HERD HEALTH CHECK HOW STRESS DUE TO WEATHER AFFECTS YOUR CATTLE AND HORSES from Pro Earth Animal Health
Keeping your livestock healthy throughout the year allows your animals to be productive and avoid diseases. Unfortunately, weather conditions can present an obstacle to livestock’s health and well-being. But how exactly do weather changes and fluctuations affect the stress levels of your cattle and horses? What can changes in weather and stress levels mean for your livestock? To keep your livestock thriving, it’s important to understand how exactly the weather impacts their stress levels and what you can do to help ease the effects of difficult weather conditions. Body Temperature Regulation: Cattle and Horses Livestock can regulate their body temperatures like humans, but only so much. The regulation of body temperature is known as thermoregulation. The body uses thermoregulation to avoid cold or heat stress. Because thermoregulation is limited, it’s important to note the weather changes that can impact the body temperature of your livestock. 1. Thermoregulation in Cattle The body temperature of cattle is affected by their body condition, diet, conditions of their shelter and the thickness of their hair coat. Weather factors, such as wind and humidity, can also influence cattle’s body temperature. Cattle hair coats vary by breed in terms of color and thickness. The hair coat also affects their ability to release heat through their skin. In a warmer region, cattle with a thick hair coat may be more susceptible to heat stress. Cattle with a thinner hair coat are more likely to be tolerant of higher temperatures in warm regions. Alternatively, cattle with a thinner hair coat may become more stressed in a colder environment. Cattle body temperature can fall into three zones –– thermoneutral, upper critical (UCT) and lower critical temperature (LCT) zone. At the basal metabolic rate, cattle will be in the thermoneutral zone. So what exactly is the basal metabolic rate? It’s the amount of energy that is expended while cattle are at rest in neutral temperatures.
26 California Cattleman December 2021
Neutral temperatures typically fall between 31 to 68 degrees Fahrenheit, though this range can vary depending on the breed of cattle and the conditions of their environment. Wind, humidity and cattle hair coat all affect the temperature range that is considered neutral for cattle. Upper critical temperatures are above the thermoneutral zone and increase the basal metabolic rate. The increased basal metabolic rate results in the body stimulating heat loss to maintain body temperature. When the temperature-humidity index is 80 or above, livestock may suffer from heat stress. Cattle produce little sweat and are not able to dissipate their heat efficiently, so producers often need to take steps to assist cattle with heat dissipation. Cattle most often fall into the lower critical temperature zone during especially cold months, such as January and February. In LCT, cattle can experience cold stress. The basal metabolic rate increases to produce heat that can maintain or raise body temperature. This means the animal also requires more energy so it can produce heat. Beware of extreme cold stress, which can result in hypothermia. 2. Thermoregulation in Horses Like cattle, thermoregulation in horses allows these animals to maintain, raise or lower body temperature. Unlike cattle, however, horses are more efficient at discharging heat in hot weather. Despite this, owners should still take measures to help their horses stay cool during hot, humid months. Horses use the following methods to maintain body temperature: Evaporation of sweat: A horse will produce sweat that then evaporates, cooling the animal down. In a humid climate, sweat may not be able to evaporate, preventing the horse from adequately cooling. Owners can assist with creating a less humid environment for their horses so that evaporation of sweat can occur. Convection: In this process, heat moves from inside the horse out into the air. Air movement and wind carry heat away from horses. To assist your horses further,
