The effect of exogenous anabolic steroids on certain body parameters and seminal characteristics of Boer goats

[摘要] Initially 20 yearling Boer goat bucks (between 14 and12 months of age, with a meanbody weight of 47 kg) were successfully trained for semen collection with the aid of anAV. Animals were randomly divided into two groups, one group (n=9) was treatedweekly with an intramuscular injection of 25 mg (1 ml) Nandrolone Deca-Durabolin(Adcock Ingram, The Netherlands), while the second group of bucks (n=10), servedas a control.The following body and other parameters were recorded for each buck at weeklyintervals: 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 thefeed 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 treatmentgroup 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 growthcurve. During the last half of the treatment phase and the entire recovery phase, thetreated bucks tended to be relatively heavier than those of the control group, howeverthese numerical differences were not statistically significant. Similarly, no significantdifferences between the two groups (treated and control groups) were recorded for allthe other body measurements (e.g. canon bone circumference, body length, shoulderwidth and shoulder height) considered in this study, with the exception of the scrotalcircumference (SC) and volume (SV) during the study period. All these changes incertain body parameters were recorded which ultimately then relate to the growthperformance.Semen was collected by a means of an artificial vagina, and different sperm analysesfor, evaluating the semen quantity, sperm concentration, sperm motility and spermmorphology, percentage alive or dead sperm were performed, while semen pH usingpH-indicator strips was also recorded.Thin semen smears were stained with eosin/nigrosin and evaluated under amicroscope for overall viability (percentage live), morphology (percentage normal orabnormal), percentage mass motility and sperm concentration during the twoexperimental (treatment and recovery) phases.Throughout the entire (31 week period) trial, the semen quality of the treatment groupand the control group were similar (P>0.05) for the two experimental groups. Despitea significant reduction in the testicular size, as indicated by the significantly (P<0.05)lower scrotal circumference and scrotal volume following exogenous testosteronetreatment, none of the semen parameters measured in this trial (i.e. sperm massmotility, semen volume, semen pH, sperm concentration, percentage live andpercentage normal sperm) were significantly affected by the steroid treatment. Fromthe current results recorded, there tended to be an insignificant decline in spermconcentration, % live and % normal sperm changes - these could be attributed tochanges in seasonality. The % normal sperm decreased by 7-8% during theobservation period and approximately 60% of the abnormalities could be attributed totail abnormalities - with both the mid-piece and sperm head abnormalities attributing30% and 10% respectively.From the data generated, it would seem that a lack in significant differences of thebody parameters in the treated animal could possibly be ascribed to the dose ofhormone used, the age of the animals, the duration of treatment and the energycontent of the diet fed.

[发布机构] University of the Free State