Abstract

This study investigated the use of annexin-V/PI assay to assess sub lethal changes in bull spermatozoa post-thawing, and to further relate these changes to results obtained by fluorometric assessment of sperm viability and sperm chromatin structure assay (SCSA), as well as field fertility (as 56-day non-return rates, 56-day NRR) after AI. Frozen-thawed semen samples were obtained from 18 Swedish Red and White bulls (one to three semen batches/bull) and fertility data was based on 6900 inseminations. The annexin-V/PI assay revealed that post-thaw semen samples contained on average 41.8 +/- 7.5% annexin-V-positive cells. Most of the annexin-V-positive cells were dying cells, i.e. also PI-positive. The incidence of annexin-V-positive cells was negatively related (r = -0.59, P < 0.01) to the percentage of viable cells, as detected by fluorometry. The incidence of annexin-V-positive spermatozoa significantly correlated to the SCSA variable (x) over bar alpha(I) (r = 0.53, P < 0.05). The incidence of annexin-V-negative, dead cells was the only annexin-V/PI assay variable that correlated significantly with fertility both at batch (r = -0.40, P < 0.05), and bull (r = -0.56, P < 0.05) levels. Among sperm viability variables, subjectively assessed sperm motility (r = 0.52-0.59, P < 0.01), CASA-assessed sperm motility (r = 0.43-0.61, P < 0.05), and the incidence of live spermatozoa, expressed as total numbers (r = 0.39-0.54, P < 0.05), or percentage values (r = 0.68-0.68, P < 0.01), correlated significantly with field fertility both at batch, and bull levels. Among the SCSA variables, only the COMP alpha(t) correlated significantly (r = 0.33-0.51, P < 0.05) with fertility results. The results indicate a certain proportion of bull spermatozoa express PS on their surface after thawing, e.g. they have altered membrane function, and that the incidence of such cells is inversely correlated to sperm viability, and positively correlated to abnormal sperm chromatin condensation since they eventually undergo necrosis. (C) 2003 Elsevier Science Inc. All rights reserved

Published in

Theriogenology
2003, Volume: 60, number: 4, pages: 743-758
Publisher: ELSEVIER SCIENCE INC

SLU Authors

• Johannisson, Anders

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Rodriguez, Heriberto

  • Department of Clinical Sciences, Swedish University of Agricultural Sciences
    

Publication identifier

DOI: https://doi.org/10.1016/S0093-691X(03)00050-5

Permanent link to this page (URI)

https://res.slu.se/id/publ/1325