Proportional assessment of X and Y chromosome-bearing spermatozoa in bull and boar ejaculates using conventional and real-time PCR techniques
type: CreativeWork
description: Considerable variation in the percentage of Y-chromosome bearing spermatozoa (%Y-CBS) between ejaculates in the same male has been reported. Collection regime has been speculated to influence the degree of variation in %Y-CBS in bull ejaculates (Chandler et al., 1998). Experiments were designed to evaluate the effects of two collection regimes on %Y-CBS. Conventional PCR combined with gel electrophoresis and image analysis was employed to determine %Y-CBS in ejaculates from two bulls collected on 7-day intervals and two bulls on 21-day intervals. Real-time PCR technology was used to quantify %Y-CBS in the same ejaculates. Boar ejaculates were also analyzed with both techniques and compared to the percent male piglets in litters resulting from the assayed ejaculates. Collection day (P<0.0001) significantly affected %Y-CBS as determined by both PCR methods. Ejaculate nested within bull (P<0.07) was significant in the conventional PCR study and collection frequency (P<0.0001) in the realtime PCR trial. Ejaculate nested within boar was highly significant (P<0.0001) for both technologies. Boar was significant (P<0.002) in the conventional PCR study. Predicted %Y-CBS determined by real-time PCR was significantly correlated (0.52, P=0.004) to percent male piglets. Both PCR techniques were effective in quantifying the variation in %Y-CBS in bull and boar ejaculates. Manipulation of %Y-CBS via collection regime may prove valuable for altering the secondary sex ratio in animal agriculture.
abstract: Considerable variation in the percentage of Y-chromosome bearing spermatozoa (%Y-CBS) between ejaculates in the same male has been reported. Collection regime has been speculated to influence the degree of variation in %Y-CBS in bull ejaculates (Chandler et al., 1998). Experiments were designed to evaluate the effects of two collection regimes on %Y-CBS. Conventional PCR combined with gel electrophoresis and image analysis was employed to determine %Y-CBS in ejaculates from two bulls collected on 7-day intervals and two bulls on 21-day intervals. Real-time PCR technology was used to quantify %Y-CBS in the same ejaculates. Boar ejaculates were also analyzed with both techniques and compared to the percent male piglets in litters resulting from the assayed ejaculates. Collection day (P<0.0001) significantly affected %Y-CBS as determined by both PCR methods. Ejaculate nested within bull (P<0.07) was significant in the conventional PCR study and collection frequency (P<0.0001) in the realtime PCR trial. Ejaculate nested within boar was highly significant (P<0.0001) for both technologies. Boar was significant (P<0.002) in the conventional PCR study. Predicted %Y-CBS determined by real-time PCR was significantly correlated (0.52, P=0.004) to percent male piglets. Both PCR techniques were effective in quantifying the variation in %Y-CBS in bull and boar ejaculates. Manipulation of %Y-CBS via collection regime may prove valuable for altering the secondary sex ratio in animal agriculture.
author: Paul, Julius Braden
keywords: sex ratio, real-time PCR, Y chromosome, spermatozoa, boar, bull
date published: 2003-01-01T08:00:00Z
date modified: 2026-07-24T02:59:31Z
provider: Lousiana State University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Dairy Science (Animal, Dairy, and Poultry Sciences)

PropertyValue
property ID: DOI
value: 10.31390/gradschool_dissertations.1506