The application of genome selection technology will improve the production level of breeding pigs

Novel coronavirus pneumonia and

new crowned pneumonia have overlaid the epidemic situation, resulting in a decline in the number of core groups of boars. The performance of some pig breeding enterprises has been reduced, genetic exchanges have been reduced, and the production level of pig has decreased, which has a serious impact on the resumption of pig production in China. In order to overcome the impact of the epidemic and speed up the recovery of the number and quality of breeding pigs, the innovation of breeding technology and mechanism is imminent. < / P > < p > in 2017, the leading group office of the national pig genetic improvement program launched the national pig genome selection work, with the participation of 7 scientific research institutions and more than 30 national pig core breeding farms. At present, genomic selection technology is still in the initial stage of application in China, but it has gradually gained the attention of breeding enterprises. As one of the first batch of national pig breeding centers, Wenshi has been in the forefront of domestic counterparts in the application of pig genome-wide selection technology. It has the characteristics of short generation interval and high efficiency of genetic selection. This technology not only improves the accuracy of individual selection, but also makes up for some shortcomings of conventional breeding. At present, the reference populations of Duroc, Landrace and Dabai have been preliminarily constructed, and the genetic evaluation platform of pig genome selection has been built, which has the basis for comprehensively promoting the application of pig genome selection technology. The implementation of genome selection technology is divided into two steps. The first is to establish a reference population for genome selection. The reference group includes phenotypic record information, pedigree information and genomic information. The general reference population should be more than 3000 in size to establish the relationship between phenotype and genomic information. The second is genetic evaluation of candidate individuals. By detecting the genotype information of candidate individuals and using the established gene phenotype relationship of reference group, the genetic potential of candidate individuals is predicted and evaluated. The key points of the successful implementation of the < p > < p > genome selection technology are as follows: first, accurately determine the phenotypic information of selected traits, accurately record individual pedigree information, so as to ensure the accuracy of reference group construction. Second, the cost of genotyping should be reduced continuously. At present, the price of commercial chips which are widely used in production is at least 150-200 yuan. If the cost of data analysis is added, the cost is relatively high, which restricts the application of technology. Thirdly, the accuracy of genotyping should be improved continuously. The accuracy includes not only the accuracy of sampling and application process and feedback, but also the accuracy of typing sites. Commercial microarray loci often come from many varieties, but for the actual population, the available loci are greatly reduced. Fourth, technical application personnel and process need to be standardized and run in step by step. Genomic selection technology is based on breeding value selection index selection, but field selection and index selection are not completely consistent. In addition, the level of grass-roots breeding personnel is also directly related to the effect of technology application. < / P > < p > since 2012, Wen has cooperated with related projects of China Agricultural University to develop and optimize a simplified genome sequencing technology suitable for pig genotyping, which can greatly reduce the cost of individual genotyping by using the second generation sequencing platform. Aiming at the problem of long time period from sampling to feedback detection results in sequencing method, a customized gene chip, porcinewens55k, was developed based on previous research. The gene loci of the microarray were obtained from the sequencing data of different strains, which ensured the reliability of microarray typing results. In addition, the chip from typing to breeding value calculation can be completed in Wen’s own laboratory, ensuring the timeliness of technology application. < / P > < p > no matter what kind of technology, its starting point and foothold is to be able to make real profits for enterprises, and genome selection technology is no exception. Whether these techniques can be applied to early breeding, and how to combine these techniques with traditional breeding methods, etc. According to the application analysis report of whole genome selection for Duroc pigs in Shahu farm of Wen’s Xinxing breeding company in 2018, the correlation between individual prediction composite index and final test composite index is more than 0.80, the accuracy of early selection is high, and the breeding cost is greatly saved. According to the situation of prevention and control of swine plague in Africa, Wen adjusted the production management workflow and established a stable genetic exchange mechanism for breeding pigs. The molecular laboratory of pig breeding company is responsible for the communication of sample collection, DNA extraction and on-site feedback, while the Animal Breeding Laboratory of group research institute is responsible for chip typing, breeding value calculation and feedback. < / P > < p > at present, Wen has established the reference group of genome selection in the main strains, and carried out the application of genome selection in the main core strains of breeding pig company. In 2019, more than 30000 piglet samples and 1844 sows from the basic group were detected. All piglet samples can feed back breeding values before weaning, which facilitates the allocation of breeding pigs. In addition, through the establishment of a dedicated OA application process, tracking each batch of samples, joint breeding site, timely feedback and evaluation of the application effect of the technology. < / P > < p > in the environment that African swine fever continues to bring threat to the industry, insisting on breeding work will accumulate strength for the long-term development of the enterprise. How to make good use of new breeding technology and accelerate the improvement of breeding pig level is becoming more and more important. There are still many links to be improved in the comprehensive promotion and application of genome selection technology. The first is to speed up the construction of the technical platform for the determination of complex traits. At present, there is no complete database of phenotypes and genotypes of meat quality and other complex traits, so it is impossible to carry out genomic selection of meat quality traits. Second, the methods of character collection need to be updated. In the current background of batch production, batch delivery, batch determination, to complete the established breeding operation in a relatively short time, the workload is large, resulting in the reduction of data accuracy. Therefore, it is urgent to develop convenient production or data acquisition equipment. Third, technology application and production still need continuous running in. The application of genomic selection technology is based on selection index. Due to the difference of breeding direction of different varieties, the selection index and breeding direction can not fully fit. In addition, the requirements of body shape and blood relationship in breeding field need to be effectively linked with the genomic selection index. Fourth, the cost and efficiency of genotyping should be improved continuously. At present, there is still room to reduce the cost of chip based genotyping method, and the use of sequencing method has a greater cost advantage, but the time of genotyping, genotype filling time and accuracy need to be further studied. The classification method with low cost, high efficiency, high accuracy and strong autonomy is the basis of large-scale application in the future. Continue ReadingYueshang group has become the third social e-commerce service platform listed in China after being gathered in pinduoduo