Variations in buck semen motility assessed by CASA system: Correlations with environmental temperature

Variations in buck semen motility assessed by CASA system: Correlations with environmental temperature

J Dorado, M Hidalgo and I Rodríguez

Animal Reproduction Unit, University of Cordoba, Spain

Several factor affect goat semen production and sperm quality and knowledge of these factors is very important to improve goat reproductive efficiency. This  study determined the influence of environmental temperature (T) upon buck semen motility using Sperm Class Analyser (SCA, Microptic). Animals were  located in southwest of Iberian Peninsula (3753¢N-446¢W; altitude 110 m). Temperature measurements (minimum, Tmin; mean, Tm; maxim, Tmax and difference in temperature, Td as Tmax-Tmin) were recorded daily at local meteorological centre. Semen data from two fertile adult Florida bucks collected  during 12 months were evaluated. In total, 110 ejaculates were diluted in DPBS to obtained 50 · 106 spermatozoa/ ml, incubated for 5 min. at 37C and  analysed to determine percentage of motile spermatozoa (MS, %) and rapidly progressive (RPMS, %), curvilinear velocity (CLV, lm/sec), average path  velocity (APV, lm/ sec), progressive speed (SLV, lm/sec), linearity (LIN); straightness (STR), wobble (WOB), beat cross frequency (BCF, Hz) and lateral head displacement (LHD,  lm). Bilateral correlation was established between those parameters. There was significant correlation in semen motility kept at different T. Tmin, Tmax and Tm  only showed correlation with MS (r = 0.21 for Tmin and r = 0.22 for Tmax and Tm). Although, Td had a negative correlation with LIN (r = (0.22), STR (r =  (0.19) and WOB (r = (0.22) and positive correlation with BCF (r = 0.20) and LHD (r = 0.21). We concluded that motion quality measurements (LIN and STR)  were significantly lower when Td was higher, whilst motility and velocity parameters were not affected.

Reprod Dom Anim 41, 311–377 (2006)