1. Lactation
For newborn calves, amniotic fluid and mucus in the mouth and nose should be cleaned immediately. To ensure that calves can breathe normally, then cut off the umbilical cord. After that, 7% of iodine liquor was applied to the abdomen around the umbilical cord and umbilical cord for disinfection for 3 days, and attention was paid to the occurrence of infection in the umbilical cord to avoid the occurrence of umbilical cord inflammation. Calves should eat about 2 kg of high-quality colostrum in time within 2 hours after birth, and ensure adequate so that they can get antibodies as soon as possible, and then feed the second time at intervals of 1-2 hours. Attention should be paid to it within 4 hours after birth, and the feeding volume is also about 2 kg. After that, they can be fed according to the working time for 3 to 4 days, three times a day, each time controlled at about 2 kg, pay attention to the colostrum temperature at 38℃. After the first colostrum is eaten, the calf can be transferred to a separate calf cage for a week of feeding, and then transferred to a loose cowshed for small group feeding.
When calves are fed with ordinary milk, they are fed three times a day, each time controlled at about 2L. It should be noted that the temperature of ordinary milk is also 38℃, and the feeding time and quantity are fixed. The ground of the calf shed is cleaned up once a day and disinfected with alkali or acid every week. The used feeding containers should be cleaned immediately to ensure that there is no milk dirt and other dirt, and the sodium hypochlorite solution should be rinsed once a day, and eventually placed in the vent to dry for reserve. Since the calves are fed in groups, they can be trained to eat granular materials. If conditions permit, they can also provide high-quality Alfalfa for their free feeding. Attention should be paid to cleaning the ground every day, replacing the mattress of the cowshed, and disinfecting once a week. To make calves easy to manage after adulthood, the electrothermal method and chemical method can be used to remove corners. The electrothermal method is suitable for calves aged 3-5 weeks, the chemical method is suitable for calves aged 4-10 days, and timely cornering can reduce stress.
2. Weaning period
From lactation to weaning, calves usually need to be prepared for a long time. Firstly, calves should be trained to feed on hay and nutrients as early as possible. They usually begin to train for nutrient intake around 7 days old, hay intake around 10 days old and silage intake around 2 months old. Secondly, attention should be paid to the preparation of diets to ensure that they contain 15% to 20% of crude protein, more than 8% of crude fiber, as well as a large number of minerals and vitamins. Finally, we need to know the time of weaning. Usually, the calves are 45 days old and can be weaned when they can eat about 1 kg of feed every day.
The calves from weaning to 6 months old are called weaned calves. At this time, they should be grouped. The calves with similar weight and age should be fed together. The number of each group should be 10-15, and the proportion of concentrate and roughage should be adjusted according to the actual situation. Grouping of calves can promote their growth and development consistently as much as possible, which is conducive to the synchronization of estrus.
Besides, calves need to provide sufficient concentrate at this time, mainly because the development of digestive organs of calves is in the fastest state at this stage, especially the volume of digestive organs of 4-6 months old changes very obviously. To satisfy the development of rumen epithelial tissue, it is necessary to feed a diet containing sufficient concentrate, which can not only meet the needs of the development of rumen epithelial tissue but also supply acetic acid and butyric acid for rumen development. When formulating diets, attention should be paid to containing more than 30% neutral detergent fibers, which can be matched with 1.8-2.2 kg of high-quality hay and 1.4-1.8 kg of mixed concentrate, to ensure that the daily gain of calves can reach about 750 g at this stage.
Moreover, to promote the development of the body, it is necessary to provide adequate clean drinking water and brush regularly. Usually, the temperature of brushing is above 15℃, and it is better to use a brush to brush the cattle's body, brushing twice a day.
3. Replacement period
Breeding dairy cows are mainly fed with roughage to expand their rumen volume and enhance the utilization ability of roughage, to ensure the maximum physical development. Cows of 7-12 months old, fed 1.4-1.6kg of concentrate, 2.4 kg of alfalfa hay, and 9-10 kg of silage every day, while 13-18 months old, fed 1.7-1.8 kg of alfalfa hay, 3.5-4 kg of alfalfa hay, and 12-15 kg of silage every day, so that its daily gain can reach 800 g. At the same time, according to the size and age of the body, the group feeding should be adopted, and the alfalfa hay should be added to the supplementary feeding trough of the playground to allow it to eat freely, to ensure that there is always clean drinking water in the trough. When dairy cows are over 16 months old and weigh 380 kg, they can be first mated.
Therefore, staff regularly measure the weight and size of dairy cows, and pay attention to the observation of oestrus at any time, to achieve timely mating. If the fatness of dairy cows is not very bad, nutrition can be provided according to the need to maintain 700 g daily gain. Attention should be paid to not provide too much nutrition to prevent the accumulation of large amounts of fat around the uterus and ovaries, which will affect pregnancy.
4. Mating Period
To ensure the best fertility rate, the replacement cows can continue to gain weight 30 days before mating and 30 days after mating, to make adequate preparations for estrus performance and mating pregnancy. During the breeding of replacement cattle, the time of sexual maturity, mating, and normal childbirth are determined by their size, not by their age. Therefore, if the replacement cattle are adequately nourished, calving at the age of 24 months can usually be achieved. The following measures can be taken for this purpose.
Replacement cattle must be mating when they reach the age of 15 months. For this reason, the first mating should be carried out at 12 months old. The remaining 90 days are used to continue mating of the first-time non-pregnant dairy cattle until pregnancy. Due to the need to anticipate the mating date several months in advance, it is necessary to observe the oestrus and record the oestrus, especially the oestrus date, so as to facilitate the prediction of the oestrus time at the next mating, at the same time, the phenomenon of the difference in the initial oestrus of the replacement cows can be found, and effective measures should be taken in time to prevent the delayed age of the mating month. After pregnancy, cows need to provide nutrition according to 900 g daily gain. Roughage is mainly high-quality hay, grass, root material, and silage maize, with 2.8-4.0 kg of concentrate provided per day.