Effect of Dietary Selenium and Vitamin E on Ganders’ Response to Semen Collection and Ejaculate Characteristics
Anna Jerysz
Ewa Lukaszewicz
0
) Institute of Animal Breeding, Division of Poultry Breeding, Wroclaw University of Environmental and Life Sciences
, Chelmonskiego 38a, 51-630, Wroclaw,
Poland
Compared to other domestic bird species, geese exhibit the lowest reproductive efficiency (poor semen quality, low egg production, and poor fertility and hatchability rates). From an economic perspective, it is a necessity of improve these reproductive traits. Studies have demonstrated that the essential trace elementseleniumplays key roles in testicular development and the maintenance of spermatogenesis. The aim of the present study was to determine the effect of feed supplementation with organic selenium and vitamin E on ganders' response to manual semen collection and semen quality. Sixteen 3-year-old White Koluda ganders were randomly divided into two groups. The control group was provided commercial feed while the experimental group was provided with the same commercial feed supplemented with selenium (0.3 mg/kg) and vitamin E (100 mg/kg). The response of individual ganders from both groups to manual semen collection and the quality of the semen collected were evaluated. The supplements increased (P0.05) the frequency and decreased the time interval of a complete ejaculatory response of the ganders to manual semen collections (82.7 % supplement vs. 73.5 % control). Males from the supplemented group had significantly higher (P0.01; P0.05) ejaculate volumes, sperm concentrations, and percentages of viable sperm and lower percentages of immature sperm (spermatids). Lipids peroxidation, expressed in terms of the malondialdehyde concentration, was lower (P0.01) in semen of the supplemented group (0.172 nmol/50 106) as compared to the controls (0.320 nmol/50 106). Moreover, the duration of the reproductive period of the ganders in the experimental group was 1 week longer. The results show that supplemental dietary selenium and vitamin E improved both the ganders' response to manual semen collection and semen quality. We conclude that such feed supplementation could lead to greater economic benefits through increased reproductive efficiency within the goose production industry.
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White Koluda goose, derived from the wild Greylag (Anser
anser L.) goose [1], constitutes more than 90 % of goose
population in Poland and other European countries. The
breeder flocks are usually kept for four seasons (from
February through June, each season). However, while semen
quality and fertility rates are acceptable at the onset of the
breeding season, both gradually decline over the following
months [24]. This may be a result of depressed semen
quality, fewer natural matings, failure of the gander to
respond to manual semen collections, or premature gonadal
regression [57]. Compared to other poultry species, the
reproductive efficiency of the domestic goose is poor due
to the following: low male to female ratio (usually no more
than three to four females per one male), low semen quality,
low egg production, and low fertility and hatchability rates.
Natural mating frequency and semen quality differs by
gander [8]. During the spring months (MarchApril), 50 to
70 % of the ganders produce good quality ejaculates. This
progressively decreases, and until late in the season, only
1734 % of ganders produce good quality semen [5, 6, 9,
10]. There are few publications addressing the issue of
reproductive efficiency in geese. However, it is apparent
that any improvement in the ganders reproductive
performance would have a positive impact on goose production.
Selenium and vitamin E are involved in many
biochemical and physiological processes in human and animal
organisms, including those related to reproduction [11].
Particularly relevant to semen quality is the antioxidant
enzyme glutathione peroxidase (GSH-Px), a
seleniumdependent enzyme that serves to protect cellular membranes
and organelles from peroxidative damages [12]. Glutathione
peroxidase assists in the maintenance of testicular function,
spermatogenesis, spermatozoa functions [13], as well as
testosterone biosynthesis [14]. Studies in mammals have
shown that dietary addition of selenium increased male
sexual activity manifested by significantly shortening
mating and ejaculation times, as well as increased mating
frequency [15]. Experiments with broiler breeders and quails
indicated that semen quality, including an increase in the
percentages of viable sperm and reductions in the
percentages of dead and abnormal sperm, can be achieved by feed
supplementation with selenium and vitamin E [1618].
Lipids associated with the sperm plasma membrane serve
as a source of energy and are involved in many biochemical
processes [19]. However, due to high concentrations of
polyunsaturated fatty acids, docosatetraenoic and arachidonic
acids in particular [11], the sperm plasma membrane is
vulnerable to lipid peroxidation [20]. This process contributes to
the loss of cell membrane fluidity and can (...truncated)