1. What is the normal delivery?
Delivery is the termination of pregnancy. In this process, one or more calves are produced by natural contraction of the reproductive system, but it does not endanger the life of cows or calves. It is called normal delivery. There are two main aspects to evaluate, one is the survival rate of calves, the other is the health of cows, which mainly includes the adverse factors to reproductive performance and production performance and other diseases.
In fact, for successful calving, young cows should start to prepare, such as the appropriate height, body condition, weight of the cows when calving. On the other hand, for young cows, it is necessary to select suitable semen, such as semen with experimental data, which can help to calve smoothly. If a bull's pedigree data showed that in the past the proportion of calving difficulties was less than 10%, the pasture would choose such semen.
2. What is the best proportion of normal natural delivery?
It should be 100% natural delivery that is the best. Though it is difficult to achieve, it should also be controlled in a certain range and proportion. According to the data of 122 714 dairy cows (Dematawewaandberger, 1997), 71.88% of the first-born cows do not need midwifery, 87.46% of the second-born cows, 88.02% of the third-born cows and above, and 78.51% of the total. So the data can reflect the important basis of our cattle breeding and health management level.
3. Focus on feeding group to control body condition score
Good management of dry dairy cows requires a body condition score. 3.25-3.75 points is a suitable range. Control of calf birth weight at 35-38 kg can make the natural delivery rate more than 70%. Controlling the fatness and nutrition of cows in late pregnancy is conducive to controlling the birth weight of the fetus, because two-thirds of the fetal weight is the growth and development of cows in late pregnancy, and prenatal obesity is the root of many problems, which is beyond doubt.
4. Improving comprehensive management
Comprehensive management measures can not be ignored, such as energy, feeding, protein, trace elements, minerals and so on, including perinatal and dry milk stage group density and good feeding trough space. In particular, we should pay attention to reducing the pre-calving cohort of dairy cows. Ideally, we should enter the perinatal group three weeks before the expected date of delivery and pay attention to the comfort of dairy cows. Including mattress, temperature, humidity, light, sports field and so on. When cattle are in labor, they are transferred to the delivery room for production, that is, they are transferred to the perinatal cattle house within 20 - 15 days of the expected delivery date, and then transferred to the delivery stall for calving at the appropriate time. Ideally, 24 hours before calving, cattle should be transferred to the barn, but this is difficult to achieve.
In practice, it is easier to strengthen the number of rounds, such as observing abnormalities every 30 minutes to 1 hour, at the beginning of the second stage of labor (calf discharge period) when the cow enters the labor stall. When the cow is transferred to the delivery bed, it should cover the mattress on the ground with less bedding and frequent replacement, and renew the mattress at least once a day after each calving, and disinfect the hind body of the cow at the same time.
5. Rate of progress in the delivery process
For the delivery process, it can generally be divided into three stages. The first stage is a relaxation of the birth canal, usually lasting 6 to 8 hours. The second stage is the discharge of the calf, into the second stage of labor, the beginning can be observed that the allantoic sac has been ruptured, the amniotic sac exposed in the doorway of the vulva, amniotic sac ruptured, the calf will expose two hoofs, then the calf will expose. Cattle have entered the birth canal in the uterus of the cattle to prepare for the next discharge, which will cause an intense nuisance of the cattle. If cow stands to produce calves, it will lose 30% of its intense nuisance and production efficiency. Therefore, it is necessary to minimize unnecessary manual intervention to affect cows lying on their stomachs. The third stage is the discharge period of the placenta, generally, 6 - 8 hours after delivery, if more than 12 hours can be not for the placenta, should be handled in time.
6. When will midwifery take place
The first kind of situation is that the labor process is too long, more than 6 - 8 hours, the cow is uneasy, anxious, and has labor symptoms, but not in intense nuisance. Uterine torsion, incomplete cervical opening, stillbirth, may lead to such a situation.
The second situation is that after the observation of allantoic sac and two hoofs in the vagina, the calves did not discharge within 2 hours or did not discharge within 1 hour after the rupture of amniotic vesicles, so it needs to be examined.
The third situation is that we can observe the cow frequently in intense nuisance at first, stop intense nuisance suddenly, or even stop it for more than half an hour, which is also a reminder that we need to check as soon as possible. Other conditions are that calf fetal abnormality, such as abnormal fetal position and fetal position such as a hind limb bending, head backward bending, etc., should also be actively artificially intervened. Besides, the swollen tongue of the calf exposes outside the vulva, which reminds us that we need to be examined.
7. Midwifery disinfection should be done according to human standards
Artificial midwifery, to the greatest extent to ensure cleanliness, the cleaner the better. First, prepare clean water to clean and add neogeramine, Lysol, suspension to disinfectant, and clean obstetric equipment, birth rope, arms, and cow vulva. After cleaning and disinfection, if cows are in intense nuisance for contamination of feces or dirty things, they must be repeatedly cleaned and disinfected. After each use of midwifery tools such as an obstetric chain or obstetric rope, a thorough disinfection should be carried out. The scoring standard of cow vulva disinfection: 1 point is a completely clean area, less than 2% of the contaminated area; 2 point is slight pollution, less than 10% of the contaminated area; 3 point is moderate pollution, about 10% - 30% of the contaminated area. With the increase of contaminated area around vulva during calving, the incidence of uterine inflammation increased from 1 to 3 points.
8. The effect of cleanliness on uterine inflammation
With the increase of the score, the proportion of uterine inflammation increased. The high incidence of late uterine inflammation can be traced back to whether the cleanliness of calving is adequate. The cow's postpartum physical weakness is the lowest stage of immunity. At the same time, the cow's reproductive system is like a big wound just after the operation. For example, the cow's feet are contaminated with feces, and the cow is delivered. Without clean hands, the uterus or the instruments are not sterilized, new infections are introduced.
9. Consideration of midwifery traction principle
(1) Does the expansion of the birth canal require more time for the opening of the birth canal?
(2) The more lubricants used, the better.
(3) Homeopathic traction; when the cow is responsible for his efforts, it should also cooperate with human and external forces for traction.
(4) When using midwifery devices, we should avoid violent midwifery devices as far as possible. We should not rush and pay attention to the rhythm of midwifery. During calving, the cow itself can give about 75 kg of thrust to the calf. When we use manual traction, the first person will increase the tension by 75 kg, and each additional person will increase the tension by 50 kg. The 75 kg thrust provided by the cow itself is enough for the calf. When three of us are pulling at the same time, the extra 175 kg can cause great damage to cattle that are not ready for delivery at all. Whether it is human or external equipment, we must pay attention to strength. If the cow is midwifery while standing, it should be followed by a calf to avoid falling to the ground, breaking or even death. Besides, when using midwifery rope and chain pull, how to tie the knot and how to bind to ensure the uniformity and stability of the force should also be noted.
How to improve the survival rate of calves?
As the basis of the cattle herd, calves are in the most critical period of cattle growth and development. The survival rate of calves has a direct impact on the healthy and sustainable development of the cattle industry. How to strengthen the calf feeding management is a highly technical work. Based on this, we briefly elaborated the technical measures to improve the survival rate of calves, including the feeding management of cows in the late pregnancy, the nursing of newborn calves, the feeding management of calves during lactation and the prevention and treatment of calf diseases, to provide technical reference for improving the survival rate of calves.
1. Strengthen the feeding management of pregnant cows in late stage
Late pregnancy cow is the perinatal period, which refers to the period of one month before and after delivery. This stage is not only an important period for cow delivery and lactation but also a critical period affecting calf birth weight, weaning weight and growth and development. Therefore, it is necessary to strengthen the perinatal feeding management of pregnant cows to ensure that the diets of cows contain sufficient protein, calcium, phosphorus, and vitamins. It can provide cows with high-quality hay and grass, leguminous forage, green fodder, and silage. It can make cows get adequate nutrition, grow normally and avoid rickets, pneumonia, and dysentery to the greatest extent.
2. Strengthening the nursing of newborn calves
After delivery, the mucus in the nostrils and mouth of calves should be cleared in time to facilitate their breathing and sucking. If the calves inhale mucus and cause their pseudo-death, the two hind limbs of the calves can be lifted and poured out of the throat amniotic fluid, and the mucus in the nostrils and mouth can be cleared before artificial respiration until the calves breathe spontaneously. If the umbilical cord of calves is not pulled naturally, it is necessary to cut off the umbilical cord artificially. After cutting off the umbilical cord, wipe off their hair as soon as possible to prevent calves from getting cold. Because calves have not yet developed their organs and body functions, and cannot adapt to the external environment, they are very vulnerable to disease and death caused by the invasion of pathogens, therefore, to ensure the health of calves and enhance their resistance, calves must be allowed to die. Eat colostrum in time.
3. Pay attention to the feeding and management of calves during lactation
(1) The purpose of feeding calves with mammals after 2 weeks of birth is to let the milk flow into the true stomach. Feeding calves with milk barrels usually results in inadequate closure of the esophageal groove and milk spilling into the forestomach, while the function of the forestomach of calves is not yet well-developed, which easily causes abnormal fermentation and in serious cases leads to calf death. It is suggested that calves should be fed in milk barrels 4 to 5 weeks after birth, and clean towels should be used to wipe off milk from calves' horns in time to prevent calves from licking their umbilical cord and papillae, to avoid the occurrence of abilities and papillitis.
(2) Normal milk can meet the needs of calf growth for protein, but its content of VC and iron is low and its energy is insufficient, which can not meet the needs of calf growth and development. Therefore, supplementary feeding management should be strengthened when feeding normal milk, and proper plant feed should be added. High-quality hay can be added to the feeding trough one week after calf birth for its development. Feeding and adding concentrate after 2 weeks can not only strengthen the exercise of digestive organs of calves, improve the adaptability of the digestive tract of calves to roughage and concentrate, but also promote their growth and development, laying a good foundation for early weaning. Frequently observe the mental state, appetite, feces and other conditions of calves, if there is a sparse stool, appropriate reduction of feeding volume and add 1-2 times warm boiled water in milk.
(3) When calves feed on plant feed, it is unavoidable that a variety of parasites enter the body. When these parasites multiply and grow to a certain number, they will produce a large number of bacterial toxins and absorb the nutritional components of calves, which will lead to poor metabolism of calves and affect the growth and development of them. Therefore, it is necessary to repel calves regularly and use broad-spectrum insecticides with better results.
(4) To save the cost of calf breeding, calves are usually weaned for 60 days, and early weaning can be advanced to 30-45 days.
To ensure adequate water supply, weaned calves are still particularly fond of liquid food, which is a continuation of instinct and lactation.
Early weaned calves can be compensated in later stages although there is slight growth retardation from birth to 6 months of age.