Transgalactooligosaccharides Research Articles

Performance and meat quality traits of slow-growing chickens stimulated in ovo with galactooligosaccharides and exposed to heat stress

In vivo performance, carcass and meat quality traits of slow-growing chickens stimulated in ovo with trans galactooligosaccharides (GOS) and exposed to heat stress were evaluated. On d 12 of egg incubation, 3,000 fertilized eggs (Hubbard JA57) were divided into prebiotic group (GOS) injected with 3.5 mg GOS/egg, saline group (S) injected with physiological saline (only to assess the hatchability rate) and an uninjected control group (C). After hatching, 600 male chicks (300 from GOS and 300 from C) were housed on floor pens (6 pens/treatment, 25 birds/pen) and reared under neutral (TN) or heat stress conditions (HS, 30°C from 36 to 50 d). BW, daily feed intake (DFI), daily weight gain (DWG), feed conversion rate (FCR), and mortality were measured. At 50 d of age, 15 randomly selected birds/treatment/environmental conditions were slaughtered and the pectoral muscle (PM) was collected for analyses. Hatchability was similar among groups. BW of the newly hatched chicks was lower (P < 0.01) in GOS compared to C. Final BW, DWG, DFI, and FCR were not affected (P > 0.05) by GOS. HS reduced final BW (−12.93%, P < 0.001). During finisher phase, DFI and DWG were lower (P < 0.001) and FCR was higher (P < 0.01) in HS compared to TN. Mortality was not affected (P > 0.05) by GOS and HS. Meat from GOS chickens had a higher (P < 0.01) pH and was darker (P < 0.05) compared to C. Proximate composition, cholesterol content, fatty acid profile, and intramuscular collagen properties of PM were not affected by GOS. The HS group showed a lower (P < 0.05) content of both collagen and monounsaturated fatty acids than TN group. Significant interactions between GOS and temperature were found for FA composition. In conclusion, the differences in performance have had an impact on the responses to HS in Hubbard chickens, but not on mortality rate. GOS did not relieve the negative effect of HS on chickens’ performance.

Enrichment of Prebiotics in Foods Using Green Chemistry Approach

Prebiotics is an exciting concept in human nutrition and digestive function for which many physiological and health claims have already been made. There are only few oligosaccharides like inulin, trans galacto-oligosaccharides and lactulose which fulfil all the three strict criteria of prebiotics. The interest in the present prebiotic research has been to justify the health claims of new and unexplored experimental materials using these criteria for prebiotics. Most of the currently available prebiotics in the market are manufactured using chemical or synthetic approach. Synthetic oligosaccharides use chemical processing like isomerisation of lactose for lactulose, trans-galactosylation of lactose for trans-galactooligosaccharides and trans-fructosylation for production of oligofructose. Conversion of sucrose to fructose oligosaccharides is the frequently used method. The enzymes like β-glucosidases, β-galactosidases, β-fructosidase are used for hydrolysis of polysaccharides into oligosaccharides. Conversion of the normal starch to resistant nature is another approach for developing the prebiotics. Synthesis or sequential extractions of prebiotic involve processing of materials with various chemicals. The chemical waste materials of such processes are a big issue for disposal. Thus, use of current chemical approach for the oligosaccharide synthesis need to be reassessed and modified. This can be done using green chemistry approach maintaining the safety issues for health. There is a need of research for finding out better alternatives in production of prebiotics. Use of fruits and vegetables for multifunctional food supplements provides safe alternative for improving the health. Present paper attempts the critical review of reported studies on prebiotic development with an emphasis on green chemistry approaches. Keywords: Fructans, GOS, inulin, prebiotics, resistant starch, synthetic oligosaccharides.

Fiber and prebiotics: mechanisms and health benefits.

The health benefits of dietary fiber have long been appreciated. Higher intakes of dietary fiber are linked to less cardiovascular disease and fiber plays a role in gut health, with many effective laxatives actually isolated fiber sources. Higher intakes of fiber are linked to lower body weights. Only polysaccharides were included in dietary fiber originally, but more recent definitions have included oligosaccharides as dietary fiber, not based on their chemical measurement as dietary fiber by the accepted total dietary fiber (TDF) method, but on their physiological effects. Inulin, fructo-oligosaccharides, and other oligosaccharides are included as fiber in food labels in the US. Additionally, oligosaccharides are the best known “prebiotics”, “a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-bring and health.” To date, all known and suspected prebiotics are carbohydrate compounds, primarily oligosaccharides, known to resist digestion in the human small intestine and reach the colon where they are fermented by the gut microflora. Studies have provided evidence that inulin and oligofructose (OF), lactulose, and resistant starch (RS) meet all aspects of the definition, including the stimulation of Bifidobacterium, a beneficial bacterial genus. Other isolated carbohydrates and carbohydrate-containing foods, including galactooligosaccharides (GOS), transgalactooligosaccharides (TOS), polydextrose, wheat dextrin, acacia gum, psyllium, banana, whole grain wheat, and whole grain corn also have prebiotic effects.

In vitroeffects of phosphatidylcholine andtransgalactooligosaccharides on the production of 1,2-sn-diacylglycerol byBifidobacterium longumbiovarinfantis

To investigate the production of the tumour promoter 1,2-sn-diacylglycerol (DAG) by a human gut isolate of Bifidobacterium longum biovar infantis. Bifidobacterium longum biovar infantis was grown in vitro using anaerobic static batch cultures in the presence of phosphatidylcholine (PC) and trans-galactooligosaccharides (TOS). Production of DAG was found to be dependent upon the presence of PC, while TOS had a reducing effect. Considerable differences in morphology, growth and metabolic end products from the micro-organism were observed under the different culture conditions. Our results have provided evidence that B. longum biovar infantis can produce DAG in vitro and that a prebiotic exerted a reducing effect upon this production. The results presented in this study demonstrate an ability of ostensibly beneficial member of the colonic environment to produce unwanted compounds under certain conditions. Therefore, it may be important that a combination of substrates and other factors are assessed when studying the behaviour of any bacterial group or species, especially when designing the dietary interventions.

Nutrient digestibility, faecal physicochemical characteristics and bacterial glycolytic activity of growing pigs fed a diet supplemented with oligofructose or trans-galactooligosaccharides

Abstract The effect of oligofructose (FOS) or trans-galactooligosaccharides (TOS) inclusion at 10 g/kg diet for growing pigs, at the expense of cornstarch (CON), on growth performance, nutrient digestibilities, and faecal physicochemical parameters was determined. In addition, concentration of volatile fatty acids (VFA) and bacterial α-glucosidase, β-glucosidase, β-galactosidase and β-glucuronidase activities in faeces were determined as markers of intestinal microflora metabolic activity. Twelve 35-day-old castrated pigs were allocated to CON, FOS and TOS dietary treatments for an experimental period of 4 weeks. Dietary treatments did not affect animal growth performance. FOS and TOS pigs tended to have a lower faecal output than CON pigs by approximately 6.0% and 1.7% respectively. FOS and TOS did not affect total tract apparent digestibility of dry matter, organic matter, fat, crude protein, crude fiber, ADF and cellulose. Digestibility of carbohydrate components such as nitrogen free extract and NDF was significantly (P ≤ 0.05) higher in TOS pigs compared to CON and FOS. Digestibility of hemicellulose in TOS pigs did not differ from FOS but was significantly higher from CON. The experimental period had a significant effect on most of the parameters determined. There were no significant (P ≤ 0.05) differences between treatments regarding total VFA concentration and faecal bacterial enzyme activities. Nevertheless, an increased saccharolytic activity in the gut of FOS and TOS pigs could be postulated by the trends for apparently higher VFA concentration and bacterial α-glucosidase and β-galactosidase activities.

Effect of fructo-oligosaccharides and transgalacto-oligosaccharides on microbial populations and microbial activity in the gastrointestinal tract of piglets post-weaning

Abstract An in vivo experiment was conducted with newly weaned piglets to study the effect of fructo-oligosaccharides (FOS) and transgalacto-oligosaccharides (TOS) on microbial populations and activity in the gastrointestinal tract. Thirty 28-day-old piglets were fed a semi-synthetic control diet or the control diet supplemented with 40 g FOS or TOS per kg ( n = 10). After 4 weeks, the piglets were slaughtered and the gastrointestinal contents were removed for analysis. Results demonstrated that the number of yeast was significantly increased in the distal small intestine, caecum and colon of piglets fed the FOS diet ( P P Bifidobacterium boum (0.71), B. suis (0.15), B. pseudolongum (0.10) and B. choerinum (0.03) based on 16S rRNA gene sequencing. The population of culturable anaerobic bacteria, lactobacilli and enterobacteria were not affected by the experimental diets. The FOS diet affected fermentation patterns in the caecum and proximal colon with significantly higher molar proportions of butyric acid ( P P

In vitro fermentation of fructo-oligosaccharides and transgalacto-oligosaccharides by adapted and unadapted bacterial populations from the gastrointestinal tract of piglets

An in vitro study was performed to investigate the fermentation of fructo-oligosaccharides (FOS) and transgalacto-oligosaccharides (TOS) by bacteria harvested from the gastrointestinal tract of piglets. In addition, the apparent ileal digestibility of FOS and TOS was measured. Thirty piglets were fed either a semi-synthetic control diet or the control diet supplemented with 40 g FOS or 40 g TOS per kg ( n = 10). After 29 days, the piglets were killed and the gastrointestinal contents collected for the in vitro experiment and chemical analysis. The results demonstrated that bacteria from the stomach were nearly incapable of degrading FOS and TOS, whereas bacteria from the distal small intestine to some extend fermented FOS and TOS. Fermentation of FOS and TOS with bacteria from the stomach and distal small intestine was not affected by the dietary treatment of the piglets. Bacteria from the caecum and mid colon of the piglets showed the highest capacity to degrade FOS and TOS in vitro and the microbiota seemed to adapt to the dietary FOS. Caecal bacteria from piglets fed the FOS diet had tendencies to increased production rate of organic acids ( P < 0.1), propionic acid ( P < 0.1) and valeric acid ( P < 0.1) and significantly higher production rate of butyric acid ( P < 0.05) from FOS as compared with bacteria from piglets fed the control and TOS diet. Colonic bacteria from piglets fed the FOS diet also had significantly higher production rates of butyric acid ( P < 0.05) and capronic acid ( P < 0.01). In addition, significantly lower molar proportions of acetic acid ( P < 0.05) and propionic acid ( P < 0.05), and a significantly higher molar proportion of capronic acid ( P < 0.05) were observed for colonic bacteria from piglets fed the FOS diet as compared with the control diet. Fermentation of TOS by bacteria from the caecum and mid colon was generally not affected by the dietary treatment of the piglets. It was estimated that the capacity for microbial degradation of the dietary FOS and TOS during passage of the stomach and small intestine of the piglets was approximately a proportion of 0.20 for FOS and 0.16 for TOS. The coefficient of apparent ileal digestibility (CAID) was 0.57 (range 0.39–0.89) for FOS and 0.56 (range 0.31–0.82) for TOS. In conclusion, a proportion between 0.20 and 0.60 of FOS and TOS are degraded by the microbiota in the small intestine of piglets and the microbiota of the large intestine adapt to the administration of FOS in the feed.

Dietary galactooligosaccharides affect ileal and total-tract nutrient digestibility, ileal and fecal bacterial concentrations, and ileal fermentative characteristics of growing pigs.

The objective of this study was to evaluate dietary galactooligosaccharide (Gal OS) addition on swine nutrient digestibility, ileal and fecal bacterial populations, and ileal short-chain fatty acid (SCFA) production, and to determine their impact on ileal fermentative characteristics in vitro. Twelve T-cannulated pigs (BW = 25 kg) were fed a diet free of Gal OS for 21 d. On d 22, ileal digesta samples were collected for an in vitro fermentation experiment (Exp. 1). Substrates included: raffinose/stachyose combination (R + S), soy solubles (SS), and transgalactooligosaccharides (TOS). Also included were the non-OS components of SS and TOS. Nine pigs (three donors per treatment) served as ileal effluent donors. Each substrate was fermented in vitro for 6 h, and pH and SCFA and gas production were determined. Pigs then were allotted to three treatments: a Gal OS-free control diet and the control diet with either 3.5% added Gal OS from SS or TOS. Diets, feces, and digesta samples collected weekly for 6 wk on d 6 (feces) and 7 (digesta) were analyzed for DM, OM, CP, and chromic oxide concentrations. Feces and ileal digesta were analyzed for bifidobacteria and lactobacilli populations. Ileal digesta samples were analyzed for SCFA. On d 64, a second in vitro fermentation experiment (Exp. 2) was conducted using ileal effluent from three pigs per treatment and the same substrates used in Exp. 1. In vivo results showed that ileal and total tract DM and OM digestion were decreased (P < 0.05) by addition of both SS and TOS to the diet. Ileal and total-tract N digestibilities were decreased (P < 0.05) by dietary addition of SS. Fecal bifidobacteria and lactobacilli were increased (P < 0.05) by addition of SS and TOS to the diet. Ileal propionate and butyrate concentrations were greater (P < 0.05) for pigs fed diets containing both sources of Gal OS. In vitro results showed that fermentation data were not affected by donor animal adaptation to treatment. For both in vitro experiments, gas and SCFA production were higher (P < 0.05) for R + S than for SS or TOS. Fermentation of R + S resulted in a higher pH (P < 0.05) than did SS or TOS. Fermentation of non-OS components of SS and TOS resulted in more (P < 0.05) gas and SCFA production, and pH values that did not differ (P > 0.05) compared to SS and TOS. The Gal OS used in this study were prebiotics, increasing beneficial bacteria in vivo and SCFA concentrations both in vivo and in vitro.

Effects of dietary oligosaccharides on microbial diversity and fructo-oligosaccharide degrading bacteria in faeces of piglets post-weaning

Newly weaned 4-week-old piglets were fed a semi-synthetic diet supplemented with 40 g fructo-oligosaccharides (FOS) or 40 g transgalacto-oligosaccharides (TOS) per kg replacing 20 g maize starch and 20 g cellulose per kg in the control diet. Faecal samples were collected on days 0, 3, 7, 14 and 28 after weaning and analysed for dry matter, pH, organic acid concentration and distribution, microbial populations and identity of dominant bacterial species able to ferment FOS. The oligosaccharide addition to diets had no effect on growth performance of the piglets. Dietary oligosaccharides and time after weaning did not affect faecal dry matter content. There was no effect of diet on faecal pH and total organic acid concentration, but the pH decreased ( P<0.001) and total organic acid concentration increased ( P<0.001) during the period after weaning. Faecal bacterial populations (total culturable anaerobic bacteria, lactic acid bacteria, lactobacilli, bifidobacteria, coliforms and lactose-negative enterobacteria) were not affected by diet. The faecal population of yeast was significantly higher in piglets fed the TOS-diet as compared to piglets fed the FOS-diet ( P<0.05) and control diet ( P<0.001). The population of yeast was also higher in piglets fed the FOS-diet as compared to those fed the control diet ( P<0.05). In the faeces of piglets fed the control diet, the level of FOS-degrading bacteria was significantly lower than the level of saccharolytic bacteria ( P<0.01). This difference was not observed in the faeces of piglets fed the FOS-diet, indicating that the microbial population changed in response to the dietary FOS. A 16S rDNA-based identification of the FOS-degrading bacteria indicated that several different species of bacteria present in faeces of piglets are able to ferment FOS. It was concluded that oligosaccharide supplementation in diets to piglets after weaning had no effect on growth performance, and no or little effect on physico-chemical characteristics and bacterial populations of faeces. A strong stimulating effect on the faecal population of yeast was observed and the impact of this on pig performance is discussed.

Effects of Dietary Non-Digestible Oligosaccharides on Microbial Characteristics of Ileal Chyme and Faeces in Weaner Pigs

Fructooligosaccharides (FOS) and transgalactooligosaccharides (TOS), which are non-digestible oligosaccharides (NDO), were included at 10 and 40g/kg in an NDO-free control diet at the expense of purified cellulose. Each of the 5 diets was fed to 4 weaner pigs and microbial characteristics of their ileal chyme and faeces were assessed. The NDO-pigs had lower ileal pH than the control pigs. Dietary NDO did not affect the ileal volatile fatty acid concentration, though FOS-pigs had a higher concentration of lactic acid and relatively more iso-valeric acid and less acetic acid than TOS-pigs. The NDO-pigs had lower ileal aerobic bacterial counts than the control pigs, whilst the FOS-pigs had a larger ileal anaerobic bacterial counts than the TOS-pigs. The NDO-pigs had an higher faecal pH and their faecal volatile fatty acid pool contained relatively more iso-butyric acid and iso-valeric acid than the control pigs. The TOS-pigs tended to have higher faecal anaerobic bacterial counts and had a smaller concentration of faecal volatile fatty acid than the FOS-pigs. We concluded that whilst effects at the faecal level may have been partly due to a reduced intake of cellulose, dietary NDO can exert precaecal prebiotic effects in weaner pigs.

Inulin, oligofructose and mineral metabolism — experimental data and mechanism

Numerous investigations performed in animal models in the past 10 years have shown repeatedly that non-digestible oligosaccharides (NDO), such as inulin, oligofructose or transgalacto-oligosaccharides (TOS), stimulate mineral absorption, mainly calcium and magnesium. Long-term beneficial effects on bone health have been indicated by accumulation of bone mineral content in growing rats or prevention of bone loss in ovariectomized rats. However, bone mineral content or density are not necessarily associated with bone quality. In recent studies both oligofructose and calcium prevented loss of trabecular bone area induced by oestrogen deficiency, this, however, occurred at different trabecular shapes. The effects of NDO on mineral metabolism may be based on the enhancement of passive and active mineral transport across the intestinal epithelium, mediated by an increase in certain metabolites of the intestinal flora and a reduction of pH. The possible impact of short-chain fatty acids, butyrate in particular, and of polyamines on the stimulation of mineral absorption capacity, and the interaction of oligofructose and antibiotics is discussed.

Inulin, oligofructose and mineral metabolism - experimental data and mechanism.

Numerous investigations performed in animal models in the past 10 years have shown repeatedly that non-digestible oligosaccharides (NDO), such as inulin, oligofructose or transgalacto-oligosaccharides (TOS), stimulate mineral absorption, mainly calcium and magnesium. Long-term beneficial effects on bone health have been indicated by accumulation of bone mineral content in growing rats or prevention of bone loss in ovariectomized rats. However, bone mineral content or density are not necessarily associated with bone quality. In recent studies both oligofructose and calcium prevented loss of trabecular bone area induced by oestrogen deficiency, this, however, occurred at different trabecular shapes. The effects of NDO on mineral metabolism may be based on the enhancement of passive and active mineral transport across the intestinal epithelium, mediated by an increase in certain metabolites of the intestinal flora and a reduction of pH. The possible impact of short-chain fatty acids, butyrate in particular, and of polyamines on the stimulation of mineral absorption capacity, and the interaction of oligofructose and antibiotics is discussed.

Characterization of a novel beta-galactosidase from Bifidobacterium adolescentis DSM 20083 active towards transgalactooligosaccharides.

This paper reports on the effects of both reducing and nonreducing transgalactooligosaccharides (TOS) comprising 2 to 8 residues on the growth of Bifidobacterium adolescentis DSM 20083 and on the production of a novel beta-galactosidase (beta-Gal II). In cells grown on TOS, in addition to the lactose-degrading beta-Gal (beta-Gal I), another beta-Gal (beta-Gal II) was detected and it showed activity towards TOS but not towards lactose. beta-Gal II activity was at least 20-fold higher when cells were grown on TOS than when cells were grown on galactose, glucose, and lactose. Subsequently, the enzyme was purified from the cell extract of TOS-grown B. adolescentis by anion-exchange chromatography, adsorption chromatography, and size-exclusion chromatography. Beta-Gal II has apparent molecular masses of 350 and 89 kDa as judged by size-exclusion chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively, indicating that the enzyme is active in vivo as a tetramer. Beta-Gal II had an optimal activity at pH 6 and was not active below pH 5. Its optimum temperature was 35 degrees C. The enzyme showed highest V(max) values towards galactooligosaccharides with a low degree of polymerization. This result is in agreement with the observation that during fermentation of TOS, the di- and trisaccharides were fermented first. Beta-Gal II was active towards beta-galactosyl residues that were 1-->4, 1-->6, 1-->3, and 1 <--> 1 linked, signifying its role in the metabolism of galactooligosaccharides by B. adolescentis.

Apparent ileal and total-tract nutrient digestion by pigs as affected by dietary nondigestible oligosaccharides.

The effects of two types of nondigestible oligosaccharides (NDO), fructooligosaccharides (FOS), and transgalactooligosaccharides (TOS) were studied on growing and weanling pigs' nutrient digestion. Dietary NDO were included at the expense of purified cellulose. Twenty-five 57-d-old growing pigs, averaging 15.9+/-.6 kg on d 0 of the experiment, were fed a corn-based control diet or the control with 6.8 or 13.5 g of FOS/kg or 4.0 or 8.0 g of TOS/kg (five pigs per diet). Feces were collected on d 28 to 32, and small-intestinal digesta were collected (slaughter technique) on d 42 to 47 of the experiment. Feeds, feces, and digesta were analyzed for DM, inorganic matter, CP, ether extract, and crude fiber. Dietary NDO did not significantly affect apparent fecal and small intestinal digestion of nutrients in growing pigs. After being fed a NDO-free diet through d 10 after weaning, 38-d-old weanling pigs (n = 20), averaging 10.4+/-.8 kg on d 0 of the experiment, were fed a control diet (based on cornstarch, casein, and oat husk meal) or the control with 10 or 40 g of FOS or TOS/kg (four pigs per diet). Feces and urine were collected on d 13 to 17, and ileal digesta were collected via a postvalve T-cecum cannula on d 33 to 37 of the experiment. Feeds, feces, and digesta were analyzed for DM, inorganic matter, CP, ether extract, starch, NDF, ADF, ADL, Ca, P, Mg, Fe, Cu, and Zn. Nonstarch neutral-detergent soluble carbohydrates (NNSC) completed the mass balance for the carbohydrates. Urine was analyzed for N and minerals. The apparent fecal digestion of NNSC increased in the NDO-supplemented diets. The TOS-fed pigs tended (P<.10) to have a higher apparent fecal digestion of CP than the FOS-fed and control pigs but excreted more N via the urine (P<.01). Nitrogen and mineral balances were not affected. The FOS was nearly completely degraded prececally. Mean fiber digestion was lower at the fecal compared with the ileal level, as was the extent of NDO effects. This indicates that fiber digestion requires more than 2 wk to adapt to dietary NDO. Apparent ileal digestion of hemicellulose increased for the NDO-supplemented diets (P<.05), but that of NNSC decreased (P<.001). Thus, under the well-controlled conditions of this experiment, dietary NDO hardly affected nutrient digestion in well-kept growing and weanling pigs. However, digestion of dietary nonstarch carbohydrates may be affected.

Effects of dietary oligosaccharides on the growth performance and faecal characteristics of young growing pigs

The effects of dietary fructo-oligosaccharides (FOS) and trans-galacto-oligosaccharides (TOS) were studied on growth performance and faecal characteristics of young growing pigs. FOS and TOS are non-digestible oligosaccharides (NDOs); they are not hydrolyzed by enzymes of endogenous origin, but are readily available as substrate for the gastrointestinal microflora. Dietary levels of NDO-rich products were 7.5 and 15 g kg −1 diet for FOS, and 10 and 20 g kg −1 diet for TOS. NDOs were included in an experimental corn-based control diet, which was low in NDOs (190 mg raffinose kg −1) and contained no additional copper, antibiotics or probiotics. NDO-rich products were included at the expense of glucose and purified cellulose. Resulting five experimental diets were fed ad libitum to 9-week old castrated male piglets ( n=10) with an initial body weight (se) of 15.6±0.3 kg. Pigs had received the control diet for 19 days before reaching this body weight. Individual body weights and feed refusals were recorded every 3–4 days during six weeks. Fresh faeces were rectally collected at day 0, day 14, and day 35, and analyzed for NDOs, pH, and dry matter content. Dry matter intake and body weight gain of the NDO-fed pigs were lower than the control pigs ( P=0.039 and P=0.031, respectively) in week one through three. Dietary NDOs did not affect mean growth performance in week one through six. FOS and TOS could not be detected in the faeces. Dietary NDOs did not affect faecal pH. Faecal pH increased with time ( P<0.01). NDO-fed pigs had a lower faecal dry matter content than control pigs ( P=0.062). Pigs fed TOS-rich diets had a lower faecal dry matter content than pigs fed FOS-rich diets ( P=0.061). It is concluded from this experiment that exchanging cellulose for NDOs in young growing pigs' diet results in a temporary depressed feed intake with little or no effects on faecal dry matter content and pH.

Relation between in vivo and in vitro fermentation of oligosaccharides in weaner pigs

Non-digestible oligosaccharides (NDOs), including fructo-oligosaccharides (FOS) and trans-galacto-oligosaccharides (TOS), are not digested by endogenous enzymes, but may be fermented by bacteria such as lactobacilli and bifidobacteria (Tomomatsu, 1994). Thus, dietary NDOs may alter fermentation characteristics of the microflora of the host. In this experiment, in vivo and in vitro fermentation characteristics of NDOs in weaner pigs were studied, using the cumulative gas production technique (Theodorou et al.,1994).A NDO-free control diet (CON), with oatshuskmeal (OHM) as a fibre source, and this diet with 40 g FOS (FOS40) or TOS (TOS40) per kg (w/w against cellulose) was restrictedly fed for 7 weeks (2.6*Em) to 3 groups of four 35-day old individually housed weaner pigs. Total faeces were collected from day 13-18 to determine crude fibre digestibility. Pigs were fitted with a PVTC-cannula on day 21 (Van Leeuwen et al, 1991). Inocula for gas production were anaerobically prepared from faeces (day 14-16) and ileal chyme (day 33-35, via PVTC-cannula). Samples were diluted (1:4) with sterile saline and filtered through cheese cloth. Five ml filtrate were injected into airtight bottles, containing 80 ml growth medium and no substrate (BLA) or 0.25 g FOS, TOS or OHM as sole energy source.