Location: Livestock and Range Research Laboratory
Project Number: 3030-31000-019-007-A
Project Type: Cooperative Agreement
Start Date: May 1, 2022
End Date: Oct 2, 2025
1. Evaluate reproductive potential of nano-purified sperm from sires identified with superior genetics for enhancing pregnancy establishment and maintenance in cattle. Cooperator agrees to work closely with USDA-ARS for nano-purification of sperm for use in a field trial sharing equipment and laboratory facilities for completion of this objective. 2. Develop new biomarker targets for nano-purification techniques to further improve fertility of genetically superior sires. Cooperator will co-advise the PostDoc involved with this objective and direct laboratory procedures necessary for sperm biomarker targets involved with nano-purification as part of this subaward.
Objective 1 - Heterospermic artificial insemination, which contains sperm from 2 sires (bulls A & B) per straw, will be used to inseminate approximately 1,000 cows. Insemination straws will contain sperm that has been treated (nano-purified) to remove acrosome damaged sperm from one, both or neither of the bulls A & B contributing sperm to the straw. Five bull A/B combinations will be evaluated with 200 inseminations per bull combination per 4 treatments to achieve the 1,000 inseminations. Pregnancy rates and offspring sire will be determined to compare improvements in fertility as a result of nano-purification. Objective 2 - We will ultimately use a traditional homospermic insemination field trial to artificially inseminate 3,000 cows to measure the improvement in fertility achieved by removing the most deleterious/damaged sperm from ejaculates of 5 sires using nano-purification of the most promising sperm biomarker affecting fertility. The most promising sperm biomarker for nano-purification will be identified by using image-based flow cytometry of novel sperm biomarkers from multiple high and low fertility sires identified by the artificial insemination industry, and/or identified via affinity purification of defective sperm surface proteins via isobaric tagging and tandem mass spectroscopy, or other techniques. In vitro fertilization studies and other laboratory measures of functional sperm morphology that best predict field fertility will also be evaluated to identify the most promising sperm biomarker for nano-purification.