(1) Feeding and management of early lactation

At this period, the cow has just given birth, the body is weak, the digestive function is reduced, the birth canal has not recovered, and the udder edema has not completely disappeared. Therefore, during this period, The main focus should be on restoring the health of the cow, and premature lactation should not be allowed. Otherwise, large amounts of milking can easily cause postpartum diseases.

The cow should be driven to stand up immediately after delivery to reduce bleeding and prevent uterine prolapse, and feed it 10 to 20 kilograms of warm bran salt water (500 grams of bran, 10 grams of salt) as soon as possible. , 50 grams of bone meal or dibasic calcium phosphate) to facilitate recovery of physical strength and discharge of the afterbirth (due to increased intestinal pressure). In order to eliminate lochia and speed up postpartum uterine recovery, you should also drink hot motherwort brown sugar water (250 grams of motherwort powder, add 1500 grams of water , after decoction into a liquid, add 1 kilogram of brown sugar, 3 kilograms of water, the temperature is preferably 40 to 45 degrees Celsius), take it once a day for 2 to 3 days. Under normal circumstances, the afterbirth of a cow falls off on its own about 8 hours after giving birth. If it does not take off for more than 24 hours, do not drag it by force. For weak and elderly cows, oxytocin can be injected intramuscularly or mixed with glucose for intravenous injection, but the dosage It is 1/4 of the intramuscular injection to promote uterine contraction and expel the afterbirth as soon as possible. Do not express all the milk after delivery, otherwise it will easily cause postpartum paralysis in high-yielding dairy cows. Generally, on the first day of calving, you can squeeze out enough milk to feed the calf (3 to 4.5 kilograms). On the second day, you can squeeze out 1/2 of the daily milk production, and on the third day, you can squeeze out 3/ of the daily milk production. 4. Express all the milk on the 4th day. Breast chambers with abnormal milk or mastitis must be squeezed out in time. Low-yielding cows or cows whose udders are not fully expanded after giving birth should be squeezed immediately on the day after giving birth.

If breast edema is severe after childbirth, it is necessary to strengthen the hot compress and massage of the breast, and pay attention to exercise to promote breast swelling. During this period, if you have good appetite, normal digestive function, loose stools, breast edema subsides, and clear lochia discharge, you can gradually increase the amount of concentrate and feed more high-quality hay. Control the feeding of green and juicy feed, and avoid premature lactation. Cause weight loss and metabolic disorders.

(2) Feeding and management during the lactation period (peak lactation period)

During this period, the physical condition has been restored, the breasts are softened, the digestive function is normal, the mammary gland function is becoming increasingly strong, and the milk production is increased. Very soon, it enters the peak lactation period. This stage refers to the period from 2 weeks after calving to the peak of milk production, including the period when milk volume has not yet declined. The entire period is 80 to 90 days. The feeding goal is to fully realize the milk production potential and extend the peak of milk production while ensuring the health of the cows. During the period of pregnancy, the milk production reaches 40% to 45% of the whole period of milk production, and the animals are bred and conceived 60 to 110 days after delivery. Judging from the milk production pattern of postpartum cows. The highest daily milk production generally occurs 4 to 8 weeks after delivery. However, the peak of feed intake does not appear until 11 to 12 weeks after calving, with a difference of 4 to 5 weeks (Figure 6). Increased milk production requires a lot of energy. If the nutrients supplied by the feed cannot meet the energy consumption of synthetic milk, the nutrients stored in the body can only be used, causing a negative balance in the body. According to the test. Cows with lactation metabolism type often lose 35-55 kg in weight 56-70 days after giving birth, and first-time cows lose 15-25 kg in weight, in exchange for a milk volume of 330-500 kg. Therefore, during this period, high-energy, high-protein diets are used to allow the cows to eat as much dry matter as possible (3% to 4% of body weight). The protein content in the diet should account for more than 16% of the total dry matter. Based on dry matter, the ratio of fine material to coarse material should be 55~60:40~45, and the crude fiber should not be less than 15%.

Figure 6 Changes in milk production, feed intake and body weight of high-yielding dairy cows during lactation

①As milk production increases, the amount of concentrate feeding increases

< p> For a daily milk production of 20 kilograms, 7.0 to 8.5 kilograms of fine feed will be given, for a daily milk production of 30 kilograms, 8.5 to 10.0 kilograms of fine feed will be given, and for a daily milk production of 40 kilograms, 10.0 to 12.0 kilograms of fine feed will be given. The maximum feeding amount of grain feed should not exceed 15 kg. When the amount of carbohydrate-rich concentrate is fed too high, the pH in the rumen will drop significantly, forming an acidic environment. In addition, the cow will eat less roughage and produce less saliva. Over time, it will cause indigestion, loss of appetite, and a decrease in milk fat rate. At the same time, it is easy to cause abomasal displacement, ketosis, etc. In severe cases, it can cause acidosis and gastric bloating. In order to prevent the occurrence of the above diseases, 120 grams of baking soda and 30 grams of magnesium oxide can be fed every day to balance the rumen pH, and 500 international units of vitamin E can be supplemented every day. It can reduce the incidence of mastitis and enhance resistance to E. coli. For high-yielding cows with a milk production greater than 35 kg, buffers should be added whether on weekdays or in summer.

②Supply high-quality roughage

Each head is provided with 20 kilograms of silage, 3 to 5 kilograms of high-quality alfalfa hay, and 0.5 kilograms of cottonseed per day. Other hay is allowed to be eaten freely to maintain the rumen. Normal digestive function.

③Provide juicy and dregs feed

This kind of feed has good palatability and can increase the cattle’s feed intake. Provide 3 to 5 kilograms of root and tuber feed per head per day. 10 to 12 kilograms of slag feed.

In addition, pay attention to the supply of minerals and vitamins in the diet.

The nutritional level during the peak lactation period is: 2.5% to 3.5% of dry matter intake (accounting for body weight), the net energy of milk production in the diet is greater than 2.2NND/kg, and the crude protein content is 18% to 19% , containing 0.7% calcium, 0.45% phosphorus, and 15% crude fiber.

Composition of mixed concentrate (reference): corn 35%, barley 15%, soybean meal 16%, cotton meal 10%, bran 18%, calcium carbonate 2%, bone meal 2%, salt 2%.

(3) Feeding and management of mid-lactation

Mid-lactation refers to the period from 101 to 200 days after delivery. At this stage, the cow's appetite is strong. After the feed intake reaches the peak, it begins to decline slowly. The milk production decreases at a rate of 7% per month, and the body weight and fat condition gradually recover. During this period, if the cow can still maintain a high milk production and slow down the decline rate, a higher milk production can be obtained. The milk production should strive to reach 30% to 35% of the whole period of milk production. The ratio of dry matter to refined roughage is 40:60. The feeding plan is based on the principle of "feed follows milk". While the fine feed is gradually reduced, the feeding amount of coarse feed is increased as much as possible to meet the nutritional needs of the cows. For cows that are too thin, the amount of concentrate feeding should be increased to facilitate recovery of body condition. For cows with medium or above body condition, the amount of concentrate feeding should be reduced to avoid excessive body condition.

①Standard feeding amount of concentrate

If the daily milk production is 15 kilograms, feed 6 to 7 kilograms of concentrate. If the daily milk production is 20 kilograms, feed 6.5 to 7.5 kilograms of concentrate. If the daily milk production is 30 kilograms, feed 6.5 to 7.5 kilograms of concentrate. Feed 7 to 8 kilograms of concentrate.

② Standard feeding amount of coarse material

15 to 20 kilograms of silage, 5 kilograms of root material, 10 to 12 kilograms of dregs, hay is allowed to be fed freely, but the minimum amount should be Guaranteed to be over 4kg.

The nutritional level of the diet in mid-lactation is: 3.0% to 3.2% of dry matter intake (accounting for body weight), the diet contains 2.1 NND/kg of net energy for milk production, 14% of crude protein, and calcium 0.7%, 0.4% phosphorus, 17% crude fiber.

Composition of mixed concentrate (reference): corn 38%, barley 10%, bean cake 17%, cotton meal 12%, bran 18%, calcium carbonate 1.5%, bone meal 1.5%, salt 2%.

(4) Feeding and management in the late lactation period

It is generally believed that the period from the 201st day after calving to dry milk is the late lactation period. At this stage, the cow needs a lot of nutrients to supply the rapidly growing fetus in the body. At the same time, affected by the increasing levels of progesterone secreted by the placenta and corpus luteum, the secretion of prolactin decreases, and the milk production rate ranges from 8% to 12% per month. The speed drops sharply, and there is a surplus of nutrients. At this stage, coarse materials are mainly used, and fine materials are appropriately mixed. At the same time, work must be done to protect the fetus and prevent miscarriage.

Special attention should be paid to the following at this stage:

① Strengthen the treatment of mastitis to prevent drying of milk from not proceeding normally or being completely cured, disrupting the normal function of the breasts.

② Effectively strengthen the treatment of limb and foot diseases. This is to prevent emaciated cattle from being unable to recover due to poor limbs and hoofs and affecting the progress of regaining fat.

③ Do everything possible to restore cows in poor body condition to 75% fat condition. However, we must also prevent cows from being overfat, that is, having a body condition of more than 80% fat.

The nutritional level of the diet in the late lactation period is: dry matter intake 3.0% (accounting for body weight), the diet contains 1.9-2.0 NND/kg of net energy for milk production, 13% crude protein, and 0.5% calcium. %, phosphorus 0.38%, crude fiber 20%. The dry matter ratio of concentrate and roughage is 30:70.

Composition of mixed concentrate (reference): 40% corn, 22% bran, 10% bean cake, 13% cotton meal, 1.5% calcium carbonate, 1.5% bone meal, 2% salt.