Influences of Plant Extract Supplementation on Performance and Blood Characteristics in Weaned Pigs

One hundred and twenty crossbred pigs [(Duroc$\times$Yorkshire)$\times$Landrace] were used to determine the effects of plant extract (PE) supplementation on performance and blood characteristics in weaned pigs fed a corn-dried whey-SBM based diet. Treatments were 1) NC (antibiotic free basal diet), 2) PC (NC diet+100 ppm apramycin and 100 ppm oxytetracycline), 3) PE 0.1 (NC diet+0.1% plant extract), 4) PE 0.2 (NC diet+0.2% plant extract) and 5) PE+AB (PC diet+0.1% plant extract). Through the entire experimental period, ADG of pigs fed PC (300 vs. 281 g/d), PE 0.2 (310 vs. 281 g/d) and PE+AB (306 vs. 281 g/d) diets was higher than that of pigs fed NC diet (p<0.05). However, no differences were found among the treatments for ADFI and gain/feed. At day 2 after the onset of the experiment, fecal consistency score of pigs fed PC, PE 0.1, PE 0.2 and PE+AB diets was lower than that of pigs fed NC diet. There were no significant differences in red blood cell, white blood cell, lymphocytes, neutrophils and monocytes concentrations of blood among the treatments. In conclusion, PE can be used to replace antibiotics in diets for weaned pigs without negative affects on performance. Optimal PE levels seemed to be 0.2% and the results obtained point out to a synergic effect of the combination of PE and antibiotic on performance in weaned pigs.