Dairy cattle heatstroke is mainly caused by physical factors (such as temperature, heat, sunlight, humidity, etc.) which lead to damage to the body, resulting in disorders of the central nervous system function, and some will die due to lack of timely treatment or inappropriate treatment. To avoid unnecessary losses in the process of dairy cattle feeding, the comprehensive control measures of the disease were summarized. Next let's get to know: the clinical symptoms of cow heatstroke and the preventive measures of cow heatstroke.
In hot summer, if dairy cows graze or exercise outside the house for a long time, the head will be exposed to the sun directly for a long time, causing congestion of the brain, blood vessels, breathing, and motor central nervous system disorders, and when the symptoms are serious, they will fall into a coma, which will lead to heatstroke. Summer house temperature is too high, too stuffy, poor ventilation or can not timely heat dissipation, too crowded, feeding density is too high, resulting in a large amount of heat accumulation in the body and can not be timely disseminated, resulting in heatstroke. Also, if the dairy cows are not properly managed, grazing for a long time or exercising a lot, they are weak and sweating a lot, but they do not replenish enough salt and drinking water in time, they will suffer from heatstroke and collapse in serious cases.
In the early stage of onset, the brain function of the diseased cattle declined rapidly, physical weakness, depression, swaying walking, weak and fast pulse, opening mouth and stretching tongue, and breathing accelerated. The course of the disease progresses rapidly, and when it is serious, it will sweat heavily, and there is a tendency of collapse and coma. At the later stage of the disease, the heartbeat of the diseased cattle was weak and accelerated, the breathing was fast, the body temperature was increased, and it could reach 42-43 C. It was exciting, and even violent or obvious nervous convulsions occurred. The mucous membranes begin to be flushed red, then gradually become blue-purple, and the tongue and mouth are dry. Subsequently, they will lie down because of physical weakness and fall into a coma. They will have difficulty breathing. Finally, they will die because of myocardial paralysis and pulmonary edema.
If the high temperature lasts for a long time, it will seriously damage the temperature-regulating center of diseased cattle. At this time, it will show a slight loss of appetite and a slightly slower reaction. After examination, there are usually no other obvious clinical symptoms. However, it will collapse due to the sudden stop of breathing or myocardial paralysis due to failure.
Western medicine treatment. Dairy cows suffering from heatstroke should immediately take measures such as cooling down rapidly, accelerating heat dissipation, strengthening nursing, calming and tranquilizing, strengthening heart and diuresis, and avoiding acidosis. The diseased cattle should immediately move to a cool, quiet and well-ventilated place, and put cold water wet cloth or ice bag on their head, and pour cold water on their body surface. However, they should pay attention to avoid the parts of the heart, and use cold water enema and plenty of cold saltwater. If the diseased cattle can not fall to the ground in a coma, they should be bloodletting 1000-2000 ml, then intravenously injecting 1000-2000 ml 5% glucose saline, 10-20 ml 2.5% chlorpromazine hydrochloride injection and 10-20 ml 20% sodium caffeine injection. If the heartbeat of diseased cattle is too fast and restless, the enema can be performed with 25-35 g chloral hydrate, or 100 mL ambroxol injection can be injected intravenously. If acidosis occurs in diseased cattle, 500-1000 ml 5% sodium bicarbonate injection can be injected intravenously. If the intracerebral pressure of diseased cattle increases significantly, 500-1000 ml 25% sorbitol solution or 20% mannitol solution can be intravenously injected; if accompanied by loss of appetite, appropriate stomach-strengthening agents can be given, such as artificial salt, rhubarb tincture, gentian tincture, etc.
Feeding and Management. In hot weather season, cows tend to show a decrease in appetite, which can properly increase the total digestible nutrients in the diet. For example, when most of the diets are corn silage, it is necessary to ensure that the protein level in the dry matter of the diet reaches 16%-17%, and feed the high-quality rumen-passing protein feed, such as distiller's grains and beer grains. In addition, adding 200 g fatty acid calcium into the diet can significantly increase the energy concentration of the diet, thereby enhancing the lactation performance. In order to avoid anorexia in dairy cows, appropriate molasses feed can be added, and a certain amount of trace elements and mineral additives should be supplemented, especially the amount of vitamin A increased from 50,000 IU per head to 150,000 IU per day
Drug prevention. Adding 300 g sodium acetate per head per day in the diet of dairy cows could alleviate the inhibiting effect of high ambient temperature on milk production performance to a certain extent, stimulate the increase of milk production, and significantly increase the total amount of milk fat. In addition, dairy cows often lose more potassium in the high-temperature season because of the obvious increase in water consumption, skin evaporation, and urination. To increase the potassium content in the diet properly, 180 G potassium chloride can be used per head per day and mixed with feed three times. If the feed of concentrate is increased, attention should be paid to increasing the use of sodium bicarbonate at the same time. It is recommended that 150-200 G be used per head per day. In the case of heat stress, the appropriate amount of yeast culture, rumen hormone, and complex enzyme preparation can be added to the diet to effectively alleviate the stress.
Heat stroke is a serious disorder of nervous system and heart and lung function caused by heat accumulation in the body.
1. Symptoms of cattle suffering from sudden depression, slow reaction, unstable gait, rapid and difficult breathing, venous enlargement, visible mucosal congestion red, severe cases of blue and purple, body surface burning, the body temperature of 42.5 C, increased heart sounds, heart rate to 110 times/min, dilated pupils. Some sick cows fell to the ground and were in a coma and convulsion.
2. Cause analysis: The main reasons are sun exposure and the cowshed not ventilated. Also, inadequate salt in drinking water is one of the reasons for the poor heat resistance of dairy cows. Severe cases are suspected to be caused by cardiac insufficiency or obesity.
3. The diagnosis was based on the course of onset, the symptoms of high respiratory and circulatory dysfunction, and the etiological analysis to determine heatstroke.
4. Therapeutic measures were to move the affected cattle to a shady place and to pour cold water into the head and body in large quantities. At the same time, cold water enema and 1% cold saline were given.
5. You should prevent and rebuild cowshed, increase shade shed, improve ventilation and ventilation conditions, ensure adequate clean drinking water, increase proper salt in the diet, and use 5-10 bales of herbal tea to be filled with boiled water.