Application of computer-assisted semen analysis to explain variations in pig fertility1

Abstract

Sperm quality is often evaluated through computer-assisted semen analysis (CASA) and is an indicator of boar fertility. The aim of this research was to study the relationship between CASA motility parameters and fertility results in pigs. Insemination records and semen parameters from a total of 45,532 ejaculates collected over a 3-yr period were used. The statistical model for analysis of fertility data from these inseminations included factors related to sow productivity. The boar- and semen-related variance (direct boar effect) were corrected for the effects of individual boar, genetic line of the boar, age of the boar, days between ejaculations, number of sperm cells in an ejaculate, number of sperm cells in an insemination dose, and AI station. The remaining variance was analyzed if semen motility parameters had a significant effect. This analysis revealed significant (P < 0.05) effects of progressive motility, velocity curvilinear, and beat cross frequency on farrowing rate (FR). Total motility, velocity average path, velocity straight line, and amplitude of lateral head displacement affected (P < 0.05) total number of piglets born (TNB). Boar- and semen-related parameters explained 5.3% of the variation in FR and 5.9% of the variation in TNB. Motility parameters, measured by CASA, explained 9% of the boar- and semen-related variation in FR and 10% of the boar- and semen-related variation in TNB. Individual boar and genetic line of the boar affected (P < 0.0001) the variation in FR and TNB. No differences (P > 0.05) were observed between effects of AI stations on fertility outcome, underscoring the objectivity of the CASA system used. Motility parameters can be measured with CASA to assess sperm motility in an objective manner. On the basis of the motility pattern, CASA enables one to discriminate between the fertilizing capacity of ejaculates, although this depends on the genetic line of the boar used in AI stations.

Relationships between rabbit semen characteristics and fertilising ability after insemination

“…Neither Alh, concentration nor the total number of sperms in the AI dose significantly affected litter size at birth. Our results are in agreement with those of Broekhuijse et al (2011) in pigs, revealing the significant influence of average path velocity on the number of piglets born, but in disagreement concerning the influence of amplitude of lateral head displacement, found to be significant in pigs. The number of total sperms per dose did not significantly influence prolificacy, unlike Tussel et al (2011) who reported a significant increase in prolificacy by increasing the number of sperms/dose from 5 or 20 × 10 6 .…”

“…Among these semen parameters, only Lavara et al (2005) obtained a negative but significant correlation between the linearity of sperm movement and fertility (r = −0.32), using heterospermic pools. In pigs, Broekhuijse et al (2011) obtained significant (P < 0.05) effects of progressive motility, curvilinear velocity and beat cross frequency on the farrowing rate. Although the presence of gel plugs in the semen is a major criterion for ejaculate rejection in some AI centres (Piles et al, 2013), our results revealed that this characteristic has no effect on either fertility or prolificacy.…”

Correlation between bull fertility and sperm cell velocity parameters generated by computer-assisted semen analysis

“…Until recently, the assessment of sperm motility was based solely on subjective microscopic evaluation of the total proportion of motile spermatozoa with results varying between 30% and 80% (Barros et al, 1973;Budworth et al, 1988;Amann, 1989;Chan et al, 1989;Auger et al, 1993;Broekhuijse et al, 2012). Due to the large variations observed, comparability of the results obtained by different laboratories is questionable (Dott and Foster, 1979).…”

Proper use and impact of ‘Computer Assisted Semen Analysis’ technique on semen evaluation of farm animals

“…On the other hand, two more recent studies by Broekhuijse et al (2011;2012) showed that progressive motility, VCL and BCF were positively related with farrowing rate, while total motility, VAP, VSL and ALH were positively related to the total number of born piglets. Holt et al (1997) also reported that the VSL was positively related to the litter size.…”