cattle, there are also several invisible signs and effects of heat stress. While they are not visible to the eye, wellness checks may show these signs through various forms of testing.
Some of the invisible signs of heat stress in beef cattle include:
- Indigestibility of feed
- Increased peripheral blood flow
- Increased respiratory infections
- Increased susceptibility to parasitic and non-parasitic diseases
- Loss of bicarbonates
- Loss of electrolytes
- Lower ruminal pH
- Reduced response to intercurrent diseases or pathogens
- Slowed gut and ruminal motility rates, resulting in slow passage of feed through the digestive tract
- Slowed recovery from environmental stresses
- Stress hormones in the blood
Heat stress can also affect the reproduction of beef cattle. Not only can it alter the production of the reproductive hormones that are essential for pregnancy, but it can also change the balance of developing follicles in the ovary. Embryonic development can also be affected while gene function is disturbed. Lower conception rates and lower fertility in bulls is also associated with heat stress, as are increased foetal and postnatal mortality rates.
By closely monitoring the health and the activity of your cattle, you can better ensure they are not suffering from heat stress and its negative – even possibly fatal – effects.