The production of dairy cows is closely related to the taiao. Cold, hot, temperature, humidity, wind and so on will have an impact on the production performance and health of dairy cows. Due to improper te whangai me te whakahaere in winter, it will lead to breast frostbite, limb disease, calf diarrhea, pneumonia and so on, which will cause great losses to dairy production. Therefore, strengthening the management of cow breeding i te takurua has become the top priority.
1. Cold is a comprehensive index.
Cold is a synthetical feeling of animals to low temperature and other environmental factors. The degree of cold is related to temperature, wind speed, humidity, sunshine, age, resistance, and health condition. When considering the effect of cold on dairy cow production performance, we should not only pay attention to temperature. For example, under the same low-temperature conditions, the effects of different herds on production performance are very different, and the incidence of the disease is also different. The adverse effect of low temperature on calf growth and development is far greater than that of high temperature on the calf.
2. The effect of cold on dairy cows
Normally, the suitable production temperature for Holstein cows is 10-20 ℃. When the ambient temperature is lower than - 5 ℃, the physiological function of the cows will be affected. When the ambient temperature is lower than - 10 ℃, the milk yield of the cows will decrease by more than 6%. The implementation of feeding and management measures will also affect the supply wai facilities and the situation of cowsheds. These adverse effects are combined, resulting in more serious economic losses for dairy farms with poor feeding conditions and low management levels. Cold not only affects the performance of kau lactating but also mainly manifests in the following aspects.
(1) It leads to an increase in dairy cow maintenance needs, feed intake and feed input costs, and a decrease in feed-to-milk ratio and milk production, thus reducing the efficiency of dairy cow breeding.
(2)It leads to the cow immunity to drop, causing the cold, the winter dysentery, viral diarrhea and so on epidemic disease occurrence, especially the calf raises. Because the climate is dry and cold and the difficulty in feeding and management increased, which has caused an enormous influence on the calf healthy growth. Poor ventilation, sanitation of ground or mat grass, dry and dirty air after heating can easily cause bacterial growth, while the ability of respiratory and intestinal mucosa to resist pathogenic bacteria is reduced, resulting in mass diarrhea and pneumonia of calves, which can lead to the death of calves in serious cases.
(3) The reproductive performance of dairy cows decreased. Cold affects the oestrus of dairy cows, such as no oestrus, less oestrus, no obvious oestrus, ovulation obstacles and so on. Observing oestrus also brings difficulties, which reduces the reproductive efficiency of dairy cows.
(4) The harm of severe cold to the breast is mainly nipple and breast frostbite, and an increase in the incidence of mastitis. In winter in the north, many factors cause irreversible frostbite to the nipples of dairy cows, such as low temperature, strong wind, lack of mat grass with a cold resting place. The nipple frostbite can cause the loss of contractile function of the nipple sphincter, the inadequate closure of nipple foramen, which increases the probability of bacterial infection and the incidence of mastitis.
3. Key points of dairy cow feeding and management in winter
(1) Strengthen the management of drinking water for dairy cows in winter
Water is an important component of dairy cow tissues and cells. Water participates in the physiological and biochemical processes of digestion, absorption, transport, metabolism, and excretion of nutrients. Water is very important to maintain the life and production of dairy cows. Because of the cold weather in winter, water is easy to freeze, drinking facilities are prone to malfunction, and the problem of insufficient drinking water for dairy cows occurs. Dairy cows need water supply all day in winter. The temperature of drinking water should be maintained at 9-15 ℃. Excessive or low water temperature will affect the drinking water quantity, feed utilization rate and health of dairy cows. For example, dairy cows weighing 500 kg need to increase their total feed energy consumption by 15%, which is 0.57 liters less than those of dairy cows drinking about 5 ℃ water every day. The milk yield was reduced by 8.7%. But it does not mean that the higher the water temperature, the better, long-term drinking of warm water will reduce the resistance of dairy cows to dramatic changes in environmental temperature, more likely to suffer from colds and etahi atu mate.
(2) Adjust dairy cow's diet in time to adapt to environmental temperature changes
After entering winter, due to the low temperature and cold climate, the heat dissipation of dairy cows becomes faster, and the energy requirement of dairy cows to maintain body temperature increases. The domestic and foreign experimental results show that the body heat production of dairy cows increases by 2.5kJ/kgW0.75.24h with an average decrease of 1 ℃ based on the environmental temperature of 18 ℃. The feed ratio of dairy cows should be adjusted in winter, which is 10%-15% higher than the normal feeding standard. The energy level of concentrate feed and the intake of dairy cows should be increased to meet the nutritional needs of dairy cows in winter.
(3) Supplementation of minerals and trace elements.
To ensure the calcium and ūkuikui content in the diet in winter, When the calcium and phosphorus in the feed are insufficient, the growth of bred cow is blocked, and cartilage disease is prone to occur. In serious cases, rickets will occur. When the calcium and phosphorus deficiency is long-term in lactating cows and pregnant cows, osteoporosis, bone, and limb deformation will occur, which seriously affects the health and milk production of cows. Then, trace element licking bricks should be set up in the farm to allow cows to lick freely to ensure the healthy development of replacement cows and give full play to the production performance of adult cows.
(4) Do a good job in reproduction and fetal protection
"Breed in spring and calve in summer, breed in autumn and calve in winter" and pregnancy in winter can not only avoid the harm caused by calving in hot summer, but also the calf care is easier. To lay a good foundation for the next year's cows production, we should do a good job of cows’ breed in winter and improve the conception rate. It can also save unnecessary expenses such as the increase in nursing costs caused by calving in summer.
In winter, cows feed rotten, frozen fodder and slipped and wrestled were all factors causing abortion. For this reason, two points should be paid attention to in order to keep pregnant cows alive in winter: first, to meet the nutritional needs of pregnant cows, especially to ensure the supply of protein, minerals and vitamins; second, not to feed frozen and deteriorated forage and frozen drinking water; third, to carry out fine management, not to treat pregnant cows roughly, and strictly prohibit frightening, slipping and crashing.
(5) Do a good job of keeping warm and windproof in cowsheds
Cowshed, milking parlor and farm are the habitats of dairy cows. To reduce the heat dissipation capacity of the cowshed and improve the heat preservation performance of cowshed, the windward windows of cowshed or milking parlor should be blocked with plastic film, brick and straw curtain, and the doors on both sides of cowshed or milking parlor should be closed in time.
A fully open feeding unit can set up plastic cloth, canvas, colored strip cloth, and other materials to shield the cold wind on the windward side, and a temporary windshield wall can be built with crop straw and building materials in the windward direction of the farm field.
For independent calf shed, the plastics film will be used to close the farm and turn it into the temporary plastic warm shed. It is a movable calf island, which can be moved to the shed. The ground of the calf shed should be paved with a thick mattress to avoid calves lying on the cold ground.
Also, we should clean up the excrement and water in time, keep the ground dry, and pay attention to ventilation when the temperature is high at noon.
4. Key points for disease control of dairy cows in winter
(1) Prevention and treatment of frostbite of breast and nipple hole
Laying mattress on the place where cows lie or on the bed in the farm can keep them dry and change in time. Cleaning up the fecal water in the farm or cowshed can prevent the direct contact between the breast and the frozen ground when cows lie down, which can effectively prevent frostbite of the breast and nipple of cows.
In winter, an anti-freezing medicinal bath solution is used for nipple medicinal baths. After milking, wipe the breasts and nipples, let the cows stay in the milking room for a while, so that the nipple surface is naturally dry. Frostbitten breasts were treated with medication and milked by hand alone.
(2) Prevention and treatment of foot and limb injuries
During the cold season, the ground is frozen, hard, slippery and uneven. Dairy cows are easy to sprain or knock their hooves during exercise. Timely treatment can effectively prevent further aggravation of injury or secondary infection.
(3) Strengthen the management of drinking water to reduce the occurrence of digestive system diseases
Drinking cold water or ice ballast water directly in winter can dramatically decrease the temperature in the rumen, thus affecting the digestive function of the rumen, leading to the decline of digestive system function, the occurrence of digestive system diseases and the decline of production performance of dairy cows. Drinking cold water is also an important inducement for diarrhea, winter dysentery and coccidiosis of dairy cows. It is also easy to cause abortion of pregnant cows.
(4) Strengthen warmth and ventilation to prevent calf pneumonia
Calf pneumonia is an acute infectious disease caused by streptococcus pneumonia in calves. It mostly occurs in the age of 6-30 days after birth, and the mortality rate can reach 39.3%. Poor ventilation, dirty air and high density of calves in cowshed are the causes of this disease, so we should pay attention to ventilation while satisfying the heating of calf shed in winter.