Location: Livestock Bio-SystemsTitle: Seasonal and cryopreservation impacts on semen quality in boars
|KRAUTKRAMER, MEAGAN - University Of Wisconsin|
|PARRISH, JOHN - University Of Wisconsin|
|LOETHER, T - University Of Wisconsin|
Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2015
Publication Date: 3/1/2015
Citation: Krautkramer, M.M., Parrish, J.J., Loether, T.M., Miles, J.R., Rempel, L.A. 2015. Seasonal and cryopreservation impacts on semen quality in boars [abstract]. Journal of Animal Science. 93(Supplement 2):185 (Abstract #413).
Technical Abstract: Seasonal boar infertility occurs worldwide and contributes to economic loss to the pork industry. The current study evaluated cooled vs cryopreserved semen quality of 11 Duroc boars collected in June (cool season) and August 2014 (warm season). Semen was cooled to 16°C (cooled) or frozen over liquid nitrogen (frozen-thawed). Quality evaluation included: % motile sperm using CASA, % viable sperm by Sybr14/propidium iodide staining, and sperm nuclear shape of Hoechst 33342 stained sperm by Fourier harmonic analysis (FHA) amplitudes 0 – 5 (HA0-5; in microns). Data were evaluated with ANOVA and MANOVA using a mixed model with collection season (June or August), preparation (cooled or frozen-thawed), and season X preparation interaction as fixed effects. Boar effect and associated interactions were considered random. An interaction of season and preparation for motile sperm (P < 0.01) existed with June better than August for cooled semen (80 vs 43%; P < 0.05) but not different for frozen-thawed semen (8 vs 8%; P > 0.05). The % viable sperm was greater for cooled vs frozen-thawed semen (72 vs 22%, P < 0.001) but no interaction or main effect of season was present (P > 0.05). Analysis of sperm nuclear shape was first evaluated with MANOVA using the composite HA0-5 measurements together. An interaction of season by preparation (P < 0.0006) associated with nuclear shape. Individual HA measures were evaluated using ANOVA. HA0 had an interaction of season and preparation with a decrease in cooled semen from June to August (2.834 vs 2.778; P < 0.001) but an increase for frozen-thawed semen (2.740 vs 2.825; P < 0.001). Similarly, HA2 had an interaction of season and preparation with cooled semen decreasing in HA2 from June to August (1.075 vs 1.065; P < 0.05) but increased for frozen-thawed semen (1.076 vs 1.092; P < 0.01). Main effects of season influenced HA3-5 (P < 0.05). In summary sperm nuclei were decreased in overall size and length for cooled semen from June to August, but the opposite was true for frozen-thawed sperm. Seasonal changes of cooled semen for compensable semen traits of motility and viability and the uncompensable trait of FHA are similar to previous studies but the impacts of season on frozen-thawed sperm are novel. Reduced motility and viability of cryopreserved semen does indicate a need for improvement of cryopreservation techniques, which is currently overcome by high sperm concentration.