| الوصف: |
The main objective of the study was to determine the seminal characteristics of warmblooded stallions, to assess a relationship between motility parameters of spermatozoa and sperm head dimensions (Experiment 1) and to compare the ability of three milk-based extenders to preserve the motility and viability of cooled shipped semen (Experiment 2) using Sperm Class Analyzer (SCA, MICROPTIC SL). In Experiment 1, 32 and 36 ejaculates were collected during breeding seasons 2016 and 2017 from 10 clinically healthy and fertile warmblooded stallions (age 3- 22 years). The volume of ejaculate (mL), sperm concentration (M/mL), motility of sperm with kinematic parameters, viability of sperm (%) and sperm morphometry with morphometric parameters were evaluated. In Experiment 2, 21 ejaculates from 11 stallions were collected before the beginning of the breeding season 2018 and diluted with Kenney, EquiPlus and INRA 96. Spermatozoa viability (VIT, %), total motility (MOT, %), progressive motility (PMOT, %) and selected kinematic parameters were evaluated for 63 semen samples. These parameters were determined 2 hours after semen processing and then in 24, 48 and 72-hour intervals of storage at 5 °C. The following average values were found in the obtained ejaculate samples for the observed periods of the breeding seasons 2016 and 2017 - volume of ejaculate 49.22 and 56.77 ml, sperm concentration 208.20 and 222.19 M/ml, MOT 82.44 and 81.38 %, PMOT 37.34 and 35.46 %, VIT 60.71 and 42.91 %, morphologically normal sperm 75.00 and 64.50 %, curvilinear velocity (VCL) 62.67 and 60.26 ?m/s, straight-line velocity (VSL) 32.10 and 27.55 ?m/s, average path velocity (VAP) 48.14 and 44.35 ?m/s, linearity coeficient (LIN) 50.64 and 44.89 %, straightness coeficient (STR) 66.56 and 62.01 %, wobble coeficient (WOB) 75.74 and 72.12 %, amplitude of lateral head displacement (ALH) 2.59 and 2.90 ?m, beat- cross frequency (BCF) 7.32 and 7.49 Hz, head length (L) 6.33 and 6,41 ?m, head maximum width (W) 3.01 and 3.11 ?m, head area (A) 15.65 and 16.37 ?m2, head perimeter (P) 16.26 and 16.55 ?m, elongation (Elong ) 0.36 and 0.35, ellipticity (Ellip) 2.11 and 2.07, roughness (Rugo) 0.74 and 0.75 and regularity (Regu) 0.96. There where significant differences among stallions in all evaluated parameters of sperm (P < 0.05). Furthermore, the influence of age and fertility of stallions was also demonstrated for the observed parameters. MOT, PMOT, VCL, VSL, VAP, LIN and WOB were positively correlated with area, width, length and perimeter of the head and negatively correlated with elongation and ellipticity of the sperm head. Sperms with larger head dimensions thus had larger MOT, PMOT, VCL, VSL, VAP, LIN, WOB, STR and smaller ALH and BCF. In contrast, sperms with greater elongation and ellipticity had lower motility and kinematic parameters. The effect of the extender (P < 0.05) and the storage time (P < 0.001) was highly significant for evaluated parameters. The ejaculates extended with INRA 96 reached significantly higher values (P < 0.01) for all evaluated parameters compared to Kenney extender. The INRA 96 extender significantly increased the values of PMOT, VCL and VAP compared to EquiPlus (P < 0.05). The results obtained from using INRA 96 showed that quality of cooled semen can be sufficiently maintained during at least 24 hours of storage. |
