Nanjing has a suitable climate, abundant water resources, a wide variety of pastures, and a large number of crop by-products and various types of straw, providing abundant forage resources for the development of dairy cow production. For family dairy farms, in addition to leading natural resources and dairy processing brigade companies, proper management of their own sites and scientific feeding management are the key to improving economic efficiency. There are many factors that affect milking ability of dairy cows, which are influenced by genetic characteristics and internal and external environment. The introduction of excellent varieties and scientific feeding and management are both indispensable and complementary. Only the organic combination of the two can produce high yields and produce good results. 1 There is a significant difference in milk production between breeds and individual dairy cows. At present, Chinese Holstein dairy cows or Chinese black-and-white flowers are the major dairy cow breeds in China. The average national milk production is 4774 kg, and Beijing, Tianjin, and Shanghai reach more than 6,000 kg. Similarly, the level of milk production within the same species is highly inconsistent among individuals and can vary from 3000 to 12,000 kg. Therefore, the selection of dairy cows or individual breeding is one of the keys to increase the milk production of dairy cows. Should try to choose from regular dairy farms. It is best to use black and white flowers, Juan Shan and other large breeds, fast growth, strong adaptability, and high performance dairy cows. In production, the general choice of bones is large, robust and strong, with a large body size and a triangular outline. The skin is fine and elastic, the blood vessels are exposed, and the coat is short and smooth and shiny. Black and white flowers are clear, limbs straight, well-proportioned structure, there is no inside and outside the arc, legs open. The breast is large and square shaped. In order to ensure that the offspring of dairy cows still maintain their excellent milk production performance, frozen semen of excellent bulls is used for artificial insemination. When the technical conditions are mature, estrus, superovulation, and embryo transfer can be performed at the same time to rapidly breed high-yielding dairy cows. 2 Scientific feeding: 2.1 Feeding dairy cows of various types, good palatability, and high quality are high-producing animals that excrete a large amount of nutrients from the body every day. Therefore, the diet of cows should be high-quality feed. Most of the dairy cattle farms in the South use the combination of grazing and house-feeding. Therefore, grazing should not be used, no matter if feeding, or only straw feeds should be added after returning home. But according to different lactation stages, replenish different dietary nutrients and supplement 1kg of concentrate per 3kg of milk produced. Or according to the annual output of 3000-4000kg of cow diets, the proportion of refined feed is 15 to 20%, 4000 to 5000kg is 25 to 35%, and 5000 to 6000kg is 40 to 50%. The concentrate feed should be full quality and high quality. For the roughage and straw, it is necessary to directly use the whole bales to feed the straw. The silage and ammoxidation are used for the straw treatment. The crude protein content of the straw and wheat straw after treatment can be more than doubled, straw utilization rate, and the use of straw. Both feed intake and milk production have increased significantly, which not only reduces feed costs but also increases economic efficiency. At the same time, in order to increase the feed intake of lactating cattle for various feeds, it is necessary to shorten the residence time of chyme in the digestive tract. Bran is often added as a diarrhea feed, and the amount accounts for 25 to 40% of the concentrate. In addition, rootstock feeds can also be fed. 2.2 Feeding method Firstly, regular quantification: Due to the conditioned reflexes developed over a long period of time, cattle begin to secrete their digestive glands before eating. It is very important to maintain the internal environment of the digestive tract and improve the digestibility of feed nutrients. . Therefore, it must be grazing on time, feeding materials on time in order to adapt to the normal activities of cattle digestion. Each time there is a certain amount of feed, the concentrate feed is fed by the amount and the rough feed is fed freely. The second is to add less ground, this method can maintain the rumen environment is constant, so that the food even through the digestive tract, it can improve the digestibility and absorption rate. In addition, the replacement of feed should be carried out step by step, because the formation of the rumen bacterial flora takes 20 to 30 days, once disrupted, recovery is very slow. Therefore, when changing the type of feed, it must be gradually carried out. Third, feed screening, to prevent foreign matter, feed cattle fine, rough feed should be cleaned with a magnet with a clear filter to remove the inclusion of nails, iron wire, glass blocks and other sharp foreign bodies, so as not to cause the net stomach, pericardial trauma. In addition, feed should be kept clean, and avoid use of rotten, frozen feed for cattle. 2.3 Number and Sequence of Feeding Domestic cows raised by grazing adopt 2 times of grazing and 2 times of milking, and formulate 3 working schedules of feeding 3 times under tether management conditions. Feeding 3 times a day more than 2 times increased the digestibility of dietary nutrients by 3.6%. However, it has greatly increased the consumption of labor. According to the law of milk secretion, cows with a milk yield of 3,000 to 4000 kg can be fed twice for 2 times. In the feeding sequence of cattle, it is generally the method of “coarse first, then fineâ€, “dry first and then wetâ€, “first feed and then drinkâ€, or the method of feeding the fine material first and then feeding the rough material and finally drinking water, and the feeding method must be determined. According to the specific conditions. 2.4 Place Salt Tanks Milk contains various minerals and trace elements. To prevent the occurrence of “different food†in dairy cows, salt tanks equipped with various mineral elements can be placed in the playground, or some salt bricks can be hung. Cows eat freely. 2.5 Addition of rare earth additive rare earth elements (Earths) Chemical elements periodic table 15 kinds of lanthanides and chemically similar yttrium, yttrium, a total of 17 kinds of elements in total. As a new type of feed additive, rare earth has the advantages of less dosage, obvious growth promotion effect, high feed remuneration, inhibition of bacterial growth, increased milk production, and milk fat percentage. In the mixed diet of dairy cows, lanthanum-based light rare earth (R2O3 ≥85%) was added at doses between 200 and 800 PPM. Experiments show that adding 600PPM to the mixed diet can increase the milk production by 8.26%, and also significantly improve the milk fat percentage. 3 Milk production of dairy cows managed in different seasons is genetically a quantitative trait, which is controlled by many pairs of micro-effect genes and is greatly influenced by the environment. The heritability of milk production by cows is low, about 0.25 to 0.30. The external environment has a greater impact and can account for 70 to 75%. Therefore, in addition to genetic factors, the increase in milk production of dairy cows cannot be ignored. 3.1 When summer temperatures rise in summer, the energy needs of dairy cows decline, and the demand for minerals, multidimensional and protein increases. Therefore, to meet the nutritional needs of dairy cows in summer, the feed ratio should be adjusted to reduce the amount of feed in the diet. . It is generally reduced by 5% to 7% of energy, 5% to 7% of protein, 2 to 3 times more vitamins, and 1 to 2 times more minerals. At the same time, consider adding more green and palatability feeds to the diet. In addition, the amount of salt to be fed is also increased. Generally, it can increase 20 to 25 g per cow per day. The summer weather is hot and the cows drink more water. The daily drinking water is around 100Kg. It must be ensured that the cows have sufficient drinking water. It is usually possible to use free drinking water and keep the water clean and cool, preferably with cool well water. In hot weather, raw gypsum water or salt bran soup (50 kg of water, salt 50 g, bran 1 to 1.5 kg, three times a day) may be added to increase the appetite of the cow, prevent heatstroke, and effectively control milk production. 3.2 Since there are few green and winter fodder in winter and winter, it is necessary to relatively increase the content of vitamins, minerals, and other nutrients in the feed, and at the same time, the treatment of fodder and the cooperation of fine materials should be done. Overcome the traditional habit of feeding valerian grass, and advocate silage silage and amination treatment to make hard grass become soft, hay become wet, and rough grass become fine. 4 Most of the management and delivery periods before and after childbirth only focus on the care of newborn calves, ignoring the management of cows, thus affecting the reproductive performance and milk production performance of dairy cows. Therefore, attention should be paid to the following points: 4.1 For laboring dairy cows, the hips, vulva and breasts should be cleaned with disinfectant and replaced with soft bedding to keep the environment quiet. 4.2 0.5 to 1 hour after childbirth, to feed warm bran bran soup (brist 1.5 ~ 5Kg, salt 100 ~ 150g), to supplement the loss of body water during delivery, increase abdominal pressure, help the discharge of the placenta. 4.3 As soon as possible after delivery, the cow should stand up to facilitate the resettlement of the genitals. To prevent the uterus from escaping, pay attention to the discharge of the placenta. If it does not fall off after 24 hours, treat it according to the retention of the placenta. Timely treatment of lochia obstruction. 4.4 In the first few days, cows often suffered from edema in the breasts, and high-yielding cows were more pronounced. At this point must not be completely squeezed milk, otherwise it will be due to a significant decline in breast pressure, resulting in increased microvascular leakage, blood calcium, blood glucose loss, increased breast edema, causing postpartum spasm, death. Usually only about 24Kg is squeezed on the first day after the delivery, and it can be enough for cows to suckle milk. The amount of milk that is squeezed every time the next day is 1/3 and the amount of milk that is squeezed every second day is 1/2. After the fourth day, it can be squeezed. net. 4.5 1 or 2 times a day after delivery to drink warm motherwort brown sugar water (ratio: motherwort 500g, add water 10Kg, add water, add brown sugar 500g), the cow's lochia net and postpartum uterus recovery promote. Intramuscular oxytocin can also be 20 ~ 40IU. 5 regulate milking 5.1 milking environment is quiet, skilled movements, milking to be stable, fast and clean. 5.2 When milking, cows and breasts should be cleaned beforehand and the breasts should be promptly bathed to prevent breast infections. 5.3 When dry milk, the dry period should not be less than 30 days. 6 comprehensive prevention and treatment of disease, usually strengthening feeding and management, feed and drinking water to be clean; cowshed to keep dry, so cool in winter and cool in summer, often brushing cattle, keep the skin clean and increase blood circulation. Disinfect the environment regularly. Each year, in conjunction with the epidemic prevention department, quarantine of tuberculosis and brucellosis is carried out, and cattle with positive test results are eliminated in time. Regular injections of foot-and-mouth disease inactivated vaccines, anthrax spores aluminum hydroxide adjuvant vaccine, bovine hemorrhagic septicemia aluminum hydroxide vaccine, prevention of anthrax, foot and mouth disease and bovine hemorrhagic sepsis and other infectious diseases. According to the prevalence of local parasites, regular extermination of parasites in vivo and in vitro, use of thiabendazole, blood worms net and other drugs for prevention or treatment. Actively prevent and treat mastitis and obstetric diseases.