The Relationship Between Post‐Thaw Sperm DNA Integrity and Non‐Return Rate Among Norwegian Cross‐Bred Rams

Abstract

With the aim of investigating the relationship between sperm DNA integrity and non-return rate (NRR) among Norwegian cross-bred rams, semen from 15 individuals was examined by flow cytometry. Sperm Chromatin Structure Assay (SCSA) quantifies the proportion of spermatozoa with denatured DNA after in situ acid treatment, and the four parameters % DFI, % HDS, MEAN DFI and SD DFI are all different measures of DNA denaturation and maturation. Field fertility, reported as NRR 25 days after insemination was based on all inseminations from a large-scale breeding programme and supplied by the Norwegian Association of Sheep and Goat Farmers. From each ram, four straws from four different weeks of the breeding season were analysed, and the associations between 25-day NRR and the mean of the four SCSA parameters were tested using a logistic regression model. The results revealed no association between fertility and % DFI or % HDS, while SD DFI and MEAN DFI showed a significant negative association with NRR. Further, the SCSA values varied significantly between ejaculates within ram among some of the rams in the study. However, no significant association was seen between these intra-individual differences in sperm DNA integrity and NRR. In conclusion, this study suggests an association between sperm DNA integrity and NRR for rams. However, further research must be conducted to confirm these findings and determine whether sperm DNA assessments can be applied to predict ram fertility.

Influence of the Temperature and the Genotype of the HSP90AA1 Gene over Sperm Chromatin Stability in Manchega Rams

“…Recently, Nordstoga et al [23] showed an association between sperm DNA integrity and the non returned rate among Norwegian cross-bred rams. In this sense, future works must be directed to assess if changes observed in DFI values of rams with alternative genotypes of the G/C −660 mutation at the HSP90AA1 gene promoter have effect on their fertility.…”

“…Thresholds for sub fertility were much lower for boars (6%) and bulls (14.2%) than that for humans (30%). Recently, in rams Nordstoga et al [23] showed an association between sperm DNA integrity and the non returned rate in Norwegian cross-bred rams.…”

Mass sperm motility is associated with fertility in sheep

“…This rapid test has the advantage of being easy to perform, inexpensive from an economic perspective and predictive of sperm fertilizing capacity . Nonetheless, other predictive criteria of sperm fertility are currently being investigated (Nordstoga et al, 2013;Vicente-Fiel et al, 2014). Using reproduction data from many French sheep breeds, the present study aimed to reassess the relationship between mass sperm motility and male fertility.…”

Sperm DNA assays and their relationship to sperm motility and morphology in bulls (Bos Taurus)

“…In the present study, SCSA assay was reliable for distinguishing different qualities of DNA in the sperm cells. This assay has long been considered valuable for measuring DNA quality and its relationship to fertility has been reported for many species (Evenson et al, 1980;Ballachey et al, 1987;Evenson et al, 1994;Sailer et al, 1996;Love and Kenney, 1998;Larson et al, 2000;Januskauskas et al, 2001;Januskauskas et al, 2003;Waterhouse et al, 2006;Morrell et al, 2008;Didion et al, 2009;Nordstoga et al, 2013;Oleszczuk et al, 2013). Therefore, it was used in the present study as a reference assay to which the other assays could be compared.…”