托曲珠利对断乳奶犊牛亚临床球虫病的防治效果

Effect of Toltrazuril in the Prevention and Treatment of Subclinical Coccidiosis in Weaned Dairy Calves

为观察托曲珠利(TOL)对断乳奶犊牛亚临床球虫病的临床预防和治疗效果,本试验将30头断乳犊牛根据球虫感染情况分为A组(治疗对照组,n=10)、B组(TOL治疗组,n=10)、C组(预防对照组,n=5)和D组(TOL预防组,n=5),其中,A组和B组犊牛均为球虫阳性,C组和D组犊牛均为球虫阴性,所有犊牛饲养在同一圈舍。B组和D组按15 mg/(kg·bw)口服5%TOL混悬液,A组和C组不给药。记录用药后84 d内犊牛粪便样品评分、平均每克粪便卵囊数(OPG)、增重和平均日增重(ADG),评估TOL对犊牛亚临床球虫病的防治效果。结果显示,与A组相比,B组犊牛粪便样品评分在用药后23、28、35和45 d显著降低(P<0.05),14~32 d的粪便样品OPG极显著降低(P<0.01),ADG无显著差异(P>0.05),增重显著提高(P<0.05)。与C组相比,D组犊牛粪便样品评分在用药后19、21、25和35 d显著降低(P<0.05),14~30 d的粪便样品OPG显著降低(P<0.05),首次检出卵囊平均时间推迟了34 d, ADG无显著差异(P>0.05),增重显著提高(P<0.05)。结果表明,使用TOL可有效治疗和预防犊牛亚临床球虫病,并改善因球虫感染对犊牛体重增长造成的不良影响。

This study aims to observe the clinical prevention and treatment effectiveness of toltrazuril(TOL)on subclinical coccidiosis in weaned dairy calves.Thirty weaned calves were divided into four groups based on their coccidia infection status:Group A(treatment control group,n=10),Group B(TOL treatment group,n=10),Group C(prevention control group,n=5),and Group D(TOL prevention group,n=5).Groups A and B consisted of coccidia-positive calves,while Groups C and D consisted of coccidia-negative calves.All calves were housed in the same pen.Groups B and D were administered 15 mg/(kg·bw)of 5%TOL suspension orally,while Groups A and C received no medication.Over an 84-day period,fecal sample scores,the average number of oocysts per gram(OPG)in feces,weight gain,and average daily gain(ADG)were recorded to assess the efficacy of TOL in preventing and treating subclinical coccidiosis in calves.The results showed that compared with Group A,Group B calves had significantly lower fecal sample scores on days 23,28,35,and 45 post-treatment(P<0.05),with a highly significant reduction in fecal OPG from days 14 to 32(P<0.01).Although there was no significant difference in ADG(P>0.05),weight gain was significantly higher in Group B(P<0.05).Compared with Group C,Group D calves exhibited significantly lower fecal sample scores on days 19,21,25,and 35 post-treatment(P<0.05),with a significant reduction in fecal OPG from days 14 to 30(P<0.05),and the average time to first detection of oocysts was delayed by 34 days.There was no significant difference in ADG(P>0.05),but weight gain was significantly higher in Group D(P<0.05).These results indicate that TOL is effective in treating and preventing subclinical coccidiosis in calves and mitigating the adverse effects of coccidia infection on calf weight gain.