Dairy farming must be done better with each generation

For dairy farming, you raise female dairy cows, because only cows can produce milk. When do cows produce milk? Only after they have conceived and given birth to a calf do they start producing milk. So getting a cow pregnant and having her calve is a very important matter. But nowadays, whether it's dairy cows raised by farming households or dairy cows raised on a large scale at dairy farms, no bulls are kept. On farms like these, who is a cow supposed to find to get her pregnant?

Once you step onto a dairy farm, all you see are cows with udders swinging. Just as you raise hens for eggs, you raise dairy cows for milk. How does this milk come to be?

When a dairy cow is raised to 1.5 years old, she needs to find a mate. After successfully conceiving and calving, she is no longer just eating without producing, and can be milked.

Criteria for judging estrus in cows

Nowadays, a cow finding a mate is completely out of the cow's hands; it is entirely arranged by people. Such careful selection is, of course, to make each generation stronger. Now not only is the cow's match arranged, even the act of entering the bridal chamber together is gone; the breeders help complete the cow's fertilization. But at this point there is also a key issue: is the cow actually willing to enter into this marriage?

Although they live in a land of women, when the time comes that they are willing to mate, the cows still show signs. These physiological signs are called estrus. Now, since cows are made to become pregnant in a timely manner by humans, as soon as physiological changes in a cow are seen, special attention must be paid.

Jiang Shichuan: Observing estrus in dairy cows is best for the breeding results. Only after the timing of the estrus period is observed well can breeding be done in a timely manner, and only then can the cow, so to speak, only then can the breeding rate be increased.

When both parties are willing, things naturally fall into place, and successful breeding can be achieved without wasting semen.

At this time, internal changes are taking place in the cow. Without clairvoyance, one can only pay attention to its external signs.

Yu Dehong: The most commonly used method on our farm is the observation method. The observation method mainly involves five looks: first, look at milk production; second, look at the demeanor; third, look at the vulva; fourth, look at mounting; and finally, look at the mucus inside, the secretions.

First, look at milk production: this is because generally, just as a cow enters estrus, its milk production fluctuates somewhat, mostly decreasing, by about 1 kilogram.

Yu Dehong: For an experienced stockman, because a cow's milk production is very stable every day, when the milk suddenly changes, the first thing he thinks is whether this cow is in estrus. If it is sick, it also drops milk. If it is not sick, then it may be estrus.

A cow in estrus also begins to show some unusual behavior in the herd, starting to look around alertly and feeling restless about eating. So demeanor is the second signal.

Yu Dehong: It doesn't stop eating all the time; it eats for a while and then stops again, and it is especially sensitive to sound. When it hears a whistle or some noise somewhere, it traces it to the source and insists on finding where the sound is coming from. This mental symptom in the cow is the early stage of estrus.

At this point the dairy cow begins to prefer being alone. It shows restlessness, does not lie down quietly, and sometimes lets out mating moos. A third look at the vulva will reveal that the vulva has become red and swollen. At this time, if they are loose-housed, they will chase each other and mount each other. So the fourth thing is to observe mounting.

Yu Dehong: In the early stage of estrus, this cow in estrus mounts a cow not in estrus. The cow not in estrus is unwilling to let it mount and runs forward, and it chases after it. After a while, because of the odor of the hormones it secretes, the other cows know it is in estrus, and the other cows begin to mount it.

Mounting is a very obvious sign of estrus. But one moment this one mounts that one, and the next moment that one mounts this one. So is it the one on top that is in estrus, or the one on the bottom?

Yu Dehong: At first, when it is mounted, it half resists and half complies, not very willing to let you mount. It also mounts a bit and walks a couple of steps, mounts a bit and walks a couple of steps. After another stage, at the peak of estrus, when other cows mount it, it very steadily lets them mount, and mucus flows out from its vulva. We call this standing estrus. This is a very typical symptom of estrus.

It seems that whether mounting or being mounted, either could be a cow in estrus. So there is a fifth look: looking at the transparent thread-like mucus flowing out from the vulva, which also proves that the dairy cow is in estrus.

In fact, the estrus process of a dairy cow is precisely because changes are also taking place in the ovaries within its body. At this time the ovaries have already begun to be somewhat larger than before, and follicles gradually appear. As the estrus symptoms become more and more obvious, the follicles also begin to change, growing into a spherical shape, about the size of a soybean, filled with fluid, with obvious fluctuation.

With the internal changes, the dairy cow shows a series of abnormal external signs. However, some dairy cows happen to show nothing at all.

Yu Dehong: A cow without these symptoms is called a silent estrus. With silent estrus there are no external symptoms, but all the internal symptoms are present.

For such dairy cows, the date serves as an estrus forecast. Careful records are kept from 60-90 days after calving, and vaginal or rectal examinations are carried out.

The Henan Dairy Cow Breeding Center raises more than 2,000 dairy cows. With so many cows, some show signs and some do not, and observing and recording them all is a strenuous task.

But when the dairy cows come into estrus, they have never missed it either. The good method is to put a tie on every dairy cow.

Miao Ting: That blue tag is equivalent to a person's ID card. It is called an electronic identifier. After each cow is born, an electronic file is set up for each cow.

The tie is the dairy cow's ID card. As soon as it enters the milking parlor, the cow number is displayed, and the data is immediately transmitted to the computer. This not only records milk production, but more importantly, some data analysis alerts the stockman.

Miao Ting: This software promptly alerts which cows have decreased milk production. Based on the cow numbers of the cows with decreased production, the technicians can go observe the cows' health condition.

Fluctuation in milk production is one signal, and the date is another.

Miao Ting: After setting it manually at 45 days or 60 days postpartum, it will remind you that this cow will reach this physiological estrus date today or tomorrow. In this way, the technicians can also observe or discover in a timely manner whether this cow is in estrus.

With special prompts, a small circle is drawn within the big circle, and observation is carried out with a clear target. By casting the net in a targeted way, naturally no fish will slip through the net.