Suliman Y, Becker F, Tuchscherer A, Wimmers K. Seasonal variations in quantitative and qualitative sperm characteristics in fertile and subfertile stallions.
Arch Anim Breed 2020;
63:145-154. [PMID:
32490150 PMCID:
PMC7256850 DOI:
10.5194/aab-63-145-2020]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 04/15/2020] [Indexed: 11/11/2022] Open
Abstract
Horses are seasonal breeders with a natural breeding season beginning in
spring and extending through midsummer. In this study, quantitative and
qualitative parameters of chilled stallion semen were compared between
fertile and subfertile stallions and between the breeding and the
non-breeding season. Semen quality parameters compared included ejaculate
volume, sperm concentration, total sperm number, sperm morphology, and
computer-assisted semen analysis (CASA)-derived sperm movement
characteristics obtained from two groups of warmblood stallions (n=8; four fertile stallions and four subfertile stallions), which differ in the seasonal
pregnancy rate 80 %–90 % (fertile) vs. 40 %–60 % (subfertile). A total of
64 ejaculates were collected from the stallions (n=8; four in the
breeding season and four in the non-breeding season of each stallion). No
significant differences in the semen quality parameters between the fertile
and the subfertile stallions in the non-breeding season were observed.
However, in the breeding season the proportion of morphologically normal
sperm, total motility, progressive motility, average path velocity (VAP),
and curvilinear velocity (VCL) were significantly higher in the fertile
group (P<0.05) when compared with the subfertile group. In
addition, a significant seasonal variation in the proportion of
morphological normal sperm was found in the fertile group between the
breeding and the non-breeding season (P<0.05). Moreover,
significant seasonal variations (P<0.05) in CASA parameters of mean
VAP, straight line velocity (VSL), and beat-cross frequency (BCF) were
observed in the fertile and the subfertile stallions, which tended to be
lower in the non-breeding season. In conclusion, differences between the
fertile and the subfertile stallions were observed only in the breeding
season, and a few of CASA-derived parameters seemed to be significantly lower
during the non-breeding season in both the fertile and the subfertile
stallions.
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