Efficacy of organic acids as an alternative to antibiotic growth promoters in weaned pigs

The objective of the experiment was to compare effects of dietary supplementation of organic acids (ProHacid Advance, PRO) and antibiotics on growth performance, diarrhea incidence, frequency of antibiotic treatment, and E. coli shedding in weaned pigs. A total of 224 crossbred weaned pigs [(Yorkshire x Landrace) x Duroc; 29 days old)] were allotted to 1 of 4 treatments with 7 replicate pens of 8 pigs each according to sex, litter origin and weight in an RCBD. The 4 dietary treatments included (1) basal diet + 50 mg/kg neomycin and 10 mg/kg enramycin (positive control, PC), (2) basal diet without antibiotics (negative control, NC), (3) As 2 + 0.25% PRO, and (4) As 2 + 0.5% PRO. Over a 4-week study, the results showed that there were no differences in the average daily gain and average daily feed intake of pigs among the 4 treatments (P = 0.328). However, pigs fed the PC diet (1.642) and 0.25% PRO-supplemented diet (1.641) had a lower feed to gain ratio (P < 0.05) than those fed the NC diet (1.808). The diarrhea incidence of pigs fed the 0.25% PRO-supplemented diet (7.36%) was lower (P < 0.01) than that of pigs fed the PC diet (11.61%), NC diet (16.70%), and 0.5% PRO-supplemented diet (10.08%). The frequency of antibiotic treatment of pigs consuming the 0.25% PRO-supplemented diet (4.67%) was lower (P < 0.01) than that of pigs consuming the PC diet (7.33%), NC diet (9.53%) and 0.5% PRO-supplemented diet (7.65%). No differences were found in the number of fecal E. coli among the 4 treatments. In brief, 0.25% PRO added to a nursery pig diet would be considered a potential alternative to the use of antibiotics in feed, but further research on this aspect is needed