42 results about "Purebred" patented technology

The invention relates to the technical field of molecular markers and animal genetic breeding, in particular to an SNP marker influencing the content of porcine inosine and application of the SNP marker. The 10 SNP molecular markers closely related to the porcine inosine content are researched and determined on the basis of American-series purebred landrace, American-series purebred large white pigs and American-series purebred duroc, the dominant allele frequency can be increased generation by generation by optimizing the dominant allele of the SNP, the inosine content can be reduced, and the molecular markers can be used for identifying the porcine inosine content. The pig genetic improvement progress is accelerated, so that the economic benefit of breeding pig breeding is effectively improved.

The invention relates to the technical field of biology, in particular to a primer combination for identifying Leyping spotted pigs and an identification method of the primer combination, six specific SNP molecular markers (SNP1-SNP6) are obtained through whole genome screening, six pairs of specific PCR primers are designed and developed on the basis of the sites, the nucleotide sequences of the primers are shown as SEQ ID NO.1-12, and the primer combination is used for identifying the Leyping spotted pigs. And when the genotypes of the to-be-detected sample at the SNP1-SNP6 sites are CC, TT, TT, AA, CC and GG respectively, the to-be-detected sample can be confirmed as a purebred individual of the Licping spotted pig. Compared with a traditional phenotype identification method, the molecular marker detection system established by the invention has the advantages of high detection efficiency, good accuracy and flux. The technical scheme provided by the invention provides important technical support for genetic resource conservation, variety purity identification and genetic improvement of the Leyping spotted pigs, and has remarkable application value in the field of livestock breeding.

The invention relates to the technical field of molecular markers and animal genetic breeding, in particular to an SNP marker influencing pig UMP content and application thereof. Whole genome re-sequencing and GWAS analysis are adopted, American-series purebred landrace pigs, American-series purebred large white pigs and American-series purebred duroc are used as research objects, seven SNP markers related to the pig UMP content are researched and determined, by optimizing dominant alleles of the SNP, the frequency of the dominant alleles can be increased generation by generation, the UMP content can be increased, and the pig UMP content can be improved. The pig genetic improvement progress is accelerated, so that the economic benefit of breeding pig breeding is effectively improved.

The invention relates to a breeding method of Lingnan pigeons, belongs to the field of poultry genetic breeding, and mainly solves the problems of low growth speed and low meat yield of meat pigeons. The method comprises the following steps: firstly, selecting purebred male Shiqi pigeons and purebred female mimassa pigeons to establish a basic group, and naturally mating according to a male-female ratio of 1: 1 to obtain F1-generation hybrid pigeons; measuring the growth performance index and the reproductive performance index of the F1 generation, calculating the breeding index through an index selection method, and selecting and remaining the first 50% of individuals; mating the selected F1-generation male and female pigeons according to a ratio of 1: 1 to obtain an F2-generation, collecting gene samples of the F1-generation male and female pigeons, carrying out whole genome sequencing, and screening out core genes CTNNB1 and MYO9A for regulating and controlling the growth speed and the meat yield; f2-generation individuals conforming to target traits are selected and reserved based on genotypes for cross-crossing fixation to form two-line hybrid pigeons; and finally, carrying out three-way hybridization on the two-line male pigeons as male parents and American king pigeons as female parents to obtain commercial generation Lingnan pigeons. According to the method, the growth performance, the meat yield and the stress resistance of commercial generation pigeons are remarkably improved through combination of multi-generation hybrid advantage integration and a molecular breeding technology.

The invention relates to an artificial cross breeding method of Jinlong hybrid spot new germplasm, which belongs to the technical field of aquatic product distant cross breeding, and comprises the following steps: (1) parent breeding; (2) collecting and storing sperms of epinephelus lanceolatus; (3) carrying out reproductive regulation and ovum acquisition on the epinephelus coioides; (4) artificial preparation and incubation of hybrid fertilized eggs; according to the method, the artificial cross breeding of the female epinephelus coioides and the male epinephelus lanceolatus is realized for the first time, and the new germplasm Jinlong hybrid spots of the epinephelus coioides, which grow fast and are high in survival rate, are cultivated. The body weight of the Jinlong hybrid Epinephelus coioides of 3 months old is increased by 46.45% compared with that of pure Epinephelus coioides; and the survival rate of the new germplasm is increased by 62.50% compared with that of the epinephelus coioides. The industrial problems that artificial spawning of large groupers is difficult, the survival rate of fries is low, and fast-growing new germplasm lacks are effectively solved.

The present application relates to the field of molecular markers and animal genetic breeding technology, and particularly relates to a SNP marker affecting pig purine base content and application thereof. Based on three test pig populations of American purebred Landrace, American purebred Large White and American purebred Duroc, the present application uses pig whole genome resequencing and GWAS analysis to research and determine 15 SNP markers significantly affecting pig purine base content. By selecting the advantageous alleles of the above SNP markers, the frequency of the advantageous alleles can be increased generation by generation, the corresponding purine content can be reduced or increased, the progress of pig genetic improvement can be accelerated, and the economic benefits of pig breeding can be effectively improved.

This invention belongs to the field of black pig breeding technology, specifically relating to a method for breeding large-sized, high-quality black pigs. The method involves crossing purebred Songliao black pigs with purebred Berkshire pigs to obtain F1 generation hybrid pigs. The F1 generation hybrid pigs are backcrossed twice with purebred Songliao black pigs to obtain B2 generation hybrid pigs. The B2 generation hybrid pigs are then crossbred to obtain a basic breeding herd of black pigs. This basic breeding herd is then subjected to closed breeding and successive selection for at least six generations to obtain large-sized, high-quality black pigs. The large-sized, high-quality black pigs of this invention have a Berkshire bloodline content of 12.5%, retaining the high fertility and excellent meat quality of Songliao black pigs, while effectively introducing the growth rate and intramuscular fat deposition advantages of Berkshire pigs. The large-sized, high-quality black pigs of this invention have all-black coats, reach 100kg at ≤175 days of age, have a live intramuscular fat content ≥3.5%, and a litter size ≥10.5 piglets, and can be self-breeding.

The invention provides a Taizhou goose germplasm analysis and identification method based on whole genome re-sequencing. The Taizhou goose germplasm analysis and identification method is used for accurately identifying and identifying different varieties of geese. Rapid identification and identity traceability of local goose germplasm are realized by constructing a local purebred goose germplasm reference library and combining with a lineage analysis and molecular identity card technology.

The invention relates to the technical field of molecular markers and animal genetic breeding, in particular to an SNP (Single Nucleotide Polymorphism) marker capable of influencing the content of IMP or GMP (Good Manufacturing Practice) of pigs and application of the SNP marker. According to the invention, based on three test swinery of American-series purebred landrace, American-series purebred large white pig and American-series purebred Duroc, pig whole genome re-sequencing and GWAS analysis are adopted, 15 SNP markers related to the content of IMP or GMP are researched and determined, and by optimizing the dominant alleles of the SNP, the frequency of the dominant alleles can be increased generation by generation, the content of IMP or GMP can be increased, and the number of SNP markers related to the content of IMP or GMP can be increased. The pig genetic improvement progress is accelerated, so that the economic benefit of breeding pig breeding is effectively improved.

The application discloses a kind of integrated hybrid information purebred genome prediction method, belong to animal genetic breeding and propagation technical field.The population genetic dataset comprising purebred population A, B and hybrid population CB is constructed, and the population genetic differentiation is verified by principal component analysis and genetic differentiation index;After the genotypes of purebred and hybrid population CB are phased, the ancestral information inference method is used to determine the origin information of each allele and process missing sites;Based on the origin information of allele, additive effect partial kinship correlation matrix and dominant effect partial kinship correlation matrix are constructed;The above matrix is integrated into three-trait mixed linear model, forming the prediction model that simultaneously incorporates purebred and hybrid population genetic information;The application distinguishes the breed origin of allele and quantifies its additive and dominant effect, significantly improves the prediction accuracy of purebred genome breeding value, is suitable for the traits difficult to directly determine in purebred population, and provides reliable technical support for animal breeding.

This invention discloses a method for accurately assessing the germplasm purity of Fujian oysters, comprising the following steps: Step 1, acquiring high-coverage whole-genome resequencing data of the oyster individual to be tested; Step 2, comparing the resequencing data with the Fujian oyster reference genome and identifying the nucleotide base types of the individual to be tested; Step 3, assigning a score to each specific single nucleotide polymorphism site and accumulating the scores of all sites to obtain a total score; Step 4, calculating the Fujian oyster germplasm purity value of the individual to be tested based on the total score. This invention utilizes high-coverage genome resequencing to screen for single nucleotide polymorphism sites throughout the Fujian oyster genome and compares them with the genome sequence of Pacific oyster to identify highly reliable Fujian oyster genome-specific nucleotide bases, constructing a purebred Fujian oyster genome sequence site set, and achieving efficient and accurate quantitative assessment of Fujian oyster germplasm purity by calculating the percentage of purebred sites in the Fujian oyster genome.

The invention belongs to the technical field of animal variety identification pharmacy, and provides an SNP site combination for accurately identifying the variety of Leiji cattle and an identification method thereof, the SNP site combination comprises six SNP sites named as SNP-1 to SNP-6 sites, and the mutation positions and genotypes of the six SNP sites are shown as follows: the mutation position of the SNP-1 site is 1321079068, and the genotype is C / C, C / T or T / T; the mutation position of the SNP-2 site is 2933934156, and the genotype is G / G, G / A or A / A; the mutation position of the SNP-3 site is 723603215, and the genotype is T / T, T / C or C / C; the mutation position of the SNP-4 site is 1177048289, and the genotype is A / A, A / G or G / G; the mutation position of the site SNP-5 is 2314770597, and the genotype of the site SNP-5 is T / T, T / C or C / C; the mutation position of the SNP-6 site is 167859165, and the genotype of the SNP-6 site is C / C, C / T or T / T. According to the invention, the six SNP sites are combined to establish the method for identifying the pure breed of the Leijia cattle, and the method is simple and convenient to operate and high in accuracy, and can effectively solve the problem of severe breed conservation situation of the Leijia cattle.

The invention discloses a molecular biological identification method for purebred Liancheng white ducks and application. According to a molecular marker, two types of ducks are distinguished by utilizing a combined haplotype of SNP1 and SNP2; the ID number of an NCBI database of a reference duck mitochondrial genome standard sequence is NC009684, the SNP1 is located at the 271bp position of the duck mitochondrial genome standard sequence and has TC polymorphism, and the SNP2 is located at the 296bp position of the duck mitochondrial genome standard sequence and has AG polymorphism; when the combined haplotype is CA, the duck is Liancheng white duck, and when the combined haplotype is TA or CG, the duck is Liancheng white duck containing foreign consanguinity hybrid. The molecular marker can quickly and accurately identify Liancheng white ducks and Liancheng white ducks containing foreign consanguinity hybrids, is simple to operate, easy to operate in laboratories and convenient to popularize and use in grassroots, and can generate considerable economic benefits and good social value.

This invention relates to the fields of molecular markers and animal genetic breeding technology, and particularly to a SNP marker affecting the total flavor nucleotide content in pigs and its application. Based on three experimental pig populations—purebred American Landrace, purebred American Large White, and purebred American Duroc—this invention employs whole-genome resequencing and GWAS analysis to study and identify nine SNP markers associated with total flavor nucleotides. By optimizing the dominant alleles of these SNPs, the frequency of dominant alleles can be increased generation by generation, thereby increasing the total flavor nucleotide content, improving pork quality, accelerating the progress of pig genetic improvement, and effectively improving the economic benefits of pig breeding.

The invention relates to the technical field of biology, in particular to a primer group for identifying Hangzhou pig breeds, a detection method and application. Four specific SNP molecular markers SNP1-SNP4 are obtained through whole genome screening, the upstream and downstream sequences of the molecular markers are shown as SEQ ID NO.1-4, four pairs of specific PCR primers are designed and developed based on the sites, and the primer group and the detection method are applied to the identification of Hangzhou pig breeds. The nucleotide sequence of the gene is as shown in SEQ ID NO.5-12. And when the genotypes of the to-be-detected sample at the SNP1-SNP4 sites are CC, CC, TT and CC respectively, determining that the to-be-detected sample is a Hangzhou pig purebred individual. Compared with a traditional phenotype identification method, the molecular marker detection system established by the invention has the advantages of high detection efficiency, good accuracy and flux. The technical scheme provided by the invention provides important technical support for germplasm resource protection, variety purity identification and genetic improvement of Hangzhou pigs, and has remarkable application value in the field of livestock breeding.

The present invention discloses a method for producing a pair of egg-laying green-shell Pu'an Panjiang black-bone chicken seed lines. The method introduces the bloodlines of red-feathered black-tailed chickens and Zhuxiang chickens on the basis of the bloodline of Pu'an Panjiang black-bone chickens, and adopts a three-line matching method to form a ZX×(PA×HH) combination, so that the commercial egg-laying green-shell Pu'an Panjiang black-bone chicken retains the "five blacks" Pu'an Panjiang black-bone chicken breed characteristics of "black feathers, black skin, black shanks, black crowns, and black meat" and the market weight. The production economic benefits are higher than those of green-shell eggs, and the egg production and egg weight are significantly improved, and the production performance is further improved. At the same time, the egg-laying green-shell Pu'an Panjiang black-bone chicken pairing obtained by the present invention has an ideal appearance, a medium body shape, a high egg production, a large egg weight, and produces green-shell eggs. The market age and market weight are similar to those of purebred Pu'an Panjiang black-bone chickens, and the egg production performance, egg weight, and eggshell color are all better than those of purebred Pu'an Panjiang black-bone chickens. It is suitable for promotion and application in the field of poultry breeding technology, especially the field of Pu'an Panjiang black-bone chicken breeding technology.

The present invention relates to a method for breeding high-quality Wagyu cattle, and belongs to the field of agricultural breeding technology. By naturalizing purebred Wagyu cattle, they are given better immunity and resistance, are less prone to illness, and achieve a better breeding state; and by combining different breeding methods for bulls, cows, and calves, and customized feeding methods, the taste of beef is unified to ensure quality. Tannins are encapsulated using encapsulating materials to improve the bitter taste of tannins. By controlling the light intensity and illumination time, reducing the light strobe, and combining medicated baths, massages, and fragrant environments, the stress caused by the environment to cattle is reduced, thereby increasing the food intake of cattle. The preparation of long-acting antibacterial agents can improve conditions such as depression caused by cattle living in cowsheds for a long time while inhibiting bacteria.

The application discloses a high-quality pig creating and breeding method, which comprises the following steps: 1) a certain blood structure of purebred Luchuan pigs is screened through molecular pedigree construction based on genome information, and the screened Luchuan pigs are used as female parents to cross with Duroc boars to generate Duroc-Luchuan crossbred pigs; 2) the Duroc-Luchuan crossbred pigs are used as female parents to cross with Barcshires boars to generate Bar-Duroc-Luchuan crossbred pigs; 3) the Bar-Duroc-Luchuan crossbred pigs are used as female parents to cross with Duroc boars to generate Duroc-Bar-Duroc-Luchuan crossbred pigs; 4) based on the Duroc-Bar-Duroc-Luchuan crossbred pigs, male and female pigs meeting the breeding target are selected according to a selection index to realize horizontal cross fixation, and an excellent horizontal cross offspring is selected to form a breeding core group; and 5) the core group in the step 4) is used as a zero generation group, a group succession breeding method is adopted, whole genome selection and genome prediction and the like are used to estimate a genome breeding value of breeding pigs and predict a phenotype, and precise intelligent breeding selection and matching are realized.

The application discloses a breeding method of a green-shell egg producing black-bone chicken with seven-features and yellow-feather and dual-purpose, which comprises the following steps: taking yellow-feather line Xuefeng black-bone chicken as a KH line material, and then performing subline pure line breeding to obtain yellow-feather male chickens as a first male parent; taking pure line yellow-feather Xuefeng black-bone chicken as an H line material, and then performing subline pure line breeding to obtain yellow-feather female chickens as a first female parent; performing cross breeding of the first male parent and the first female parent to obtain a terminal male parent F1; taking yellow-feather pure line green-shell egg producing Xuefeng black-bone chicken as a LH line material, and then performing subline pure line breeding to obtain yellow-feather green-shell egg producing female chickens as a terminal female parent; and performing cross breeding of the terminal male parent and the terminal female parent to obtain a commercial generation green-shell egg producing black-bone chicken with seven-features and yellow-feather and dual-purpose. The black-bone chicken obtained by the breeding method has the basic features, flavor and nutritional value of the local pure breed Xuefeng black-bone chicken, can produce green-shell eggs, has a high egg production rate, has a fast growth speed, has good meat performance, has a high survival rate, and the like.

The invention relates to an artificial cultivation method of low-temperature-resistant Yunjin hybrid spots, and the method belongs to the technical field of aquatic product distant hybridization breeding, and the method comprises the following steps: (1) low-temperature-resistant grouper group breeding and grouper blue-body group breeding; (2) collecting and storing sperms of epinephelus coioides; (3) epinephelus moara reproduction regulation and ovum acquisition; (4) artificial preparation and incubation of hybrid fertilized eggs; compared with the prior art, the fertilization rate of the bred fries is increased by 2.91%, the hatching rate is increased by 9.58%, and the malformation rate is reduced by 11.33%. The survival rate of hybrid seeds is increased by 69.56% compared with that of purebred epinephelus moara, the low-temperature semi-lethal tolerance temperature of new germplasm seeds is 5.8 DEG C, meanwhile, 'Yunjin hybrid spots' have better hybrid growth advantages, and the weight of 7-month-old seeds is increased by 79.72% compared with that of female parent epinephelus moara; compared with that before breeding, the weight gain rate of the hybrid at the same time is increased by 23.20% compared with that of the female parent epinephelus moara.

The invention relates to the technical field of genome information analysis, in particular to a local pig optimal heterosis prediction method based on genome information. According to the method, pure parents with clear genetic backgrounds are accurately identified and screened out by utilizing high-density SNP marker information covering a whole genome, a reference population is constructed, large-scale hybridization propagation is simulated, structured virtual population data is formed, and multi-character phenotype data of filial generations are standardized and weighted, so that the genetic backgrounds of the filial generations are optimized, and the genetic backgrounds of the filial generations are optimized. The method comprises the following steps of: dividing a plurality of characteristic groups such as a production performance type and a reproductive performance type, and analyzing the correlation between phenotypic deviation and genotype in each group, so as to separate and quantify dominant effect caused by heterozygous genotype and recessive effect caused by homozygous genotype, construct explicit and recessive weight parameters, and determine the genetic relationship between the dominant effect and the recessive effect; finally, the non-additive effect parameters are superposed to a traditional additive breeding value model, direct quantitative prediction of heterosis is achieved, and therefore the accuracy and efficiency of hybrid combination matching are greatly improved.

This invention relates to the fields of molecular markers and animal genetic breeding technology, and particularly to a SNP marker that affects porcine inosine content and its application. Based on purebred American Landrace, purebred American Large White, and purebred American Duroc pigs, this invention studies and identifies 10 SNP molecular markers closely related to porcine inosine content. By optimizing the dominant alleles of these SNPs, the frequency of dominant alleles can be increased generation by generation, reducing inosine content, accelerating the progress of pig genetic improvement, and thus effectively improving the economic benefits of pig breeding.

The invention provides a method for identifying a peacock eye color character genotype, namely a method for quickly performing genetic typing on the peacock eye color character based on PCR (Polymerase Chain Reaction) and Sanger sequencing technologies. The invention provides two groups of primers (a primer combination I: SEQ ID NO: 1-3 and a primer combination II: SEQ ID NO: 4-5) based on two eye color character variation sites on an OCA2 gene and a TYR gene of the peacock fish respectively, and the two groups of primers are used for detecting and identifying the genotypes of the two variation sites respectively. According to the method, the genotype of the eye color character of the peacock can be quickly identified without test cross, and pure breeding of the peacock with different eye colors is realized. In practical application, the method is simple and convenient to operate and high in accuracy.

The invention relates to the technical field of molecular markers and animal genetic breeding, in particular to an SNP (Single Nucleotide Polymorphism) marker influencing the pig AMP (Adenosine monophosphate) content and application thereof. On the basis of three test swinery of American-series purebred landrace pigs, American-series purebred large white pigs and American-series purebred Duroc, pig whole genome re-sequencing and GWAS analysis research are adopted, 14 SNP molecular markers remarkably related to the AMP content are determined, dominant alleles of the SNP are optimized, the frequency of the dominant alleles can be increased generation by generation, the AMP content can be increased, the number of the SNP molecular markers is increased, and the number of the SNP molecular markers is increased. The pig genetic improvement progress is accelerated, so that the economic benefit of breeding pig breeding is effectively improved.

The invention relates to the technical field of molecular markers and animal genetic breeding, in particular to an SNP (Single Nucleotide Polymorphism) marker capable of influencing the content of porcine purine bases and application of the SNP marker. According to the invention, based on three test swinery of American-series purebred landrace, American-series purebred large white pig and American-series purebred Duroc, pig whole genome re-sequencing and GWAS analysis are adopted, 15 SNP markers which significantly influence the content of pig purine bases are researched and determined, and by optimizing the dominant alleles of the SNP markers, the frequency of the dominant alleles can be increased generation by generation, and the number of the dominant alleles can be increased. The corresponding purine content is reduced or increased, and the genetic improvement progress of pigs is accelerated, so that the economic benefit of breeding of boars is effectively improved.

The invention discloses a computer device and method for predicting animal sample ancestor bloodline and variety purity and application. Characteristic SNP marker sites for predicting pig varieties are obtained from local pig varieties through screening, a prediction model for predicting the varieties of to-be-detected pigs is constructed by using a machine algorithm on the basis of the sites, whether the to-be-detected pigs belong to known pig varieties or not can be predicted through the model, and for pigs predicted to belong to unknown varieties, the method has the advantages that the prediction accuracy is high, and the prediction cost is low. According to the method, a hybrid population data set and an unknown variety data set are constructed, and a classifier model for predicting whether an unknown variety pig belongs to an out-of-library variety or a hybrid individual is obtained through training. According to the method disclosed by the invention, the correlativity between different markers is considered, and the purebred and bloodline mixing of the animal to be detected can be accurately judged by using the computer device and the method disclosed by the invention.

The invention discloses a pure genome prediction method integrating hybridization information, and belongs to the technical field of animal genetic breeding and reproduction. Constructing a population genetic data set containing purebred populations A and B and a hybrid population CB, and verifying population genetic differentiation through principal component analysis and genetic differentiation indexes; carrying out phasing treatment on genotypes of the purebred and hybrid populations CB, determining origin information of each allele by adopting an ancestral information inference method, and processing deletion sites; constructing an additive effect partial genetic correlation matrix and a dominant effect partial genetic correlation matrix based on allele origin information; integrating the matrix into a three-character mixed linear model to form a prediction model simultaneously incorporating genetic information of purebred and hybrid populations; by distinguishing variety origins of allelic genes and quantifying additive and dominant effects of the allelic genes, prediction accuracy of the breeding value of the purebred genome is remarkably improved, the method is suitable for characters which are difficult to directly measure in purebred populations, and reliable technical support is provided for animal breeding.

The present invention relates to the technical field of pig breeding, and specifically discloses a reverse hybridization breeding method for pigs, comprising the following steps: constructing a synthetic maternal S line: performing multivariate hybridization and breeding with two or more breeds such as Landrace, Large White, Duroc or local breeds to fix favorable genes; hybridizing S line sows with Landrace boars to obtain the F1 generation SL line; hybridizing SL line sows with Large White boars to obtain the parent generation SLY line. The present invention completely overturns the traditional hybridization and matching hybridization methods, can avoid the degeneration of pure breeding, and is the world's first hybridization breeding method without purebred sows, saving more than 15 billion in purebred costs nationwide. The various performances of sows are synergistically improved, the cost of commercial pigs is reduced by 100 yuan per head, and the meat quality is better. Pig farms do not need to introduce live sows, but only need to introduce boar semen to breed high-quality breeding pigs, which is very beneficial for the prevention and control of African swine fever and can easily solve the problem of blue ear and ring disease. Disease-resistant breeding is the trend in the future, and it is convenient to transmit disease-resistant genes through boars.

The invention relates to the technical field of medicinal breeding of special insects, in particular to a method for ecologically and cyclically domesticating high-quality maggot and a domesticated population thereof, and the method comprises the following steps: seed source acquisition and identification: acquiring chrysomyia megacephala adults, performing purebred identification and health detection, and pre-screening an initial seed source; hatching eggs of the obtained provenance in an artificial environment, feeding larvae of 1-3 years old, applying primary environmental stress, and screening individuals; putting imagoes into the natural environment after emergence of the individuals, and recovering spawning blocks; the recovered egg masses are hatched and fed with larvae of 1-3 years old, composite environmental stress is applied, and individuals with tolerance reaching the standard are screened out; after the individuals emerge adults, putting the adults into a complex natural environment, and recovering the spawn blocks; the recovered egg masses are hatched and fed with larvae of 1-3 years old, ultimate environmental stress is applied, and domesticated populations with solidified characters are obtained through screening. Through three-generation directional domestication, artificial stress, natural energizing and fresh fish waste utilization, the effects of pure maggot variety, strong stress resistance, high activity and stable breeding are achieved.

The invention relates to a method for increasing the daytime delivery ratio of purebred sows, which comprises the following steps of: 1, injecting 2mL of (+)-cloprostenol sodium injection into each sow at 8 a.m. in the morning before the expected delivery period of the purebred sows; step 2, injecting 1mL of carbetocin injection at 8 a.m. on the same day of the expected date of confinement of the purebred sows to promote the purebred sows to deliver in the daytime. The (+)-cloprostenol sodium injection is injected one day before the expected date of confinement of the purebred sow, so that the cervix uteri and the birth canal of the sow can be softened, the cervix uteri and the birth canal can be loosened and opened, and delivery can be started conveniently; the carbetocin injection is injected on the day of the expected delivery period of the purebred sows, the delivery process and the farrowing interval are shortened, the occurrence of postpartum hysteritis of the sows is reduced, and concentrated delivery is achieved.