Cattle frozen sperm to five
At present, bovine artificial insemination frozen semen is more commonly used. In order to ensure the conception rate of yellow cattle frozen sperm, attention should be paid to the following five links in the implementation process. First, the preservation, distribution and transportation of frozen semen Semen frozen in the preservation process, if the temperature rises to a certain extent, will result in sperm weakness, decreased vitality, and even death and so on. Therefore, it is necessary to ensure that frozen semen is kept below -130°C. For this purpose, frozen semen must be carefully handled in the process of distribution and transportation: 1 Always check the effectiveness of the sperm storage container; 2 When trapping granular frozen semen, do not leave the neck of the liquid nitrogen tank too far, the action should be rapid, so as to avoid temperature rise Affect the survival rate; 3 During the preservation period, check the consumption of liquid nitrogen frequently. When the capacity is less than 1/4, it must be replenished in time; 4 When dispensing the count, it should be carried out in liquid nitrogen. Regular sampling of frozen sperm, unqualified semen is not issued. Second, a good insemination during the appropriate period off cow estrus occurs a series of estrus symptoms, according to these symptoms to conduct accurate estrus identification is the key to the full match. The estrus manifested in four stages: 1 early estrus, cows nervous, urinary frequency, climbing across the bull, vaginal wet pink, slightly swelled vulva; 2 estrus, obviously swollen vulva, mucus increased, was egg clear , The cervix relaxes, takes the initiative to raise the tail, and is stable when the local acceptance of the bull's climb, willing to mate; 3 late estrus, the vulva swelling began to disappear, mucus became thick and turbid, the trial bull still follow, but the cow is not To approach; 4 estrus, estrus symptoms completely disappeared, mucus was yellow block, the trial bull has not followed the cow. According to many years of experience, the author believes that the best time for insemination is: 1 cows in the "stabilizing bar" that estrus cows do not let the test bulls begin to inseminate 12-18 hours after the climb; 2 out of the vaginal mucus sticking Thick, yellow, blocky, slightly tight and hard outside the cervix, the mouth is soft, the insemination device is easy to insert when the insemination begins, interval 12-18 hours for the second insemination; 3 when the rectum touch the ovary, the follicles Thinning of the wall, obvious fluctuations in the follicular fluid, and even a feeling of touch, the spermatozoa can be inseminated and inseminated every 12-18 hours. Cattle is commonly used for sperm insemination in early and late insemination, ie the first insemination in the morning and the second in insemination in the evening; if the first insemination in the evening, the second time can be lost in the morning the next morning. fine. Old and frail cows have short estrus duration, early ovulation, and appropriate breeding time. Young cows have long estrus, ovulation is late, and breeding time should be properly delayed. The masses often say that “older and younger, younger, and youngerâ€, is the truth. Third, the good granules (tubes) thawing frozen thawing faster, quasi-steady, that is, from the liquid nitrogen tank pocket to extract particles faster, the particles into the test tube to be accurate, the entire operation process should be stable to prevent sperm The live rate is affected. To control the temperature and quality of thawing, the thawing solution and test tube must be sterile. After thawing, check the viability and deformity rate of the sperm and fail to use the index. Fourth, the insemination of a good insemination disinfection insemination is not thorough, will reduce the sperm viability, after each insemination, the inseminator should immediately wash with water seven or eight times, and then rinse with distilled water three or four times, rejection of the net Water, finally sterilized with alcohol cotton balls, dried for use. Before insemination, rinse with sterilized thawing twice and preheat to 40°C. Then take semen, or wipe the inseminator with alcohol cotton ball before taking semen, ignite and preheat, wait for the temperature of the insemination device. When the temperature drops to about 40°C, semen is drawn. 5. Pregnancy examination should be conducted within 18-20 days after the early pregnancy check and compounding of cows are mated. If it is determined that there are no pregnancies, the reasons for failure to match should be detected as soon as possible, and corresponding measures should be taken to supplement them in time. To avoid cows emptying for too long.