OBJECTIVE MEASUREMENT OF SPERM MOTILITY BASED UPON SPERM PENETRATION OF ACCUDENZ(R)

When a suspension of rooster sperm was overlaid upon 6% (wt/vol) Accud enz(R), immotile sperm did not enter but motile sperm entered rapidly. The absorbance of the Accudenz(R) layer increased as a result. These phenomena were used to measure sperm motility objectively at body temp erature. The intra-assay coefficient of variation (CV) was 2.6% (n = 3 ). When roosters (n = 36) were ejaculated repeatedly and sperm motilit y data analyzed by two-way ANOVA, a male effect was observed (P < 0.00 1). When roosters were ranked by mean motility scores (n = 3 evaluatio ns per male) and representative males selected as semen donors, a diff erence in fertility (P less than or equal to 0.001) was observed betwe en males characterized by minimal and maximal sperm motility. Frequenc y analysis with data from a second flock of roosters (n = 100) reveale d a normal distribution. Roosters categorized by average sperm motilit y (n = 18) or sperm motility greater than one standard further analysi s by repeated measurements. A split-plot ANOVA revealed a difference b etween categories (P less than or equal to 0.0001) and variation among males within a category (P less than or equal to 0.0001). In contrast sperm motility was independent of time and there was no interaction b etween category and time. Thereafter, five roosters from each group we re ejaculated weekly and interassay CV estimated with semen-pooled by category (n = 3 observations per category). During this interval, sper m motility of average roosters was 55 +/- 5.9% of that of roosters wit hin the high motility category. Interassay CV were 18.1 and 9.2% for r oosters originally categorized by average and high sperm motility, res pectively. The assay described has potential for: 1) selecting males b ased on sperm motility, and 2) standardizing the measurement of poultr y sperm motility.