绵马贯众可溶性粉对人工感染鸡传染性法氏囊病的疗效评价

通过建立人工感染鸡传染性法氏囊病病毒(IBDV)模型,本试验旨在验证绵马贯众可溶性粉对IBDV的治疗效果。试验将95只21日龄的SPF鸡随机分为7组,包括绵马贯众可溶性粉高(198 mg/kg)、中(99 mg/kg)、低剂量组(50 mg/kg)及朝鲜绵马贯众组(99 mg/kg)、黄芪多糖组(99 mg/kg)、感染对照组(染毒不给药)和健康对照组。以IBDV LX毒株经鼻腔感染36 h后,连续口服以上药物5 d,评价其增重率、治愈率、成活率和免疫器官指数。结果显示:①人工感染IBDV后,绵马贯众可溶性粉中、低剂量组相对增重率均极显著高于朝鲜绵马贯众组(P<0.01),绵马贯众可溶性粉低剂量组显著高于绵马贯众可溶性粉中剂量组和黄芪多糖组(P<0.05),且绵马贯众可溶性粉中剂量组与黄芪多糖组相比差异不显著(P>0.05);②绵马贯众可溶性粉高、中、低3个剂量组成活率分别为80%、80%和73.3%,均显著高于朝鲜绵马贯众组(66.7%)、黄芪多糖组(53.3%)和感染对照组(60.0%)(P<0.05);其相对应的治愈率也均显著高于朝鲜绵马贯众组和黄芪多糖组(P<0.05)。③在胸腺指数、脾脏指数方面,绵马贯众可溶性粉中、低剂量组与朝鲜绵马贯众组、黄芪多糖组相比差异均不显著(P>0.05),但显著高于感染对照组(P<0.05);法氏囊指数差异均不显著(P>0.05)。结果显示绵马贯众可溶性粉以50 mg/kg连续口服5 d,通过提高胸腺指数和脾脏指数而发挥免疫增强功效,有效治疗人工感染鸡传染性法氏囊病,且成活率和治愈率均高于黄芪多糖。

Evaluation of Efficacy of Rhizoma Dryopteris Crassirhizomae Soluble Powder against Artificial Infection with Infectious Bursal Disease Virus

The present study was aimed to determine the efficacy of Rhizoma Dryopteris Crassirhizomae (RDC) soluble powder in artificial infection with infectious bursal disease virus (IBDV). Firstly, SPF chicken were inoculated with the IBDV LX strain in order to induce virus infectious model, and then the chicken of high,middle,low 3 groups were administered orally with 198, 99 and 50 mg/kg RDC soluble powder while the chicken were administered with Korean RDC oral solution or Astragalus polysaccharide for 5 days as the control group. Meanwhile, chicken inoculated with IBDV and without IBDV were regarded as the infectious control and healthy control groups. Body weight gain, cure rate, survival rate and immune organ index were employed to determine the efficacies. After experimental infection with IBDV, an extremely significant increase of body weight gain was found in the RDC soluble powder middle and low dose groups compared to Korean RDC group (P<0.01).RDC soluble powder low dose group was significantly higher than RDC soluber powder middle dose group and Astragalus polysacharide group (P<0.05), however, no significant difference was found between RDC soluble powder middle dose group and Astragalus polysaccharide group (P>0.05). With respect to the survival rate, 80% chicken recovered from IBDV infection in the RDC soluble powder high,middle,low dose groups, which were significantly higher compared to Korean RDC group (66.7%) and Astragalus polysaccharide group (53.3%) (P<0.05). In terms of immune organ index, the significant increase of thymus and spleens indexes was found in RDC soluble powder middle and low does groups compared to that of the infectious control group (P<0.05). However, no significant difference of bursal index was found among RDC soluble powder high,middle and low dose groups, Korean RDC group and Astragalus polysaccharide group (P>0.05).In summary, chicken administered orally with 50 mg/kg RDC soluble powder for 5 days would contribute to the immune activation by improvement of thymus and spleen indexes, leading to high survival rate against the artificially challenge with IBDV. With respect to survival rate and recovery protection, it was higher than that of Astragalus polysaccharide.