Effect of antibiotics and synbiotic on growth performance, nutrient digestibility, and faecal microbial shedding in growing-finishing pigs

This study evaluated the efficacy of antibiotics and a synbiotic in growing-finishing pigs. One hundred twenty-eight pigs (25.29 +/- 1.33kg) were randomly assigned to 4 dietary treatments: (1) control, basal diet throughout the experiment (CON); (2) basal diet during days 0-42 and basal diet supplemented with synbiotic (1g/kg probiotics and 1g/kg prebiotic) during days 42-119 (CS); (3) basal diet supplemented with 1g/kg antibiotics during days 0-42 and basal diet during days 42-119 (AC); (4) basal diet supplemented with 1g/kg antibiotics during days 0-42 and basal diet supplemented with synbiotic during days 42-119 (AS). During days 0-42, pigs fed the AC and AS diets had higher average daily gain and gain to feed ratio compared with pigs offered CON and CS diets (P<0.05). Pigs offered the AC and AS diets had greater (P<0.05) apparent total tract digestibility of dry matter and gross matter (days 40-42) and lower (P<0.05) counts of lactic acid bacteria (day 42) compared with those fed the CON and AC diets. In conclusion, these results demonstrate that supplementation with synbiotic in pigs had no effects on growth performance, nutrient digestibility, and faecal microbial shedding after supplementation with or without antibiotics in growing phase.