Semen quality has traditionally been assessed by measuring the concentration, morphology and motility of sperm cells. However, these parameters fail to take into account the integrity (or fragmentation) of the genetic material that the sperm cells carry, which, if damaged, may decrease dramatically reproductive success rates.
Measuring Sperm DNA Fragmentation (SDF) can be used to select more productive breeding males, increase the quality of semen samples and therefore reduce costs. This is because Sperm DNA Fragmentation is related to fertility rates and litter size.
Fertility Rates
Bull:
The lower the SDF value, the greater the number of pregnant females and the lower the number of females that return to heat following insemination (García-Macías, et al., 2007, Didion et al., 2009)
Boar:
There is a 25% increase in the number of pregnant females when the SDF value is lower than 6% (OR=1.5, p=0.0003, CI=1.21-1.94)
Litter Size
Inseminations using semen with low SDF values increases the number of offspring.
Bull:
In heterospermic inseminations, more calves were obtained from the seminal fractions with the lowest SDF values (r=0.87, p<0.001)
Boar:
Boars with a low SDF value produce a greater number of sucklings. The litter size is smaller when the SDF value is higher
For SDF values greater than 6%, litter size is reduced by 0.5, 0.7 and 0.9 sucklings per deliver in Hampshire, Landrace and Danish Large White, respectively
Because Sperm DNA Fragmentation is sensitive to external factors that affect an animal’s health, this parameter can also be useful in monitoring a breeding male’s health.
Sperm DNA Fragmentation can be induced iatrogenically and therefore this parameter can provide a quality control in improving semen handling and/or cryopreservation protocols.
