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Sperm sorting for sex preselection is one of the major achievement in reproductive biotechnology that hasgreatly influenced worldwide dairy industry.Basically,semen is labeled with a fluorescent by Hoechst 33342 whichbinds to the DNA of each spermatozoon,and then exposed to UV light during flow cytometry to measure theamount of fluorescent dye.As the X-chromosome is larger than the Y chromosome,X and Y sperm will be sorted interms of the difference of the DNA content by computer system.The high speed sperm sorter,SX-MoFlo flowcytometer was developed for commercial purpose and licensed to XY Inc,in 2000,which be able to sort X or Y sperm at a rate of 5000-7000 per second and could obtain greater than 90％ purity.However,the number of sortedsperm to produced sexed semen only 30-50 thousand doses per sorter each year which still limits widespreadapplication.We developed a new technology for sexed semen production in dairy cattle based on SX-MoFlo flowcytometer and mix the sorted sperm with xenosemen which can improve more than two times of sexed semenproduction compared to original ability to 60-80 thousand doses per sorter each year.Since 2005,over 1.4 milliondoses of the sexd dairy cattle X-semen were applied for AI in China,which resulted 50-60%conception rate ofeach sex cycle and 94% heifers of average sex preselection rate in the sexed generations.These results indicatedthat feiled application of sex controling by sorted X-semen and AI is feasible with both of our developedtechnology and new product quality for dairy industry in China.