The effect of exogenous anabolic steroids on certain body parameters and seminal characteristics of Boer goats
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Date
2011-05
Authors
Makae, Thapelo
Journal Title
Journal ISSN
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Publisher
University of the Free State
Abstract
Initially 20 yearling Boer goat bucks (between 14 and12 months of age, with a mean
body weight of 47 kg) were successfully trained for semen collection with the aid of an
AV. Animals were randomly divided into two groups, one group (n=9) was treated
weekly with an intramuscular injection of 25 mg (1 ml) Nandrolone Deca-Durabolin
(Adcock Ingram, The Netherlands), while the second group of bucks (n=10), served
as a control.
The following body and other parameters were recorded for each buck at weekly
intervals: Testicular size and testis volume (ml), weekly body weights (kg), body length
(cm), shoulder height (cm), shoulder width (cm) and the canon bone circumference
(cm). Weekly feed intake (kg) was also recorded for each animal to determine the
feed conversion ratio (FCR).
No significant differences were recorded during the entire period of the study period,
regarding the mean body weight gain, ADG and FCR of the bucks in the treatment
group and those in the control group. The ADG was similar for both experimental groups, due to the fact that the animals were in an advanced phase of the growth
curve. During the last half of the treatment phase and the entire recovery phase, the
treated bucks tended to be relatively heavier than those of the control group, however
these numerical differences were not statistically significant. Similarly, no significant
differences between the two groups (treated and control groups) were recorded for all
the other body measurements (e.g. canon bone circumference, body length, shoulder
width and shoulder height) considered in this study, with the exception of the scrotal
circumference (SC) and volume (SV) during the study period. All these changes in
certain body parameters were recorded which ultimately then relate to the growth
performance.
Semen was collected by a means of an artificial vagina, and different sperm analyses
for, evaluating the semen quantity, sperm concentration, sperm motility and sperm
morphology, percentage alive or dead sperm were performed, while semen pH using
pH-indicator strips was also recorded.
Thin semen smears were stained with eosin/nigrosin and evaluated under a
microscope for overall viability (percentage live), morphology (percentage normal or
abnormal), percentage mass motility and sperm concentration during the two
experimental (treatment and recovery) phases.
Throughout the entire (31 week period) trial, the semen quality of the treatment group
and the control group were similar (P>0.05) for the two experimental groups. Despite
a significant reduction in the testicular size, as indicated by the significantly (P<0.05)
lower scrotal circumference and scrotal volume following exogenous testosterone
treatment, none of the semen parameters measured in this trial (i.e. sperm mass
motility, semen volume, semen pH, sperm concentration, percentage live and
percentage normal sperm) were significantly affected by the steroid treatment. From
the current results recorded, there tended to be an insignificant decline in sperm
concentration, % live and % normal sperm changes - these could be attributed to
changes in seasonality. The % normal sperm decreased by 7-8% during the
observation period and approximately 60% of the abnormalities could be attributed to
tail abnormalities - with both the mid-piece and sperm head abnormalities attributing
30% and 10% respectively.
From the data generated, it would seem that a lack in significant differences of the
body parameters in the treated animal could possibly be ascribed to the dose of
hormone used, the age of the animals, the duration of treatment and the energy
content of the diet fed.
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Keywords
Boer goats -- Effect of drugs on, Boer goats -- Breeding, Boer goats -- Nutrition, Anabolic steroids in animal nutrition, Dissertation (M.Sc.Agric. (Animal, Wildlife and Grassland Sciences))--University of the Free State, 2011