| Currently,Eimeria tenella is one of the strongest virulence,the most widely distributed parasitic protozoa,particularly in intensive animal farming which is easy to break out of Eimeria tenella.Eimeria tenella predominantly affects chicken cecum,resulting in intestinal necrosis,hemorrhage,infection,the mortality rate is high,and also have a significant effect on the healed chickens' weight gain and egg production.Use of anticoccidial drugs can prevent Eimeria coccidiosis occuring,control the outbreak and epidemic,reduce losses.However,the irrational use of chemical synthetic anticoccidial drugs may cause coccidiosis resistance strengthening,and therefore,to develop new anticoccidial drugs which is safer,lowwer or non-toxic,difficult to produce drug resistance is very important.Attapulgite clay is an aqueous-rich magnesium aluminosilicate minerals,rich in trace and constant elements which animals need.And because of its special and strong adsorption capacity to all kinds of cations,pathogens and toxins,a certain amount of the Zn2+,Cr3+ can be loaded on attapulgite clay.Zinc can promote the metabolism,immunity,chicken skeletal growth and digestive tractepithelial cell growth,and chromium is indispensable in reducing stress,enhancing immunity,gaining weight.So the attapulgite clay loaded Zn2+,Cr3+ not only have absorption capacity for Eimeria tenella and its metabolites,but also can enhance immunity,and the resistance to infection.As a feed additive,the loaded attapulgite clay can prevent zinc or chromium deficiency,and improve weight gain of broilers and laying rate.In the first experiment,Eimeria tenella oocysts were obtained proliferated in vivo.Approximately of 1×105 of Eimeria tenella oocysts acquired were used to infect 2 weeks-old chicks by gavage way.After Eimeria tenella's life cycle of seven days,about 4.2×107 Eimeria oocysts were produced,by dissecting chick's cecul,and then digesting,filtrating,and separating the contents.Proliferation of the Eimeria oocysts was by about 400 times.In the secondexperiment,took the method of ion exchange to load Zn2+,Cr3+ on attapulgite clay,and preparation conditions were optimized.Attapulgite clay were baking,milling,and acidification to be refined.By exploring different temperature,reaction time and the order of the ion,concentration of Zn2+,Cr3+ that could be loaded on attapulgite clay had a great range of variation under different reaction conditions.Results on quantitative analysis by ICP spectroscopy showed 0.05 mol/L Cr3+ and 1mol/L Zn2+ and 100 g/L of attapulgite clay in shaking water bath at 55 ? conditions for 3.5 h,would make the largest sum of the ions contained in,and the reaction time is shorter,temperature is lower.In the third experiment,used the attapulgite clay contained with Zn2+ Cr3+ on Eimeria tenella infection treatment.2-week-old chicks were artificially infected.Compared to the blank,the original attapulgite clay,the contained ion attapulgite clay,Diclazuril,diclazuril joint attapulgite clay and the positive control,by observing its clinical manifestations,feces,the autopsy cases,analyzing its anticoccidial index(ACI),sliced cases,electron microscopy sections,There are the following conclusions:loaded Zn2+,Cr3+ attapulgite has certain anticoccidial effect,and better than the original soil;when diclazuril and Zn2+,Cr3+contained attapulgite clay joint use,ACI of diclazuril is increased,the anticoccidial effect is better than using either alone. |
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