Bovine sperm sex‐selection technology in Japan

Abstract

BackgroundIn Japan, Livestock Improvement Association of Japan started commercially producing sexed bovine semen 10 years ago, and sexed bovine semen is currently used for the artificial insemination (AI) in the farms. In this review, the authors introduce the technology for sperm sexing by flow cytometry, the efforts at commercializing sexed semen in Japan, and recent field data on artificial insemination of the cattle with sexed semen.MethodsIn the procedures of the flow cytometric method, X‐chromosome‐bearing sperm and Y‐chromosome‐bearing sperm were fluorescently stained, separated from each other by analyzing the difference in the DNA content, and cryopreserved. The authors surveyed the conception rates after AI with these sperm and sex ratios of the offspring with the cooperation from livestock associations, AI technicians, and farmers.Main findings (Results)Although AI with sexed semen was associated with lower conception rates in comparison with AI with conventional semen, the accuracy of sex selection using AI with sexed semen was beyond >90%.ConclusionSexed semen produced by flow cytometry has the potential to produce offspring of the preferred sex with high accuracy and reliability. Thus, it is expected that sexed semen is used for AI more frequently in the farms.

The enriched Y-bearing sperm combined with delayed fixed-time artificial insemination for obtaining male Simmental crossbred offspring

“…The pregnancy of the T0 delayed FTAI cows (96.08%) was higher compared to a previous study (83.33%) for cows inseminated with the Simmental bull non-sexed post-thawed semen [18]. This result was also higher than 40.1-52.8% conception rates for post-insemination using sexed semen [32]. The dosage of sperm cells packaged in a straw for freezing ranged from 20 [33] to 100 million [34].…”

Game-Changing Approaches in Sperm Sex-Sorting: Microfluidics and Nanotechnology

“…Therefore, specific and efficient reproductive technology for sperm sex-sorting would be immensely helpful for the dairy sector. In contrast, in beef farms, male calves are those whose economic value makes a difference [ 20 , 21 ]. There is also interest in other species, such as equines, as well, for the use of sex-sorting semen [ 22 ].…”

“…Presently, the only effective sperm-sorting system is flow cytometry, a high-speed analysis tool for the counting and sorting of cells. This technology is commonly used in the medical field and clinical laboratories to perform for a large variety of assays [ 20 , 52 ]. For semen to be sorted using flow cytometry, firstly the sample must be diluted and labeled with a specific fluorescent dye called Hoechst 33342 which binds to the DNA of each sperm cell [ 3 ].…”

Utilização De Progesterona Em Receptoras De Embriões Equinos

“…Utilizando-se espermatozoides sexados para inseminação artificial, a diminuição das taxas de concepção (Baruselli et al, 2007;Borchersen e Peacock, 2009;Norman et al, 2010;Healy et al, 2013;Naniwa et al, 2019) e de prenhez (Bodmer et al, 2005;Andersson et al, 2006;Seidel e Schenck, 2008;Schenk et al, 2009;Underwood et al, 2010) Na inseminação artificial com tempo fixo, Baruselli et al, (2007) As pesquisas continuam no sentido de ajustar protocolos e a escolha de touros para melhorar taxas de fertilidade após a utilização de espermatozoides sexados na IATF (Pellegrino et al, 2016;Silva et al, 2018).…”

“…Como reflexo, além das modificações no processo de sexagem, surgem os relatos que demonstram que os resultados de taxa de prenhez variam em função da fertilidade e manejo das fêmeas, categorias de fêmeas a serem utilizadas para inseminação (Rhinehart et al, 2011;Healy et al;Karakaya et al, 2014;Naniwa et al, 2019) e da fertilidade dos touros doadores de sêmen (De Jarnette et al, 2011;Sales et al, 2011). O efeito do touro (Lu e Seidel, 2004;Wheeler et al, 2006;Xu et al, 2009;Sá Filho et al, 2013) Também a intensidade de pressão do citômetro diminui aquela taxa (Barceló -Fimbres, 2011).…”