Genetic parameters and breeding values for semen characteristics in Hanoverian stallions.

The research study aims to establish if the semen traits of 30 Hanoverian stallions, commonly used for artificial insemination, could be beneficial for breeding purposes. The study found that semen characteristics do indeed have a substantial impact and could be used to make informed breeding decisions to improve semen quality.

Study Description and Methods

• This research was carried out by observing 30 Hanoverian stallions that are frequently used for artificial insemination.
• The data studied comprised 15,149 ejaculates obtained from these stallions between the years 2005 and 2009, collected at the State Stud Celle of Lower Saxony.
• The semen characteristics examined included gel-free volume, sperm concentration, total and motile sperm count, and progressive motility.
• A linear multivariate animal model was used for estimating heritabilities and permanent environmental variances, as well as predicting breeding values for all traits simultaneously.

Results and Findings

• High heritabilities were observed for gel-free volume (0.43), whereas moderate heritabilities were found for total sperm (0.29) and progressive motility (0.20).
• A negative genetic correlation was found between gel-free volume, sperm concentration, and total sperm number with progressive motility.
• The effect of the stallions’ permanent environment accounted for between 9% and 55% of the variance in traits.
• The total variance among stallions explained 37-69% of the trait variance.
• The average reliabilities of the breeding values were between 0.43 and 0.76 for the 30 Hanoverian stallions under study.

Conclusion

• The study was able to show significant effects of the stallions used commonly in breeding programmes on the analysed semen characteristics.
• It demonstrated that estimated breeding values with sufficient reliability can be predicted using data from these stallions, and these can be used in horse breeding programmes to achieve genetic improvement in semen quality.