Summer is a good season to eat ice cream, but the temperature and humidity can cause production and even life-threatening for cows. Heat stress reduces milk production and the health of dairy cows. The new threshold of heat stress temperature and humidity index has been changed from the original72Adjust68because inTHIReach68Most cows will begin to suffer.heat stress. WhenTHIReach80If no cooling measures are taken, most cattle will suffer severe heat stress.

Heat stress can reduce the feed intake of dairy cows, which can lead to daily10pounds or even higher milk yield loss. It can also suppress the immune system of cows, leading to increased susceptibility to disease, and can increase the incidence of many diseases. In addition, heat stress can also lead to an increase in standing time, a decrease in reproductive performance, and a decrease in production throughout the lactation period.

Due to the large volume of the rumen, the digestive system of dairy cows can effectively degrade fiber feed, but dairy cows are very sensitive to heat stress. The rumen microbial flora also generates a lot of heat while digesting roughage fiber, just like a big stove in the rumen.

The higher the milk yield and the greater the feed intake, the more heat production and the more sensitive to heat stress. Large cows, such as Holstein cows, have a weak ability to dissipate heat and are naturally sensitive to heat stress.

HainThe doctor has given us ten tips to help us fight against heat stress.

Adequate drinking water: in a cold environment (e. g.4degree),1500If a pound cow produces milk every day80Pound average need to drink water25Gallons. Similarly, if a cow is in a hot environment (26.7degrees) need to drink33gallons of water. The more productive cows need more water, and the higher the temperature, the greater the amount of water to drink. The drinking water area of each cow in the enclosure is at least8Centimeters; this will reduce competition for drinking water from cows to ensure that all animals have access to clean drinking water.

Shade: Studies have shown that cows in grazing or sports fields are more productive under shade than without shade.10-20%of the milk. For high-yielding cows, this is critical, but don't forget the reserve and dry cows on the playground or pasture, and don't forget the sick cows and the more vulnerable cows, because they are less able to avoid direct sunlight.

Fans: Fans can help remove radiant heat. The diameter of the selected fan should be36-48Inches, the installation height should be from the ground8feet high, spacing between fans20ft., fan tilted down15-25degree to ensure that continuous wind speed can be formed. Fans should be installed crosswise to provide good air circulation in all areas.

Spraying: Spraying in the harvesting esophagus is combined with a fan. In most pastures, the fan plus spraying can provide the best heat dissipation method. The fan combined with spraying uses the evaporation heat dissipation of cows to achieve the purpose of cooling. Sprinkler should be installed at a distance from the ground8Feet of height, immediately below the fan, requires the nozzle to be able to reach180There is no dead angle in the degree jet, and the water flow is about10pounds per square inch (pressure approx.69kPa). Spray directly to the entire back of the cow, different areas according to the temperature and humidity to set the appropriate spray-fan on interval, recommend here is15minute cycle,3Minute spray,12Minute blow-dry (translator's note: the procedure is not the same for all pastures, requiring pastures to explore the best circulation mode according to their own conditions, one principle is to spray thoroughly and blow dry). This spray can spray through the cow and can be dried by a fan to remove heat by evaporation to achieve a cooling effect. Sleeping bed is not recommend to install the nozzle, because it will increase the humidity, resulting in environmental mastitis.

Spray: In dry areas, the pasture can be considered to be equipped with a fan system installed above the bed with spray, which reduces the air in the barn by evaporating the mist. Because the spray droplets are small, they evaporate and dissipate before falling to bed. This evaporation can slightly lower the air temperature, but is not suitable for high humidity areas and closed cattle houses because it can increase humidity and increase heat stress.

Dietary adjustment: increasing the supply of fat and reducing the proportion of concentrated feed can increase energy concentration and reduce the heat produced by fermentation. The amount of fat added should not exceed that of the diet.6.5%(dry matter calculation). Reducing the feeding amount of roughage or feeding high-quality roughage can reduce the heat production of fermentation. In the hot season, cows like to be picky about concentrate feed, but enough roughage should be fed to avoid digestive problems and milk fat reduction. Mineral potassium should be increased during heat stress (1%of dry matter), as well as the addition of organic chromium, which can help increase thermal tolerance.

Focus on new cattle: In the hot season, cows are more susceptible to endometritis, mastitis, ketosis and other diseases. Because the cows in this important period of feed intake itself is low, itself is in a state of immune suppression. By closely monitoring new cattle production, these problems can be detected early and the necessary measures can be taken to intervene before the problem becomes serious. additional heat stress,12Hours can turn a sick cow into a dead cow.

Pay attention to the milking hall and the milking hall: Due to the high density of the milking area, the milking hall is the hottest area of the ranch, because there is not enough space for heat dissipation in this area. Cows need at least26-48Square feet of space to stop the spread of heat between cattle. When driving cattle, you can consider dividing them into small groups instead of driving the whole group together. This means that there will be fewer cows waiting in the huddling hall and less contact between cattle. In this high-risk area, the need for fans and sprinklers is even greater. Adding some water tanks to the back-to-cow channel in summer can increase water intake and slow down the milk reduction of cows.

Do not increase stress: do not move cattle casually (move, group or transport), do not inject vaccines when it is very hot, etc. Avoid any factors that can increase stress-Vaccines can of course also increase stress on the body's immune system-This will have significantly different consequences for the cows.-Cows could have resisted heat stress by themselves, but they were on the verge of death because of the aggravation of heat stress by external stress factors. Due to excessive stress can also cause abortion of dry cows.

Tunnel ventilation with wet curtain: It is a good model for small pastures to use wet curtain with tunnel ventilation. This combination can reduce the indoor temperature10degrees above. This is an effective way to cool down, but it may be difficult for large pastures.

2 Heat stress cooling priorities (lactating and dry cows)

1.heat stress measures in the first place to ensure the supply of water15-20One sink for cows, and the best drinking area for each cow is up10Centimeters, to ensure the cleanliness of the water and water temperature

2.The cowshed, the shade of the waiting room.

3.Reduce walking distance

4.Reduce the waiting time of cattle in the waiting hall.

5Improvement of ventilation in crowded halls and cattle barns

6.Increased cooling at the exit of milking parlors and milking parlors

7.perinatal cow cooling, perinatal cooling is preferred over lactating cow

8.Heatstroke Prevention and Cooling of Newly Produced, Early Lactation Cows