TITLE:
Variation among Beef Bulls in the Ratio of X- to Y-Chromosome Bearing Spermatozoa
AUTHORS:
Rick W. Rorie, Pedro A. Delgado, Toby D. Lester
KEYWORDS:
Sex Ratio, Spermatozoa, Ejaculates, Semen, Bulls
JOURNAL NAME:
Advances in Reproductive Sciences,
Vol.2 No.4,
September
22,
2014
ABSTRACT: A study was conducted to evaluate variation in the ratio of X- to Y-bearing sperm of individual ejaculates and to determine any relationship between skewed sex ratio and either routine morphological evaluation or computer assisted sperm analysis (CASA). Semen was collected from bulls weekly for 6 consecutive weeks, sperm DNA was recovered and quantitative, and real-time PCR was used to determine the ratio of X- to Y-bearing sperm in each ejaculate. The overall mean of X-bearing sperm within ejaculates was 54.7% over the 6 weeks of semen collections. The percentages of X-bearing sperm were similar (P > 0.5) across all collections. Between bulls, there were differences (P