1. Importance of selective feeding
To maintain rumen stability, animals are fed most of the day, especially with a relatively slow intake of grass and straw. If selective feeding is required, cows must be guaranteed to have feed most of the time. In pastures, the maximum forage intake can be achieved only when the forage is over-supplied. Generally speaking, the amount of forage provided should be 3 to 4 times of the intake to achieve maximum potential autonomous intake.
2. Control target of turf surface height
The simple index of forage supply is the surface height of turf. Regular measurements of turf height are helpful to pasture management. For dairy cows in growth, lactation and dry milk periods, the control target of turf height should be 7-15 cm. It is very important to measure the height of turf in grazing areas. Because the grass is polluted by feces and urine or trampled, it is unlikely to be eaten until the turf height in grazing areas is at the appropriate height, at which time the absorption is limited and the maximum value cannot be reached.
3. Buffer feeding
The concept of buffer feeding is proposed as a method to reduce the loss of pasture output, especially when the forage intake is below the maximum due to the sufficient supply of forage due to bad weather, inadequate growth of grass, short days or less time on the pasture. Buffer feed is not as popular as a pasture grass, but it is a substitute for grazing grass rather than a supplement. In general, silage or hay are used as a buffer feed. After milking in the cattle farm, the cows are allowed to feed freely, while the other cows are allowed to feed on the pasture.
4. Feeding frequency and rumen acidosis
It is important to eat only a little at a time when cereal concentrates are freely available. Therefore, in feeding grounds and places where milk is produced by feeding high-concentrate diets, it is customary to allow cows to eat all the feed for 24 hours to avoid acidosis. This condition is caused by the rapid fermentation of starch and sugar, or by occasional ingestion of large quantities of concentrate. Essentially, this condition is due to lactic acid produced by rumen fermenting bacteria. Therefore, cattle fed concentrate freely should also be fed with long and coarse fodder such as straw, which accounts for about 15% of total dietary dry matter.
Traditionally, dairy cows are fed concentrate in the milking hall, usually crushed mixed feed, and free to ingest grass at other times. With the increase of milk production per cow, the pressure in the milking hall makes it difficult for lactating cows to consume a large amount of mixed concentrate. Furthermore, the rapid fermentation of two large-scale feedings will decrease the rumen pH value, slow the digestion of cellulose, and consequently reduce the intake.
When cows acidosis occurs, baking soda can be added to the diet. The problem is that baking soda is not palatable and needs to be used at a quantity to achieve significant results, so compared with 3 kg of carbonate produced in saliva every day, the effect of adding 100-150 g per cow per day is not obvious.
5. Feeding TMR or complete ration
The main principle of feeding complete ration is that cows receive a fine mixture of slow and fast fermentation feed, so the feed can flow into the rumen at different fermentation rates to maintain the state of the rumen environment. However, due to the high proportion of concentrate in the mixture, the acid content in the rumen is also high, and the digestion of cellulose is inhibited for a long time. In this case, the propionate content of volatile fatty acids in the rumen increases, resulting gain and lower fat content in milk. So fattening cattle with fatty liver are all caused by poor management when they are fed complete ration at an early stage.
Therefore, cows in late lactation and dry period should not be fed with high-energy mixed feed as high-yielding cows. The complete ration is a good method of feeding management. By-products are easier to be mixed into the diet than other feeding systems. Autonomous feeding is usually higher than separate feeding because of the high energy level of animals and the improvement of cellulose digestion in the rumen, the quality of milk components has been improved. On the other hand, the investment of feed mixer is very large, and the cows fed mixed diet did not improve the total utilization ratio of feed compared with those fed separately with concentrate and crude feed on the same day.
How to feed cows scientifically
To select Chinese black-and-white cows, the appearance has the following characteristics: tall, well-proportioned structure, large and plump breasts, extending forward and backward, moderate nipple size, obvious mammary veins, large and deep breast wells, strong limbs, good posture, and distinctive black-and-white patches. The production performance is better: under general feeding conditions, the lactation period is 270-305 days, the milk yield is about 4500 kg, and the average milk fat rate is 3.4%. At the same time, it has strong adaptability, long service life, and stable genetic performance.
2. Construction of cowshed
According to the farmer's courtyard structure, the cowshed can be built in the spare area. The brick and tile structure is suitable. The average farmer's dairy cattle feeding scale is 7 heads. The feeding trough and feeding passage can be built 75 square meters. If there is space for the sports ground, the doors and windows of the shed should be set reasonably to ensure cool ventilation and non-humidity in summer. Thermal insulation facilities should be adopted in winter. The fecal and urinary ditches in the cowshed should be unblocked. Green hay, wheat straw, and other materials can be stacked and stored and can be selected in the open outdoor area. Corn silage kilns can be built outdoors. If the courtyard is not equipped with a playground, cattle can be driven outdoors regularly to ensure adequate exercise. In a word, the layout should be reasonable, the management should be convenient and the size should be appropriate.
To meet the nutritional needs of adult dairy cows, their diets should be based on their own and all kinds of nutrients needed for production, and their diets should be mainly composed of green and coarse fodder with appropriate concentrates.
⑴. Feeding management during the dry period.
When dairy cows enter the dry period, no matter how much milk they produce each day, timely weaning measures should be taken to make necessary preparations for the next lactation period. The following two methods can be used for dry milk. The first is the gradual dry milk method. Within 1-2 weeks of dry milk, we should begin to change cows’ living habits and dietary composition, reduce the number of milking and concentrates, stop feeding or reduce the feeding of juicy feed or green material, and stop breast massage and so on to inhibit milk production, and finally gradually stop milking.
The second is the fast dry milk method. The method is to massage the breasts carefully on the day of the planned dry milk date, stop milk immediately after all the milk is milked, and soak the nipples with 5% iodine tincture after milking to prevent infection. The dry period should be fed with better quality roughage, but also strengthen exercise. Brush cattle every day to prevent hoof and limb disease and reduce dystocia. Before parturition, cows are required to be moderately fat, strong but not too fat. Due to the nutritional needs of cows and fetuses, concentrate feeding began to increase about six weeks before delivery. In the beginning, concentrate feeding was 2-2.5 kg a day, and then 0.5-1.5 kg a week. The aim is to make cows accustomed to full feeding of concentrate, prepare for postpartum lactation. Pay attention to observation, and prepare for midwifery when signs of labor are found, to ensure the safety of cows and calf.
⑵. Feeding and management of lactating cows.
Feeding and management in early lactation:
After calving, cows should adopt reasonable feeding methods according to their postpartum physiological characteristics. Firstly, clean and sufficient warm water should be provided, and 50 grams of salt, 0.5-1 kg of bran, sugar, and Leonurus should be added to the first drinking water. The second is to feed high-quality green and coarse fodder and allow them to eat freely. Thirdly, concentrate feeding should be determined according to cow's health status, appetite, and breast edema. Generally, according to the prenatal diet supply, the next day can be increased by 0.5-1 kg concentrate as appropriate. Fourth, we should adopt the "guided" feeding method. That is to say, for high-yield cows with high lactation potential, the method of increasing concentrate is used to promote high-yielding of cows. The principle is that as long as cow milk production continues to increase with the increase of concentrate, it should continue to increase. Its purpose is to make full use of cow lactation potential and create conditions for reaching a new lactation peak.
Management of lactation in the middle and late stages:
First, nursing breasts well and eliminating breast edema. Second, improve maternal environmental hygiene. Third, pay attention to sports and ensure rest. From the peak lactation period to the dry period, a series of physiological changes took place in cows. From estrus to mating and conception, with the enlargement of the fetus, the cow first satisfies the growth and development needs of the fetus, and its weight drops, milk production will inevitably decline. During this period, concentrate feeding can be adjusted weekly or two weeks according to the decline in milk production.
Once a cow is ill, it is necessary to contact the local veterinary station in time. Experienced veterinarians are invited to make a careful diagnosis to determine whether it is a common disease or an infectious disease.