Relationship of Sperm Quality to Fertility after 4 Days of Cooled Storage of Equine Semen
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
This study evaluated measures of sperm quality in relation to fertility achieved with fresh semen or semen cooled and stored. Semen from 1 stallion was collected and processed to provide 3 treatments: group 1 received fresh semen; group 2 received cooled semen containing 50% seminal plasma (SP) stored for 4 days; and group 3 received cooled semen containing 50% SP stored for 1 day, then centrifuged and resuspended in fresh extender containing 10% SP on days 1 to 3. Inseminates were evaluated for sperm motion characteristics and the percentage of sperm with intact membranes (SMI). Mares (n = 34) in estrus were treated with an ovulation-inducing drug and inseminated with 100 million membrane-intact sperm on the following day. Pregnancy status was determined via transrectal ultrasonography 2 weeks after ovulation. The mean percentage of SMI was higher in group 1 (81%, initial) than in group 2 (74%, day 4) or group 3 (74%, day 4) (P < .05). The median percentages of total sperm motility differed among the groups (77%, 5%, 59% for groups 1, 2, and 3 respectively; P < .05). Median values for the percentages of progressively motile sperm and curvilinear velocity for group 1 (55%, 216 m/s) and 3 (37%, 186 m/s) were higher than for group 2 (1%, 73 m/s) (P < .05). Pregnancy rates did not differ among groups (5 of 11, 45% in group 1; 5 of 11, 45% in group 2; and 7 of 12, 58%, in group 3; P = .77). These data suggest that, at least for this stallion, sperm membrane integrity may be a more valuable means of assessing potential fertility of cooled-stored semen than sperm motion characteristics. 2014 Elsevier Inc.
