How Long Is a Cow Pregnant Before Giving Birth to a Calf? Judging Pregnancy, Signs of Impending Calving, and Handling Difficult Birth

In breeding cattle farming, early pregnancy diagnosis in cows has always troubled the vast number of farmers. Judging as early as possible whether a cow is pregnant is of great significance for reducing empty pregnancies, improving production efficiency, and increasing economic benefits. So how do you judge whether a cow is pregnant? How many days is a cow pregnant before giving birth to a calf? What signs appear before calving? What should be done in case of difficult birth?

Whether a cow is pregnant is mainly shown through six changes:

1. Identification by behavior

After a cow is mated, it no longer shows estrus behavior, its temperament becomes docile, its appetite increases, and its coat becomes glossy and plump; it can roughly be judged to be pregnant.

2. Identification by the vagina

After a dairy cow becomes pregnant, the vaginal mucosa changes from pink to pale, loses its luster, and the surface becomes dry. Mucus characteristics: two months after pregnancy, there is thick mucus near the cervix; three months after pregnancy, the amount of mucus increases and becomes thicker, while the vagina contracts, creating resistance when a vaginoscope is inserted. This is because the opening of the cervix is sealed by a dull, thick fluid.

3. Identification by appetite

Three months after a dairy cow becomes pregnant, its appetite generally increases, its food intake grows, its body condition improves, its weight increases, and its coat color becomes glossy.

4. Identification by the udder

If the udder is swollen and the teats are hard and upright, the cow is pregnant. Otherwise, it is not pregnant.

5. Identification by the cow's eyes

On the iris directly above the pupil of a pregnant cow, three especially prominent vertical blood vessels appear, the so-called pregnancy blood vessels. They are filled and raised above the surface of the iris and appear purplish red. In a non-pregnant cow, the blood vessels on the iris are thin and not prominent.

6. Identification by the oral cavity

Open the cow's mouth and look at the sublingual caruncles on both sides. If they are bright red, the cow is pregnant; if they are pink or pale red, the cow is not pregnant.

How many days is a cow pregnant before giving birth to a calf

The rate of single births and twin births in cattle generally accounts for only 1 to 2.3% of total pregnancies. Except for yaks in high-cold regions, which are grazed year-round and, affected by climate, have seasonal estrus, housed cattle generally have multiple estrus periods throughout the year and can conceive in all four seasons. The estrous cycle is basically similar in all of them, averaging about 21 days, and the gestation period is about 280 days.

Signs of a cow before impending calving

Accurately predicting the time when a cow will calve and doing a good job of assisting the birth is an important link in improving the survival rate of calves. The signs of impending calving in cows are as follows:

1. Udder enlargement

The cow's udder begins to enlarge about 15 days before calving, and before calving a thick, pale yellow fluid can be squeezed from the first two teats. When milky white milk can be squeezed out, calving will occur after another 1-2 days.

2. Swelling of the vulva

In the later stage of pregnancy, the cow's labia gradually swell, becoming soft and with the wrinkles smoothed out. 1-2 days before calving, transparent mucus flows out of the vulva.

3. The cow shows restlessness

Before calving, the cow repeatedly stands up and lies down, keeps looking back at its abdomen, walks back and forth, and urinates frequently. At this point, farmers should make preparations for assisting the birth.

What should be done if a cow has a difficult birth?

Difficult birth in cows is usually caused by abnormalities of the birth canal, calving strength, or the fetus, and can damage the cow's birth canal and uterus, causing diseases such as peritonitis, disseminated intravascular coagulation, and shock. If the sick cow does not undergo obstetric assistance in time, it can even lead to the death of the cow and the fetus, causing unnecessary losses in production.

1. Causes of difficult birth

Among the various livestock raised by people, because dairy cows are the largest in size among all livestock, difficult birth is unavoidable during the calving process, especially when the dairy cow's fetus is too large, the fetal posture is incorrect, feeding and management are improper, or nutrition is unbalanced, all of which can cause difficult birth in dairy cows. Therefore, once a similar phenomenon is found during the calving process of a cow, attention should be paid to the cow's calving progress and the cow's calving condition should be watched at all times. A designated person should be responsible for watching and tending it, so as to avoid the occurrence of death in dairy cows due to difficult birth.

2. Symptoms of difficult birth

Before calving, a dairy cow often strains hard, sometimes standing, sometimes lying down, making sounds. The two hooves of the dairy cow's fetus have already emerged, fetal water flows out, the abdomen is distended, and if the udder is squeezed by hand, milk can be found overflowing. No matter how hard the dairy cow tries to give birth, the fetal head does not come down. From this, the symptoms of difficult birth in a dairy cow can be diagnosed.

3. Manual assistance in calving

Lead the calving dairy cow to a relatively flat and spacious place, preferably tie the rope to a sturdy tree, and secure the cow in a posture with the front head slightly higher and the hindquarters slightly lower. Wash the cow's labia, perineum, and tail base with warm water. After washing clean, thoroughly disinfect all the above parts with potassium permanganate solution. If the cow cannot be kept standing all the time, the cow can also be made to lie on its side, so as to relieve the cow's tense nerves and anxious mood. At the same time, prepare relatively soft ropes and various obstetric instruments for assisting the birth. The veterinary personnel delivering the calf should wash their hands clean, thoroughly disinfect them with potassium permanganate solution, put on rubber gloves, then wash them clean with soap lather, and then insert a hand into the cow's birth canal for examination. If the fetal head is not felt and only the fetal buttocks are felt, and the fetus is found to be coming out backward, then first slowly push the two protruding hooves back into the dairy cow's birth canal, so that the fetus returns into the uterine cavity, then slowly correct the fetal birthing posture, so that the fetus's front hooves and head come out first. Then make the cow lying on its side strain hard to give birth. At this point, if the dairy cow is found to have no strength to give birth and only lies on its side panting, then the assisting veterinary personnel should promptly consider manually pulling the fetus out, otherwise if too much time passes, it is easy to cause fetal death. Therefore, according to the matters of obstetric assistance, traction should be used to pull the fetus out of the mother's body. During the procedure, one person should pull the cow's tail to deviate it in one direction, and the assisting veterinary personnel should insert a hand into the birth canal to straighten the fetus's two hind legs respectively, and slowly pull the head out along the vagina. When passing through the vulva, do not pull too hard, but slowly follow the cow's straining force. When the fetus slowly comes out, the assisting personnel should promptly catch the fetus's head and abdomen to prevent the fetus from hitting the ground, and then use a hand to remove the fluid from the calf's mouth. If calving occurs in winter, a fire should be lit near the cow to keep warm, so as to ensure that the body temperature of the cow and the fetus does not drop too much.

4. Cleaning, disinfection, and care

After the calf fetus is pulled out, the vagina and the area around the vulva should be rinsed with potassium permanganate solution, or penicillin powder or oxytetracycline powder can be placed into the dairy cow's vagina for anti-inflammatory purposes, so as to prevent infection. Afterward, the dairy cow should also be injected with tetanus vaccine to prevent wound infection and tetanus. After a cow with difficult birth gives birth to a calf, because of the relatively large physical exertion, care should be strengthened so that the cow's body can recover in time. The cow should be given food and feed that are nutritionally complete and easy to digest. Millet soup is quite suitable for a cow that has just given birth to drink. At the beginning, feed a small amount and feed more frequently. Later, gradually return to the normal level. For concentrated feed, bran, soybean meal, and other foods with good palatability can be fed, and trace elements should also be added, so as to maintain the balance of electrolytes in the dairy cow's body, which is both beneficial to health and can increase milk production.

Veterinary personnel should make a correct diagnosis of a cow with difficult birth and find out the real cause of the dairy cow's difficult birth. Whether it is caused by animal disease, long-term malnutrition, or by excessive force in the early stage of calving and weak calving strength in the later stage, or by pelvic deformity, poor development, a narrow vagina, or by an overly large fetus or abnormal fetal position, all these factors can cause difficult birth in cows. Therefore, once a dairy cow has a difficult birth, veterinary personnel should be allowed to conduct a comprehensive examination in time and make a meticulous and patient diagnosis, so as to formulate a relatively good treatment plan and carry out delivery assistance for the cow with difficult birth under conditions that do no harm to the cow.