According to the research, adding fat has a good feeding effect when the food intake decreases under heat stress. Oily seeds such as whole cottonseed or soybean, beef and sheep fat and fatty acid calcium are all good sources of fat. The feeding amount of whole cottonseed is limited to 2.3 ~ 3.0 kg per day, which is due to the toxicity of gossypol and the effect of cyclopropane fatty acid. At the same time, when feeding whole cottonseed, milk protein decreased by about 0.65438 0%, and the proportion of long-chain fatty acids in milk increased. Therefore, when cottonseed is added, the calcium content of dry matter in the diet must be increased (by 65438 00%).
Hassan and other experiments showed that when the temperature fluctuated from 17.8℃ to 32.8℃, the protein level of dairy cows increased from 14.3% to 20.8%, the feed intake increased by 1 1.3%, and the milk yield increased by 6%. However, we should be careful not to overdo it, otherwise, excessive protein will deaminate for energy supply, increase "heat consumption" and aggravate heat stress. Generally speaking, the content of rumen bypass protein in the diet of high-yield dairy cows is increased from 28% ~ 30% to 35% ~ 38%.
In summer, try to feed more green and juicy feed, such as carrots, wax gourd, pumpkin, melon skin and so on.
(2) Pay attention to supplement sodium, potassium and magnesium. In hot season, cows sweat more and lose more sodium, potassium and magnesium, so they should be supplemented. A recent study in Florida, USA, confirmed that dairy cows' diets contain 0.4% ~ 0.5% sodium, 1.5% potassium and 0.3% ~ 0.35% magnesium in summer, which is helpful to relieve heat stress and improve milk yield.
(3) Prolonging feeding time and increasing feeding times. Since the peak stage of heat energy production is 2 ~ 3 hours after eating, it is suggested that the feeding amount in summer should account for more than 60% of the daily diet, especially the roughage should be arranged from 20: 00 to 5: 00 the next day, so that the peak of heat consumption and temperature appear alternately. At the same time, feeding measures such as increasing feeding times, extending feeding time and preparing porridge can also be taken to increase appetite and food intake. In addition, fresh, clean and sufficient cold water should be given to cows in summer, which will help to lower body temperature and increase appetite. Drink it 5 ~ 7 times a day, i.e. 1.5 ~ 2.0 hours, preferably with an automatic water dispenser.
(4) Increase cooling measures. Install a fan with large exhaust volume in the cowshed to accelerate the air flow in the cowshed and reduce the humidity in the cowshed, which is beneficial to the heat dissipation of the cowshed. Spray facilities are installed in the cowshed to spray the cows automatically, so that the body surface temperature of the cows drops rapidly.
(5) Improve the microclimate of the cattle farm, and keep the cattle body and barn clean. Planting trees around cowshed and playground can reduce solar radiation and beautify the environment.
In addition, in summer, mosquitoes, flies and other insects greatly harass cattle, suck a lot of blood from cattle and spread diseases, which have great influence on the health and milk production of cattle. Active measures should be taken to eliminate this phenomenon. First of all, the breeding of mosquitoes and flies should be eliminated as much as possible, and any accumulated water and weeds in dairy farms should be removed. Catch and ditches should be regularly sprayed with effective and harmless pesticides, such as trichlorfon. Secondly, keep the cow body and cowshed clean, remove feces and sewage in time, keep the cowshed and cowshed dry and clean, and remove the cow dung around the playground and site as much as possible, because cow dung is the main breeding ground for cattle flies.
(6) adjust the schedule. Take night stocking exercise, but pay attention to the release time. Only release the cows after the geothermal heat is released (such as after 6 pm) to avoid sudden heatstroke of the cows due to the dual effects of their own heat and geothermal heat.