The technical method of synchronous estrus in sheep at a certain stage
2022-01-14
The sheep estrus regulation techniques in the same period mainly include: ewe estrus induction, sympathetic estrus, and current ewe estrus induction. Sheep estrus at the same time is an important high-tech biotechnology, and it is also a necessary technical measure to achieve two-year production or two-year three-production, and to adjust the breeding period of ewes according to market needs. Simultaneous estrus technology is a well-organized, scientific and rigorous technical system. Only correct operation according to technical regulations can produce due production benefits.
1. The scope of application of estrus technology at the same time:
1. Reduce the time and frequency of estrus identification, make rational use of housing, climate and pasture resources, and improve the utilization rate of excellent breeding rams.
2. In the sheep high-efficiency breeding system, the ewes have two productions in one year or three productions in two years, and the mating period and lambing period of the ewes are adjusted according to the market demand.
3. In pastures or areas with limited mating time, ewes are concentrated in estrus in batches, which facilitates the planning, organization and implementation of artificial insemination and breed improvement.
4. It is beneficial for professional sheep raising households and individual sheep farmers to organize the centralized breeding of mixed flocks. There is no need to test the situation, and the breeding and production are centralized according to their own breeding plan.
5. Reasonably arrange feeding according to good pregnancy and pregnancy cycle, adjust the diet formula according to the needs of ewes' pregnancy, and improve the management level.
6. Regularly plan insemination, centralized breeding, and centralized lambing, which is conducive to making full use of climate, pastures, pens, and labor resources.
7. Monitor the production process of ewes, reduce the mortality rate of newborn lambs, and reasonably arrange foster care.
8. In the factory and intensive sheep production system, it plays an important role in mass production of commodity sheep, balanced supply throughout the year and market sales.
9. Strictly control the disease.
10. Simultaneous treatment of donor and recipient in embryo transfer technical procedures.
11. Implement ovulation control to overcome infertility.
12. Implement centralized lambing, combined with double lambing technology and frozen semen technology to improve lambing rate.
13. Treat the ewes and primiparous ewes of the current year to make them estrus and ovulate normally and increase the reproductive rate.
2. Types of Simultaneous Estrus Treatment Programs
1. The young ewes are treated with oral progesterone and gonadotropin.
2. Treat adult ewes with vaginal progesterone and heavy gonadotropins.
3. The young ewes or adult ewes are treated with an intramuscular injection of estrus compound hormones at the same time.
4. PGS uterus and labia injection treatment.
5. Progesterone ear or subcutaneous implantation treatment.
3. Simultaneous estrus hormone preparations
The selection of drugs is one of the key links in the simultaneous development of treatment effects and must be strictly controlled. The main drugs to be tested are: pretreatment gonadal hormone, vaginal progesterone releasing device (CRID) PMSG, LRH-A3, oxytocin HCG. The selected treatment drug must undergo actual measurement or preliminary experiments to confirm its effect before it can be used in production. Except for progesterone, the rest of the drugs must be stored at low temperature (5 degrees). When handling in the field, avoid direct sunlight and constant heat. Medicines must be stored in vials. Special attention should be paid to temperature changes during transportation.
4. Technical regulations for simultaneous estrus
1. Oral medroxyprogesterone (MAP) treatment program
The first pre-treatment of young ewes; intramuscular injection of compound progesterone preparations in middle-aged ewes; oral administration of MAP for 10 consecutive days; intramuscular injection of PMSG on the ninth day of oral MAP; breeding 56 hours after PMSG treatment; intravenous injection of HCG or LRH at the same time of breeding -A3; Add 1 unit of OXT semen to each milliliter of semen at the same time of mating; put the ram on the 14th day after the second mating and start the test for 20 days; withdraw the ram.
2. Treatment plan of vaginal progesterone release device (CRID)
First pretreatment of primiparous ewes; intramuscular injection of compound progesterone preparation in adult ewes; CRID implantation for 10-12 consecutive days; PMSG intramuscular injection on 12-13 days after implantation of CRID (on the day of thrombus withdrawal); PMSG treatment 56 Breeding within an hour; intravenous injection of HCG or LRH-A3 at the same time; 1 unit of OXT semen per milliliter of semen was added to the semen at the same time; the ram was put into the ram on the 14th day after the second breeding and began to test for 20 days; the ram was withdrawn.
3. One-time injection of compound hormone preparation treatment plan
Adult ewes or primiparous ewes are injected intramuscularly with compound hormone preparations; the ewes are tested for estrus and breeding; the second estrus is compounded;
4. Prostaglandin treatment program
Adult ewes or primiparous ewes are injected into the labia or intramuscular cloprostenol; gonadotropin is injected to test for estrus, estrus, and breeding; recombination in the second estrus;
5. Inducing estrus
Estrus induction can not only control the estrus time of the ewe, shorten the breeding cycle, and increase the lambing frequency, but also adjust the lambing season of the ewe.
The treatment method of estrus induction is basically the same as that of sympathetic estrus, the difference is that progesterone pretreatment must be performed to induce estrus, the time of implanting sponge plugs is 1-4 days longer than that of estrus in the same period, and the dose of PMSG injection is 100 units higher, according to research reports , The use of oxytocin to induce goat estrus, subcutaneous injection of 5IU every morning and evening, can shorten the estrus cycle from the original 17.5 days to 6-8 days. The short-day treatment was replaced by melanin treatment, but the treatment period was continued for at least 5 weeks.
6. The female lambs induced estrus that year
When the ewe's weight reaches more than 60-65% of the adult ewe's weight in that year, and when the birth is over 7 months old, the use of reproductive hormones can make the ewe reproduce successfully. According to the anatomical characteristics of the reproductive organs of young ewes, the treatment plan for inducing estrus can use vaginal implanted sponge suppository and oral progesterone + PMSG (the dose of PMSG should be strictly controlled below 400 ml).
7. The optimal supporting technology of estrus regulation hormone program
From a theoretical and practical point of view, the progestin-PMSG method should be the first choice. The best choice of progesterone: medroxyprogesterone sponge suppository (MAP) in breeding season, fluprogesterone (FGA) in non-breeding season, and vaginal sponge device is the best dosage form. Oral progesterone can also be used for ewes that are not suitable for embolization. The injection time of PMSG should be carried out on the day of withdrawal of the thrombus, so as to eliminate the ovulation disorder caused by the estrogen peak caused by the sudden withdrawal of the thrombus. This processing method meets the requirements of safety and reliability. The first estrus is not fetus, and the second and third estrus will appear normally, which will not affect the final conception of the ewes.
In estrus regulation, especially when inducing estrus of ewes in non-breeding seasons, it is necessary to adhere to the normal breeding of three estrus periods. While inducing estrus to treat ewes in non-breeding seasons, attention must be paid to the reproductive health care of rams. The technology of ram reproductive health care is adopted, and the ram is also treated correspondingly while the ewes are processed to ensure the breeding ability of the ram. Maintain a high conception rate.
The ewes treated with estrus regulation must maintain good body condition and body condition, otherwise the conception rate of the treated ewes will be affected. At the same time, there must be a weaning interval of more than 40 days.
In the estrus control treatment, the supporting technology should also be specially selected. Supporting technologies include drugs, unified procedures, optimization of artificial insemination technology, first mating time, determination of estrus status of ewes, early pregnancy diagnosis and compound management, etc. Only by adopting the supporting technology can the treatment effect be guaranteed, so that the technology can exert the highest efficiency and play a role in efficient sheep raising.
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