Techniques for improving the fertility rate of donor ewes

Measures Embryo transplantation technology is an effective way to speed up the reproduction rate of elite breeders, but due to inadequate preparation of work and carelessness in the process of operation, it may lead to low utilization rate and difficulty in fetuses after oviposition of donor sheep. . Based on the actual application experience of the sheep breeding farm in Shunyi District in Beijing in the past two years, I briefly discussed some measures for improving the conception rate of female ewes after surgery.

The choice of donor ewes

1. To choose age between 1 and a half years to 4 years old, having more than 1 child, having good lyrical condition, healthy without reproductive disease, and having a normal estrus cycle in the estrus season as a donor.

2. During the feeding period, we must be weaned for 30 days, make up for nutrition, and recover the sensation.

3. If broilers are selected, they must be mature, healthy and free of reproductive disease, have more than two estruss and have a normal cycle.

Arrangement of transplant time

Sheep embryo transfer is usually arranged during the estrus season. From the end of September to the end of November in the general autumn, the estrus of the sheep grows vigorously from February to April in the early spring, and the endocrine activity is most active. Selecting this period is conducive to the conduct of super-discharge work, and after the wound healing can be timely estrus mating, artificial insemination should be used as far as possible when mating, lose no time to check out the series of problems of donor sheep, such as pollution caused by endometritis and Vaginitis, abnormal estrus and persistent corpus luteum. Take timely treatment measures to increase the conception rate.

Surgical methods and use times

1. Use tuber flushing method from 68 hours to 72 hours after mating. The best use of the donor sheep is not more than twice, and once used, the birth of a child and the use of the second time can show that the donor sheep did not leave reproductive disorders and other sequelae after the embryo flush, guaranteeing the next time and receiving Body sheep support. Avoid economic losses.

2. Using laparoscopic intrauterine flushing method (7 days) is best but 3 times. If the uterus is not contaminated, the knife wounds will recover quickly and the estrus cycle will be normal.

Emphasis on the process of embryonic injection

1. When the embryo is washed, the wool around the operation site must be scraped and strictly sterilized to prevent inflammation, leaving behind trouble and reducing sheep utilization.

2. After the estrus is super-disposed, the donor sheep will be bred with fresh sperm for 1 hour and 3 times at intervals of 10 hours to 12 hours to prevent the genital passages from being contaminated by too many times and affect the next use and re-breeding conception rate.

3. When flushing embryos, the operation should be light and detailed, prevent fallopian tubes, fallopian tubes and other parts of the bleeding, resulting in adhesions, blockage, so that the ewes lose fertility.

4. The antibacterial fluid used to wash wounds and blood during surgery was previously added with penicillin in normal saline. It is better to change to normal saline and Lincomycin hydrochloride to prevent blisters on the surface of the uterus, resulting in decreased utilization and conception rate.

5. After flushing the embryo, dilute 800,000 international units of penicillin and 1 million international units of streptomycin into the uterus with 20 ml of normal saline to prevent contamination of the uterus during breeding and surgery, and to increase the amount of the next donor sheep. Reuse rate and conception rate.

6. After the embryo is sutured, use the index finger and middle finger to separate the peritoneum from the intestine to avoid suturing the intestine. When the peritoneum is sutured, the needle should be pulled out from the inside, the line should be tightened to prevent the peritoneal line from opening later, the sagging of the intestine and reoperation or donor sheep death, causing unnecessary losses.

Post-embryo breeding

1. After the donor sheep flushes embryos, about 10 days from the time of estrus, intramuscular injection of cloprostenol 0.8 ml to 1 ml to dissolve multiple corpus luteum in the ovary to facilitate estrus and avoid formation of persistent corpus luteum.

2. After the donor sheep flushes the embryo, because the exogenous hormone in the body still persists to a certain level, after the first oestrus, try not to breed. There will be some estrus cycle disorders, ovulation is not normal, and it is not easy to be affected. Some sheep have lower rates of fertility even if they are mated. Therefore, it is more suitable for the second-term match, and the rate of fertility of the LRH-A3 intramuscularly at the time of mating is higher.

3. During the estrus of the donor sheep, it was found that the secretion was cloudy and uterine inflammation, vaginitis, timely flushing, anti-inflammatory treatment and then breeding. Prevent pregnancy difficulties and delays missed breeding opportunities.

4. The hedgerow embryo can not be used for a long period of time after the embryo can only be used CIRD into the vagina, placed in 13 days after intramuscular injection of cloprostenol 0.8 ml removed 10 hours, estrus can be used to breed. For the ewes in the late spring, as the weather is getting hotter and hotter, the long-lasting estrus should be based on the situation as far as possible without aphrodisiac breeding. Because of the anti-seasonal aphrodisiac, high temperatures can easily result in genital tract contamination of the ewe, and the conception rate is also lower. Therefore, it is possible to make it fall off and seize the opportunity in the early autumn to greatly increase the utilization rate and conception rate.

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