Measures to improve the fecundity of meat donkey by breeding meat donkey

I. strengthening seed selection

Fecundity is greatly affected by genetic factors, and the reproductive performance of different varieties and individuals is also different. In particular, male donkeys have a great impact on their offspring, so choosing male and female donkeys with high fecundity is the premise to improve the reproduction rate of donkeys. For the selection of female donkeys, attention should be paid to the morning and evening of sexual maturity, estrus arrangement, foal interval, conception ability and lactation performance under normal feeding conditions. In the selection of male donkeys, attention should be paid to the genetic performance, physical appearance, reproductive history and reproductive performance of male donkeys. Attention should also be paid to the examination of general physiological status, reproductive organs (texture and size of testis and epididymis, sperm excretion duct, function of accessory gonad), semen quality (sperm motility, density, sperm morphology) and reproductive diseases.

Second, increase the number of female donkeys

The female donkey is the basis of the multiplication of the donkey herd. the more the number of the female donkey in the donkey group, the faster the multiplication speed of the donkey group. Therefore, the rapid development of large-scale donkey industry is the most effective way to improve the breeding rate of donkeys.

III. Scientific feeding and management

Strengthening the feeding and management, especially in the estrus and breeding season, is the material basis to ensure normal estrus and ovulation of the female donkey. Lack of nutrition will make female donkey thin, endocrine activity affected, sexual function decreased, reproductive function disorder, often no estrus, quiet estrus, estrus does not ovulate, ovulation decreased; male donkey shows poor semen quality, decreased libido and so on.

Fourth, do a good job of estrus identification and timely breeding

Under normal circumstances, the eggs just excreted have strong vitality and are highly energized. Generally speaking, the closer the time between insemination or natural mating and ovulation, the higher the conception rate. This requires that the identification of estrus on the female donkey is as accurate as possible in order to achieve timely insemination. The estrus identification of female donkeys usually focuses on rectal examination on the basis of external observation. Rectal examination according to the existence, size, texture and other changes of the follicle, grasp the degree of follicular development and ovulation time to determine the most appropriate time of insemination. In recent years, the implementation of rectal insemination combined with touch follicular development has reached about 60% of the estrus conception rate.

Abide by the operating rules and adopt new techniques for popularizing reproduction

The popularization of artificial insemination technology, especially the application of frozen semen, has greatly improved the production level of donkeys with the utilization value of breeding male animals. In the process of promoting artificial insemination technology, we must abide by the operating rules, from estrus identification, cleaning and disinfection instruments, semen collection, semen treatment, freezing, preservation and insemination, is a set of very meticulous and rigorous operation, all links are closely related. Poor mastery of any link can lead to mismatch and infertility. In order to improve the fecundity of donkeys, suitable and mature new reproductive techniques were gradually applied, such as estrus synchronization, embryo transfer, superovulation, controlled delivery, induced estrus, sex control, gene introduction, artificial fertilization, embryo cryopreservation and preservation. The correct use of reproductive hormones can restore the normal reproductive function of female donkeys with reproductive disorders, so as to maintain and improve their fecundity.

Diagnosis of early pregnancy to prevent mismatch and emptiness

Through early pregnancy diagnosis, we can determine whether the female donkey is pregnant as soon as possible and treat it differently. For the female donkey who has confirmed the pregnancy, the protection of the fetus should be strengthened to make the fetus develop normally, which can prevent the mismatch of estrus after pregnancy. For non-pregnant female donkeys, we should carefully and timely find out the reasons, take corresponding measures, seize the opportunity to make up, and reduce empty time.

VII. Reduce embryo death and miscarriage

The scope of this issue is wide and complex, and there are many factors affecting it. An early embryo that has not yet formed a fetus dies once it stops developing in the donkey's womb, which is generally absorbed by the uterus, and some are excreted with estrus or urination. Because the disappearance and excretion of embryos are not easy to find, it is called recessive abortion. The average abortion rate of donkeys is about 10%, and most miscarriages occur around 5 months of pregnancy. In this period, to avoid sudden changes in feeding conditions, a reasonable amount of labor or exercise is an effective preventive measure. It has been suggested that subcutaneous implantation of 300 mg of progesterone after 120 days of pregnancy may also be effective in preventing miscarriage.