Effects of dietary supplementation with two potassium formate sources on performance of 8- to 22-kg pigs.

Dietary inclusion of salts of organic acids may modulate intestinal microbiota and enhance performance of pigs. Published data on the effects of potassium formate (KF; pH 6.0-8.5) on pig performance are scarce compared with that of potassium diformate (KDF; pH 4.1-4.5). Therefore, the objective was to evaluate the effects of KDF or KF supplementation on performance of 8- to 22-kg pigs. A 35-d growth trial was conducted with 144 PIC pigs (initial BW of 7.9 ± 0.69 kg) with 6 pigs (3 gilts and 3 barrows) per pen and 8 pens per treatment. Pigs were assigned to 3 diets based on corn (Zea mays), wheat (Triticum aestivum), and soybean (Glycine max) meal for each of the prestarter (days 1-14) and starter phases (days 15-35). The basal diet was supplemented with KDF at 1.20% or KF at 1.56% replacing corn starch to create diets 2 and 3, respectively, to provide a constant formate content. The ADG and feed conversion ratio (FCR) were not affected by the addition of KDF or KF during the prestarter phase. Addition of KDF or KF to the basal diet increased (P < 0.01) ADG and final BW and improved FCR (P < 0.05) during the starter and the overall 35-d period. The ADFI was not affected by the treatments. Performance of pigs fed diets supplemented with KF and KDF were similar. Diarrhea incidences were observed during week 1 but no differences were observed (P > 0.05) among treatments in term of the number of antibiotic treatments or fecal consistency scores. Overall, the supplementation of 1.56% KF or 1.20% KF improved performance of weaned pigs.