ABSTRACT
Little information exists about boar sperm chromatin quality and fertility within a commercial setting. The objective of this report is to provide information about boar sperm chromatin integrity and its relationship to fertility. The sperm chromatin structure assay (SCSA) was used retrospectively to characterize sperm from 18 sexually mature boars having fertility information. Boar fertility was defined by farrow rate (FR) and average total number of pigs born (ANB) per litter of gilts and sows mated to individual boars. Fertility data was compiled for 1867 matings across the 18 boars. The SCSA uses flow cytometry to evaluate the structural integrity of sperm nuclear DNA. The SCSA parameters measured in this retrospective analysis were the percentage DNA fragmentation index (%DFI) and standard deviation of the DNA fragmentation index (SD DFI). The %DFI and SD DFI showed the following significant negative correlations with FR and ANB; %DFI vs FR, r = -0.55, P < .01; SD DFI vs FR, r = -0.67, P < .002; %DFI vs ANB, r = -0.54, P < .01; and SD DFI vs ANB, r = -0.54, P < .02. Although more information is required to better understand the relationship between DFI and boar fertility, this report suggests that the SCSA assay may be an important assay for identification of boars having potential for lowered fertility.
Subject(s)
Chromatin/ultrastructure , DNA Fragmentation , Infertility, Male/veterinary , Swine/genetics , Animal Husbandry/methods , Animals , Flow Cytometry/methods , Male , Reproductive Techniques, Assisted/veterinary , Retrospective Studies , SpermatozoaABSTRACT
OBJECTIVE: To investigate how moderate and/or high levels of DNA fragmentation (DFI), as measured by the sperm chromatin structure assay (SCSA), affect either IVF or IVF with intracytoplasmic sperm injection (ICSI) fertilization, cleavage, blastulation, implantation, and pregnancy. DESIGN: Retrospective clinical study. SETTING: Academic human reproduction laboratory. PATIENT(S): Eighty-nine couples undergoing IVF with conventional fertilization or ICSI. INTERVENTION(S): Sperm chromatin structure assay testing (SCSA) of semen aliquot taken from ejaculate used for assisted reproductive technology (ART). MAIN OUTCOME MEASURE(S): Related DFI to conventional semen parameters and cycle-specific outcomes after ART. RESULT(S): No patients achieved clinical pregnancy if SCSA values exceeded the DFI (27%, P<.01), moderate DFI (15%, P<.01), or high DFI (15%, P<.05) thresholds. Dividing the DFI sperm population into moderate-fragmentation and high-fragmentation categories did not improve the prognostic value of the SCSA. No coefficient of determination (r(2)) between SCSA parameters and conventional parameters exceeded 0.29. CONCLUSION(S): Sperm chromatin structure assay identified thresholds for negative pregnancy outcome after ART not identified using conventional semen parameters. This is the first study analyzing the clinical value of sperm DFI to [1] include a large number of ART patients (n = 89), [2] perform SCSA analysis on a semen aliquot from the ejaculate used for ART, and [3] examine how the extent (moderate and high DFI) of DFI influenced ART outcomes.
