1. Adjusting Feed Formula and Feeding Time
In summer, to alleviate heat stress, feed formulation can be adjusted appropriately.
Firstly, the proportion of roughage and concentrate should be controlled at 1:1 to reduce the proportion of high-fiber feed which produces more heat in digestion and metabolism, and the proportion of concentrate should be increased by 10%. Fatty acid calcium and cottonseed can be added appropriately to ensure that the fat content is not less than 5%. If the concentrate feed is soaked in water and fed after being prepared into porridge, the effect will be better. Sodium bicarbonate supplementation of 150g per day can alleviate stress.
Secondly, in summer, when the weather is hot and the animal body sweats a lot, we should pay attention to the supplementation of potassium, magnesium, sodium, phosphorus, and calcium.
Thirdly, the feeding time in the morning was advanced to 7 o'clock when the temperature was low, and the afternoon was postponed to 6 o'clock sunset. In addition to adjusting the feeding time, it can also increase the feeding times, such as four times a day, or one more feeding at night. In a word, it should be ensured that dairy cows can feed at lower temperatures every day and avoid high-temperature feeding.
Fourth, attention should also be paid to feed management to prevent mildew of feed and forage grass. It should be placed in a ventilated and cool place, with a special person responsible for the supervision, daily observation of whether there is rot. Timely treatment of feed problems, to prevent the body function decline caused by eating moldy feed by mistake, or even the occurrence of death.
2. Summer Heat Protection and Cooling in Cowshed
Cowshed should be conducive not only to winter heat preservation but also to summer ventilation and cooling. In the hot summer season, cows raised in well ventilated and spacious cowshed, shady shed or shade can reduce the solar radiation heat by more than 20%. Family retail households can build simple shacks according to local conditions, or stack grass on the roof to achieve a cooling effect. If the cattle are tethered feeding, they should be tied under the shade of trees, and cattle should not be exposed to the sun for a long time.
The common methods to strengthen ventilation are installing fans in the cowshed, strengthening mechanical ventilation and accelerating airflow, which can take more heat away from the cow body and help to reduce heat stress. Attention should be paid to the installation height of the fan to be about 2m from the back of the cattle and to the slope of 20-30 degrees with the ground. The wind speed is controlled from 120 to 180 m/min.
Strengthening greening in farms and surrounding areas is conducive to purifying the air and reducing the environmental temperature. If conditions permit, when the temperature is the highest at noon, high-pressure sprayers can be used to sprinkle the cold water in the cowshed, or the spray equipment sold in the market can be installed on the dairy farm and the entrance of cattle shed. The best sprinkler site is the cement floor while preventing wet slippage and falling. When the temperature is above 30 ℃, spray 1 times every 4 days, and each spray should be about 30~45 min. After spraying, the indoor temperature is reduced by 5~10 ℃. Dairy cows should be transported in the morning or evening to ensure proper drinking water and feeding before transporting. The transporter should be well ventilated and the distance should not be too long. Pregnant cows are not suitable for long-distance transportation.
3. Health Management and Disease Prevention and Control
In summer, the temperature rises and bacteria are easy to grow. Corruption and deterioration of feed and feces are beneficial to the reproduction of bacteria. Summer is also the season of outbreaks of viral diseases. Therefore, we should first do a good job of disease prevention and control from the aspects of feeding and management. Only by controlling calving in summer can we reduce the incidence of obstetric diseases and heat stress during pregnancy. Keeping cowshed and playground clean and hygienic is one of the key points of management.
Do regular disinfection, timely removal of feces, wash feed tanks and sinks, storage tanks, and sewage ditches. Regular replacement and rotation of cowshed disinfectants to prevent mosquitoes and flies. It is better to spray lime powder on the entrance of cowshed, which can not only disinfect but also dehumidify. Special attention should be paid to reducing the occurrence of breast diseases, especially acute mastitis. Before collecting milk, wipe the breasts with a warm and sterilized towel (0.0l% potassium permanganate solution). At the same time, carefully observe whether there are breasts and papilla swelling, breakage, and so on, and treat them in time. Trim hoofs regularly, remove foreign bodies such as stones on the playground and reduce the occurrence of footrot.
4. Breeding and Management of Calves in Summer
After calves are born, they have disinfected with 20% iodine liquor at 10 cm away from the umbilical cord, which is tied and cut. Attention should be paid to the disinfection of the section with iodine liquor. After cleaning, they should be transported to the calf shed. Before shedding, they should be disinfected with iodine liquor once or twice a day. If disinfection is not thorough or improper, it may cause umbilical cord inflammation. The treatment method is to use 1.6 million IU Penicillium and 0.5% of procaine 20 ml to close the peri-umbilical cord foramen. Thirdly, use 5% of iodine tincture to disinfect the abscess site and remove gangrene or abscess. Finally, if the condition is serious, use antibiotics to treat it.
The temperature of the calf shed should not be too high. It is better to keep it at about 25 ℃. For large-scale farms, the artificial assistant method can be used to let calves eat colostrum at 38 ℃ within 12h after birth. The artificial formula can also be used instead: cod liver oil 20 ml, fresh milk 500 ml, salt 10 g, eggs 3-4, fed after heating, 3 times a day. Three days later, the usage was increased to 900 ml. Frequently change the matted grass of calf shed and keep it dry, to ensure that there is no draught or thieves wind entering the calf shed.
Feeding Methods of Dairy Calves
1. Feeding colostrum as early as possible
Calves must be fed with their first colostrum 30 to 60 minutes after birth. The stomach of newborn calves is empty and there is no mucus in the stomach wall. The resistance to bacteria is very weak, It is a low survival Rate of Calves. The colostrum of cows one hour after delivery has a high content of immunoglobulin. Colostrum replaces gastrointestinal mucus and sticks to the gastrointestinal wall to prevent bacteria from entering the blood. Studies have shown that colostrum is rich in nutrients, its dry matter and mineral content are twice as high as that of normal milk, its protein is 4-5 times as high as that of normal milk, and its vitamin A, carotene, lysosome and antibody are also relatively high. It has protective, laxative and bactericidal effects on the stomach and intestine of calves.
Although colostrum has many advantages, it also has some limitations. Generally, the first day of colostrum feeding is 1/6 of the calf's birth weight. After that, it can be increased by 0.1 kg to the third or fifth day. Then it can be replaced by some artificial milk or milk substitutes. The colostrum should not be overfed to prevent diarrhea. Normally, calves can be fed normal milk or mixed colostrum and normal milk 5 days after birth. If they are still fed colostrum, they should be diluted by 2:1 and water. The ratio of normal milk to colostrum is 1:2 when they are fed mixed milk.
Quantitative, constant temperature, fixed time and the fixed person should be done when feeding. The daily feed is about 10% of calf weight. With the increase of age, increase the daily milk volume by 0.1 kg (20-30 days), to weaning day about 5 kg, 3-4 times a day feeding, each feeding interval should be equal, to "feed on time, do not feed at other time", if the milk is not enough, you can add boiled water, cows must not eat too full. In summer, milk can be fed immediately without heating. In the cold season, milk barrels should be heated in a boiling water pot. Do not heat directly on the stove. The milk temperature should be 38-40 ℃. Based on constant temperature and quantity, we should pay attention to the quality of milk. Firstly, we should avoid adding antibiotics to cow feed to prevent diseases or feeding forbidden feed additives and animal feed. Secondly, we should pay attention to hygiene during milking, and control the listing and feeding of milk from cows infected with mastitis and infectious diseases.
2. Feeding of artificial milk and roughage
To save fresh milk, artificial milk has been widely used to feed calves abroad. At about 10 days old, artificial milk is used instead of milk. Generally, artificial milk contains skim milk, animal fat, lactose, and other essential minerals and vitamins. Artificial milk has been commercialized and scaled abroad. They produce dairy substitutes for calves at different stages of production, and the amount of water added should also be formulated according to the instructions.
The protein in artificial milk is provided by skim milk powder, which is expensive, so it can be replaced by soybean protein, but the digestibility of calves to vegetable protein is low. All raw materials of dairy substitutes must be of good quality, and inferior dairy substitutes are not only liable to cause calf diseases, but also hinder the feeding of calves, resulting in growth retardation and serious diarrhea and death of calves. Milk temperature is a part that must be paid attention to when feeding artificial milk, too high or too low is not conducive to the digestion and utilization of calves, too cold is easy to cause diarrhea, and too high is easy to burn calves, resulting in the next refusal to eat.
Training calves to eat grass as soon as possible can promote the development of the rumen. The activity of calves' rumen strengthens with the increase of grass or hay. Generally, calves can be trained to eat high-quality hay in the second week after birth. Sprinkle a small amount of high-quality hay in front of the fence. Calves will try to eat a little, and gradually it will meet the needs of physical development to increase their intake. Some calves are fed with high-quality hay powder mixed with milk or milk substitutes, but too fine hay powder is not conducive to the development and digestion of the rumen.
The amount of starter is usually one on the first day, and then gradually increases. Calf starter should not be ground too fine, otherwise, it is not conducive to the healthy development of calf rumen, and even damage the digestive tract of the calf. The starter should be ground roughly, preferably with hay to make a high-quality mixture, hay can provide a "grinding" effect. The purpose of the starter is to make calves adapt to the transition from feeding mainly to completely feeding on concentrate and forage, so it is related to the success or failure of early weaning of calves.