Views:99 Author:Site Editor Publish Time: 2019-10-15 Origin:Site
Animals have estrus at different stages. Mastering the estrus period of animals can effectively implement breeding programs, making animal artificial insemination intensive. This article will focus on the cow breeding.
When reserve Cows developing to a certain stage (generally between 8-12 months old), the matured follicular wall cells secrete estrogen and enter the blood to change the behavior and physiology of the cow, which is called estrus. The first estrus is the starting date of the cow breeding file. The cows in 14 months old without priming signs, we should check them, find the causes and take measures
Each insegrant should grasp estrus cycle days and the estrus of individual cow. Keep it in your mind and implement the breeding plan.
1) Rectal examination of uterus and ovary (bubble) situation and grasping cervical insemination is a standardized artificial insemination technique.
2) Touching the mature state of the follicle, inseminate in the process of ovulation or just ovulation, you will get a high insemination rate.
3) Before and in the insemination, the cows residence and insemination devices should be kept dry and hygienic. (The insemination gun should be covered with membrane protective cover).
4) Uterine traumatic bleeding is harmful for the survival of sperm and fertilized ovum, so trauma should be avoided as much as possible. Lubricant that is harmless to sperm and not irritating to the reproductive tract can be used.
5) When the insemination utensil is close to the external cervix, the correct way is to move the cervix holding hand to the vaginal side so that it can be close to the front end of the insemination utensil, instead of pushing the insemination utensil to the cervix. Put the insemination utensil into the cervix with the feeling of your fingers.
6) The technique of the insemination utensil front end traversing through the cervix and irregularly aligning is the key technique of insemination. You can use the operating techniques such as changing the direction of the insemination utensil, back pumping, swinging, rolling, etc., so that the front end of the technique can pass through the cervix. It is strictly forbidden to enter the cervix by hard punctuation.
7) Quality and Access of Semen
Quality: The vigor is more than 0.35, linear movement sperm density ≥ 10 million, acrosome integrity rate ≥ 40%, abnormal sperm rate ≤ 20%, non-pathogenic bacteria ≤ 1000 / ml.
Storage: Semen is stored in a liquid nitrogen tank with high vacuum insulation. The liquid nitrogen tank should be placed in a clean, dry, ventilated wooden backing plate, and the liquid nitrogen level should be kept above 18cm. Liquid nitrogen should be added when it is 16cm.
Extraction of semen: Except for the frozen sperm that needs to be taken out this time, other frozen sperm should not be under the 3. 5cm line below the tank mouth. If the frozen sperm is found for more than 10 seconds, the sub-tank should be returned to the liquid nitrogen, and then lift it to find again, so that keep the coldness of the frozen sperm. Each bull semen should be placed in the same sub-bucket, and there should be a packing list, on the list including the bull number, quantity and access record. When cleaning the liquid nitrogen tank, the prepared cleaning liquid nitrogen tank should be placed side by side for quick transfer. The time of the frozen sperm exposed outside the tank should not exceed 3-5 seconds.