In this investigation, the genotoxic properties of mestranol were examined in vitro. Human lymphocyte cultures were exposed for 72 h to mestranol at concentrations of 7.5, 15 and 30 µg/g. The genotoxic effects of the chemosterilant were assessed by numerical and structural chromosome aberrations.
Mestranol induced certain genotoxic effects in human lymphocytes. There was a dose-dependent significant (p<0.01) increase in the number of numerical aberrations in comparison to the control, but without significant differences (p>0.05) between the doses applied. Further, structural aberrations increased significantly (p<0.01) in the presence of mestranol, being most frequent in cultures exposed to the highest mestranol dose.
The frequency of Robertsonian translocations increased significantly only in cultures treated with mestranol at concentration of 30 µg/g in comparison both with the control (p<0.01) and the lowest chemosterilant dose (p<0.01).
There were significant differences (p<0.01) in the levels of chromosome gaps and fragments compared to Robertsonian translocations, whilst the frequencies between gaps and fragments were not significantly different (p>0.05).
Control of swine dysentery with antibiotics is often ineffective due to the resistance of Brachyspira hyodysenteriae. The potential of some herbal-based components against B. hyodysenteriae was previously studied in vitro. This study aims at the evaluation of in vivo efficacy of phytogenic feed additives in the control of swine dysentery
The study involved 64 seven-week old weaned pigs allotted to 4 groups: two were fed on feed supplemented with either Patente Herba® or Patente Herba® Plus, the third received tiamulin (positive control), while the negative control was not given antibiotics or additives. Fecal consistency was recorded daily. The presence of B. hyodysenteriae in the feces was investigated weekly using microbiological assays and the PCR test. Weight gain and feed conversion ratio were calculated for each week, and for the whole experiment.
B. hyodysenteriae was detected in all samples by both methods. The additives showed efficacy in the prevention and control of swine dysentery as only normal and soft stool was observed in the treated groups. By contrast, in the negative control all feces categories were detected. Frequencies of feces categories significantly differed (p<0.001) between feed-supplemented groups and the negative control. Efficacy of both additives in the prevention of SD is comparable to tiamulin, based on insignificant differences in the frequency of the various feces categories.
Beneficial effects of both additives resulted in significantly (p≤0.05) higher weight gain and lower feed conversion ratio in comparison to the negative control. The average weight gains between additive-fed groups and tiamulin-treated group did not differ significantly.