Five key considerations for dairy cow feeding management in summer
The suitable temperature for dairy cows is 10°C to 20°C. In summer, high temperatures and humidity easily cause reduced appetite, lethargy and decreased milk production in dairy cows. Strengthening feeding management can reduce the degree of heat stress and maintain stable, high production in dairy cows during summer. 1. Use cooling facilities and increase air circulation inside the barn 2. Improve feeding methods 3. Increase the nutrient concentration of the ration 4. Ensure clean drinking water 5. Strengthen hygiene management and disinfection
For semi-enclosed barns, doors, windows and windproof curtains should be opened to increase ventilation. For open barns, if conditions permit, ventilation facilities or electric fans can be installed, which can lower the barn temperature by 2°C to 3°C and speed up heat dissipation from the cows' bodies.
Install water mist spraying facilities. Spray the heads and chests of the cows with cold water mist to lower their body temperature, but note that spraying should generally be done during the hot midday period, and the duration should not be too long nor the frequency too high, otherwise it will cause excessive humidity inside the barn and make it difficult for the cows to dissipate heat. Generally, the barn should be kept dry with no standing water, and the relative humidity should be kept below 80%.
Adjust feeding times to feed during the cool early morning and evening hours (before 7 a.m. or after 9 p.m.).
Appropriately increase the number of feedings and add night feeding. It is recommended that in summer the amount of feed given at night should account for more than 60% of the daily ration, which can compensate for the insufficient feed intake of dairy cows caused by high-temperature anorexia.
Adjust the composition of feed ingredients in the ration. First, adjust the concentrate-to-roughage ratio in the ration, that is, increase the proportion of concentrate and reduce the amount of roughage fed. Note that the maximum proportion of concentrate generally should not exceed 60%. Second, adjust the feed ingredients in the ration, reduce the amount of ordinary feed and increase high-quality feed such as whole cottonseed, soybeans, high-quality forage and whole-plant silage. For early-lactation and high-yielding dairy cows, rumen-bypass feed varieties such as calcium salts of fatty acids and amino acids should also be added to the ration.
Use rumen buffers. Because the proportion of concentrate in the summer ration is increased, 0.75% to 1.5% sodium bicarbonate (baking soda) or 0.35% to 0.40% magnesium oxide, etc., should be added to the ration, which is beneficial to the digestion and absorption of nutrients in the rumen.
Add substances that alleviate heat stress. The supply of potassium, sodium and magnesium needs to be additionally increased in the ration. Per cow per day, 30 to 50 grams of potassium carbonate, 60 to 100 grams of magnesium sulfate and 120 to 160 grams of salt can be added to the ration.
Because heat stress increases the consumption of vitamin A in dairy cows, the amount of vitamin A in the summer ration should be doubled.
In summer, the drinking water supply for lactating cows can be provided at 3 to 5 times the milk production volume. Water troughs should be cleaned frequently, disinfected regularly and the water changed to keep it fresh and cool, allowing the cows to drink freely.
In summer there are many mosquitoes and flies. Aerosol insecticides can be sprayed regularly on the cows' bodies and the surrounding environment to eliminate mosquitoes and flies. Manure should be removed promptly to keep the barn and exercise yard clean and dry. Disinfect once a week with 5% Lysol or 2% caustic soda solution. Lime powder can also be scattered in the barn regularly for disinfection, deodorization and moisture removal, reducing the occurrence of summer diseases.