188results about How to "High protection rate" patented technology

The invention relates to a method for preparing a duck virus hepatitis divalent refined egg yolk antibody. The method is that vaccines of a duck virus hepatitis virus 1 type YBH1 strain and novel YBHX strain with good immunogenicity are selected from duck virus hepatitis superior prevalent strains to prepare strains, the strains are respectively inoculated to a chicken embryo and a duck embryo, a dead embryo body and the embryo juice are respectively obtained, the virus liquid is collected after grinding and freeze thawing, ultrafiltration concentration and inactivation with formaldehyde solution are carried out, and oil adjuvant is added to mix and emulsify to produce the vaccine. The vaccine is inoculated to a laying hen, the egg with high immunity is obtained, the yolk is separated, inactivated, extracted and refined to produce the duck virus hepatitis divalent refined egg yolk antibody which can prevent the duck virus hepatitis which is caused by the 1 type and novel duck hepatitis viruses, so the egg yolk has the advantages of high efficiency, good safety, high protection ratio and the like.

The invention discloses methods for preparing a duck virus hepatitis strain and an inactivated vaccine. The strain is obtained with the method comprising the following steps of: collecting duck hepatitis material with obvious pathological changes in a duck farm where duck virus hepatitis prevails, washing with bi-anti-sterilization PBS, diluting and grinding, freeze thawing twice and performing centrifugal separation; diluting virus separated by sterilization PBS, vaccinating chick embryo, selecting chick embryo with classic pathological changes that is dead 48-96h after vaccination, respectively gaining chick embryo liquid, transferring for 18-25 generations continuously to obtain a duck virus hepatitis virus chick embryo suitable strain. The strain can be in production, vaccinated in the chick embryo to gain chick embryo liquid, and is emulsified after vaccination to prepare the inactivated vaccine. The inactivated vaccine is high in safety, has good immune efficacy to young ducks, long immune time for breeding ducks and high level of antibody of breeding ducks, and the young ducks bred by the breeding ducks can resist duck virus hepatitis strains.

The invention provides a method and a device of realizing a backup route. The method comprises the steps that a first node uses the Remote LFA technology to calculate a PQ node after calculating a main route from the current node to a second node; if the PQ node is calculated, the first node adds a route table entry corresponding to the backup route in a route forwarding table, wherein the route table entry comprises a node segment label of the second node, an outlet port and a corresponding label stack, wherein the outlet port is a port used for connecting a backup next hop node on the current node, and the label stack comprises a node segment label of the PQ node and the node segment label of the second node; and when it is detected that a link between the current node and a main next hop node is disconnected, the first node compresses the label stack in the route table entry in a user message to be sent to the second node according to the route table entry corresponding to the backup route to acquire a package message, and forwards the package message through the outlet port in the route table entry.

The invention provides a preparation method of I-type duck hepatitis refined yolk antibodies. The preparation method comprises following steps: I-type duck hepatitis virus hyper-immune egg yolk is collected, is subjected to primary inactivation, is subjected to primary acidification extraction with an acetate buffer solution, and then is subjected to secondary inactivation taking octanoic acid as the inactivator and extraction agent; filtering clarification, filtering sterilization, and ultrafiltration concentration are carried out; and then formaldehyde is used for a third time of inactivation so as to obtain a yolk antibody solution. According to the preparation method, content of lipid in the finished product is reduced effectively via acidification water-octanoic acid method, occurrence rate of adverse reaction is reduced, the step of ultrafiltration concentration is beneficial for ensuring product antibody concentration, and increasing protection rate, in application, dilution ratio of the finished product is relatively high because of the high antibody concentration, so that impurity content is reduced indirectly, and safety is improved.

The invention discloses an egg yolk antibody for preventing novel goose astrovirus and a preparation method thereof. The egg yolk antibody contains a goose astrovirus strain resistance antibody; the preservation number of the goose astrovirus strain is CCTCC NO:V201808. The prepared egg yolk antibody is good in safety, and no any partial or whole adverse reaction is caused by the egg yolk antibody; infections caused by novel goose astrovirus can be effectively prevented and / or treated, and the good commercialization development prospect is achieved.

The invention discloses a preparation method of a complex live vaccine for porcine reproductive and respiratory syndrome, belonging to the technical field of veterinary biological products. The preparation method comprises the following steps: (1) culturing master cells; (2) performing suspension culture on vaccine preparation cells; (3) culturing and harvesting viruses; (4) performing mixed adsorption on the harvested full-suspension virus solution and chicken anti-porcine reproductive and respiratory syndrome virus egg yolk antibody; (5) adding the adsorbed antigen-antibody compound into an immunoenhancer-containing freeze-drying protecting agent, sub-packaging and then performing freeze vacuum drying to prepare the complex live vaccine for the porcine reproductive and respiratory syndrome. The method is used for preparing the vaccine, and has the characteristics that the production period can be shortened, the personnel allocation is reduced, the pollution probability is low, the floor area is small, the virus titer is high, the difference between the prepared vaccine batches is small, the product has stable and high-efficiency quality, the side effect is small and the quality of the vaccine can be completely improved.

The invention discloses a traditional Chinese medicine for treating bacterial diseases in poultry, which is prepared from the following raw materials in parts by weight: 10-15 parts of wild chrysanthemum flower, 5-10 parts of Chinese goldthread, 8-10 parts of Scutellaria baicalensis, 8-10 parts of golden cypress, 10-15 parts of Chinese thorowax, 10-12 parts of Cape jasmine, 20-25 parts of Fagopyrum cymosum root, 25-30 parts of common andrographis herb, 8-10 parts of burdock, 25-30 parts of Chinese pulsatilla root and 30-35 parts of folium artemisiae argyi. The traditional Chinese medicine for treating the bacterial diseases in the poultry, disclosed by the invention, has the effects of preventing and treating the bacterial diseases caused by colibacillosis, salmonellosis, necrotizing enterocolitis, enterovirus syndromes, cholera fowls and the like in the poultry.

The invention provides a pig pseudorabies virus and the application of the pig pseudorabies virus. The preservation number of the pig pseudorabies virus is CGMCC No.10266. The selected pig pseudorabies virus has the characteristics of high safety and high protection rate. A pig pseudorabies virus PRV-QD strain is inoculated with a Vero cell to form cell venom, the DNA (deoxyribonucleic acid) of the strain is extracted, the separated strain is subjected to deletions of virulence gene TK, gE and gI gene by a genetic engineering method, the virus is propagated after cell retrieval, and after a protecting agent is added into the virus, a vaccine is formed. The protection rate of the manufactured bacterin to piglets is 100 percent, the efficiency is obviously more excellent than that of a Bartha-K61 group (20 percent), and the vaccine has the advantages of high efficiency and high safety.

The invention relates to a disinfectant for a pond water body, comprising the following components in parts by weight: 10-100 parts of potassium ferrate, 100-300 parts of polymeric aluminium, 200-500 parts of polymeric ferric sulphate and 100-700 parts of clinoptilolite. Ferrate used in the invention is taken as a non-chlorine water treatment agent, bacteria, viruses and algaes in water can be rapidly killed, organic matters, inorganic matters and heavy metal ions in the water also can be removed, and the effects of disinfection, decolourization, deodorization and coagulation assistant can be realized. The disinfectant for the pond water body disclosed by the invention has reasonable components and low cost, is simple to prepare and is convenient to use, development and application curative effects are assured, toxic and side effects are small, and application range is wide.

The invention belongs to the technical field of biology, and in particular relates to a protective agent for vacuum freeze drying of lactobacillus johnsonii, and application thereof. The protective agent provided by the invention contains no sorbitol substances, has lower cost, can provide effective protection for lactobacillus johnsonii in a vacuum freeze drying process, and is favorable to improvement of the utilization efficiency of a lactobacillus microbial feed additive, the protective rate of the protective agent is high, and the yield of produced live bacteria is above 109.

The invention discloses recombinant porcine reproductive and respiratory syndrome virus (PRRSV) virus-like particles (VLP) and a preparation method and an application thereof. Based on comparative analysis of GP5 of a PRRSV epidemic strain and an M gene sequence, a GP5 and M tandem sequence GP5M is synthesized artificially, the synthesized GP5M gene sequence is cloned into a vector with a pBAC5 plasmid as a skeleton, the baculovirus transfer vector pBAC-PRRSVGP5M is obtained, the recombinant bacmid rBacmid-GP5M is obtained, sf9 cells are transfected with the bacmid, and the recombinant baculovirus Ac-PRRSVGP5M is obtained. The PRRSV GP5 and M protein are expressed efficiently by the recombinant baculovirus, and the virus-like particles are formed. A subunit vaccine prepared by the proteinexpressed by the recombinant baculovirus can induce a body to produce a specific immune response after immunizing animals and can protect the pig body against the strong poison attacking of porcine reproductive and respiratory syndrome virus.

The invention aims to provide an egg yolk antibody for preventing and curing muscovy duck parvovirus diseases, and the egg yolk antibody is prepared by using muscovy duck parvoviruses the preserving number of which is CGMCC (China General Microbiological Culture Collection Center) No.8504 as an antigen. The egg yolk antibody is characterized in that a muscovy duck parvoviruse YBMDP plant is inoculated with a muscovy duck embryo, a die embryo body and embryo liquid are respectively obtained and are grinded and are subjected to freeze thawing so as to obtain a virus solution, and the oil adjuvant mixing emulsification is added in the virus solution after ultrafiltration concentration and formaldehyde solution inactivation so as to obtain a vaccine. The vaccine is utilized to inoculate a laying hen, eggs are obtained, yolks are separated, and the antibody is obtained after inactivation and extraction and rectification. The prepared antibody can prevent ducklings from the parvovirus infection because of muscovy duck parvoviruses, and the egg yolk antibody has the advantages of high efficiency, good safety, high protection rate and the like.

The invention relates to a method for producing avian adenovirus inactivated vaccine through an LMH clone line. The method comprises the following steps: firstly, preparation continuous cell line LMH cell; secondly, virus-seed reproduction; thirdly, virus collection, concentration and purification; fourthly, virus content determination; fifthly, inactivation and emulsification of virus, and forming emulsion inactivated vaccine. Compared with the traditional technical method for producing avian adenovirus through cell culture, the method has the advantages that high-quality inactivated vaccine with higher antigen titer through the optimization of the concentration of digestive LMH cell pancreatin-EDTA, the culture time of LMH cell and the inoculation concentration and harvest time of virus, injection immunization is performed at different doses, and all the vaccine protection rates reach 100 percent, so that the immune efficiency of the avian adenovirus type IV inactivated vaccine produced through the method is high, and the vaccine has complete immune protection effect on avian adenovirus type IV.

The invention discloses a fusion gene of mycoplasma hyopneumoniae and a preparation method of the fusion gene, and belongs to the field of genetic engineering technology. P46 and P65 genes adopted in the invention can directly design specific primers containing corresponding restriction sites according to a coding region sequence released in NCBI GeneBank. A PCR product of the P46 gene is subject to double enzyme digestion and connection with a prokaryotic expression vector pET-28a, so as to construct a recombinant expression vector pET-28a-P46; and the recombinant expression vector pET-28a-P46 is subject to double enzyme digestion and connection with a PCR product of the P65 gene, so as to directly construct a recombinant expression vector pET-28a-P46-P65. The fusion gene and the preparation method have the following advantages: instead of Linker connection, the P46 and P65 genes are directly subject to double enzyme digestion connection so as to prepare the recombinant expression vector pET-28a-P46-P65; and compared with a process of connecting genes by virtue of Linker and then connecting to a prokaryotic expression vector, the recombinant vector construction process is simple and is easy to prepare the recombinant expression vector, and consumed time is significantly shortened.

The invention provides a preparation method of a goose parvovims and muscovy duckling parvovirus bivalent egg yolk antibody. According to the technical scheme, an inactivated vaccine prepared from a goose parvovims GPV-HB strain and a market sold goose parvovims live vaccine are jointly used as a goose parvovims antigen; an inactivated vaccine prepared from muscovy duckling parvovirus MDPV-FJ strains is singly used as a muscovy duckling parvovirus antigen; the immune is totally performed for three times; the basic immune of the goose parvovims live vaccine and the self-made goose parvovims inactivated vaccine is performed once; the reinforced immune is performed twice; the interval between every two times is three weeks; the dose is 1ml / individual for each kind of vaccine in each time; theimmune times and the interval of the muscovy duckling parvovirus are identical to those of the goose parvovims, but the immune time is delayed for one week through being compared with that of the goose parvovims; the immune dose is 1ml / individual. Through the antigen and the immune measures, the valence of two antibodies in high-immunity eggs can reach the relatively high level. The egg yolk antibody prepared by the method provided by the invention can realize the simultaneous prevention and treatment on goose parvovims and muscovy duckling parvovirus diseases; the protection rate is very high.

The invention provides an egg yolk antibody used for preventing and treating Muscovy duck source gosling plague. The egg yolk antibody is prepared with a Muscovy duck source gosling plague virus with the preservation serial number of CCTCC NO: V201620 as an antigen. Muscovy duck embryos are inoculated with the Muscovy duck source gosling plague virus strain YBGPV-M, idiosome and blastochyle of dead embryos are obtained respectively, virus liquid is obtained after grinding and freeze thawing, an oil adjuvant is added for mixing emulsification after ultrafiltration concentration and formaldehyde solution inactivation, and a vaccine is obtained; laying hens are inoculated with the vaccine, eggs are obtained, yolks are separated, inactivation, extraction and refining are carried out, and the antibody is obtained. The prepared antibody can prevent young Muscovy duck gosling plague virus infection caused by the gosling plague virus; the egg yolk antibody has the advantages of being efficient, good in safety, high in protection rate and the like.

The invention discloses a soft-shelled turtle systemic septicemia spherical virus inactivated vaccine and its preparation method, and is characterized in that the vaccine contains the inactivated soft-shelled turtle systemic septicemia spherical virus with the collection number being CGMCCNo.5378. The preparation method comprises the following steps of: cutting internal organ of sick soft-shelledturtles into pieces, adding into a TNE buffer, centrifuging, taking a supernatant, centrifuging, taking a white precipitate, suspending in the TNE buffer, centrifuging the precipitate, taking the supernatant, and centrifuging to obtain a white precipitate, namely the purified virus; diluting the purified virus by the use of aseptic normal saline until the final concentration of viral protein reaches 0.5-1mg / ml, and adding 0.5% (final volume) of formalin for inactivation in a thermostat water bath cauldron; and completely emulsifying inactivated virus and a complete Freund's adjuvant accordingto the volume ratio of 1:1 to obtain the inactivated vaccine. The soft-shelled turtle systemic septicemia spherical virus inactivated vaccine proposed for the first time is safe and effective and hasstrong immunity, and the preparation method is simple and easy to operate.

The invention discloses an infectious bursal disease antigen-antibody complex as well as a preparation and a preparation method thereof. The preparation method of the antigen-antibody complex comprises the following steps of: (1) preparing a VP2 protein as an antigen; (2) preparing an egg yolk antibody from an infectious bursal disease virus inactivated vaccine as an antibody; and (3) mixing the antigen and the antibody according to the prescription proportion, and performing sterilization treatment. The antigen-antibody complex preparation mainly refers to a common liquid preparation, an oil emulsion and a solid preparation prepared from the infectious bursal disease antigen-antibody complex. The antigen-antibody complex disclosed by the invention has the characteristics of stable performance, good safety, fast immunization effect after animal immunization, strong immunity and high protection rate; and the prepared complex preparation is simple and quick to prepare and safe and convenient to use.

The invention relates to an escherichia coli (E. coli) trivalent enterotoxin fusion gene and application thereof, and belongs to the field of genetic engineering subunit vaccines. The enterotoxigenic E. coli (ETEC) is a main pathogen causing baby-animal and infantile diarrhea. Aiming at the defects that the conventional TEC vaccine has narrow protection range and cannot induce high-level antitoxin, the invention designs a trivalent E. coli enterotoxin fusion with the fusion mode of 5'-STa-LT-STb-3' or 5'-STb-LT-STa-3'. After the multivalent enterotoxin gene or protein immunizes animals, high-level STa, STb and LT resistant antibodies can be induced to be generated. Therefore, the escherichia coli (E. coli) trivalent enterotoxin fusion gene can neutralize the toxicity of a key pathogenic factor enterotoxin, improve the immunity protection rate and widen the protection range without being limited by E. coli pilus types so as to effectively control ETEC diarrhea.

The invention discloses a preparation method of an immune-enhanced recombinant PRRSV virus-like particle subunit vaccine. The subunit vaccine is prepared from PRRSV virus-like particles and compound immunological adjuvants. By a genetic engineering means, a PRRSV GP5-M gene is modified, and PRRSV virus-like particles with high immunogenicity are prepared by constructing a rhabdovirus expression vector. In addition, by improving the immunological adjuvants, the immuno-enhanced recombinant PRRSV virus-like particle subunit vaccine is obtained, and the subunit vaccine has better immunization effects.

The invention provides a PEDV (porcine epidemic diarrhea virus), an inactivated vaccine and a preparation method of the inactivated vaccine and belongs to the field of bioengineering. The collection registration number of a PEDV NJ strain is CGMCC NO.13283. The invention provides an application of the virus strain in preparation of a PED vaccine, a preparation method of a virus solution of the virus strain as well as the obtained virus solution and the inactivated vaccine. The preparation method of the inactivated vaccine comprises steps as follows: the inactivated virus solution and tween-80 in the volume ratio being 96:4 are mixed uniformly, and a water phase is obtained; white oil for injection and span-80 are mixed uniformly in the volume ratio being 96:4 and an oil phase is obtained; the water phase and the oil phase are mixed in the volume ratio being 1:(2-3) and then emulsified. The NJ strain is a recent prevalent virus, has good immunogenicity, adapts to cell culture and can be subjected to large-scale fermenting culture, and pregnant sows inoculated with the inactivated vaccine of the virus strain can effectively protect newly-born suckling pigs during toxicity attacking by the recent prevalent virus.

The invention relates to the field of molecular biology and immunology and particularly discloses an Edwardsiella tarda recombinant subunit vaccine as well as a preparation method and application thereof. The vaccine has a base sequence in a sequence table SEQ ID No.1. The preparation method of the Edwardsiella tarda recombinant subunit vaccine comprises the following steps of constructing a vaccine antigen expression plasmid pETXV21, converting the vaccine antigen expression plasmid pETXV21 into escherichia coli BL21 (DE3), recovering a recombinant protein after induced expression, mixing the recombinant protein with a strain B187, and dissolving the mixture in PBS (Phosphate Buffer Saline) to obtain a vaccine mixed liquor which has the function of immune protection to Edwardsiella tarda. The vaccine mixed liquor is intraperitoneally injected to fishes to achieve the purpose of immune protection.

The invention provides a preparation method of a duck type 2 adenovirus inactivated vaccine. According to the technical scheme, duck adenovirus is proliferated by utilizing chicken liver cancer cells;after the duck adenovirus is inactivated, gamma-interferon is added; an imported white oil adjuvant is utilized to prepare the safe and effective duck type 2 adenovirus inactivated vaccine. The ducktype 2 adenovirus inactivated vaccine prepared by the preparation method has good safety, can be used for stimulating organisms to generate antibodies earlier and has a high protection rate. The vaccine provided by the invention can be used for effectively ensuring immunogenicity; the defect that the vaccine is lacked in the prior art is overcome; meanwhile, the duck type 2 adenovirus inactivatedvaccine can have an exact effect on prevention of the duck type 2 adenovirus.

The invention provides a traditional Chinese medicine formula capable of improving animal immunity. The traditional Chinese medicine formula is prepared from, by weight, 25 parts of radix astragali, 25 parts of radix angelicae sinensis, 12.5 parts of herba epimedii, 25 parts of radix isatidis, and 12.5 parts of licorice. The invention also provides a preparation method of the traditional Chinese medicine formula. The preparation method comprises following steps: the ingredients are weighed at the above weight ratio, and are smashed using a pulverizer respectively; obtained powder products are sieved using a sieve of 150 meshes, and are mixed using a V-type mixer for 15min; and then an obtained product is subjected to subpackage, and is sealed. The traditional Chinese medicine formula is capable of repairing immune system and improving body immunity, releasing immunosuppression, improving immune effect, reducing medicine dosage, and extending drug application range, and is suitable to be applied to chicken, pigs, horses, cattle, sheep, ducks, geese, and rabbits.

A process for preparing the vaccine of chicken coccidiosis includes such steps as separating the oogonia from chicken coccidian, culturing in the solution of potassium bichromate until more than 90% of oogonia become spores, storing in refrigerator at 4 deg.C, adding distilled water, centrifugal removal of potassium bichromate solution, counting, ice bath, and ultrasonic weakening.

The invention discloses an egg yolk antibody for preventing and treating novel duck reoviruses and a preparation method of the egg yolk antibody. The egg yolk antibody comprises an anti-duck reoviru strain antibody, and a duck reoviru strain has a preservation number of CCTCC NO: V201818. The egg yolk antibody disclosed by the invention is good in safety, free of partial or whole-body adverse reaction caused by the egg yolk antibody, is capable of effectively preventing and / or treating infection of the novel duck reoviruses, and has a very good commercial development prospect.

The invention relates to a traditional Chinese medicinal composition used as both food and medicine for treating porcine respiratory tract infection, and a preparation method thereof. The medicinal composition comprises, by weight, 100 to 120 parts of cordate houttuynia, 40 to 60 parts of pyrrosia leaf, 40 to 60 parts of perilla fruit, 120 to 140 parts of gypsum, 40 to 60 parts of white mustard seed, 15 to 35 parts of licorice, 40 to 60 parts of aster, 40 to 60 parts of radix stemonae, 40 to 60 parts of platycodon grandiflorum, 100 to 120 parts of semen raphani, and 15 to 35 parts of herba ephedrae. All the above raw materials are prepared according to the weight proportion, and ground into fine powder to be mixed in pig feed to feed pigs. The traditional Chinese medicinal composition provided by the invention mainly cures diseases with the main symptoms of cough and asthma caused by porcine respiratory tract infection, has the advantages of fast curative effect, short course of treatment, no recurrence, and no toxic side effect, and the total effective rate is more than 99%.

The invention discloses an intramolecular adjuvant-containing recombinant gene for preventing and treating helicobacter pylori, protein and a biological product. the multi-target recombinant gene comprises a multi-target fusion polypeptide having an amino acid sequence shown in a SEQ ID NO:2, a multi-target recombinant gene for coding the multi-target fusion polypeptide having the nucleotide sequence shown in a SEQ ID NO:2, and invention also has an application of a specific antibody of the above multi-target recombinant gene or the above multi-target fusion polypeptide or the multi-target fusion polypeptide as the biological product for preventing and treating helicobacter pylori infection. According to the invention, an intramolecular adjuvant CTB for removing signal peptide is added at N segment of a recombinant helicobacter pylori multi-target fusion polypeptide (rIB), so that prevention and treatment effect for the helicobacter pylori infection can be increased.

The invention discloses an immune-enhanced recombinant PRRSV (Porcine Reproductive and Respiratory Syndrome Virus)-like particle subunit vaccine. The immune-enhanced recombinant PRRSV virus-like particle subunit vaccine consists of PRRSV-like particles and a compound immunologic adjuvant. The immune-enhanced recombinant PRRSV-like particle subunit vaccine disclosed by the invention has the beneficial effects that by the means of gene engineering, PRRSV GP5-M gene is modified, and the PRRSV-like particles with high immunogenicity are prepared by constructing rhabdovirus expression vectors. In addition, by improvement on the immunologic adjuvant, the immune-enhanced recombinant PRRSV-like particle subunit vaccine is obtained and the subunit vaccine has a better immune effect.

The invention relates to a Chinese herbal medicine additive for promoting growth of laying hens and improving egg quality and a feeding method thereof. The additive is prepared from the following Chinese herbal medicines in parts by weight of 2-4 parts of radix astragali, 1.5-3.5 parts of poria cocos, 1-3 parts of radix isatidis, 1-3 parts of radix codcnopsitis pilosulas, 1-2.5 parts of radix glycyrrhizae, 2-4 parts of fructus crataegi, 3-5 parts of rhizoma dioscoreae, 3-5 parts of fructus hordei germinatus, 1-2 parts of massa medicata fermentata, 1-2 parts of agastache rugosus, 1-2 parts of pericarpium citri reticulatae and 1-2.5 parts of herba ephedrae. Various Chinese herbal medicines are ground and sieved, and the sieved materials are mixed to obtain a mixture, namely the Chinese herbal medicine additive. 2 kg of the additive is added into every 100 kg of chicken compound feed according to the weight ratio to obtain chicken feed. 10-36 g of the chicken feed is used for feeding eachbrooding chicken every day, 40-80 g of the chicken feed is used for feeding each growing chicken every day, and 85-120 g of the chicken feed is used for feeding each laying hen every day. The additive has the characteristics of strong safety, small toxic and side effects and low residue, avoids tolerance of livestock and poultry to the additive, and basically realizes antibiotic-free breeding.