Xinjiang local multifetal mutton sheep hybridization breeding method suitable for farming in agricultural and pastoral areas

Abstract

The invention relates to the technical field of genetic breeding, in particular to a Xinjiang local multi-fetal mutton sheep hybridization breeding method suitable for farming in agricultural and pastoral areas, which comprises the steps of S1, multi-fetal hybridization breeding, S2, grouping management, S3, high-yield mutton hybridization breeding and S4, cross-crossing fixation. According to the Xinjiang local multifetal mutton sheep hybridization breeding method suitable for breeding in the agricultural and pastoral areas, Hu sheep, Altay sheep and Xinjiang local ewes are subjected to three-way hybridization, and a grouping management mode is combined, so that the inbreeding probability is reduced, the population genetic diversity is maintained, and the character separation risk is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of genetic breeding, and in particular to a method for hybridizing and breeding Xinjiang local multi-birth mutton sheep suitable for breeding in agricultural and pastoral areas. Background Art

[0002] As people's living standards improve, the demand for mutton is also increasing. However, the supply of mutton in Xinjiang sometimes cannot meet local demand, and mutton needs to be transported from outside Xinjiang. In order to increase the local supply of mutton and improve the efficiency of mutton sheep breeding, Xinjiang urgently needs a multi-birth mutton sheep breed that is suitable for breeding in agricultural and pastoral areas. Xinjiang local ewes usually have a strong physique and a strong body structure. For example, the Altay sheep is known for its large physique and high meat and fat production performance. Its tail is round and fat, and its limbs are tall, thick and strong. These characteristics enable Xinjiang local ewes to adapt to the climate and breeding conditions in Xinjiang.

[0003] Existing hybrid breeding technologies design a breeding method that combines hybridization, backcrossing and cross-crossing, which can improve the birth rate of future generations of meat sheep to a certain extent. However, in the process of genetic selection and fixing birth genes in some hybrid breeding methods, the hybrid offspring may cause trait separation due to gene recombination (such as increased birth rate but decreased meat yield), and there is a risk of decreased birth rate and meat yield due to the increased probability of inbreeding.

[0004] Therefore, it is necessary to propose a hybrid breeding method for Xinjiang local multi-birth meat sheep that is suitable for breeding in agricultural and pastoral areas, which can reduce the probability of trait separation and inbreeding while ensuring multi-birth and lamb fat production performance, and create long-term benefits for farmers. Summary of the invention

[0005] To solve the above problems, the present invention provides a method for hybridizing and breeding Xinjiang local multi-birth meat sheep suitable for breeding in agricultural and pastoral areas, which uses Hu sheep and Altay sheep to carry out three-way hybridization with Xinjiang local ewes, and combines the method of grouping management to reduce the probability of inbreeding, maintain the genetic diversity of the population, and reduce the risk of trait separation.

[0006] In order to achieve the above object, the technical scheme of the present invention is as follows: A method for hybrid breeding of Xinjiang local multi-birth mutton sheep suitable for breeding in agricultural and pastoral areas, comprising the following steps:

[0007] S1, polygynous hybrid breeding: Xinjiang local ewes are used as the female parent, and polygynous rams from Hu sheep are selected as the male parent for hybridization to obtain F1 hybrid mutton sheep;

[0008] S2, group management: the ewes in the F1 generation of hybrid mutton sheep are divided into 5 subgroups according to AE, and the ewes in each subgroup are used as the F1 generation female parents, and different Altai rams with high meat production are selected as the male parents for each subgroup;

[0009] S3, high-yield meat hybrid breeding: after the ewes of each subgroup in the F1 generation hybrid mutton sheep enter the breeding period, they are hybridized with the corresponding sires to obtain the F2 generation hybrid mutton sheep;

[0010] S4, cross-breeding fixation: In the F2 generation of hybrid meat sheep, select rams and ewes from different subgroups for cross-breeding to fix fecundity and meat production performance.

[0011] Furthermore, in S1, local ewes in Xinjiang are tested and selected, and a pedometer is fitted on each local ewe in Xinjiang to record the estrus cycle of the ewe, and historical breeding data is collected. Ewes with a breeding record of one litter of two lambs or more are preferentially selected as female parents for hybridization.

[0012] Furthermore, in S2, the Altai rams corresponding to each subpopulation were replaced every two years.

[0013] Further, in S3, the F1 generation ewes in each subgroup are managed with a nutritional formula. The specific nutritional formula management is to feed the ewes according to different feed ratios according to different physiological stages, including the following formulas prepared according to mass percentage:

[0014] Formula for pregnant ewes: 60% corn straw, 20% alfalfa, 15% cottonseed meal and 5% premix, 2.5-3 kg per ewe per day;

[0015] Formula for lactating ewes: 50% corn straw, 25% alfalfa, 20% cottonseed meal and 5% premix, 3-3.5 kg per ewe per day;

[0016] Lamb fattening formula: 40% corn straw, 30% alfalfa, 25% cottonseed meal and 5% premix, feed 1.5-2 kg per lamb per day.

[0017] Furthermore, in S3, after the F2 generation hybrid mutton sheep are born, an automatic weighing device is installed at the entrance of the sheep house, an electronic ear tag is put on each F2 generation lamb, and the weight is recorded by the automatic weighing device during the weaning and fattening stages, and the weight information is recorded and transferred to the electronic ear tag.

[0018] Furthermore, in S3, the F2 generation hybrid mutton sheep are assigned to the subgroups of their paternal and maternal lines after birth.

[0019] Furthermore, in S4, before cross-crossing fixation, local purebred gene backup is required, including: selecting 10% of the sheep from the local ewes in Xinjiang, establishing a separate purebred subgroup X for breeding, and using local rams in Xinjiang for purebred breeding.

[0020] Furthermore, during the process of local purebred gene backup, the Xinjiang local rams used for breeding need to be updated every one year.

[0021] Furthermore, during the local purebred gene backup process, it is necessary to detect the average reproductive cycle of subgroup X. Taking the reproductive cycle as the time limit, the performance of local ewes is measured every other reproductive cycle, and the reproductive rate, lamb survival rate and disease resistance of each ewe are recorded.

[0022] Furthermore, in S1, S3 and S4, the ratio of crossbred rams to ewes was 1:50.

[0023] The above scheme has the following beneficial effects:

[0024] 1. This plan introduces Hu sheep (multiple births) and Altay sheep (high meat production) for three-way hybridization. The F1 generation ewes inherit the multi-birth gene, and the F2 generation combines the high meat production gene of Altay rams through group management to achieve synergistic optimization of multi-birth and meat production performance.

[0025] 2. This plan is designed to divide the F1 generation ewes into 5 subgroups (AE), and assign different Altai rams to each subgroup, and replace the rams every 2 years. Through subgroup hybridization and regular introduction of new sires, the probability of inbreeding is reduced (the inbreeding coefficient is controlled below 5%), the genetic diversity of the population is maintained, and the risk of trait separation is reduced.

[0026] 3. Design dynamic feed formulas based on the nutritional needs of ewes during pregnancy, lactation and lamb fattening to improve feed utilization, reduce breeding costs, and at the same time ensure the reproductive performance of ewes and the growth rate of lambs.

[0027] 4. Collect lamb weight data in real time through electronic ear tags and automatic weighing equipment, and combine with pedometer records to evaluate the breeding value of local ewes in Xinjiang, screen individuals with multiple births, high meat yields and strong adaptability, and improve the efficiency of genetic breeding.

[0028] 5. Before cross-breeding, retain 10% of Xinjiang local ewes to establish a purebred backup group, update local rams every year, regularly measure the reproduction rate, lamb survival rate and disease resistance, prevent the loss of genetic resources caused by hybridization, and ensure the long-term stability of the adaptability advantages of local sheep breeds.

[0029] 6. Combining Xinjiang's local feed resources with a mixed grazing and stall-feeding model, the F2 generation of sheep has been bred to be tolerant to roughage and disease, and can maintain growth performance in harsh environments such as severe cold and drought, thereby increasing the survival rate of lambs.

[0030] 7. Reduce the cost of breeding rams through efficient artificial insemination technology with a male-to-female ratio of 1:50; automated equipment reduces labor input, shortens the investment recovery period, increases comprehensive benefits, and promotes the industrial development of agricultural and pastoral areas.

[0031] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of a hybrid breeding method of an embodiment of a hybrid breeding method for Xinjiang local multiple-birth mutton sheep suitable for breeding in agricultural and pastoral areas according to the present invention;

[0033] Figure 2 It is a schematic diagram of a purebred sheep flock backup method according to an embodiment of the method for hybrid breeding of Xinjiang local multiple-birth meat sheep suitable for breeding in agricultural and pastoral areas of the present invention. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] The following is further described in detail through specific implementation methods:

[0036] Embodiment 1:

[0037] As attached Figure 1 As shown: A method for hybrid breeding of Xinjiang local multi-birth mutton sheep suitable for breeding in agricultural and pastoral areas, comprising the following steps:

[0038] S1, polyparous hybrid breeding: take Xinjiang local ewes as maternal parents, firstly test and select Xinjiang local ewes, put a pedometer on each Xinjiang local ewe, record the estrus cycle of the ewe, and collect historical breeding data, give priority to ewes with a breeding record of one litter with two lambs or more as maternal parents for hybridization (the beneficial effect of selecting local ewes for polyparousness); then select polyparous rams from Hu sheep as sires, carry out hybridization, and obtain F1 generation hybrid mutton sheep. Under good feeding and management conditions, Hu sheep can achieve two litters a year or three litters in two years, with a lambing rate of up to 230%-270%, and even a higher lambing rate in some cases. Therefore, by selecting polyparous Hu sheep as sires, the probability of multiple births in offspring ewes can be increased, thereby improving the breeding efficiency of the entire breeding group.

[0039] S2, group management: The ewes in the F1 generation of hybrid meat sheep are divided into 5 subgroups according to AE. Through subgroup hybridization, the genetic structure of the population can be optimized, avoiding over-reliance on a specific genotype, which helps to maintain the health and stability of the population and improve overall production performance. In addition, it can ensure that the genetic differences between ewes in different subgroups are large, thereby reducing the possibility of gene duplication. By selecting rams from different subgroups for breeding, the risk of inbreeding can be further reduced.

[0040] Then, the ewes in each subgroup are used as the F1 generation mothers, and different Altay rams with high meat production are selected as the fathers for each subgroup. Since Altay sheep have outstanding meat fat production performance, can adapt well to the conditions of year-round grazing and four-season transfer of pastures, are tolerant to roughage, have a high utilization rate of feed, and can maintain a good growth state even under relatively harsh conditions, they are especially suitable for breeding in agricultural and pastoral areas. Therefore, by selecting Altay sheep as the father, the meat fat production performance of offspring can be increased, and the survival rate and adaptability of subsequent lambs can be improved; in addition, compared with traditional binary hybridization, this plan designs a ternary hybridization model of Xinjiang local ewes, Hu sheep and Altay sheep. On the basis of combining the advantages of the three breeds, it has the characteristics of rapid growth, high feed conversion efficiency, good meat production performance, etc., and can introduce new genetic material to avoid genetic problems caused by inbreeding and reduce the limitations of genetic improvement.

[0041] The Altai rams corresponding to each subgroup are replaced every two years to ensure that ewes from different subgroups are bred with new rams, thereby avoiding genetic defects and disease risks caused by long-term inbreeding, helping to maintain the genetic diversity and vitality of the population, and improving the adaptability and production performance of offspring; in addition, regular replacement of Altai rams can eliminate old and weak rams with reduced production performance, and retain young, strong, and high-production-performance rams, which helps to optimize the population structure and improve overall production performance and market competitiveness.

[0042] Experiment 1

[0043] Purpose of the experiment: To evaluate the effect of group management strategy on reducing the probability of inbreeding (inbreeding coefficient).

[0044] Subjects: A flock of multiple sheep, including rams and ewes of different relationships.

[0045] Grouping strategy: Divide the flock into two or more subgroups, and try to keep the sheep in each subgroup with the lowest possible kinship.

[0046] Observation indicators: inbreeding coefficient, breeding success rate, health status of offspring, etc.

[0047] Control group: a flock of sheep that was not managed in groups.

[0048] The experimental table data is as follows:

[0049]

[0050] Experimental conclusion: The initial inbreeding coefficient of all groups was 6.0%, which served as the starting condition of the experiment. After a certain period of group management, the inbreeding coefficient of each group changed. Among them, the inbreeding coefficient of group A (grouped by kinship) was significantly reduced to 3.2%, much lower than the 7.5% of the control group, indicating that the group management strategy effectively reduced the probability of inbreeding. The breeding success rate of group A was also relatively high, reaching 90%, which was related to the reduction in the inbreeding coefficient, because inbreeding leads to a decrease in the breeding success rate. The offspring of group A also had the best health, with excellent and good proportions reaching 60% and 40%, while the proportion of offspring with poor health in the control group and random group was higher.

[0051] S3, high-yield meat hybrid breeding: Since the F1 generation ewes inherit the multi-birth gene of the Hu sheep father, it is necessary to manage the nutritional formula when feeding the F1 generation ewes. The specific nutritional formula management is based on different feed ratios according to the different physiological stages of the ewes, including the following formulas prepared according to mass percentage:

[0052] Formula for pregnant ewes: 60% corn straw, 20% alfalfa, 15% cottonseed meal and 5% premix, 2.5-3 kg per ewe per day;

[0053] Formula for lactating ewes: 50% corn straw, 25% alfalfa, 20% cottonseed meal and 5% premix, 3-3.5 kg per ewe per day;

[0054] Lamb fattening formula: 40% corn straw, 30% alfalfa, 25% cottonseed meal and 5% premix, feed 1.5-2 kg per lamb per day;

[0055] By managing the feed ratio and adjusting the feed ratio according to the nutritional needs of ewes at different physiological stages, ensuring full utilization of feed, it helps to reduce feed waste and reduce breeding costs. Reasonable feed ratios can also provide vitamins, minerals and other nutrients required by ewes and lambs, enhance their immunity, help reduce the occurrence of diseases, and reduce breeding risks; in addition, adequate nutritional support can ensure that ewes maintain good physical condition during pregnancy and lactation, improve their reproduction rate, and help increase the number of flocks and expand the scale of breeding.

[0056] After the ewes in each subgroup of the F1 generation hybrid mutton sheep enter the breeding period, they are hybridized with the corresponding sires to obtain F2 generation hybrid mutton sheep. After the F2 generation hybrid mutton sheep are born, they are assigned to the corresponding subgroups of their sires and maternal lines. The F2 generation hybrid mutton sheep are classified by subgroups, which provides a basis for the subsequent cross-breeding to fix the multi-birth genes and facilitates the subsequent allocation of the sire and maternal parents for the hybridization.

[0057] In addition, automatic weighing equipment is installed at the entrance of the sheep house, and an electronic ear tag is put on each F2 lamb. The weight is recorded by the automatic weighing equipment during the weaning and fattening stages, and the weight information is recorded and transmitted to the electronic ear tag. By continuously recording and analyzing the weight data of the F2 lambs during the weaning and fattening stages, a growth curve can be drawn to intuitively reflect the growth rate and health status of the sheep, which is helpful to timely discover growth abnormalities or health problems and provide a scientific basis for timely adjustment of feeding management. In addition, through weight detection and growth curve reflection, it can be clear whether the F2 lambs have successfully inherited the high meat yield performance from the Altay paternal sheep, so that measures can be taken to intervene early and reduce breeding risks.

[0058] Experiment 2

[0059] Experimental purpose: To verify the effect of three-way hybridization on improving fecundity and meat production performance.

[0060] Experimental subjects: Xinjiang local ewes (basic population), Hu sheep (introduced breed with high reproductive capacity), and Altay sheep (introduced breed with excellent meat production performance).

[0061] Hybrid combination: Xinjiang local ewes × Hu sheep produce the first generation of hybrid sheep (F1), and then select the ewes in F1 to cross with Altay sheep to produce three-way hybrid sheep (F2).

[0062] Control group: Xinjiang local ewes (not hybridized).

[0063] Observation indicators: multiple birth rate, number of lambs born, lamb birth weight, lamb weight at 6 months of age, slaughter rate, net meat rate, etc.

[0064] The experimental data table is as follows:

[0065]

[0066] Experimental conclusion: The birth rate and average number of lambs of the three-way hybrid sheep are 100% and 27.7% higher than those of the control group, and 40% and 11.1% higher than those of the first-generation hybrid sheep, indicating that the three-way hybrid effectively improves the birth rate. The birth weight and 6-month-old weight of the three-way hybrid lambs are 10-15% higher than those of the control group and the first-generation hybrid, indicating that the three-way hybrid can inherit the excellent growth traits of the parents.

[0067] S4, cross-breeding fixation: In the F2 generation of hybrid meat sheep, select rams and ewes from different subgroups for cross-breeding to fix fecundity and meat production performance.

[0068] Embodiment 2:

[0069] As attached Figure 2 As shown, the difference from Example 1 is that conventional hybrid breeding means, which over-rely on foreign male parents for hybridization, may weaken the original adaptability advantage of local sheep breeds. That is, the adaptability of Xinjiang local sheep breeds to the local environment of Xinjiang formed in the long-term evolution process is the basis for their survival and reproduction. Once this adaptability is lost, it will seriously affect their survival ability and production performance. For this reason, before cross-crossing fixation, local purebred gene backup is required, including: selecting 10% of the sheep from Xinjiang local ewes, establishing a separate purebred subgroup X for breeding, and using Xinjiang local rams for purebred breeding. The Xinjiang local rams used for breeding need to be updated every 1 year. By retaining a part of purebred local ewes as a backup group, the loss of gene resources caused by excessive hybridization is prevented. These purebred local ewes can not only serve as a gene bank for future breeding, but also can be used to restore and rebuild the adaptability advantage of local sheep breeds when necessary.

[0070] In addition, it is necessary to detect the average reproductive cycle of subgroup X during the process. With the reproductive cycle as the time limit, local ewe performance testing is carried out every other reproductive cycle to record the reproductive rate, lamb survival rate and disease resistance of each ewe. Through continuous monitoring and management of the backup group, individuals with excellent traits and adaptability can be discovered and retained in time, providing a new source of genes for future breeding work.

[0071] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for hybrid breeding of Xinjiang local multi-birth mutton sheep suitable for breeding in agricultural and pastoral areas, characterized in that: The following steps are involved: S1, polygynous hybrid breeding: Xinjiang local ewes are used as the female parent, and polygynous rams from Hu sheep are selected as the male parent for hybridization to obtain F1 hybrid mutton sheep; S2, group management: the ewes in the F1 generation of hybrid mutton sheep are divided into 5 subgroups according to AE, and the ewes in each subgroup are used as the F1 generation female parents, and different Altai rams with high meat production are selected as the male parents for each subgroup; S3, high-yield meat hybrid breeding: after the ewes of each subgroup in the F1 generation hybrid mutton sheep enter the breeding period, they are hybridized with the corresponding sires to obtain the F2 generation hybrid mutton sheep; S4, cross-breeding fixation: In the F2 generation of hybrid meat sheep, select rams and ewes from different subgroups for cross-breeding to fix fecundity and meat production performance.

2. The method for hybridization and breeding of Xinjiang local multiple-birth mutton sheep adapted to farming and pastoral areas according to claim 1, characterized in that: In S1, local ewes from Xinjiang were tested and selected. A pedometer was fitted to each ewe to record the estrus cycle and collect historical breeding data. Ewes with a breeding record of one litter of two lambs or more were given priority as female parents for hybridization.

3. The method for hybridization and breeding of Xinjiang local multiple-birth mutton sheep adapted to farming and pastoral areas according to claim 2, characterized in that: In S2, the Altai rams corresponding to each subpopulation were replaced every two years.

4. The method for hybridization and breeding of Xinjiang local multiple-birth mutton sheep adapted to farming and pastoral areas according to claim 3, characterized in that: In S3, the F1 generation ewes in each subgroup are managed with nutritional formulas. The specific nutritional formula management is based on different physiological stages of the ewes and different feed ratios, including the following formulas prepared according to mass percentage: Formula for pregnant ewes: 60% corn straw, 20% alfalfa, 15% cottonseed meal and 5% premix, 2.5-3 kg per ewe per day; Formula for lactating ewes: 50% corn straw, 25% alfalfa, 20% cottonseed meal and 5% premix, 3-3.5 kg per ewe per day; Lamb fattening formula: 40% corn straw, 30% alfalfa, 25% cottonseed meal and 5% premix, feed 1.5-2 kg per lamb per day.

5. The method for hybridization and breeding of Xinjiang local multiple-birth mutton sheep adapted to farming and pastoral areas according to claim 4, characterized in that: In S3, after the F2 generation hybrid mutton sheep were born, an automatic weighing device was installed at the entrance of the sheep house, and an electronic ear tag was put on each F2 generation lamb. The weight was recorded by the automatic weighing device during the weaning and fattening stages, and the weight information was recorded and transferred to the electronic ear tag.

6. The method for hybridization and breeding of Xinjiang local multiple-birth mutton sheep adapted to farming and pastoral areas according to claim 5, characterized in that: In S3, the F2 hybrid mutton sheep are assigned to the subgroups of their paternal and maternal lines after birth.

7. The method for hybrid breeding of Xinjiang local multiple-birth mutton sheep adapted to farming and pastoral areas according to claim 6, characterized in that: In S4, before cross-crossing fixation, local purebred gene backup is required, including: selecting 10% of the sheep from Xinjiang local ewes, establishing a separate purebred subgroup X for breeding, and using Xinjiang local rams for purebred breeding.

8. The method for hybridization and breeding of Xinjiang local multiple-birth mutton sheep adapted to farming and pastoral areas according to claim 7, characterized in that: During the process of local purebred gene backup, the Xinjiang local rams used for breeding need to be updated every year.

9. The method for hybrid breeding of Xinjiang local multiple-birth mutton sheep adapted to farming and pastoral areas according to claim 8, characterized in that: During the local purebred gene backup process, it is necessary to detect the average reproductive cycle of subgroup X. The performance of local ewes is measured every other reproductive cycle, with the reproductive cycle as the time limit, and the reproductive rate, lamb survival rate and disease resistance of each ewe are recorded.

10. The method for hybrid breeding of Xinjiang local multiple-birth mutton sheep adapted to farming and pastoral areas according to claim 9, characterized in that: In S1, S3 and S4, the ratio of crossbred rams to ewes is 1:50.

Images