Fig. 4AFrom: Investigation and analysis of porcine epidemic diarrhea cases and evaluation of different immunization strategies in the large-scale swine farming systemThe duration of PED epidemic with different immunization strategies. All data from the PED outbreak farms in the swine farming system. Bars represent the mean ± standard error. Statistical analyses were performed using two-way ANOVA. ** represents significant difference (p < 0.01)Back to article page