Recipient Organization
MISSISSIPPI STATE UNIV
(N/A)
MISSISSIPPI STATE,MS 39762
Performing Department
ANIMAL & DAIRY SCIENCE
Non Technical Summary
The majority of sperm evlauation systems and techniques are subjective, while the aquisition of a Computer-Assisted Sperm Analyzer (CASA) will provide a more quantitative analysis of spermatozoa characteristics and likely deliniate more subtle changes in sperm quality in relation to study treatment effects. The aim of the present application is to acquire a Computer-Assisted Sperm Analyzer (CASA) for multi-investigator use to apply CASA as an objective research tool for assessing in vivo and in vitro influences on sperm quality and fertility to improve reproductive efficiency in livestock, and provide added research infrastructure
Animal Health Component
70%
Research Effort Categories
Basic
30%
Applied
70%
Developmental
(N/A)
Goals / Objectives
The aim of the present application is to acquire a Computer-Assisted Sperm Analyzer (CASA) for multi-investigator use to apply CASA as an objective research tool for assessing in vivo and in vitro influences on sperm quality and fertility to improve reproductive efficiency in livestock. Five research projects will utilize the acquired CASA as an objective assessment tool for new and existing research applications, and provide added research infrastructure from which additional research activities and funding opportunities are anticipated. Acquisition and application of CASA to the following five research projects addresses the following priority areas as defined by the FY2005 USDA-NRI Animal Reproduction Program: (1) Basic mechanisms regulating fertility (Project I - Use of CASA to assess bull, ram, stallion and rooster sperm responsiveness to relaxin for enhancing sperm motility, and the role of relaxin as a sperm chemotaxis agent in vitro; and Project II - Evaluation
of sperm-mediated gene transfer (SMGT) methods on sperm motility kinetics and the fertilizing capability of transgenic sperm following IVF); (2) Identifying and ameliorating the causes of infertility (Project III - Use of CASA as a supplement to breeding soundness evaluations for bulls maintained on forage bull test and traditional bull test stations; and Project IV - Assessment of the effects of endophyte-infected tall fescue forage consumption on stallion fertility and sperm quality characteristics as determined by CASA); and (3) Improved cryopreservation of gametes (Project V - Use of computer-assisted sperm analysis in the assessment of a novel frozen semen packaging system for use in the stallion).
Project Methods
This is an equipment grant to aquire a Computer-Assisted Sperm Analyzer (CASA) for multi-investigator use on the following five research projects. Project I: Use of CASA to assess bull, ram, stallion and rooster sperm responsiveness to relaxin for enhancing sperm motility and sperm chemotaxis in vitro. Fresh, cooled and/or frozen-thawed semen from bulls, rams, stallions and roosters will be used in these studies and placed with semen in a time- and dose-dependent manner. Finally, with CASA chambers relaxin will be placed in one end of the chamber and chemotaxis by sperm examined for the rate and number of sperm moving in the direction of the chemoattractant (relaxin). Project II: Evaluation of sperm-mediated gene transfer (SMGT) methods on sperm motility kinetics and the fertilizing capability following IVF. Fresh and frozen-thawed sperm from bulls will be transfected with exogenous DNA via permeabilization, liposome-mediated transfer and/or linker-based transfer and
examined post-transfection via CASA for comparison to untransfected sperm from the same ejaculate. Transfected and non-transfected sperm will also be examined for their fertilizing capability in an in vitro fertilization (IVF) assay. Project III: Use of CASA as a supplement to breeding soundness evaluations for bulls maintained on forage bull test and traditional bull test stations. We propose to use the CASA as a supplement to the traditional BSE to address bull test station variability, and more precisely quantify differences among bulls within and between bull test stations. Semen collected from bulls at different test stations will be processed in the same manner, assessed via CASA following the traditional BSE, and site-specific differences in sperm measures and the degree of variability among bulls analyzed. Project IV. Assessment of the effects of endophyte-infected tall fescue forage consumption on stallion fertility and sperm quality characteristics as determined by CASA.
Ejaculates from stallions consuming E+ tall fescue pasture or diets will be collected to assess ejaculate volume, sperm production, and sperm quality using CASA. In addition, these parameters will be correlated with endocrine parameters (serum prolactin, LH, dopamine, testosterone and responsiveness to the GnRH-testosterone challenge test) and urine and seminal plasma will be assayed for ergot alkaloid content. Project V. Use of computer-assisted sperm analysis in the assessment of a novel frozen semen packaging system for use in the stallion. The primary objective of this project is to compare alternative packaging systems (APS) with conventional (straws) semen packaging. Multiple stallions would be collected and the collections from each stallion split for cryopreservation in the different systems. Both prior to freezing and post-thaw, percent intact acrosomes as well as progressive motility and sperm velocity will be determined using the objective CASA system. Secondary objectives
of this study include evaluations of different freezing protocols and cryoprotectants with this novel semen packaging system using standardized CASA measures as a comparative analysis tool.