To explore a fast detection method for exogenous avian leukosis virus(ALV) with DF1 cells instead of DF1 supernatants,22 ALV p27 antigen positive and 2 negative anticoagulant blood samples were collected and centrifuged for leukocytes,which were used to inoculated DF1 cell cultures in 9 repeated plates with 24 wells.The supernatants and DF1 cells were collected every other 24 h one by one and stored at-20 ℃,respectively.And then ALV p27 antigen was detected by ELISA.Besides,the otherness and the correlation coefficients of the S/P value between supernatants and DF1 cells was compared and analyzed with SPSS Statistics 17.0.The results showed that 15 positive samples were detected in supernatants at the 8th day,while at the 4th day,all positive samples could be detected in DF1 cells.And at the time when the samples were detected in supernatants,S/P value in DF1 cell was much higher than that in supernatants,and there was a significant difference(P<0.01);Furthermore,the correlation coefficients between DF1 cells cultured 4 d and 5 d and supernatants cultured 9 d were most highest,0.946 and 0.923,respectively.Therefore,there could be the same effect to detect ALV p27 antigen in DF1 cells cultured 4 to 5 d as the classic way as to detect p27 antigen in supernatants cultured 9 d.

Avian leukosis (AL) is one of the most harmful diseases to the poultry industry in China. The detection of the avian leukosis virus (ALV) p27 antigen plays a decisive role in the elimination of avian leukosis. To explore the influence of passaging cells on the detection rate of the ALV p27 antigen, 21 aseptic anticoagulated blood samples were collected from 21 chickens for which the cloacal swabs were positive for the p27 antigen to inoculate two sets of cell culture plates containing DF1 cells. The cells were cultured for 4 d, one set was passaged, and the other set was not. After the DF1 cells had been cultured for 9 d, the ALV p27 antigen in the supernatants of the two sets was detected by ELISA. The results showed that the p27 antigen-positive rate for the passaged cells was 71.43% (15/21), higher than that of the cells that were directly cultured, which was 42.86%. There was a strong correlation, as high as 0.928, with respect to the S/P value of the p27 antigen in the supernatant between the two sets. In conclusion, there was a strong correlation between the results for the passaged and unpassaged cells, and the passage of cells greatly improved the detection of the p27 antigen.

This study was designed to explore the effects of different dosage of allicin on the growth performance and immune function of SPF chickens. A total of 105 7-day-age SPF chickens were randomly divided into three groups:Group A was the control group fed with basic daily diet;Group B and C were the trial groups,fed with adding 150 mg/kg and 300 mg/kg allicin in basal diets,respectively. Each group was weighed at the first to sixth and eighth weeks after fed allicin;antibody againrt Newcastle disease virus (NDV) and H9 subtype avian influenza virus (H9 AIV) in plasma were measured at the third to fifth and the ninth weeks after fed allicin,and the number of erythrocyte,granulocyte and lymphocyte in the whole blood were also measured;6 chickens were randomly picked at the fifth and sixth weeks,and the indexes of the thymus,spleen and bursa of fabricius were measured and compared. The results showed that the weight of group B was higher than others from the forth week after fed allicin,and the weight of group C was always lower than that of group A and B;there was no significant difference among the three groups on antibody levels;The numbers of erythrocyte,granulocyte and lymphocyte of group B and C were higher than group A at the third week (P0.05),and at the fifth week the granulocyte number of group B was obviously higher than group A (P0.05);the bursa of Fabricius and indexes of the thymus of group B were obviously higher than that of group A and C at the fifth and sixth weeks,respectively (P0.05). The results indicated that 150 mg/kg allicin could promote growth performance and immune function of SPF chickens,which were restrained by 300 mg/kg allicin in the basal diets.

By the homology analysis for gp85 genes of 5 strains of ALV-J isolated from Hyline laying hens,the molecular evolution of ALV-J was studied in the present study.The 5 strains of ALV-J were obtained from Beijing,Shanxi and Shandong.The gp85 genes were cloned by PCR and the sequence was measured and compared with 14 published reference ALV-J strains.The homology analysis showed that the 5 isolated strains of ALV-J shared 96.6%(96.4%-96.8%) and 89.6%(89.3%-89.9%) homology with the HPRS-103 strain isolated from white meat-type broiler and SD07LK1 strain isolated from egg-type chickens.The homology of the 5 strains was exceeded 98.1%(98.1%-100%).The result indicated that ALV-J strains from Hyline egg-type chickens may have the same origin,the white meat-type broiler chickens imported abroad.