ASSESSMENT OF EJACULATE QUALITY AND SPERM CHARACTERISTICS IN TURKEYS - SPERM MOBILITY PHENOTYPE IS INDEPENDENT OF TIME

Given a pool of genetically superior male turkeys, the subsequent sele ction of toms as semen donors for artificial insemination should be ba sed upon criteria that are predictive of the tom's fertility and fecun dity over the course of a production cycle. Recently, sperm mobility p henotype has been shown to correlate highly with fertility. Therefore, the objectives of this study were to determine: 1) whether sperm mobi lity phenotypes of individual toms were independent of time, and 2) th e extent to which traditional semen quality variables changed as a fun ction of time during the study interval. Sperm mobility phenotype was determined by objectively measuring the ability of sperm to penetrate 2% Accudenz(R) solution at body temperature. During the initial assess ments of a flock (n = 94), sperm mobility indexes (SMI) were significa ntly higher for the High Mobility Phenotype toms (56.61 +/- 1.03% SMI) compared to the Low Mobility Phenotype (30.46 +/- 1.27% SMI, P less t han or equal to 0.0001) toms. Over the 5 mo of this study, the High Mo bility Phenotype toms consistently had higher (P less than or equal to 0.05) SMI values than the Low Mobility Phenotype toms, with SMI value s similar to those of the initial screen. Ejaculate volume, concentrat ion, and plasma membrane integrity showed no significant differences b etween phenotypes (P greater than or equal to 0.05). Sperm viability r emained significantly lower (P less than or equal to 0.05) over the co urse of this study for the High Mobility Phenotype toms than for the L ow Mobility Phenotype toms. Because sperm mobility phenotype remained consistent through time, the Sperm Mobility Test provides a potentiall y important tool for selecting semen donors in turkeys.