Influence of Sperm Number on Fertility of Frozen Bovine Semen

Open Access
Publisher Website
Google Scholar
Abstract
Eighty-three ejaculates from ten Holstein bulls were split and 40% extended to 20 x 106 and 60% extended to 30 x 106 progressively motile spermatozoa per milliliter (dose) before freezing and storage in liquid nitrogen (LN). The 60- to 90-day % nonreturn rate (NR) was 71.7 from 5,607 first service inseminations for 20 million concentration and 72.2% NR from 5,638 first services for 30 million. A weighted mean difference of 0.17% NR infavor of the 30 million was not statistically significant (p<0.05). Measurements were made which included motility, % survival, sperm number, and cooling time and correlated with %NR on a within treatment split-ejaculate basis. No correlation was of sufficient magnitude to be of value in predicting fertility.