What are the methods for achieving synchronized estrus in dairy cows?
In order to make breeding more uniform and convenient, people need to control the timing of estrus so that dairy cows can conceive at the same time as much as possible, allowing calves to be born at the same time for rearing, which is more conducive to uniform feeding by the breeders. So how can dairy cows be brought into synchronized estrus? Below, Shuashuai will explain it to everyone!
1. Progesterone vaginal sponge method
The advantage of this method is that its effect is long-lasting, it can act continuously, and it is very simple to use, but it easily falls out. First, we tie a piece of soft foam plastic or sponge block with a thin string, then after disinfection soak it in a progesterone preparation solution. The size of the sponge block should be determined according to the cow's body size. Getting it inside is also a problem. Long-handled forceps can be used to place the sponge block into the vagina near the cervix, and then one end of the string should be left outside. When it is finished, use the string to pull it out. Generally, after leaving it inside for 9-12 days, it can be taken out. Then at the same time as removing it, inject the dairy cow with progesterone, and after 2 to 4 days the dairy cow will come into estrus.
2. Progesterone implantation method
Implant a special implantation compound under the ear skin of the dairy cow, take it out after 12 days, and at the same time inject pregnant mare serum gonadotropin intramuscularly. After 2-4 days, the cow will come into estrus.
3. Injection method
Directly inject the dairy cow with a drug. The injected substance is similar to prostaglandin F2a and similar substances. This substance can dissolve the corpus luteum, shorten the luteal phase of the dairy cow, and enable synchronized estrus. Generally, dairy cows come into estrus within 2-4 days after injection. The scope of use of this method is dairy cows with a corpus luteum on the ovary. It has no effect on some dairy cows without a corpus luteum, so when choosing the method, it is also necessary to see whether the dairy cow has a corpus luteum. After injecting prostaglandin, some dairy cows will show no effect. You can wait 11-13 days and inject again. This can increase the probability of synchronized estrus to 80 percent. Moreover, prostaglandin has the effect of dissolving the corpus luteum, but it must be used with caution. If the dairy cow is already pregnant, absolutely do not use prostaglandin, otherwise it will cause miscarriage. Before use, it must be confirmed that the dairy cow is not pregnant.
The above are the methods for synchronized estrus in dairy cows. Did everyone learn them? The methods are very simple. The key lies in which one is suitable for you. The third one must be used cautiously, otherwise if not done properly it will cause miscarriage. I hope this article can help everyone.