Fiber effects in nutrition and gut health in pigs

Dietary fiber is associated with impaired nutrient utilization and reduced net energy values. However, fiber has to be included in the diet to maintain normal physiological functions in the digestive tract. Moreover, the negative impact of dietary fiber will be determined by the fiber properties and may differ considerably between fiber sources. Various techniques can be applied to enhance nutritional value and utilization of available feed resources. In addition, the extent of fiber utilization is affected by the age of the pig and the pig breed. The use of potential prebiotic effects of dietary fiber is an attractive way to stimulate gut health and thereby minimize the use of anti-microbial growth promoters. Inclusion of soluble non-starch polysaccharides （NSP） in the diet can stimulate the growth of commensal gut microbes, inclusion of NSP from chicory results in changes in gut micro-environment and gut morphology of pigs, while growth performance remains unaffected and digestibility was only marginally reduced. The fermentation products and pH in digesta responded to diet type and were correlated with shifts in the microbiota. Interestingly, fiber intake will have an impact on the expression of intestinal epithelial heat-shock proteins in the pig. Heat-shock proteins have an important physiological role in the gut and carry out crucial housekeeping functions in order to maintain the mucosal barrier integrity. Thus, there are increasing evidence showing that fiber can have prebiotic effects in pigs due to interactions with the gut micro-environment and the gut associated immune system.

Chicory(Cichorium intybus L.) and cereals differently affect gut development in broiler chickens and young pigs

Dietary fiber, resistant to host-mediated digestion in the small intestine due to lack of endogenous enzymes, impacts many facets of animal health and is associated with gut development especially in young monogastrics. Furthermore, it can be used as in-feed antibiotic alternative. Chicory （Cichorium intybus L.） forage with high content of pectin （uronic acids as building blocks） is a novel class of dietary fiber that is chemically different from cereal grains （with high content of arabinoxylans）. In the present study, we investigated effects of dietary inclusion of chicory forage on digestibility, gut morphology and microbiota in broilers and young pigs. In the chicken experiment, 160 1-d old broiler chicks were fed 3 nutritionally balanced diets for 30 d including a cereal-based diet and 2 diets with part of the cereals substituted with 60 and 120 g/k9 chicory forage （CF60 and CF120], whereas in the pig experiment, 18 seven-wk old Yorkshire pigs were fed 3 diets for 18 d including a cereal-based diet and 2 diets with 80 and 160 g/kg chicory forage inclusion （CF80 and CF160）. Our results showed that young pigs were capable to utilize chicory forage well with higher total tract apparent digestibility （TTAD） of all fiber fractions, particularly uronic acid, compared with the control （P 〈 0.01）. In contrast, a decreased TTAD of all fiber fractions was observed in chickens fed on diet CF120 （P 〈 0.05）. Moreover, diet induced changes in gut morphology were observed in the large intestine of chickens. The alteration of cecal mucosal thickness was further positively correlated with TTAD of non-starch polysaccharides （NSP） and its constituent sugars （P 〈 0.05）. In addition, in pigs, terminal restriction fragment length polymorphism （T-RFLP） analysis of intestinal microbiota revealed substantial dietary effects （cereal control diet vs. chicory forage inclusion） on the relative abundance of 2 dominant bacterial phylotypes （Prevotella sp. vs. Roseburia sp.） respectively （P 〈 0.05）. In conclusion, our data showed that chicory forage （Cichorium intybus L.）, a novel dietary fiber source in animal nutrition, have potential beneficial properties as fiber ingredient in diets for both pigs and chickens.

Fecal microbiome of growing pigs fed a cereal based diet including chicory(Cichorium intybus L.) or ribwort(Plantago lanceolata L.) forage

Background： The purpose of this study was to investigate how inclusion of chicory forage or ribwort forage in a cereal-based diet influenced the fecal microbial community（microbiome） in newly weaned（35 days of age） piglets.The piglets were fed a cereal-based diet without（B） and with inclusion（80 and 160 g/kg air-dry forage） of vegetative shoots of chicory（C） and leaves of ribwort（R） forage in a 35-day growth trial. Fecal samples were collected at the start（D0）, 17（D17） and 35（D35） days after weaning and profiles of the microbial consortia were generated using terminal restriction fragment length polymorphism（T-RFLP）. 454-FLX pyrosequencing of 16 S r RNA gene amplicons was used to analyze the microbial composition in a subset of the samples already analyzed with T-RFLP.Results： The microbial clustering pattern was primarily dependent on age of the pigs, but diet effects could also be observed. Lactobacilli and enterobacteria were more abundant at D0, whereas the genera Streptococcus, Treponema,Clostridium, Clostridiaceae1 and Coprococcus were present in higher abundances at D35. Pigs fed ribwort had an increased abundance of sequences classified as Treponema and a reduction in lactobacilli. However, the abundance of Prevotellaceae increased with age in on both the chicory and the ribwort diet. Moreover, there were significant correlations between the abundance of Bacteroides and the digested amount of galactose, uronic acids and total non-starch polysaccharides, and between the abundance of Bacteroidales and the digested amount of xylose.Conclusion： This study demonstrated that both chicory and ribwort inclusion in the diet of newly weaned pigs influenced the composition of the fecal microbiota and that digestion of specific dietary components was correlated with species composition of the microbiota. Moreover, this study showed that the gut will be exposed to a dramatic shift in the microbial community structure several weeks after weaning.