Effects of Microbial Feed Additives on Performance of Starter and Growing-finishing Pigs

Abstract

Three trials were conducted to evaluate the effect of lactic acid-producing microbial feed additives (Probiotics) on performance of starting and growing-finishing pigs. Two commercially available probiotics, Probios (L. acidophilus) and Feed-Mate 68 (Streptococcus faecium type Cernelle 68), were used. In the first of two starter trials, 192 crossbred pigs (initial weight 7 kg) were used in a 2 × 4 factorial arrangement of treatments, with Probios and antibiotics (ASP-250, lincomycin, tylosin) as the main effects. Addition of antibiotics, regardless of source, improved (P<.05) average daily gain (ADG) and feed conversion (FC). ADG and FC were improved by 2.6 and 3.6%, respectively, with probiotics (P< .10). A suggestion of an additive effect was observed for lincomycin plus Probios. In the second trial, with 224 pigs, virginiamycin was evaluated in combination with Probios, Feed-Mate 68 and DL-lactic acid. The antibiotic effect was not significant; addition of probiotic products and DL-lactic acid improved FC (P</.05). Probios improved ADG 9.7% and FC 4.4%, while Feed-Mate 68 decreased performance. A growing-finishing trial was conducted with 144 crossbred pigs (average initial weight 34 kg) to determine the effect of probiotics, lincomycin or a combination on ADG and FC of growing-finishing swine. Probiotics did not affect performance, but addition of lincomycin increased ADG by 3.6% (P<.05) and FC by 2.5%(P<.10).