LAUSR

Abstract This study investigated the effect of a synergistic blend of free and buffered organic acid (FMP) on the performance of piglets born to sows supplemented with a blend of short- and medium-chain organic acids (SGG) during the late gestation and lactation period. A total of 150 multiparous sows (n = 50/treatment, Landrace × Yorkshire) were blocked (2.4 parity) and assigned to 1 of 3 dietary treatments: CON - corn-soybean meal-based basal diet, SGG-Low − CON+ 1.5 kg/ton SGG, and SGG-High − CON + 3kg/ton SGG. During weaning, 600 piglets (6.72 ± 0.5kg) which weaned from sows supplemented with 3 levels of SGG were allocated to 2 weaner diets (Control and FMP - 3kg/ton) following 3 × 2 factorial arrangement. Supplemental effects on performance were measured at d0–d21 and d 21–42, and the entire period. Pigs fed with FMP and born to sows supplemented with SGG-High gained more weight and ate more (p < 0.05) compared with those in the CON group in both phases, and with SGG-Low in the second phase. Over the entire post-weaning period, piglets born to sows supplemented with SGG-Low and SGG-High had a higher average daily gain (ADG) and body weight (BW) (p < 0.05). Regardless of sow treatment, pigs fed with an FMP diet had higher ADG (p < 0.001), BW (p = 0.045), and a lower feed conversion ratio (p = 0.033). Also, feeding FMP diets reduced the fecal Escherichia coli and Clostridium perfringens counts at d42. The current study indicates that sows fed SGG supplement had a positive carry-over effect on the post-weaning growth rate, and FMP supplement enhances the growth performance and reduced the number of C. perfringens and E. coli. Thus, the application of 3 kg/ton of SGG in sows’ diet and subsequent feeding of piglets with FMP would be an effective strategy to improve growth rate and reduce pathogenic bacteria in post-weaned piglets.