Study On The Anti-eimeria Tenella Effect Of Four Compounds

Chicken coccidiosis is a parasitic protozoan disease caused by Eimeria,which damages the intestinal health of chickens.Because of its high infection rate,wide infection range,difficult to completely eliminate,and seriously affect the growth of chickens,it is one of the important diseases endangering the health of chickens all over the world.Chicken coccidiosis has brought huge economic losses to poultry industry.At present,the main treatment for coccidiosis in the market is to add anti coccidiosis drugs to the feed.However,due to improper use of drugs and other reasons,many anti coccidiosis drugs have accelerated the development of drug resistance.Now it is urgent to develop new anti coccidiosis drugs and existing anti coccidiosis drugs for alternate use,so as to inhibit the outbreak of coccidiosis and alleviate its drug resistance.This test is mainly to screen the clinical anti Eimeria tenella activity of the new anti coccidial compound developed by central China Normal University(because it is still in the clinical trial stage,the following are called a,B,C and D),and to test the effective dose safety of the two effective compounds.The anti Eimeria tenella activities of four new compounds were screened.Sixty four13 day old healthy chicks of similar weight were divided into 8 groups with 8 chicks in each group.The four tested compounds were mixed fed at the dose of 100mg/kg respectively.At the same time,the infection no drug group,no infection no drug group,and diclazuril and decavoxyquinate drug control group were set.The drug was administered the day before the attack and continued for 9 days.The clinical symptoms,bloody diarrhea,weight gain,oocyst excretion,cecal lesions and other conditions of each experimental group were observed and counted.After integrating all the conditions,the anti coccidial index(ACI)was used as the main index to evaluate its anti Eimeria tenella efficacy.The results showed that compound A and compound C had the best effect.ACI reached 152.20 and 173.36 respectively,which was much higher than that of the control group.Further dose screening tests were carried out on the two screened effective compounds a and C.Increase the dose of compound A and set the dosage of 100 mg/kg and 150 mg/kg;For compound C with good effect,reduce the dose,and set five dosing concentrations of 100 mg/kg,50 mg/kg,30 mg/kg,10 mg/kg and 1 mg/kg;At the same time,the control groups such as infection non administration group,non infection non administration group,diclazuril and decavoquinate were set up.The administration was started the day before the attack and continued for 9 days.The clinical symptoms,bloody diarrhea,weight gain,oocyst excretion,cecal lesions and other conditions of each experimental group were observed and counted.After integrating all the conditions,the anti coccidial index(ACI)was used as the main index to evaluate its anti Eimeria tenella efficacy.The results showed that the ACI of compound A in 100 mg/kg group and 150mg/kg group were the same,both of which were 158.00;The 100 mg/kg group of compound C was still effective,and the ACI reached 164.00,but the low-dose group of compound C at or below 50 mg/kg had poor effect,and the ACI was below 75.00,suggesting that the low-dose compound C had no anti coccidial effect.Carry out safety test on the effective dose of screened compound A and compound C.Compound A is provided with two concentrations of 100 mg/kg and 150 mg/kg,and compound C is provided with a 100 mg/kg group,both of which are given only without infection.At the same time,the non infection and non administration group is set as the control.The clinical symptoms,weight gain,blood physiological and biochemical parameters were measured on the seventh day and the 14 th day after administration,and the experimental chickens were examined by gross dissection and liver and kidney histopathology.The aim was to determine whether the effective doses of these compounds had toxic effects on chickens.The results showed that 100 mg/kg and above of compound A,especially 150 mg/kg,could delay the weight gain of chickens.At the same time,there was a significant difference in urea nitrogen content between the two groups and the non infection and non administration group(p=0.0216).There was no significant difference between the compound C 100 mg/kg group and the non infected group(p=0.8625).Therefore,it was considered that the Administration Concentration of compound C 100 mg/kg could effectively inhibit the activity of Eimeria tenella and was safe for chickens.