Symptoms and Prevention Measures of Heat Stress in Dairy Cows
Dairy cows are cold-tolerant but heat-sensitive animals. High temperatures disrupt their body temperature regulation, causing a heat stress response. Heat stress is extremely harmful to dairy cows, not only affecting milk production, but also easily leading to a decline in their resistance and making them prone to disease. However, many people do not know much about this heat stress and are unfamiliar with its symptoms and prevention measures. Let's take a look together with Qinnongwang below.
1. Symptoms of Heat Stress
When dairy cows experience a heat stress response, the clinical symptoms include a significant rise in body temperature, reduced appetite, rapid breathing, accelerated heartbeat, abnormal metabolism, and decreased body function. In addition, it is also extremely harmful to cows. When a cow experiences heat stress, it secretes more progesterone, causing abnormal estrus or cessation of estrus, reducing the conception rate. Pregnant cows are also prone to miscarriage and stillbirth.
2. Judgment Methods
We can also use some methods to determine whether dairy cows have a heat stress response, such as measuring the humidity and temperature of the rearing environment, body temperature, pulse, and respiration.
Dry and wet temperature of the rearing environment: According to the area of the cowshed, install a dry and wet thermometer inside. When the cowshed temperature is above 30 degrees and the humidity is above 70%, dairy cows generally experience mild heat stress; when the cowshed temperature reaches 35 degrees and the humidity is above 75%, dairy cows experience moderate heat stress; when the cowshed temperature reaches 40 degrees and the humidity is above 80%, dairy cows experience severe heat stress.
Body temperature judgment method: Under normal circumstances, the body temperature of dairy cows is around 38.5 degrees. Randomly select 10 dairy cows in the shed and measure their body temperature. If the average body temperature is above 39 degrees, it indicates heat stress, and if the average body temperature exceeds 40 degrees, it indicates that the heat stress response is extremely severe.
Pulse judgment method: Under normal circumstances, the pulse of dairy cows is 40-80 beats per minute. Similarly, conduct random checks. If the average pulse is above 80, it indicates heat stress, and if it is above 85, it indicates that the heat stress is relatively severe.
Respiration judgment method: Under normal circumstances, the respiration of dairy cows is about 30 times per minute. Conduct random checks. If the average is above 30 times, it indicates heat stress, and if it is above 40 times, it indicates that the heat stress is relatively severe.
3. Prevention and Control Measures
The first thing to do is to reduce the temperature of the cowshed. A shade shed can be built around the cowshed or trees can be planted to avoid direct sunlight. Strengthen feeding management. During heat stress, dairy cows have a poor appetite, so feed according to temperature changes. Try to feed during the relatively cooler times in the morning and evening, avoiding the high-temperature periods. Add a higher proportion of concentrated feed when feeding to supplement nutrition. During heat stress, the water intake of dairy cows is several times that of usual. Insufficient drinking water will cause a series of harms, so provide sufficient clean drinking water, and the water temperature should be below 10 degrees.
The above are the symptoms and prevention measures of heat stress in dairy cows brought to you by Qinnongwang. I believe everyone has also gained some understanding of the symptoms and prevention measures of heat stress in dairy cows. If you want to learn more, please stay tuned to Qinnongwang.