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The lesser mealworm (LMW, Alphitobius diaperinus (Panzer); Coleoptera: Tenebrionidae) is increasingly used as a novel food and feed source. The feed materials on which this insect species is reared may contain residues of insecticides from agricultural use. The objective of this study was to determine whether selected insecticides, spiked to the substrate, could bioaccumulate in LMW and/or affect growth or survival. Insecticides were selected and spiked at concentrations equal to the legal limit in EU. Tested substances were chlorpyrifos, propoxur, imidacloprid, spinosad, tebufenozide, fipronil, pirimiphos methyl, cypermethrin, and the synergist piperonyl butoxide (PBO). Cypermethrin and PBO were also tested together. Insecticide concentrations in the spiked substrate and larvae were determined by LC-MS/MS. Concentrations in the larvae were largely below the limit of quantification, meaning that bioaccumulation did not occur. Significant reductions in total yield were observed for spinosad (present in the substrate at 1.6 mg/kg) and imidacloprid (0.12 mg/kg). Spinosad is one of few insecticides that is permitted to be used in organic agriculture, which raises questions over the safety of organic produce for insect rearing. More research on the safety of organic produce treated with this insecticide for rearing of LMW is therefore highly recommended. The reported harmful effects of insecticide residues on LMW need to be accounted for by lowering the current legal limits or reconsidering approval for use. More research is advised particularly on sublethal effects of insecticide residues on LMW on adult beetles.

To quantify the energy value of fermentable starch, 10 groups of 14 pigs were assigned to one of two dietary treatments comprising diets containing 45% of either pregelatinized (P) or retrograded (R) corn starch. In both diets, a contrast in natural 13C enrichment between the starch and nonstarch components of the diet was created to partition between enzymatic digestion and fermentation of the corn starch. Energy and protein retention were measured using indirect calorimetry after adapting the pigs to the diets for 3 wk. Fecal 13C enrichment was higher in the R-fed pigs (P

An experiment was conducted to examine changes in VFA and ammonia concentrations at different time points using 4 fermentable carbohydrate-rich feed ingredients as substrates and feces of unweaned piglets as inoculum. Fecal inoculum was collected, pooled, and mixed from 9 specially raised (no creep feed or antibiotics) crossbred piglets at 3 wk of age. Inulin, lactulose, molasses-free sugar beet pulp, and wheat starch were used as substrates and were fermented in vitro for 72 h (3 replicates per substrate). Cumulative gas production was measured as an indicator of the kinetics of fermentation. In addition, 3 bottles of substrate per time point with similar contents (amounts of substrate, inoculum, and media) were incubated but were allowed to release their gas throughout incubation. For these latter bottles, fermentation fluid was sampled at incubation time points including every hour between 1 and 24 h and at 48 h, and fermentation end products (VFA, lactate, and ammonia) and OM disappearance were measured. Dry matter and ash were analyzed from the postfermentative samples. The pH of the contents from these bottles was also recorded. The correlation in time between fermentation end products and cumulative gas produced was determined. The results showed that the prolongation of fermentation to 72 h, especially in the case of fast-fermenting inulin and lactulose, may lead to a different end product profile (P < 0.001) compared with the profile observed at the time at which most of the substrate has disappeared. Therefore, we concluded that the fermentation product profile at the end of in vitro fermentation at a specific time point cannot be used to compare fermentability of carbohydrate sources with different fermentation kinetics in terms of gas production.

An experiment was conducted to examine differences in the in vitro fermentability of four carbohydrate-rich feed ingredients and two weaning piglet diets with and without these ingredients, using both the ileal contents and the faeces of unweaned piglets as inocula. In the first part of the experiment, cumulative gas production was measured over time, using faecal inocula mixed from nine specially raised crossbred piglets (no creep feed or antibiotics) at 3 weeks of age. Inulin, lactulose, unmolassed sugar beet pulp, wheat starch and the two diets were used as substrates and fermented in vitro for 72 h. Gas production was measured as an indicator of the kinetics of fermentation. Fermentation end-products, including volatile fatty acids and ammonia, and organic matter loss, were also measured. For the fermentations of feed ingredients, samples were also collected for polymerase chain reaction/denaturing gradient gel electrophoresis analyses initially and after the fermentation process, to study changes in the composition of the bacterial community. This procedure was repeated 1 week later, using ileal contents from the same piglets as inoculum. There were significant differences between the inocula, in terms of both overall fermentation characteristics and composition and between the substrates. There was also a significant interaction between inocula and substrates, which suggests that there were potentially important differences in the microbial activity occurring in these two areas of the gastrointestinal tract (GIT). For the two diets, one with and one without addition of these fermentable ingredients, there were significant differences in terms of the kinetics, but less so in terms of the end-products of fermentation. It was concluded that inocula from both the small and large intestine should be used to obtain a more accurate assessment of potential feed ingredients which will stimulate fermentation in the piglet GIT. Copyright © 2005 Society of Chemical Industry

Recently, it has become apparent that GIT fermentation is not only of interest for ruminant animals, but also for monogastrics. While it is now widely accepted that the fermentation process and its resultant end-products can have important influences on animal health, little is known about the microbiological and immunological processes involved. In terms of animal health, most interest at the moment is focussed on those moments in animals' lives when they are faced with sudden changes resulting in stress. The period of weaning in piglets is a typical example of this. The most easily accomplished and appropriate way to influence GIT fermentation processes is that of dietary intervention. This is reflected by the widespread interest in so-called pre- and pro-biotics. Given the complexities of the interactions occurring in the animal itself, it is hardly surprising that in vitro techniques are being widely used: firstly to examine potential substrates for their fermentability and possible inclusion in diets, and secondly, to assess changes in the microbial populations in response to these substrates. This paper will review the techniques currently in use for these two aspects of monogastric fermentation, and provide examples of their use.

Interest in fermentation within the monogastric digestive tract is growing, particularly relative to animal health. This is of particular importance in relation to the forthcoming European ban on inclusion of anti-microbial growth promotors in animal diets. Fermentable carbohydrates are recognized as having an important role in fermentation in the monogastric digestive tract, and are often added to diets without having been examined for their actual fermentability, particularly in relation to the target animal. We describe an in vitro method to assess feed ingredients, as potential components of monogastric diets, which stimulate a positive fermentation (i.e., ones which will be well fermented and produce more short-chain fatty acids (SCFA) and less ammonia). This technique requires use of a batch culture containing the test substrate and an inoculum of appropriate origin. During fermentation, cumulative gas production is measured at regular intervals, as an indicator of kinetics of the reaction. When fermentation is complete, organic matter losses and end-products such as SCFA and ammonia, are measured. This paper illustrates use of the technique with 45 carbohydrate-based ingredients using faeces from unweaned piglets as inoculum. By assessing potential fermentability of a large number of ingredients, it is possible to make an informed choice as to which substrates are most suited for inclusion in a diet. By combining results with information about transit time, diets can be designed which should stimulate desirable fermentation along the entire digestive tract. In vitro fermentability is a potentially valuable characteristic in diet design, in order to stimulate microbial activity in the digestive tract.

Twenty Landrace and twenty Min piglets, with an average initial body weight of 22.4 kg, were randomly divided into 5 groups with 4 animals per group, within each of the breeds. The piglets were housed in individual concrete pens. Each group of the piglets was fed one of 5 diets. The diets contained either 20% raw Argentine soybeans, 20% processed Argentine soybeans (118°C for 7.5 min.), 20% raw Chinese soybeans, 20% processed Chinese soybeans (118°C for 7.5 min.) or no soybean products (control diet). Faecal samples were collected on days 6, 7 and 8 of the treatment period. Digestibilities of dietary nutrients were determined with AIA (acid insoluble ash) as a marker. After a 17 day treatment, three piglets were killed from each of the groups. Tissue samples of small and large intestine for light and electron microscopy examination were taken immediately after the opening of abdomen. Then, the weight or size of relevant organ sw as measured. The results show that the digestibilities of dry matter (DM), crude protein (CP) and fat were higher in Min piglets than in Landrace piglets (p

A pig diet, processed in three different ways, was evaluated in an ileal digestibility trial. The complete diet contained mainly pea, tapioca and soybean meal and was processed by steam-pelleting (SP), high-shear conditioning (expander treatment; E) and expander-pelleting (EP), respectively. Expander-pelleting clearly improved the physical quality of pellets in terms of hardness and durability as compared to steam-pelleting. The apparent ileal digestibility of dietary nitrogen, dry matter, organic matter and crude fat determined with piglets in the weight range of 20–25 kg was not affected by the technological treatments under investigation. Only the crude fibre digestibility was significantly improved by single expander conditioning (P

Summary Argentine and Chinese soybeans were steam heated at 100°C for 40 min, 118°C for 5 rnin or 136°C for 1.5 min. The heating effects on the protein quality of the soybeans were evaluated by both in vitro and in wiwo experiments. In the in vitro evaluation, trypsin inhibitor activity (TIA), protein dispersibility index (PDI) and fluorodinitrobenzene (FDNB) reactive lysine were analysed. A digestion and nitrogen (N) balance trial was conducted with 32 castrated male pigs (Dutch Landrace × Dutch Yorkshire). The results show that the highest residual TIA for both Argentine and Chinese soybeans was observed in the beans heated at 118T for 5 min. The soybeans heated at 100°C for 40 min had the highest PDI. Lowest PDI was found in the soybeans heated at 136T for 1.5 min. The Chinese soybeans had higher TIA than the Argentine soybeans heated at the corresponding conditions. The FDNB reactive lysine changed irregularly. The net protein utilization (NPU) of the soybeans heated at 118°C for 5 min was significantly (p < 0.05) lower than those heated at other conditions. The N digestibility of the soybeans heated at 11 8°C for 5 min was also lower than others, but the difference was not significant. A significant (p < 0.05) interaction between soybean origin and heating condition was observed in the fat digestibility of soybeans. The fat digestibility of Chinese soybeans was improved more by the heating at high temperature for a short time (136°C for 1.5 min). It was concluded that Argentine and Chinese soybeans differ in response to steam heating. Heating at 118°C for 5 min was not as effective as heating at 100°C for 40 rnin and at 136°C for 1.5 rnin in view of the improvement of the nutritional value of the soybeans. Zusammenfassung Der Einflus einer unterschiedlichen Dampferhitzung auf die Verdaulichkeit und N-Verwertung von argentinischen und chinesischen Sojabohnen beim wachsenden Schwein. Argentinische und chinesische Sojabohnen wurden bei 100°C fur 40 min, 118°C fur 5 min bzw 136°C fur 1,5 min dampferhitzt. Die Behandlungseffekte wurden sowohl in vitro als auch in vivo untersucht. Die in vitro-Untersuchungen umfasten die Trypsininhibitor-Aktivitat (TIA), die Proteinloslichkeit (PDI) und das FDNB reaktive Lysin. Die in vivo-Untersuchungen, Verdaulichkeit und N-Bilanzversuch) wurde an 32 kastrierten mannlichen Schweinen (Hollandische Landrasse × Hollandische Yorkshire) ermittelt. Die hochste, restliche Trypsininhibitor-Aktivitat fur beide argentinische und chinesische Sojabohnen wurde bei der Dampferhitzung mit 118°C fur 5 min beobachtet, die groste Proteinloslichkeit bei 100°C und 40 min. und die niedrigste bei 136°C und 1,5 min. Grundsatzlich wiesen chinesische Sojabohnen unabhangig von der Art der Behandlung hohere TIA-Werte auf. Die Gehalte an FDNB reaktivem Lysin verhielten sich nicht gerichtet. Die Netto-Proteinverwertung (NPU) lag bei den Sojabohnen nach der Dampferhitzung bei 118°C fur 5 min signifikant (P < 0,05) niedriger als bei den anderen beiden Behandlungen. Das gilt auch fur die N-Verdaulichkeit, allerdings waren hier die Unterschiede nicht signifikant. Es konnte eine signifikante (P < 0,05) Interaktion zwischen der Herkunft und der Behandlung hinsichtlich der Fett-Verdaulichkeit beobachtet werden. Die Fett-Verdaulichkeit zeigte nach der Erhitzung mit 136°C fur 5 min die hochsten Werte. Das Dampferhitzen bei 118°C fur 5 min scheint trotz der Unterschiede bei den Herkunften der Sojabohnen nicht so effektiv zu sein, als das Erhitzen bei 100°C fur 40 min und bei 136°C fur 1,5 min, um eine Verbesserung des Futterwertes von Sojabohnen zu erreichen.

A study was carried out with piglets fed a complete diet containing mainly peas, soybean meal and tapioca. The diet had been processed in four different ways: by pelleting without steam addition (CP), steam pelleting (SP), expander treatment (E) and expander-pelleting (EP). Expander-pelleting clearly increased pellet durability and pellet hardness as compared with CP and SP treatment. The effect on the diet starch gelatinization degree (SGD) was small due to the high SGD of the unprocessed meal. A total tract digestibility experiment with piglets revealed no differences in the apparent digestibility coefficients for dietary protein, dry matter and nitrogen-free extract. The digestibility coefficient for fat was significantly (P < 0.01) lower for the expandate compared with the SP diet. Both expander treatments decreased the digestibility of crude fibre (P < 0.10). N-balance (g body N retained day−1) in pigs was similar for all diets but a trend was observed for a higher N-balance of pigs fed the CP diet. Under the conditions of the present study, the use of high-shear conditioning (expander treatment) prior to pelleting had no favourable effect on the apparent digestibility of nutrients in diets for growing pigs.

Summary The pre-manufacture of separate diet ingredients into pellets and subsequent mixing the different pellets to a complete feed was examined as an alternative method to the routine manufacturing procedures. The main objective of the study was to compare the performance of piglets following ad libitum offering of diets composed of three different pellets. In a growth trial, feed intake and weight gain were studied using six dietary treatments in a 3 × 2 split-plot design. Three diets were tested, a control and two experimental diets in the presence or absence of a feed flavour. The diets were of similar ingredient and nutrient composition but the experimental diets were composed of three separate pellets that were either equal or differing in their net energy content. Sixty cross-bred piglets [initial liveweight 30.4 (s.e. 0.54 kg)] were individually housed and fed the feeds ad libitum in the dry form once a day and in only one feed trough. No significant effects of the dietary treatments on daily gain, feed intake and feed conversion efficiency were observed and no interaction between diet and feed flavour was found. From the design of the experiment it was not definitely clear that single-fed piglets selected between the different pellets as measured by the difference between the offered and consumed quantity of pellets. Feed intake behaviour, as measured by the cumulative scores of 10 piglets during 20 days, did not differ between dietary treatments or flavour. Diet selection and feed intake behaviour can only be indicative since the trial design was inherent to the main objective of study, which was the performance response. Zusammenfassung Pelletieren von Futtermitteln. Der Einflus der Futterprasentation auf Leistungsparameter, Futterselektion und Futteraufnahme bei Ferkeln Es wurde die Vorverarbeitung von unterschiedlichen Futtermitteln zu Pellets und anschliesendem Mischen mit der ublichen Futtermittelherstellung in einem Wachstumsversuch mit Ferkeln (60 Kreuzungsferkel mit einem Lebendgewicht von 30,4 (s.e. 0,54 kg) kg) verglichen. In einem 2 × 3 split-plot Design wurden Futteraufnahme und Gewichtszuwachs von einer Kontroll- und zwei Versuchsdiaten mit und ohne Geschmacksstoffe ermittelt. Die Rationen hatten die gleichen Komponenten und die gleiche Nahrstoffzusammensetzung mit unterschiedlichen Nettoenergiegehalten der Pellets aber gleichen Nettoenergieghalten in der Gesamtration. Die Futterung erfolgte individuell, einmal taglich ad libitum in trockener Form uber die gesamte Versuchsperiode. Es konnten keine signifikanten Einflusse des Futterungsregime auf die taglichen Zunahmen, die Futteraufnahme und die Futterverwertung festgestellt werden. Das gilt auch fur den Zusatz von Geschmackstoffen. Aus den Untersuchungen geht keine eindeutige Futterselektion, gemessen als Differenz zwischen der angebotenen und verzehrten Menge an Pellets, durch die Ferkel hervor. Auserdem wurden keine nennenswerte Unterschiede in der kumulativen Futteraufnahme, ermittelt an zehn Ferkeln uber zwanzig Tage, beobachtet. Das trifft ebenfalls fur die Futterdiaten mit Geschmacksstoffen zu. Das Verhalten der Ferkel hinsichtlich Futterselektion und Futteraufnahme, kann mit der vorliegenden Versuchsanstellung nur andeutungsweise gepruft werden, die als eigentliches Ziel die Ermittlung der Leistungs-Parmeter hatte.

In four change-over experiments, wilted grass silages, differing in cell wall content (neutral detergent fiber (NDF) content ranging from 44.6 to 67.3% of dry matter (DM)), were fed ad lib. to dairy cows in early and late lactation. The influence of cell wall content of the grass silages on rumen contents and on fractional passage rates of particulate (kp, %/h) and liquid (k1, %/h) phases, was determined using Cr-NDF and Tritium (3H) labeled hay as particulate markers and Co-EDTA as a soluble marker. The kp increased with an increase in NDF content of the diet, and with an increase in intake level, whereas the k1 was not affected by diet composition. Rumen content (total as well as DM, kg) increased with an increasing proportion of concentrates in the diet and thus an increasing DM intake, but did not show any significant relation with silage cell wall content. Total chewing time (CT), rumination time (RT) and eating time (ET) were recorded for six 24 h periods per cow. When the animals ruminated for more than 9 h a day, an increase in cell wall content of the diet did not further increase RT, but resulted in a decreased intake. CT, RT and ET per kg DM tended to increase with an increase in cell wall content, whereas CT, RT and ET per kg ingested NDF tended to decrease. The pool of rumen dry matter (DM) able to flow to the omasum (passing a 1.25 mm sieve), was not influenced by cell wall content of the silages. The pool of rumen DM passing a 0.071 mm sieve, however, decreased with increasing cell wall content. The mean faecal particle size (MFP) significantly increased with cell wall content, and was negatively correlated (r= −0.90, P

Pre-weaning development of microbial activity has an effect on post-weaning establishment of the gastro-intestinal tract (GIT) microbiota. An in vivo study was conducted, to evaluate the effect of age on fermentation end-product profiles during the post-colostrum suckling period, as the variation in composition of mature milk is minimum. Sixteen piglets from two litters (eight per litter) were selected. During the study, piglets had free access to sow's milk, but no creep feed, nor antibiotic treatments. Two piglets from each litter were sacrificed on d 11, 18, 25 and 32 of age. The digesta samples were collected from the beginning and end of the small intestine, caecum and colon. Samples were analyzed for fermentation end-product concentrations. Combining the results from all the GIT sites, it was observed that, total VFA concentration increased with age of the piglets. There was a significant rise in acetic acid concentrations, with a significant decrease in lactic acid concentrations from d11 to d32, while the proportions of SCFA, (acetic acid not, vert, similar 72%, propionic acid not, vert, similar 15% and butyric acid not, vert, similar 6% of total VFA) and ammonia concentrations remained unchanged. These results clearly suggest that, the microbial activity in terms of fermentation end-product profile skewed from lactic acid to acetic acid as a major product during the post-colostrum suckling period. This may be attributed to lower substrate availability due to increased number of microbes or increased diversity in the microbiota in time.

An in vivo experiment was conducted to monitor the changes in fermentation end products in the feces of weaning piglets due to the inclusion of selected fermentable carbohydrates in the diet. The experiment involved 3 groups of 16 piglets each. Specially raised piglets (neither antibiotics nor creep feeding) were weaned abruptly at 4 wk of age. The piglets were offered 1 of 2 dietary treatments [a control diet (CON), or a fermentable carbohydrate-enriched diet (CHO)] and were subjected to 1 of the 2 fasting treatments (fasting for 2 d at the beginning of the experimental period or nonfasting). Fecal samples were collected per rectum every day during the experimental period. Piglets were slaughtered at the end of the 10-d experimental period, and digesta samples were collected from different parts of the gastrointestinal tract (GIT): the first half of the small intestine, the second half of the small intestine, the cecum, and colon. The DM, VFA profile, and ammonia concentrations were analyzed from the fecal and digesta samples. Daily feed intake was also recorded. There was no difference in concentrations of VFA in feces between the treatment groups. Ammonia concentration was lower (P < 0.05) in piglets fed the CHO diet compared with those fed the CON diet in both feces and digesta from different parts of GIT. Fasting had no effect on fermentation end products in feces. This study demonstrated that the inclusion of fermentable carbohydrates in weanling diets reduces protein fermentation along the GIT and also reduced the fecal concentration of ammonia.

The in vitro cumulative gas production technique can be used to assess microbial activity of a complex community, in relation to fermentation of a particular energy source. Therefore, in combination with an in vivo study to examine the effects of two different diets for weaning piglets, microbial activities of faeces were compared from animals on the two different diets. The two diets were: CHO diet [containing added fermentable carbohydrates, including sugarbeet pulp (SBP) and wheat starch (WST)], and control diet without any added fermentable carbohydrates. Neither diet contained antibiotics or extra added copper. Twenty-four piglets were selected from 12 litters (two per litter), weaned at 4 weeks of age (neither creep feeding nor any antibiotic treatment before and during the study), and introduced to one of the two diets. After 9 days on the diet, faecal samples were collected from selected animals, and tested for their activity in terms of gas production kinetics, and end-products such as volatile fatty acids, ammonia and dry matter disappearance of the two test substrates SBP and WST. The bacterial diversity was also analysed before and after in vitro fermentation using denaturing gradient gel electrophoresis analysis of amplified 16S rRNA genes. There were differences both in kinetics and end-products of the substrates. More interestingly, significant differences were detected between inocula, although mainly in terms of fermentation kinetics of the two substrates. With the CHO inoculum, SBP was fermented faster than with the control, while this effect was reversed for WST. Significantly higher diversity, as measured by DGGE fingerprint analysis, was detected in the microbial community enrichment on SBP as compared with WST at the end of fermentation. The difference between the kinetics of SBP compared with WST fermentation by faecal microbiota from the CHO diet fed piglets suggests better adaptation to SBP fermentation than to WST fermentation. The WST fermentation was more unexpected, given that a significant amount of starch is known to be fermentable by the small intestinal microbiota. It was concluded that the microbial community composition and activity in the GIT may be changed in response to diet, and that this change can be detected in vitro. Copyright © 2005 Society of Chemical Industry

To determine whether faecal microorganisms can represent the entire large intestinal population, samples from caecum, mid-colon and rectum of three adult pigs were used for the in vitro fermentation of fructo-oligosaccharide (FOS), potato starch, wheat bran and oat hulls. The cumulative gas production technique measured fermentation kinetics and end-products such as total gas, NH3 and volatile fatty acids (VFA). There were significant differences in the fermentability of substrates, in terms of both kinetics and end-products. More relevant to this study, there were also differences between pigs in respect of total gas production, the rate of gas production (RM) and VFA production. For large intestine sections, there were more VFA from mid-colon and rectal inocula compared with that from the caecum (p < 0.0001). Total gas, RM and NH3 were highest for rectal, intermediate for mid-colon and lowest for caecal inocula (p < 0.0001). It was concluded that, while faecal sampling might overestimate caecal fermentation, its use is valid for in vitro assessment of large intestinal fermentation. However, differences between pigs indicate that a mix of samples from several animals remains important. Copyright © 2004 Society of Chemical Industry

Fructooligosaccharides (FOS) and transgalactooligosaccharides (TOS), which are non-digestible oligosaccharides (NDO), were included at 10 and 40 g/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.

We studied whether dietary non-digestible oligosaccharides (NDOs) affected pH and volatile fatty acids (VFAs) in gastrointestinal contents and in portal plasma of young pigs. Five groups of five 57-day-old pigs received for 44 days either a corn-based control diet or this diet with 7.5 or 15 g/kg fructooligosaccharides (FOSs, Raftilose P95?) or the control diet with 10 or 20 g/kg transgalactooligosaccharides (TOSs, Oligostroop?). The pigs weighed on average 45.5±1.3 kg during dissection, which took place 3 h after feeding. Dietary NDOs tended to lower the pH of the stomach content from 4.5 to 4.2 (P=0.06). Pigs fed the high TOS diet had more caecal VFAs than the control pigs (30.4 vs. 15.6 mmol, P

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

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 day0, day14, and day35, 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

Two experiments were conducted to quantify the effects of protein intake on protein and fat deposition rates at two protein-free, energy intake levels in 90 preruminant Holstein Friesian x Dutch Friesian calves. The two experiments were similar in design, but were performed in two different weight ranges: 80 to 160 kg BW and 160 to 240 kg BW in Exp. 1 and 2, respectively. In each experiment, calves were allocated to either an initial slaughter group or to one of 12 treatments (three calves per treatment), which consisted of six protein intake levels at each of two protein-free energy intake levels. Calves were slaughtered and analyzed for body composition when they had reached the target weight. A balance study was conducted when calves reached 120 and 200 kg BW in Exp. 1 and 2, respectively. Protein digestibility increased with increasing protein intake in both experiments (P < .001). Average daily gain of the empty body varied between 640 and 1,340 g/d and between 420 and 1,370 g/d in Exp. 1 and 2, respectively, and was affected by protein (P < .001) and protein-free energy intake (P < .001). The calves responded to increased protein intake by increasing their protein (P < .001) and fat (P < .01) deposition rates. Maximum protein deposition was reached in the second experiment at 244 g/d. Extra protein-free energy intake resulted mainly in extra fat deposition (P < .001), but also increased the protein deposition (P < .01), even at low protein intake levels. In both experiments, the response of protein deposition rate to increased protein intakes was low: about 30% of the extra ingested protein was deposited. These results clearly demonstrate a low priority for partitioning dietary protein into protein gain in these calves.

Forty-eight commercial hybrid gilts were used to determine the effects of energy intake from 20 to 45 kg on the relationship between energy intake and weight gain of the body and body components from 45 to 85 kg. Two groups of 24 gilts received a single diet either at 2.2 (restricted) or 3.7 (control) times maintenance ( M ) from 20 to 45 kg. From 45 to 85 kg the pigs were fed the same diet at one of six intake levels (1.7, 2.2, 2.7, 3.2, or 3.7 × M, or ad libitum). At 85 kg, the gilts were dissected into organs, lean tissue (trimmed major joints), and other carcass parts (fat fraction). In the restricted gilts, body and lean tissue gain between 45 and 85 kg increased curvilinearly with increasing energy intake from 432 to 1,412 g/d and from 228 to 507 g/d, respectively. In the control gilts, body and lean tissue gain increased from 394 to 1,201 g/d and from 238 to 508 g/d, respectively. The percentage of lean tissue in the carcass decreased curvilinearly with increasing energy intake from 62.9 to 56.5%, and from 62.5 to 53.9% in the restricted and control gilts, respectively. The restricted gilts gained on average 140 g/d faster ( P < .001) and their carcass lean tissue content at slaughter was approximately 3% higher ( P < .001). These differences increased with increasing energy level between 45 and 85 kg. The increased gain was largely the result of an increase in organ growth and gut contents and was only evident up to 65 kg. The higher lean content at 85 kg in previously restricted gilts was not the result of compensation in lean gain but was already present at the end of the restriction phase at 45 kg.

Two experiments were conducted to investigate the effects of steam processing on the nutritional improvement of full-fat soya beans. In a kinetic study, soya beans were toasted at 102, 120 and 134°C for various durations (19 temperature/time combinations [ T t ]). The raw and processed soya beans were measured for their functional lectins, trypsin inhibitor activity (TIA), urease activity (UA) and protein dispersibility index (PDI). The raw soya beans contained 7638 μg g−1 functional lectins, 23.44 mg g−1 TIA, 2.22 UA (ΔpH) and 85.7% PDI. These criteria all decreased as the heating time increased. Of all criteria measured, the level of functional lectins was found to be most effectively inactivated by high temperature. In the second experiment, 35 piglets of approximately 30 kg liveweight were used. The animals were fitted with a post-valvular T-caecum (PVTC) cannula and divided into seven groups, which were fed a control diet and six experimental diets. The diets consisted of 80% control diet and 20% processed soya beans which were treated under the following conditions: 102°C for 10 min, 102°C for 20 min, 102°C for 40 min, 120°C for 2 min, 120°C for 7.5 min and 134°C for 1.5 min. The apparent ileal digestibilities of the soya beans processed in these conditions [ T t ] were: 37.0, 49.1, 61.3, 48.2, 57.0 and 56.8%, respectively, for dry matter (DM); 51.1, 68.3, 81.2, 70.3, 82.0 and 82.2%, respectively, for nitrogen (N); 82.2, 84.1, 89.2, 89.6, 93.0 and 91.8%, respectively, for ether extract. The apparent digestibilities of DM and N increased as the level of antinutritional factors decreased. It appears that a certain amount of energy is required to achieve the inactivation of antinutritional factors, either by treatment at a high temperature for a short time (e.g. 134°C for 1.5 min), or for a longer time at a lower temperature (e.g. 102°C for 40 min). It was noticed that the residual TIA content of the processed soya beans was correlated to the variation in digestibility among the animals, which indicates that there are considerable differences between individual animals in their responses to the soya bean antinutritional factors.

The effect of mixing on energy metabolism was studied in 8-wk-old pigs. In each of two trials, two clusters of 20 pigs (two litters of 10 pigs) were randomly assigned to one of two treat- ments: control or mixing. Each cluster was housed in one of two climatic chambers with each litter in one of two pens. In each trial, after a preliminary period of 2 wk, the two litters within the mixing treatment were mixed at the start of a 2-wk experimental period. During mixing, the five heaviest pigs of each litter were put together in one pen, and the five lightest pigs of each litter were put together in the other pen. In the control treatment, the social structure of both litters in one climatic chamber was not altered. After mixing, a short-term effect on total heat production and activity-related heat production was present. Both were increased ( P < .01) only during the 1st h after mixing. Only 57.3% of this increased total heat production was caused by an increased activity. However, no long-term effects of mixing on energy partitioning were present during the total experimen- tal period. The absence of a long-term mixing effect might be caused by the optimal conditions at the moment of mixing. In the preliminary period the transposition of GE into ME increased 1.3% ( P < .05), and ME for maintenance decreased 80 kJ·kg -.75 ·d -1 ( P < .01) between wk 1 and 2. These large alterations in energy metabolism are probably a carry-over effect of the transportation of the pigs and(or) the changes in housing environment.

Two experiments were performed. The first experiment was done to study the effects of dietary energy source on plasma insulin concentration using five gilts in a Latin square design with two diets over two periods. The diets contained either 200 g/kg of cornstarch (Starch) or soybean oil (Fat) as energy sources. Results indicate that insulin response was greater in the Starch-fed than in the Fat-fed gilts. A second experiment was performed in which 18 multiparous sows were fed one of the two experimental diets from farrowing until slaughter at d 35 of subsequent pregnancy. All sows nursed nine pigs. Blood samples were taken from a permanent jugular vein catheter every 12 min during a 12-h period on d 109 +/- 1 of pregnancy, on d 7 +/- 1, 14 +/- 1, and 21 +/- 1 of lactation, and on the day of weaning ( d 22 +/- 1). From 48 h after weaning, blood samples were taken every 4 h until 24 h after ovulation. After that, blood samples were taken at 12-h intervals until d 10 after ovulation. Differences between diets in insulin response were not significant. In Starch-fed sows, LH pulsatility at d 7 of lactation was greater (P < .05), the preovulatory LH surge was greater ( P < .05), and progesterone production was greater (P < .05) from 108 h until 256 h after the LH surge than in the Fat-fed sows. Results indicate that feeding Starch-rich diets to multiparous sows compared with Fat-rich diets, on an isocaloric basis, increases LH pulsatility during early lactation, the preovulatory LH surge, and progesterone production after the LH surge.

Zusammenfassung Die Katheterisierung der portalen Vene beim Schwein und Schaf sowie postprandiale Veranderungen der Blutgase, pO2 und pCO2, des pH-Wertes und der Konzentrationen an Harnstoff, Ammoniak, Kreatinin und Protein im portalen und arteriellen Blut beim Schwein Der vorliegende Artikel beschreibt eine Methode zur Katherisierung im Gebiet des Leberhilus zur Gewinnung von portalen Blutproben. Bei dieser Methode ist ein Katheter zur Blutennahme direkt in die Vena portae zwischen Pankreas und Leber mittels einer Gefasklemme gelegt worden. Die Lange dieses Katheters in der portalen Vene betragt 3–4 cm. Ein weiterer Katheter wurde in die Arteria carotis communis implantiert. Beide wurde bei Schweinen und Schafen uber einen Zeitraum von 8 Wochen bzw. 6 Monaten genutzt. In einem Pilotversuch mit zwei Schweinen, die mit o.g. Kathetern ausgestattet worden waren und zweimal taglich Futter enthielten (8 und 20 Uhr), sind der postprandiale pH Verlauf und die Konzentrationen an Blutgasen, Harnstoff, Ammoniak, Kreatinin und Protein im Plasma des portalen und arteriellen Blutes gemessen worden (0, 1.5, 3.5, 6, 9 h postprandial). Die Messungen ergaben signifikante (p < 0,05) portale-arterielle (P-A) Unterschiede im pO2 and pCO2. Die P-A Differenz der Ammoniakkonzentration im Plasma war ebenfalls gesichert (p < 0,05). Sowohl pCO2 und pH im Portalblut als auch P-A Unterschiede von pCO2 und pH unterliegen postprandialen Veranderungen.

In four change-over experiments, wilted grass silages, differing in growth stage at harvesting and as a consequence in cell wall content, were fed ad libitum to dairy cows in early and late lactation. Ruminal degradation rate of the crude protein fraction of the silages was investigated using nylon bag incubations. No significant relation between the degradation rate (%h-1) and the cell wall content of the silages was found. The soluble and undegradable fractions of the crude protein both increased with an increase in silage cell wall content. The soluble fraction was more closely related to dry matter content and date of harvesting than to cell wall content of the silages. The fraction of dietary protein escaping rumen fermentation increased with cell wall content.In duodenal protein, the fraction originating from the diet, estimated using amino acid profiles of dietary, microbial and duodenal protein, decreased with cell wall content.

Ninety-five female pigs from 20 to 45 kg body weight were used to elucidate the effects of energy and protein intake on the amino acid composition of the protein in the carcass, organs and empty body of growing pigs. In a 2 x 15 factorial arrangement, protein intake ranged from 127 to 350 g/d in 15 graduated steps; and the digestible energy allowances were 15.8 and 18.8 MJ/d. Whole-body amino acid contents (g/16 g nitrogen) were (means +/- SEM) lysine 6.64 +/- 0.028, methionine 2.11 +/- 0.012; threonine 3.62 +/- 0.016 and total essential amino acids 42.8 +/- 0.16. The organ fraction contained 14.8 and 15.8% (SEM 0.13) of whole-body protein at the low and high energy levels, respectively. The concentrations of essential amino acids were 41.8 +/- 0.19 and 48.4 +/- 0.13 g/16 g nitrogen in the carcass and organs, respectively. Concentrations of a number of amino acids (in carcass, organ and whole-body protein and in protein deposited between 20 and 45 kg, were affected by protein and/or energy intake. The amino acid pattern of the newly deposited protein was slightly different from that of the empty body protein. The changes in amino acid contents were presumably the result of effects of protein and energy intake on the proportions of muscle and non-muscle carcass tissues and on relative weights of blood and viscera. Consequences of these changes for the amino acid requirements are discussed.

Fractional rumen passage rates of three particle sizes of CrNDF (less than 0.3, 0.6–1.0 and 15–25 mm) and of CoEDTA were estimated in an experiment with three lactating and three non-lactating rumen-fistulated cows, fed grass silage ad libitum and 7 kg and 1 kg of concentrates, respectively. Total feed intake was higher for the lactating cows, but silage intake did not differ significantly. Fractional passage rates of CrNDF and CoEDTA were derived from the descending parts of the faecal excretion curves and from CoEDTA measured directly in the rumen fluid, following a pulse dose into the rumen. The faecal excretion curves of the 15–25 mm CrNDF particles showed no decline until the last sampling time at 86 h after dosage, so fractional passage rates of these particles could not be determined. Fractional passage rates did not differ significantly between lactating and non-lactating cows, and were on average 2.0% h−1, 4.1% h−1, 8.6% h−1 and 14.9% h−1 for CrNDF (0.6–1.0 mm), CrNDF (less than 0.3 mm), CoEDTA-faeces and CoEDTA-rumen, respectively. The results of this experiment indicate that the particle size of the CrNDF marker has a great influence on the determined passage rates.

In four change-over experiments, dairy cows were fed wilted grass silages (G1, G2, G3, G4 and G5) ad lib. In early lactation, silage was supplemented with 7 kg of concentrates and in late lactation with 1 kg. The silages were harvested at different growth stages, resulting in different cell wall contents (G1 44.6%, G2 54.7%, G3 54.8%, G4 64.1% and G5 with 67.3% neutral detergent fibre (NDF)). With an increase in cell wall content, crude protein (CP) content decreased (21.3% CP for G1 to 11.2% CP for G5), and organic matter (OM) digestibility decreased (P

It is now accepted that the microbial communities living within the gastro-intestinal tract (GIT) can influence pig health, especially at stressful times such as weaning. Careful design of the animal diet is considered to be an easy way to influence the microflora positively. In this work, fermentable carbohydrates were selected after an in vitro test (cumulative gas production- Bosch et al., 2002) for both rate and extent of fermentability. The ingredients were chosen both for their end-products and in terms of their fementation kinetics so as to stimulate fermentation along the entire GIT. They were incorporated into a test diet (TEST), and compared with a control diet (CONT) which contained minimal fermentable carbohydrates. Digesta were analyzed both in terms of microbial species (molecular techniques) and their end-products (e.g. lactic acid), to determine whether fermentation had, in fact, been stimulated by the TEST diet.

The gastro-intestinal tract (GIT) microflora is thought to remain essentially stable in terms of the range of species present, but it is hypothesized that its activity can be influenced by the diet of the host. The addition of fermentable carbohydrates to an animal diet, may therefore affect the activity of the GIT microflora.

In the absence of sufficient energy from a carbohydrate source, the GIT microflora can also use protein as a source of energy, by splitting amino acids leading to the formation of volatile fatty acids and ammonia (NH3). Therefore, it is hypothesized that the addition of fermentable carbohydrates to an animal diet, could reduce the concentration of NH3 of the gastro-intestinal tract (GIT) digesta, particularly in relation to the area where the fermentation takes place.

The dose response effect of dietary nonstarch polysaccharide (NSP) content on physical activity in relation to metabolic rate in pigs was studied. Twelve clusters of 14 pigs (50-kg castrated males) were fed one of four diets, similar in composition, except for the starch and NSP content. The difference in starch and NSP ratio was created by exchanging sugar beet pulp silage (SBPS) for tapioca. On a DM basis, diets contained 0, 5, 10, or 15% SBPS. Pigs were housed in groups and fed at 2.5 times the maintenance energy requirements. Nitrogen and energy balances were measured per cluster during a 7-d experimental period, which was preceded by a 2-wk adaptation period. Dietary composition did not affect ADG. Metabolizability decreased with increasing dietary SBPS content (P.01). Heat production as well as energy retention were unaffected by the exchange of starch for NSP (P.1). However, dietary composition affected energy expenditure on physical activity (P.10). Pigs were more quiet when dietary NSP content increased. Based on heat production data and on apparent digestibility of crude protein, crude fat, and NSP, the estimated net energy value of fermented NSP was 14.8 kJ/g. This relatively high energy value of fermented NSP was mainly related to the lowered energy expenditure for physical activity, 3.9 kJ/g of fermented NSP. The present study demonstrated that the lower energetic utilization of fermented NSP compared with that of starch can be fully compensated in pigs by reducing their physical activity. Thus, energy evaluation systems should account for systematic dietary influences on physical activity.

In intensive animal production, surplusses of nitrogen (N) are polluting the environment. Therefore it is important to compose diets matching the requirements of the animals as close as possible. Untill now mostly apparently digestible N or amino acids (feacal) have been used as criteria. It is also well established that amino acids disappearing from the hindgut do not contribute much to amino acid supply of the animal. Moreover, big differences between ileal digestible amino acids and faecal digestible amino acids are found, depending on the feed composition. Because the amounts of absorbed amino acids is more reflected by the amounts of ileal digestible amino acids than by the amounts of faecal digestible amino acids, contents of the ileal digestible amino acids of the commonly used feed stuffs in the Netherlands have been determined. Diets can now be formulated on contents of ileal digestible amino acids.

Wilted lucerne and grass silages were given for 9 weeks (3 weeks adaptation, 6 weeks experimental) to mature wethers. Fractional rate of passage of particles (kp) from the reticulorumen, as determined with chromium-mordanted neutral detergent fibre (Cr-NDF), was negatively related to digestibility, but positively to feed intake. Ratio of kp to kl (liquids) decreased with higher intake of indigestible material. Models were developed to interrelate cell wall pool in the reticulorumen, passage of undegraded cell walls in the proximal duodenum, fractional rate of passage of particles, fractional rate of degradation of cell walls (kd), and the proportion of large particles (fL) within the total particle pool in the reticulorumen. Although estimates of kd and fL were not very accurate yet, differences between silages could be characterized. The kd values of cell walls in grass silages were negatively related and fL positively related to stage of maturity at harvesting. For silages with similar kd, the extent to which cell walls left the reticulorumen was higher with lucerne than with grass silage. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Wilted lucerne and grass silages were given to mature wethers. Estimates of degradability of proteins in the reticulorumen were lower with diaminopimelic acid (38-71%) than those based on amino acid profiles of dietary, microbial and duodenal proteins (64-87%). Microbial protein synthesis was related to extent of organic matter fermentation in the reticulorumen. Efficiency of protein synthesis was not different between silages. Apparent digestibility of protein and amino acids in the small intestine was lower for lucerne silage (54%) than for grass silage (60-63%), probably caused by a higher DM passage in the small intestine of lucerne silage. Relative to the amino acid profiles of milk protein and beef, histidine and methionine were the first limiting amino acids. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Zusammenfassung Der Einflus von Futterungsintensitat, Laktationsstadium und Art der Milchprobennahme auf die Milch- und Milchfettzusammensetzung bei Sauen An 21 Erstlingssauen der Hollandischen Landrasse wurde der Einflus zweier Futterungsintensitaten (H = 1,8 kg plus 0,4 kg Futter pro Ferkel; L = 1,8 kg plus 0,2 kg Futter pro Ferkel), des Laktationsstadiums (12. und 26. Tag der Laktation) und Art der Probennahme (Handmelken verschiedener Zitzen 6 mal pro Tag bzw. Injektion von 1 ml oder 2 ml Oxytocin, 1 ml = 10 IU) untersucht. Die Milchleistung der Sauen wurde durch Wagung der Ferkel vor und nach dem Saugen ermittelt. Die Sauenmilch wurde auf ihren Gehalt an Trockensubstanz, Protein, Asche, Fett und einzelnen Fettsauren analysiert. Die Milchleistung zeigte keine Beeinflussung durch Futteraufnahme oder Laktationsstadium. Die Gehalte an Trockensubstanz, Fett und Energie lagen am 2. Mespunkt niedriger als am 1. Mespunkt. Diese Unterschiede waren bei geringerer Futteraufnahme ausgepragter als bei hoherer Futterzuteilung (P < 0,05). Der Protein- und Laktosegehalt blieb unbeeinflust. Wahrend der C-18:1-Gehalt bei niedrigerer Futterungsintensitat erhoht war, lagen die Gehalte an C-10, C-12, C-14, C-16 und C-16:1 im Milchfett niedriger als bei den H-Sauen. Auch hier waren die Unterschiede in der Periode 1 deutlicher ausgepragt als in Periode 2 (P < 0,05). Der relative Anteil an Stearin- und Olsaure stieg mit zunehmendem Fettgehalt der Sauenmilch. Nach Injektion von 2 ml Oxytocin wurden signifikant niedrigere Trockensubstanz-, Fett-, Laktose- und Energiegehalte in den Milchproben ermittelt als nach Handmelken. Bei Injektion von 1 ml Oxytocin ergaben sich dazwischen liegende Werte.

The quantitative aspects of the electrophoresis of the muscle proteins of the myogen-globulin-X group, soluble in dilute salt solutions, were studied. The most sensitive method of detecting differences between diagrams appears to be visual inspection of superposed projections (magnification 10-fold to a base length of 34.5 cm). With respect to symmetry of the diagrams, the number of details detectable in the diagrams and the time required for full development along the basis of the diagrams, a KCl-phosphate solution of p H 7.15 and ionic strength 0.13 appeared to have most adequate properties. As the diagrams change upon aging of the extracts this solution was also used for extraction in order to shorten the time required for dialysis. With 12 hours' dialysis at 2°C and 13,000 seconds of electrophoresis diagrams could thus be obtained within 24 hours after the animal was bled in narcosis. 1 ml of this solution per g muscle was shown to provide complete extraction of the group of proteins studied. Skeletal muscle of the rabbit gave after 13,000 seconds of electrophoresis patterns in which nine protein components could be detected, eight of these occurring in concentrations sufficiently high to permit their numerical evaluation from the diagrams. The protein components do not gradually change in number and amounts upon increasing the ionic strength of the solution used for extraction, dialysis and electrophoresis. Thus the proteins studied constitute a sharply defined class, for which the diagrams obtained may be considered to be representative. While diagrams of extracts of various samples of one batch of muscle pulp appeared to be quite identical upon visual inspection of the superposed projections, small differences could be detected between extracts of randomly chosen different parts of the white muscle system of one rabbit. More pronounced differences appeared to exist between white muscles of different rabbits. The differences between white and red muscles of one rabbit are only small, while the smooth muscular tissue of the stomach gives a completely different pattern.

Keywords: fermentation, gas production, pigletsThe generalized theory behind the carbohydrate to protein fermentation in the GIT is that in presence of fermentable carbohydrate substrate, microbes prefer to ferment carbohydrate source to derive energy and use the nitrogen available for their own growth. With this background information, it was hypothesized that inclusion of fermentable carbohydrates in the piglet diet will reduce the protein fermentation, which will be confirmed by reduced levels of ammonia and branched chain fatty acids in end product profile of the fermentation. The aim of this thesis was to study the effects of inclusion of fermentable carbohydrates in weaning piglets' diet, on GIT fermentation and any changes in microbial community composition and activity. Weaning process in an intensified pig production system brings many sudden changes in the environmental and physical factors in piglets' life. These sudden changes, especially in diet cause serious imbalance in the microbial community. Quicker stabilization and diversification of microbial community post weaning, is crucial in attending the gut health and reducing the risk of pathogenic infections by 'Colonization resistance: As part of this overall aim, the in vitro cumulative gas production technique was used to study the fermentation of selected fermentable substrates. While these substrates namely lactulose, inulin, wheat starch and sugar beet pulp (SBP) were included in test diet and their effect on GIT fermentation was studied in vivo. The combination of microbial community analysis based on fingerprinting techniques such as denaturing gradient gel electrophoresis (DGGE) with nutritional analysis of fermentation end product profiles, was used in vivo and in vitro studies. In in vivo trials, emphasis was given on using combination of slow fermenting carbohydrate sources such as, SBP and wheat starch with fast fermenting lactulose and inulin. The hypothesis behind this approach was to induce carbohydrate fermentation along the GIT, by providing carbohydrate substrate for the microbiota in different parts of GIT. Especially by taking in to account the difference in the transit time of feed in the different parts of GIT, it was expected that fast fermenting lactulose and inulin would be fermented in small intestine while wheat starch somewhere in the beginning of the large intestine while, SBP will reach the distal part of colon. It was found that fermentation along the GIT was improved or in other words skewed more towards the carbohydrate fermentation in vivo. It was observed in vivo that inclusion of fermentable carbohydrates in the diet reduces the protein fermentation in the GIT and ammonia concentration in end product profile. This decrease was observed along the GIT and in time in faecal fermentation end product profiles post weaning. Microbial community analysis using fingerprinting techniques revealed that inclusion of fermentable carbohydrates stabilized and diversified microbial community in the ileum as well as in the colon by day 10 post weaning. This way, the prebiotic effects of fermentable carbohydrates was evidenced.

Some carbohydrates in young pig diets escape enzymatic digestion and form substrates for the gastrointestinal microflora. These include the non-digestible oligosaccharides ( NDO ), which are found in e.g. cereals and legumes. Certain NDO may selectively stimulate the growth and/or activity of one or a limited number of favourable bacterial species, and as such beneficially affect (gut) health of the host. They are referred to as prebiotics. A series of studies was carried out to elucidate the role of dietary NDO as feedstuff components and their potential as prebiotic feed additives in young pig diets.The two types of NDO studied, fructooligosaccharides ( FOS ) and transgalactooligosaccharides ( TOS ), were included in NDO-free diets up to 40 g/kg. The NDO were also used as substrates for in vitro fermentation, using young pigs' digesta and faeces as inoculum. Dietary NDO hardly affected pig performance and apparent ileal and faecal nutrient digestion. More than 90% of the FOS was degraded pre-caecally; this was 30% for TOS (estimated by others). Pre-caecal saccharolytic activity enhanced for both types of dietary NDO, resulting in prebiotic effects at the ileal level (reduced pH, reduced concentration of aerobes). However, the FOS- and TOS diets differed in terms of ileal volatile fatty acid composition and concentration of anaerobes (including lactobacilli). These may have been related to differences in rate of fermentation (FOS>TOS) and types of volatile fatty acids produced, as observed during in vitro fermentation. The observed prebiotic effects at the ileal level were not maintained throughout the total large intestine, due to the fast rate of fermentation of FOS and TOS. As a result, some of the stimulated microflora probably started to use proteins as a source of energy, resulting in the increased proteolytic activity observed at the faecal level (increased pH and concentration of volatile fatty acids of protein origin).It was discussed that cereal- and legume-based diets may exert a certain level of prebiotic activity. Therefore, the use of FOS and TOS as prebiotic feed additives in such diets may be limited. However, prebiotic carbohydrates which can be fermented throughout the gastrointestinal tract, rather than only in the small intestine and/or the proximal colon, may result in prolonged prebiotic effects and prove useful as feed additive in young pig diets.