The stillbirth of dairy cows is a kind of reproductive disorder of dairy cows, and its incidence is affected by feeding conditions and management levels. Nowadays, due to limited feeding conditions and management level, the stillbirth of dairy cows is still a major problem in the dairy industry. Abortion or stillbirth of dairy cows will not only bring losses to dairy farmers but also hinder the development of the dairy industry.
For a dairy farm with 1,000 adult cows in stock, the stillbirth rate is 10% based on 90% calf production per year, which means that there will be 100 stillbirths of dairy cows. If the average cost per calf is 400 yuan, the direct loss will be up to 40,000 yuan. Therefore, it is urgent to solve the problem of stillbirth in dairy cows.
1. Disease analysis of stillbirth in dairy cows
Anatomical examination of stillbirths revealed that there were purulent exudates in the lumbar spine, skin ulceration in the shoulder, swelling of lower limbs, suppuration of wrist joints and hoof crowns, enlargement of breast, hard and gray-yellow in section, enlargement of breast lymph nodes, yellowish-gray spots and calcification in section, hepatomegaly, yellowish, steatosis and granular degeneration in section, splenic congestion. Hemosiderosis; the uneven color of the kidney (grey yellow and grey red areas), degeneration, necrosis, congestion, edema; adhesion between lung and chest wall, large abscess in lung parenchyma; effusion in son organs.
2. Influencing factors of stillbirth in dairy cows
(1) Parity
The parity has a great influence on the stillbirth of cows. It was found that the stillbirth rate of primipara cows was much higher than that of midwifery cows, which was closely related to the improper feeding and management of young cows: young cows were in the right growth stage, their physique was not perfect, their pelvis was narrow, and a large amount of concentrate feeding in the late pregnancy made the size of the fetus incompatible with that of the maternal cattle's birth canal. It leads to an increase of dystocia in dairy cattle and a higher stillbirth rate. Besides, the stillbirth rate of multiparous old cows is also relatively high, which is mainly related to the decline of reproductive system function and various damage to the environment inside the uterus.
(2) Season
The stillbirth rate of dairy cows varies in different seasons. Seasons have a great impact on animal husbandry. The stillbirth rate of dairy cows in the first and fourth quarters is very high, while the stillbirth rate of dairy cows in the second quarter is relatively low. The main reasons are as follows: Firstly, because of the lower temperature in the first and fourth quarters, the thermoregulation function of the newborn cows has not yet been fully developed, and the role of the defense system is limited.
In the process of dairy cow production, because of the large temperature difference between the internal and external environment, calves have poor adaptability, often die at delivery, and the survival rate is very low. The second is the influence of feed. The low temperature in the first and fourth quarters makes the forage nutrient deficient and the feeding conditions worse. The maternal and fetal health is weak because of the lack of nutrition facts, and the probability of stillbirth is greatly increased.
(3) Fetal size and sex
In the process of maternal and livestock delivery, fetal excessive assembly leads to maternal and livestock dystocia and difficult delivery, which easily causes the death of the fetus when it is squeezed during production. Besides, fetal too small also easily causes stillbirth, because the fetus is likely to be malnourished and has died in the belly of the cow. Besides, sex is one of the reasons. Under the same conditions, the resistance of male cows is higher than that of female cows, so the birth mortality rate of female cows is much higher than that of male cows.
3. Solutions to stillbirth in dairy cows
The reasonable mix of feed to provide adequate nutrition. The feeding of dairy cows should increase the source of feed, give more green and juicy fresh forage so that dairy cows can get a long-term supply of high-quality forage, which can improve the nutritional supply of cows, and also have a good effect on enhancing their own and fetal physique. Besides, for lactating cows, vitamin A can be supplemented appropriately, while providing more nutrition, it can also make the fetus develop healthier, the mother and livestock have good health during childbirth, and reduce the stillbirth rate during childbirth.
Strengthen daily management. The facilities and equipment of dairy farms should be improved so that dairy cows can live in a better environment. We should not be too rough to dairy cows and pay more attention to the physical condition of dairy cows to prevent accidents.
Enhance nutrition. In the cold season of the first quarter and the fourth quarter, low temperatures will bring difficulties to the delivery of cows. Therefore, during this period, some cold-proof concentrates should be provided to cows, especially in the case of insufficient feed supply and poor quality, and cows absorb too much nutrition, concentrates are indispensable. Only in this way can we better prevent the increase of stillbirths caused by the weakness of cows and fetuses at low temperatures.
Scientific midwifery. Scientific midwifery is an effective measure to reduce the stillbirth rate. The external intervention has a great impact on the delivery of cows. Some wrong methods may make natural cows dystocia, and scientific and reasonable methods may also make dystocia cows successful delivery. However, scientific midwifery requires high technology, and dystocia itself is very dangerous. If not handled properly, both the mother and the fetus may face the threat of death; even if one side is saved, it may lead to poor health. Therefore, midwifery should be conducted under the guidance of professional and technical personnel to prevent accidents due to improper handling.
4. Conclusion
The stillbirth of dairy cows is due to the obstruction of fetal development caused by cow disease or malnutrition, and the death in the uterus of the mother; or the death of calves at birth due to the influence of the internal and external environment of the cow. The high stillbirth rate of dairy cows not only affects the development of the dairy industry but also increases the cost of feeding and breeding, resulting in greater economic losses. To reduce the stillbirth rate, we need to improve the feeding conditions and management level of dairy cows, using scientific, reasonable and professional methods to raise.