Location: Livestock and Range Research Laboratory
Project Number: 3030-31000-019-005-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jan 1, 2022
End Date: Dec 31, 2025
1. Evaluate reproductive potential of nano-purified sperm from sires identified with superior genetics for enhancing pregnancy establishment and maintenance in beef and dairy cattle. One of these studies will be conducted in Brazil because of the ability to obtain large numbers of inseminations within the same herds and led by ARS investigator. 2. Develop new biomarker targets for nano-purification techniques to further improve fertility of genetically superior sires. This objective will be led by ARS and non-ARS investigator.
ARS investigator will lead studies that use the magnetic nano-particles coated with specific surface compounds or antibodies that bind and remove subfertile sperm from the ejaculate of bulls prior to extension and freezing of semen for use with artificial insemination and use similar techniques with straws of frozen/thawed sperm from bulls of known field fertility to restore fertility in subfertile bulls following nano-purification and in vitro fertilization for the beef and dairy industries. Furthermore, a laboratory assay will be developed using nano-purification of sperm by coating specific substances and/or antibodies on nano-particles that bind biomarkers on the surface of subfertile sperm to develop a fertility index of bulls. Based on preliminary studies in our laboratory, it is estimated that fertilization by subfertile sperm (that are still motile and mostly normal) accounts for 10 to 20 percent of pregnancy failures in beef and dairy herds worldwide. The purpose of conducting one of these nanopurified semen trials in Brazil is due to greater than 60% adoption of artificial insemination in the beef industry and availability of inseminating 3,000 cows in one herd with semen that has been purified with one (or more) of several magnetic nano-particles. Thus, the ARS investigator will lead field studies in objective 1 and co-lead field studies in objective 2.