Potassium diformate alleviated inflammation of IPEC-J2 cells infected with EHEC

Potassium diformate (KDF) is a kind of formate, which possesses the advantages of antimicrobial activity, growth promotion and preventing diarrhea in weaned piglets. However, the researches of KDF in animal production mostly focused on apparent indexes such as growth performance and the mechanisms of KDF on intestinal health have not been reported. Thus, porcine small intestinal epithelial cells (IPEC-J2) infected with Enterohemorrhagic Escherichia coli (EHEC) was used to investigate the role of KDF on alleviating intestinal inflammation in this study. The 0.125 mg/mL KDF treated IPEC-J2 cells for 6 h and IPEC-J2 cells challenged with 5 × 107 CFU/mL EHEC for 4 h were confirmed as the optimum concentration and time for the following experiment. The subsequent experiment was divided into four groups: control group (CON), EHEC group, KDF group, KDF+EHEC group. The results showed that KDF increased the cell viability and the gene expression levels of SGLT3 and TGF-β, while decreased the content of IL-1β compared with the CON group. The cell viability and the gene expressions of SGLT1, SGLT3, GLUT2, Claudin-1, Occludin and TGF-β, and the protein expression of ZO-1 in EHEC group were lower than those in CON group, whereas the gene expressions of IL-1β, TNF, IL-8 and TLR4, and the level of phosphorylation NF-кB protein were increased. Pretreatment with KDF reduced the content of IgM and IL-1β, the gene expressions of IL-1β, TNF, IL-8 and TLR4 and the level of phosphorylation NF-кB protein, and increased the gene expression of TGF-β and the protein expression of Occludin in IPEC-J2 cells infected EHEC. In conclusion, 0.125 mg/mL KDF on IPEC-J2 cells for 6 h had the beneficial effects on ameliorating the intestinal inflammation because of reduced pro-inflammatory cytokines and enhanced anti-inflammatory cytokines through regulating NF-кB signaling pathway under the EHEC challenge.

The effects of pharmacological levels of zinc, diet acidification, and dietary crude protein on growth performance in nursery pigs

This experiment was conducted to evaluate potential replacements for pharmacological levels of Zn (provided by Zn oxide), such as diet acidification (sodium diformate) and low dietary crude protein (CP: 21 vs 18%) on nursery pig performance and fecal dry matter (DM). A total of 360 weaned pigs (Line 200 × 400, DNA, Columbus, NE; initially 5.90 ± 0.014 kg) were used in a 42-d growth study. Pigs were weaned at approximately 21 d of age and randomly assigned to pens (five pigs per pen). Pens were then allotted to one of eight dietary treatments with nine pens per treatment. Experimental diets were fed in two phases: phase 1 from weaning to day 7 and phase 2 from days 7 to 21, with all pigs fed the same common diet from days 21 to 42. The eight treatment diets were arranged as a 2 × 2 × 2 factorial with main effects of Zn (110 mg/kg from days 0 to 21 or 3,000 mg/kg from days 0 to 7, and 2,000 mg/kg from days 7 to 21), diet acidification, (without or with 1.2% sodium diformate), and dietary CP (21% or 18%, 1.40% and 1.35% in phases 1 and 2 vs. 1.20% standardized ileal digestible Lys, respectively). Fecal samples were collected weekly from the same three pigs per pen to determine DM content. No 2- or 3-way interactions (P > 0.05) were observed throughout the 42-d study for growth performance; however, there was a Zn × acidifier × CP interaction (P < 0.05) for fecal DM on day 7 and for the overall average of the six collection periods. Reducing CP without acidification or pharmacological levels of Zn increased fecal DM, but CP had little effect when ZnO was present in the diet. From days 0 to 21, significant (P < 0.05) main effects were observed where average daily gain (ADG) and gain:feed (G:F) increased for pigs fed pharmacological levels of Zn, sodium diformate, or 21% CP (P < 0.065). In the subsequent period (days 21 to 42) after the experimental diets were fed, there was no evidence of difference in growth performance among treatments. Overall (days 0 to 42), main effect tendencies were observed (P < 0.066) for pigs fed added Zn or sodium diformate from days 0 to 21, whereas pigs fed 21% CP had greater G:F than those fed 18% CP. Pig weight on day 42 was increased by adding Zn (P < 0.05) or acidifier (P < 0.06) but not CP. In summary, none of the feed additives had a major influence on fecal DM, but dietary addition of pharmacological levels of Zn or sodium diformate independently improved nursery pig performance.

The Microbiota Dynamics of Alfalfa Silage During Ensiling and After Air Exposure, and the Metabolomics After Air Exposure Are Affected by Lactobacillus casei and Cellulase Addition

Both inoculants treatment and enzyme treatment promote the reproduction of lactic acid bacteria (LAB) to produce enough lactic acid to lower pH in silage. The present study investigated the microbial community and metabolome in cellulase, Lactobacillus casei, and air treated alfalfa silage. Chopped and wilted alfalfa (first cutting, 29% dry matter) was ensiled without (CON) or with L. casei (1 × 10⁶ cfu g^–1 fresh matter) (LC) or cellulase (20,000IU, 0.5% of fresh matter) (CE) for 56 days, then exposed to air for 3 days (PO). Greater ensiling quality was observed in LC and CE, which had lower pH and higher lactic acid content than CON at 56 days of ensiling and 3 days post-oxygen exposure. Air exposure was associated with decreased lactic acid concentrations and increased yeast and mold counts in all silages. SEM showed that the structure of leaf epicuticular wax crystals were intact in fresh alfalfa, totally decomposed in CON silage, and partly preserved in CE and LC silage. Gas chromatography mass spectrometry revealed that 196 metabolites and 95 differential concentration were present in the 3 days air exposure samples. Most of these metabolites, mainly organic acids, polyols, ketones, aldehydes, are capable of antimicrobial activity. The bacterial communities were obviously different among groups and Lactobacillus developed to a dominant status in all silages. Lactobacillus became dominant in bacterial communities of LC and CE silages from days 7 to 56, and their relative abundances reached 94.17–83.93% at day 56, respectively. For CON silage, until day 56, Lactobacillus dominated the bacterial community with abundance of 75.10%. After 3 days of oxygen exposure, Lactobacillus and Enterococcus were predominant in CON, and Lactobacillus remained dominant in LC and CE silages. The results indicated that, compared to untreated silages, L. casei could be a priority inoculant for alfalfa silage to boost Lactobacillus abundance and improve fermentation quality. Our high-throughput sequencing and gas chromatography mass spectrometry results provide a deep insight into the bacterial community and metabolites in alfalfa silage.

Effects of potassium diformate on the gastric function of weaning piglets

Potassium diformate (KDF), as an acidifier, has been shown to improve growth performance in pigs, but it is not yet known whether KDF regulates gastric function. Thus, the objective of the present study was to investigate the effects of dietary KDF on gastric function in weaning piglets. One hundred and eighty Landrace × Large White piglets (bodyweight = 5.80 ± 0.15 kg) were weaned at 28 days old and randomly allocated into two groups, with six pens in each group and 15 piglets in each pen. Piglets in the control group were fed the basal diet, whereas the KDF-treated group was fed the basal diet supplemented with 10 g/kg KDF. After 35 days of feeding, the KDF treatment improved the bodyweight (P = 0.034) and reduced the relative weight of stomach (P = 0.050), decreased the hydrochloric acid concentration (P = 0.016) in the gastric digesta and the pepsin activity in the gastric oxyntic mucosa (P = 0.001) and increased the lactic acid concentration (P = 0.001) in the gastric digesta. Furthermore, KDF treatment increased the level of somatostatin (SS) (P = 0.009), but did not change the concentration of gastrin (P = 0.497) and the activity of H+-K+-ATPase (P = 0.575) in the gastric oxyntic mucosa. However, KDF treatment downregulated the expression of SS mRNA in the gastric oxyntic mucosa (P = 0.031) and upregulated the mRNA expression of gastrin (P < 0.001) and H+-K+-ATPase (P < 0.001) in the gastric oxyntic mucosa. These results suggest that the effects of KDF on weaning piglets may be related to the regulation of gastric function gene expression.

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.

Response of pigs to dietary inclusion of formic acid and ammonium formate1,2

The objective of this study was to determine the optimal inclusion rate of dietary formic acid-ammonium formate (composition by weight was 62% formic acid and 37% ammonium formate) in nursery and grower-finisher diets or grower-finisher diets only. At weaning (d 21 +/- 2), 224 pigs (equal numbers of gilts and barrows) were blocked by BW within sex (28 pigs per BW block, 4 pigs per pen) and assigned randomly to 1 of 7 dietary treatments within each block. Dietary treatments (TRT), listed as percentage of dietary formic acid-ammonium formate in the nursery (NR) and the grower-finisher (GRF) diets, were as follows (NR and GRF): TRT 1: 0.0 and 0.0; TRT 2: 1.2 and 1.0; TRT 3: 0.0 and 1.0; TRT 4: 1.0 and 0.8; TRT 5: 0.0 and 0.8; TRT 6: 0.8 and 0.6; and TRT 7: 0.0 and 0.6. During the grower 2 (GR2) period, pigs fed treatments containing formic acid-ammonium formate in the nursery diets (TRT 2, TRT 4, and TRT 6) had greater (P < 0.05) ADG and G:F than pigs fed diets containing formic acid-ammonium formate in the grower period only (TRT 3, TRT 5, and TRT 7). Average daily feed intake tended to decrease (NR1, P = 0.07) or decreased (NR2, P < 0.05) for pigs fed formic acid-ammonium formate in the nursery (TRT 2, TRT 4, and TRT 6) compared with pigs fed control diets (TRT 1, TRT 3, TRT 5, and TRT 7). The ADFI also decreased (P < 0.05) during the GR1 and GR2 periods for pigs fed diets containing formic acid-ammonium formate compared with pigs fed control (TRT 1). In the combined nursery data, there was no effect (P > 0.10) of treatment on ADG. Pigs on diets containing formic acid-ammonium formate ate less feed (P < 0.05) and had improved G:F (P < 0.05) compared with pigs on the control treatments (TRT 1, TRT 3, TRT 5, and TRT 7). Combining the grower-finisher phases, G:F was greater (P = 0.05) for pigs fed diets containing formic acid-ammonium formate than for pigs fed the control feed. The efficiency of gain (i.e., G:F) was improved by 3.5% for pigs fed all formic acid-ammonium formate treatments and ranged from 2.3 (TRT 7) to 5.9% (TRT 4) compared with pigs fed control (TRT 1). Combining all phases from nursery to finisher, the G:F ratio tended (P = 0.08) to be greater for pigs fed formic acid-ammonium formate compared with pigs fed control. The efficiency of gain was improved by 3.0% for pigs fed all formic acid-ammonium formate treatments, ranging from 1.8 (TRT 7) to 5.2% (TRT 4), compared with pigs fed the control diet (TRT 1).

Reduced use of antibiotic growth promoters in diets fed to weanling pigs: dietary tools, part 2

Diets formulated to maximize performance of weanling pigs need to support the development of intestinal tissue, support intestinal colonization with beneficial, mainly lactic acid-producing bacteria, and support development of the intestinal and overall immune system. This objective is not likely to be achieved using one single strategy, but there is strong evidence that diets formulated with cereal grains other than corn, with a low concentration of crude protein and with the use of direct-fed microbials, will improve intestinal health and performance of weanling pigs. Further improvements may be observed if the grain part of the diet is fermented prior to feeding or if the diet is fed in a liquid form, but the need for specialized equipment limit the implementation of this strategy. Dietary supplements such as essential oils and nucleosides or nucleotides may also be useful, but more research is needed to verify the effects of these substances.

Dietary self-selection for organic acids by the piglet

Two feeding trials using 48 weaned crossbred piglets each were carried out to determine the effect of acidifying diets with potassium diformate (K-diformate), formic or sorbic acid on dietary preferences in piglets. In Exp. 1 two reference groups were fed either an unacidified diet or a diet containing 2.4% of K-diformate with no choice for selection. Furthermore, piglets in choice group 1 and 2 had the choice between an unacidified diet and a diet supplemented with 1.2 and 2.4% K-diformate, respectively. In Exp. 2, animals of three reference groups received exclusively an unacidified diet or diets supplemented with 1.2% formic acid or 1.2% sorbic acid, respectively. The animals of the choice groups had the choice between an unacidified diet and diets with 1.2% formic acid or 1.2% sorbic acid, respectively. In Exp. 1 average daily feed intake, daily gain and feed conversion ratio were 751 g, 458 g and 1.64 kg/kg, respectively, with no significant differences between treatments. In both choice feeding groups animals chose the diets on offer at random (each around 50%). In Exp. 2 growth and feed intake were not affected by the treatment, but feed conversion ratio was enhanced due to the 1.2% formic acid supplementation. Animals of both organic acid choice groups showed a significant preference for the unacidified diets in each experimental week. The formic acid and sorbic acid diets represented on average only 13.5% and 23.5% of the total feed intake. The present results demonstrate that the inclusion of 1.2% sorbic or formic acid or 2.4% of K-diformate in piglet diets has no negative impact on feed intake, but in a situation of choice feeding, piglets will refuse diets acidified with 1.2% formic or sorbic acid, presumably because of negative taste cues. Acidifying the diets with varying amounts of a K-diformate had no effect on dietary preferences of piglets.