The Effect Of Gossypol On Rumen Microbial Population And Fiber Degradability

This paper adopts the research approach of combing in vitro and In vivo test to study the effect of free gossypol on the Ruminal Environment, the dry matter degradability and the number of rumen bacteria, fiber degrading bacteria, anaerobic fungi and rumen protozoon on sheep.The results show that:1. The free gossypol Content was in the range of national standard in the six Cotton meal. whereas there was great difference about content. The content of6#was highest (500.56mg/kg) and5#was lowest (241.86mg/kg).2. The effects of different cotton meals on the ruminal environment were not significant compared with soybean meal (P>0.05). The pH value changes between6.0～7.0. concentration of NH3-N of treated groups were significantly higher than those of control group in the48h.(P<0.05). Acetic acid concentration of low soybean meal group significantly higher than the high soybean meal group (P<0.05). The dry matter degradability is not significant between the two treated groups (P>0.05).3. The different concentration of gossypol (0.5mg/g,0.1mg/g,0.05mg/g,0mg/g) have no significant effects on the changes of pH value, total gas production and VFA concentration (p>0.05). The NH3-N concentration of the treatment group of0.1mg/g significantly higher than those of control group through48h fermentation (P<0.05), but there were no significant between treated groups. The number of bacteria in all the treated groups was significantly higher than the control group (P<0.05) through6h.the treated group of0.5mg/g and0.1mg/g also were significant higher than those in the control group through12h, the treatment group of0.05mg/g was through24h.All of those revealed that the rumen bacteria was strong tolerability to gossypol. Except the treated groups of6h (0.05mg/g), the number fiber degradation bacterium of the treated groups were significantly higher than those in the control group at other time point, the change was as same as rumen bacteria law. The fungi was opposite to the change trends of the bacteria, The quantity of fungi of the treated group was lower than those of the control group.0.5mg/g and0.1mg/g treated groups in the24h and48h respectively significantly reduced the quantity of fungi (P<0.05). The results show that rumen fungi was more sensitive to gossypol. The treated groups showed a significant increasing trend in the number of protozoon (P<0.01or P<0.05) at all time points compared with the control group. Dry matter degradability of0.5mg/g and0.1mg/g treated groups were significantly higher than those in the control group (P<0.05). Dry matter degradability of0.1mg/g treated group is66.37%, which is the highest of all the groups.4. The treated group of0.1mg/g had no significant effects on the ruminal environment. The number of rumen bacteria, fiber degrading bacteria and rumen protozoon of treated groups were significantly higher than those of the control group (P<0.05),but the number of anaerobic fungi was significantly lower than the control group(P<0.05). There were no significant differences on dry matter degradability. After feeding4h, free gossypol was158.59mg/1in rumen fluid.The average value of free gossypol was0.033mg/1which was lower then the safety level (5ug/ml) in the blood at the end of the experiment.