Effects of dietary crude protein level and sodium butyrate protected by medium-chain fatty acid salts on performance and gut health in weaned piglets.

To reduce the use of antibiotics, research into nutritional strategies designed to improve the gut health of weaned pigs is underway. This study sought to examine the effects of reducing dietary crude protein (CP) and/or supplementing the feed with sodium butyrate protected by the sodium salts of medium-chain fatty acids on the growth performance and gut health of weaned piglets. Ninety-six weaned piglets (Landrace × large white, 21 days of age) were allotted to four experimental treatments for 14 d. The experimental design was factorial with 2 CP levels and 2 feed-additive doses (0 vs. 1 kg/t). Results showed that reducing CP from 22.2% to 18.8% diet had no effect on piglet growth performance parameters during the first post-weaning week (P > 0.05), but did compromise growth in the second week (P = 0.011), impacting overall growth performance results (P = 0.019). Nonetheless, dietary CP level reduction led reducing crypt depth (P = 0.03657). In addition, Lactobacillus counts that were increased in the ileum (P = 0.032) and reduced in the colon (P = 0.032). Furthermore, apparent ileal digestibility of organic matter (P = 0.026) and fecal consistency (P < 0.05) were improved throughout the experiment. Moreover, in piglets fed diets containing 22.2% CP, the use of the feed-additive tended to improve the gain-to-feed ratio (P = 0.091) compared to those fed supplemented diets containing 18.8% CP. In addition, feed supplementation increased ileal numbers of goblet cells (P = 0.036), as well as apparent ileal digestibility of dry matter (P = 0.057) and organic matter (P = 0.003). Supplementation also had beneficial effects on the microbiota of the colon, increasing Lactobacillus counts (P = 0.006) and diminishing Enterobacteriaceae counts (P = 0.003), as well as affecting microbial metabolite profiles in that acetic acid concentrations tended to be increased (P = 0.088) and valeric acid concentrations were reduced (P = 0.002). These findings support the use of both strategies can improve the gut health of weaned piglets and prompt further research into the possible benefits of combining these two nutritional strategies on gut health and growth performance.

Reducing dietary levels of crude protein (CP) and the use of feed-additives such as sodium butyrate protected by medium-chain fatty acid salts are currently under investigation as nutritional strategies with beneficial effects on the intestinal barrier, and consequently on the health of weaned piglets. The intestinal barrier is a dynamic complex ecosystem that includes morphological structure and microbial composition. Reducing CP intake from 22.2% to 18.8% in piglets was found here to compromise their growth 2 wk after weaning. However, considering the effect of reducing CP on gut health, crypt depth was reduced and the Lactobacillus population was expanded in the ileum and diminished in the colon. In addition, organic matter digestibility and fecal consistency were improved. Supplementation with sodium butyrate protected by the sodium salts of medium-chain fatty acids at 1 kg/t increased the number of mucin-secreting cells, thereby reinforcing the intestinal barrier, and improving ileal digestibility. In addition, it modified the microbiota in the colon. These findings on different parameters of intestinal barrier prompt further investigation into the effects of both strategies on gut health and growth performance of piglets.

Short Communication: Evaluation of Intestinal Release of Butyric Acid from Sodium Butyrate Protected by Salts of Medium-Chain Fatty Acids in Broiler Chickens.

Butyric acid has received great attention as a feed additive to maintain or increase the gut integrity and health of broiler chickens. Particularly, the protection of butyrate is under research to allow slow intestinal release of butyric acid and to promote its beneficial effects throughout the intestine. This study evaluated in vivo the intestinal release of butyric acid from sodium butyrate protected by salts of medium-chain fatty acid in broilers. Brilliant blue was used as an inert marker, so it was included in the feed additive that broilers ingested for two days. The gastrointestinal tract was then colored in blue from jejunum and backward. Considering the digesta color of the broilers non-supplemented as blank, it allowed quantification of the amount of brilliant blue, and consequently, butyric acid delivered in the intestine from the protected feed additive. Few traces of butyric acid were released in the duodenum and proximal jejunum, whereas the major amount (45.9%) was delivered in the distal ileum (p < 0.001). These results suggest that this in vivo approach allows for evaluation of the intestinal delivery of butyric acid supplemented as protected sodium butyrate by medium-chain fatty acids, showing a gradual intestinal release of butyric acid in broiler chickens.

Impact of in-feed sodium butyrate or sodium heptanoate protected with medium-chain fatty acids on gut health in weaned piglets challenged with Escherichia coli F4.

Short and medium-chain fatty acids (SCFA and MCFA, respectively) are commonly used as feed additives in piglets to promote health and prevent post-weaning diarrhoea. Considering that the mechanism and site of action of these fatty acids can differ, a combined supplementation could result in a synergistic action. Considering this, it was aimed to assess the potential of two new in-feed additives based on butyrate or heptanoate, protected with sodium salts of MCFA from coconut distillates, against enterotoxigenic Escherichia coli (ETEC) F4+ using an experimental disease model. Two independent trials were performed in 48 early-weaned piglets fed a control diet (CTR) or a diet supplemented with MCFA-protected sodium butyrate (BUT+; Trial 1) or sodium heptanoate (HPT+; Trial 2). After 1 week of adaptation, piglets were challenged with a single oral inoculum of ETEC F4+ (minimum 1.4 · 109 cfu). One animal per pen was euthanised on days 4 and 8 post-inoculation (PI) and the following variables assessed: growth performance, clinical signs, gut fermentation, intestinal morphology, inflammatory mediators, pathogen excretion and colon microbiota. None of the additives recovered growth performance or reduced diarrhoea when compared to the respective negative controls. However, both elicited different responses against ETEC F4+. The BUT+ additive did not lead to reduce E. coli F4 colonisation but enterobacterial counts and goblet cell numbers in the ileum were increased on day 8 PI and this followed higher serum TNF-α concentrations on day 4 PI. The Firmicutes:Bacteroidetes ratio was nevertheless increased. Findings in the HPT+ treatment trial included fewer animals featuring E. coli F4 in the colon and reduced Enterobacteriaceae (determined by 16S RNA sequencing) on day 4 PI. In addition, while goblet cell numbers were lower on day 8 PI, total SCFA levels were reduced in the colon. Results indicate the efficacy of MCFA-protected heptanoate against ETEC F4+ and emphasise the potential trophic effect of MCFA-protected butyrate on the intestinal epithelium likely reinforcing the gut barrier.

Exploring Additive, Synergistic or Antagonistic Effects of Natural Plant Extracts on In Vitro Beef Feedlot-Type Rumen Microbial Fermentation Conditions.

Six Essential oils (EO) (tea tree oil-TeTr, oregano oil-Ore, clove bud oil-Clo, thyme oil-Thy, rosemary oil-Ros, and sage oil-Sag) in Experiment 1; and different combinations of selected oils in Experiment 2, were evaluate at four doses in an in vitro microbial fermentation system using ruminal fluid from beef cattle fed a 10:90 straw: Concentrate diet. In Experiment 1, TeTr, Ore, Clo and Thy improved rumen fermentation profile in a direction consistent with better feed utilization. In Experiment 2, TeTr mixed with Thy, Ore, Thy + Ore or Clo at 200 and 400 mg/L increased the molar proportion of propionate and decreased that of acetate, and the acetate to propionate ratio. However, the size of the effect was similar to that obtained with TeTr alone, suggesting that effects were not additive. When Thy, Ore or Thy + Ore where mixed with Clo, most effects on rumen fermentation profile disappeared, suggesting an antagonistic interaction of Clo with Thy and Ore. Results do not support the hypothesis of additivity among the EO tested, and antagonistic effects of Clo mixed with Thy or Ore were demonstrated at least in a low pH, beef-type fermentation conditions.

Soybean Lecithin High in Free Fatty Acids for Broiler Chicken Diets: Impact on Performance, Fatty Acid Digestibility and Saturation Degree of Adipose Tissue.

Two experiments were conducted to evaluate the inclusion of soybean lecithin with a high free fatty acid content (L) in starter and grower-finisher broiler diets, as well as its influence on performance, energy and fatty acid (FA) utilization and the FA profile of the abdominal fat pad (AFP). A basal diet was supplemented with soybean oil (S; Experiment 1) or acid oil (AO; Experiment 2) at 3%, and increasing amounts of L (1%, 2% and 3%) were included in replacement. The inclusion of L did not modify performance parameters (p > 0.05). The S replacement by L reduced energy and total FA utilization (p ≤ 0.05) in starter diets; however, in grower-finisher diets, a replacement up to 2% did not modify energy and FA utilization (p > 0.05). The AO substitution by L produced no modifications on energy and FA utilization (p > 0.05) during the starter phase, while the blend of 1% of AO and 2% of L resulted in the best combination in terms of the FA digestibility. The FA profile of the AFP reflected the FA composition of diets. The addition of L could replace, up to 2% or be blended with AO in broiler grower-finisher diets as an energy source.

Response of gastrointestinal fermentative activity and colonic microbiota to protected sodium butyrate and protected sodium heptanoate in weaned piglets challenged with ETEC F4.

This study aimed to evaluate the potential of two new fat-protected butyrate or heptanoate salts to improve gut health and control post-weaning colibacillosis in weaning piglets challenged with enterotoxigenic Escherichia coli (ETEC) F4+, particularly focusing on their impact on intestinal microbiota and fermentative activity along the gastrointestinal tract (GIT). Seventy-two 21-d-old pigs were fed a plain diet (CTR) or supplemented with sodium butyrate (BUT) or sodium heptanoate (HPT), both at 0.3%. After a week of adaptation, animals were orally challenged at days 8 and 9 with 5.8 · 109 and 6.6 · 1010 cfu, respectively, and were euthanised on d 4 and d 8 post-inoculation (PI) (n = 8) to collect blood, digesta and tissue samples and characterise microbial groups, pathogen loads (qPCR), fermentation, ileal histomorphometry and immune markers. Colonic microbiota was analysed by 16S rRNA gene MiSeq sequencing. Supplementing both acid salts did not compensate clinical challenge effects nor performance impairments and neither histomorphometry nor serum biomarkers. Changes in the gastric fermentative activity were registered, BUT reducing lactic acid concentrations (day 8 PI), and with HPT fewer animals presenting detectable concentrations of propionic, butyric and valeric acids. At ileum BUT increased acetic acid concentration (day 8 PI), and both additives reduced short-chain fatty acids (SCFA) in the colon. Increases in enterobacteria and coliforms counts in ileal digesta (day 4 PI, p < 0.10) and mucosa scrapes (p < 0.05) were registered although E. coli F4 gene copies were unaffected. Regarding changes in the colonic microbiota (day 4 PI), Prevotellaceae and Prevotella were promoted with BUT supplementation whereas only minor groups were modified in HPT-treated animals. Summarising, although the pathogen loads or inflammatory mediators remained unresponsive, butyrate and heptanoate showed a significant impact on microbial fermentation along the whole GIT, being able to modify different bacterial groups at the colon. It could be hypothesised that these effects might be mediated by a carry-over effect of the changes observed in gastric fermentation, but possibly also to a better nutrient digestion in the foregut as a result of the reduced colonic SCFA concentrations.

Effects of dietary supplementation of Bacillus amyloliquefaciens CECT 5940 and Enterococcus faecium CECT 4515 in adult healthy dogs.

The aim of this study was to evaluate the effect of a probiotic preparation consisting of two probiotic strains, Bacillus amyloliquefaciens CECT 5940 and Enterococcus faecium CECT 4515 (each 5 · 10(8) CFU/g feed), on faecal consistency, faecal microbiology and nutrient digestibility in adult healthy dogs. Sixteen beagles (eight males and eight females) were divided into two groups: the Control group (CON), which was fed the basal diet, and the probiotic group (PRO), which received the basal diet supplemented daily with 1 · 10(8) CFU for 39 consecutive days. Faecal score was assessed before (BS) and throughout the supplementation period (SP). Fresh faecal samples were collected before supplementation, before finishing the supplementation period and after 6 days of withdrawal for microbial enumeration and pH measurement. During the supplementation period, a digestibility trial was performed. There were no differences in faecal scores or the digestibility coefficients between groups. Between groups no statistical differences were found in most microbiota analysed or in faecal pH. However, during the supplementation period, pathogenic clostridia dropped significantly in Group PRO (5.64 vs. 2.94 ± 0.53 CFU/g faeces; p < 0.001), when compared with the period BS. The use of the probiotic preparation had no impact on nutrient digestibility by adult healthy dogs; however, it could stabilise faecal microbiota by decreasing pathogenic clostridia.