Effect of postweaning feed intake on performance, intestinal morphology, and the probability of diarrhoea in piglets.

Changes in gastrointestinal architecture, high incidence of diarrhoea, and low feed intake (FI) are commonly observed around weaning of pigs, but the relationship between postweaning FI and diarrhoea is unclear. This study aimed to determine the effect of low or high FI during the first days after weaning on growth performance, diarrhoea probability, intestinal permeability, and morphology in pigs until postweaning day (PWD) 28. A total of 120 pigs (7.20 ± 0.26 kg) weaned at 28 days of age (PWD 0) were randomly allocated to five diets and housed individually until PWD 28. Two diets differed in CP and three diets differed in threonine and tryptophan levels. At PWD 4, pigs with the 25% lowest accumulated FI (LOW; n = 30) and 25% highest accumulated FI (HIGH; n = 30) were selected for the study. Faecal consistency was evaluated daily using a 4-scale visual scoring system. Blood was collected at PWD 4, 14, 21 and 28, and small intestinal and colonic tissue was obtained at slaughter on PWD 28. Until PWD 4, LOW pigs consumed approximately 20% (35.7 ± 5.9 g/day) of the FI of HIGH pigs (181 ± 5.75 g/day; P < 0.05) and their average daily gain (ADG) was -103 ± 15.1 g/day. At PWD 28, average daily feed intake, ADG, and feed conversion ratio were still negatively affected by the FI level (P < 0.05) and pigs in the LOW group were on average 4.4 kg lighter than HIGH pigs. Pigs in the HIGH group showed a 55% higher probability of diarrhoea compared with LOW pigs during PWD 0-28. The number of antibiotic treatment days against diarrhoea was 2.38 days higher for HIGH compared with LOW pigs (P = 0.04). The intestinal permeability markers diamine oxidase and D-lactate in plasma were unaffected by the level of FI (P > 0.10). The systemic inflammatory markers haptoglobin and C-reactive protein were higher for HIGH pigs at PWD 4 (P = 0.005), but not affected in the following periods (P > 0.10). Pigs in the HIGH group had an increased area of acidic mucin-producing cells in the small intestine compared with LOW pigs (P < 0.05), but other intestinal morphology measurements at PWD 28 were unaffected by the level of FI. In conclusion, high FI just after weaning was associated with higher growth performance but also higher probability of diarrhoea and more frequent use of antibiotics until PWD 28.

An increased weaning age and liquid feed enhances weight gain compared to piglets fed dry feed pre-weaning.

Increasing age and providing liquid creep feed could potentially increase the solid feed intake in pre-weaning piglets, which may in turn promote gut maturation and post-weaning feed intake, possibly lessening the severity of the growth-check associated with the suckling-to-weaning transition. Therefore, this study aimed to investigate if feeding dry- versus liquid creep feed (DF vs. LF) and weaning in week 4 or 5 (4W or 5W) could accelerate maturational changes to the small intestines of pre-weaning piglets by increasing digestive and absorptive capacity. In a 2 × 2 factorial study the effect of weaning age (WA) and feeding strategy (FS) on weaning weight, pre-weaning accumulated gain (AG), and average daily gain was measured for 12 923 piglets. A subpopulation of 15 piglets from each treatment group (4WDF, 4WLF, 5WDF and 5WLF; n = 60) were sacrificed to assess the effects of WA and FS on weight of digestive organs, activity of maltase, lactase and sucrase, and gene expression level of sodium-glucose linked transporter 1 (SGLT-1), glucose transporter 2 (GLUT2) and peptide transporter 1 (PepT1) in the proximal part of the small intestine (SI). No interactions were found but average weaning weight was affected by WA (P < 0.001) and FS (P < 0.001), where 5W were heavier than 4W and LF were heavier than DF. Correspondingly, the average daily gain (ADG) was affected by both WA (P = 0.003) and FS (P < 0.001). Only WA affected the relative weight of the digestive organs, where stomach weight, weight of SI and colon weight were heavier in 5W piglets compared to 4W. Lactase activity tended to decrease with age (P = 0.061), but there was no difference in the activity of maltase or sucrase between any of the treatment groups. Similarly, there was no differences in gene expression level of SGLT1, GLUT2 or PepT1 between neither the two ages nor feeding strategies. In conclusion, both WA and FS affect weaning weight and weight gain of piglets in the pre-weaning period.

Influence of dietary fibre on nutrient digestibility and energy utilisation in growing pigs fed diets varying in soluble and insoluble fibres from co-products.

The co-products from the industry are used to reduce costs in pig diets. However, the co-products used in pig diets are limited because of a high fibre content which is not digested by endogenous enzymes and is resistant to degradation in the small and large intestines. The aim of this study was to investigate digestibility of nutrients and energy, and energy utilisation in pigs fed diets with various soluble and insoluble dietary fibre (DF) from co-products. The experiment was performed as a 4 × 4 Latin square design (four diets and four periods) using four growing pigs (66.2 ±â€¯7.8 kg) surgically fitted with a T-cannula in the end of the small intestine. The pigs were fed four experimental diets: low-fibre control (LF), high-fibre control (HF), high-soluble fibre (HFS) and high-insoluble fibre (HFI) diets. The apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of ash, organic matter, CP, fat, carbohydrates, starch and non-starch polysaccharides (NSP) divided into cellulose and soluble and insoluble non-cellulosic polysaccharide residues were measured using chromic oxide as marker. The recovery of total solid materials, organic matter and total carbohydrates in ileal digesta in pigs fed the HF and HFS diets was higher than in pigs fed LF and HFI, whereas recovery of organic matter and total carbohydrates in faecal materials in the HFS diet was lowest (P < 0.05). AID of organic matter, total carbohydrates and starch was lowest for HFS diet (P < 0.05). ATTD of organic matter and CP was higher for LF diet compared with other diets (P < 0.05), whereas total NSP, cellulose and non-cellulosic polysaccharides residues were highest for HFS diet (P < 0.05). Lactic acid in ileal digesta was influenced by dietary composition (P < 0.05) whereas neither type nor level of DF affected short chain fatty acids. The digestible energy, metabolisable energy, net energy and retained energy intake were similar among diets without influence of DF inclusion (P > 0.05). The metabolisable energy:digestible energy ratio was lower when feeding the HFS diet because of a higher fermentative methane loss. Faecal nitrogen and carbon were positively correlated with DM intake and insoluble DF in the diets (P < 0.05), but nitrogen and carbon (% of intake) were similar among diets. The present findings suggest that high-DF co-products can be used as ingredients of pig diets when features of DF are considered.

Non-targeted metabolomics of saliva to explore potential biomarkers for gastric ulceration in pigs fed hemp.

Gastric ulceration is a common disease in pig production worldwide and is associated with economic losses as well as animal health and welfare issues. The aim of this study was to explore potential salivary biomarkers for gastric ulceration in pigs. In addition, the aim was to study the effect of hemp on the incidence of gastric ulcers. Approximately 440 growing-finishing pigs in the period from 30 to 110 kg BW were allocated to four different diets: meal feed (Meal); pelleted feed (Pellets); pelleted feed added 4% hempseed cake (Hemp Cake); pelleted feed added 4% hempseed hulls (Hemp Hulls). The day before slaughter, saliva samples from each pig were collected. After slaughter, the stomachs were emptied to assess the consistency of the stomach content and examined for gastric ulceration using an index scale (0-10). Noticeable changes of the gastric mucosa (total index score ≥ 6) were observed in 291 pigs. The odds of having index scores 0-5 relative to index scores 6-8 and 9-10, respectively, were higher (P < 0.001) for pigs fed Meal compared to pigs fed Pellets. The odds of suffering from severe gastric ulcers tended (P = 0.08) to be lower in pigs fed Hemp Hulls compared to pigs fed Pellets. A non-targeted liquid chromatography mass spectrometry based metabolomics analysis was performed on saliva samples to determine any separation between pigs with healthy stomachs and those with gastric ulcers and to examine a possible correlation between gastric ulcer index and potential biomarkers. Partial least-squares discriminant analysis showed a separation between pigs with ulcers and those with healthy stomachs/hyperkeratosis (HK). Metabolites contributing to the separation between groups were identified. Levels of oxylipins deriving from linoleic acid were lower (P < 0.001) in pigs with ulcers compared to healthy/HK pigs. This may indicate a shift in the metabolic pathways towards more pro-inflammatory arachidonic acid-derived eicosanoids, which might reflect an increased inflammatory response. Thus, reduced levels of oxylipins derived from linoleic acid seemed to be associated with active gastric ulcers, and thereby they might function as biomarkers for gastric ulceration in pigs. In addition, supplementation of hempseed hulls had a beneficial effect on severe gastric ulcers, as hempseed hulls changed the consistency of the gastric content by conferring more solidness. However, it was not possible to observe any reliable separation between pigs fed pellets supplemented with hemp products and pigs fed non-supplemented pellets according to the identified salivary metabolites.

Age-dependent development in protein digestibility and intestinal morphology in weaned pigs fed different protein sources.

Today, weaner diets are optimised using digestibility coefficients obtained from grower-finisher pigs, which may overestimate the digestibility in weaners. The aim of this study was to evaluate the standardised ileal digestibility (SID) of CP and amino acids (AAs), and the intestinal morphology in pigs 0-4 weeks postweaning when fed different protein sources. The experiment included 128 pigs weaned at day 28 and the protein sources were wheat, soybean meal (SBM), enzyme-treated soybean meal (ESBM), hydrothermally treated rapeseed meal (HRSM) and casein. The experiment was conducted as a difference method study including wheat in all diets. Eight pigs were slaughtered on the day of weaning (day 0) and six pigs/treatment were slaughtered at days 7, 14, 21, and 28 postweaning. The SID of CP and AA, as average over the four weeks, was lowest for ESBM and highest for wheat and casein, with SBM and HRSM being intermediate. The SID of CP and AA increased (both linear and quadratic, P < 0.05) over time after weaning. The average SID of CP for all protein sources postweaning was 0.38, 0.59, 0.76, and 0.71 on days 7, 14, 21, and 28, respectively. These differences were significant (P < 0.05) between days 7 and 21, and between days 7 and 28 (P < 0.05), whereas there tended to be a difference between days 7 and 14 (P = 0.06). Protein source did not affect the small intestinal morphology response parameters, whereas time after weaning did. Villous height and villous height to crypt depth ratio differed (P < 0.05) between the days 0 and 7, with shorter villi and a higher ratio at day 7. Crypt depth was not altered between days 0 and 7, or between days 7 and 14. For villi density, crypt density and small intestinal length, a significant increase from days 7 to 14 was observed, but there was no further increase to or difference between days 21 and 28. In conclusion, the low SID of CP in casein on day 7 (0.50) illustrates the challenges related to protein digestion in weanling pigs. The SID of CP and AA is very low during the first two weeks postweaning and time after weaning is more important for protein digestibility, than the source of protein. Fewer mature epithelial cells and less absorptive area in the small intestine in the early postweaning period may partly explain the poor protein digestibility.

Glucagon-like peptide 2 treatment may improve intestinal adaptation during weaning.

Transition from sow's milk to solid feed is associated with intestinal atrophy and diarrhea. We hypothesized that the intestinotrophic hormone glucagon-like peptide 2 (GLP-2) would induce a dose- and health status-dependent effect on gut adaptation. In Exp. 1, weaned pigs (average BW at weaning 4.98 ± 0.18 kg) were kept in a high-sanitary environment and injected with saline or short-acting GLP-2 (80 µg/(kg BW·12 h); n = 8). Under these conditions, there was no diarrhea and GLP-2 did not improve gastrointestinal structure or function. In Exp. 2, weaned pigs (average BW at weaning 6.68 ± 0.27 kg) were kept in a low-sanitary environment, leading to weaning diarrhea, and injected with saline or short-acting GLP-2 (200 µg/(kg BW·12 h); n = 11). Treatment with GLP-2 increased goblet cell density (P < 0.05) and reduced short chain fatty acid concentration in the colon (P < 0.01) but had limited effects on diarrhea. In Exp. 3, weaned pigs (average BW at weaning 6.90 ± 0.32 kg) were kept in a low-sanitary environment and injected with saline or a long-acting acylated GLP-2 analogue (25 µg/(kg BW·12 h); n = 8). In this experiment, GLP-2 increased intestinal weight (+22%; P < 0.01) and activity of brush border enzymes (+50-100%; P < 0.05). Circulating GLP-2 levels were in the pharmacological range in Exp. 3 (constant levels >20,000 pmol/L) and Exp. 2 (increases to 20,000 pmol/L for a few hours each day) while they were in the supraphysiological range in Exp. 1 (50-200 pmol/L). In conclusion, GLP-2 may improve gut structure and function in weanling pigs. However, the effects may be significant only under conditions of diarrhea and if GLP-2 exposure time is extended using long-acting analogues.

Effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile and inflammation markers in metabolic syndrome -- a randomized study (SYSDIET).

BACKGROUND: Different healthy food patterns may modify cardiometabolic risk. We investigated the effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile, blood pressure and inflammatory markers in people with metabolic syndrome. METHODS: We conducted a randomized dietary study lasting for 18-24 weeks in individuals with features of metabolic syndrome (mean age 55 years, BMI 31.6 kg m(-2) , 67% women). Altogether 309 individuals were screened, 200 started the intervention after 4-week run-in period, and 96 (proportion of dropouts 7.9%) and 70 individuals (dropouts 27%) completed the study, in the Healthy diet and Control diet groups, respectively. Healthy diet included whole-grain products, berries, fruits and vegetables, rapeseed oil, three fish meals per week and low-fat dairy products. An average Nordic diet served as a Control diet. Compliance was monitored by repeated 4-day food diaries and fatty acid composition of serum phospholipids. RESULTS: Body weight remained stable, and no significant changes were observed in insulin sensitivity or blood pressure. Significant changes between the groups were found in non-HDL cholesterol (-0.18, mmol L(-1) 95% CI -0.35; -0.01, P = 0.04), LDL to HDL cholesterol (-0.15, -0.28; -0.00, P = 0.046) and apolipoprotein B to apolipoprotein A1 ratios (-0.04, -0.07; -0.00, P = 0.025) favouring the Healthy diet. IL-1 Ra increased during the Control diet (difference -84, -133; -37 ng L(-1) , P = 0.00053). Intakes of saturated fats (E%, beta estimate 4.28, 0.02; 8.53, P = 0.049) and magnesium (mg, -0.23, -0.41; -0.05, P = 0.012) were associated with IL-1 Ra. CONCLUSIONS: Healthy Nordic diet improved lipid profile and had a beneficial effect on low-grade inflammation.

The effects of feed restriction on physical activity, body weight, physiology, haematology and immunology in female mink.

The aim of the present study was to investigate if adult mink females characterised as having a high or low residual feed intake (RFI) differed in their response to feed restriction with regard to activity, body weight loss and physiological parameters. For RFI-High, the activity was higher prior to the expected feeding time both in the cases of restrictive and ad libitum feeding indicating a changed RFI-High feeding motivation and a higher risk of developing stereotypic activity. The body weight gain and the feed consumption were higher for RFI-High than for RFI-Low when feeding ad libitum indicating that RFI-High has a higher growth potential and/or a higher energy requirement than RFI-Low. Signs of immunosuppression were shown in connection with restrictive feeding compared to ad libitum feeding, and RFI-High females seemed to be more susceptible to immunosuppression than RFI-Low females. Based on the present results, mink characterised as RFI-Low would be preferable as breeders because they involve lower feed costs and seem to be less susceptible to immunosuppression. They also seem to have less risk of developing stereotypic activity, which is beneficial for the welfare.

Metabolic profiling of plasma from sows before parturition and during lactation using a liquid chromatography-mass spectrometry-based approach.

During transition from late gestation to lactation, the sow undergoes large and sudden metabolic changes to adapt from anabolic to catabolic metabolism. Little is known about changes in nutrient uptake and intermediary metabolism of transition sows. This study was undertaken to screen the metabolic profile for qualitative changes in nutrient uptake and metabolism during transition. Four sows were fitted with permanent catheters in artery femoralis (AF), portal vein (PV), and hepatic vein (HV) (sampling sites). Sows were fed a standard lactation diet from 15 d prior to 28 d after parturition. Blood samples were taken 1.5 h after feeding on days -10, -3, 3, and 17 relative to parturition and plasma metabolites were analyzed by a liquid chromatography-mass spectrometry-based approach. Principal components analysis was performed to visualize the metabolic profiles and to screen for intermediary metabolites altered during the transition period. The metabolic profile of sows on day 3 after parturition was distinct from other days. Plasma betaine, Pro, and some unidentified lipid compounds contributed to the separation on day 3; betaine and Pro were lowered by 30% at day 3 compared to day -10 and day -3 (P < 0.001). Plasma choline, Pro, creatine, and unidentified lipid compounds contributed to the separation due to sampling sites. Plasma choline was lowest in HV, intermediate in AF, and highest in PV (P < 0.001) plasma, indicating net absorption from the gastrointestinal tract (PV vs. AF) and liver metabolism (HV vs. PV). The majority of unidentified metabolites found using the loadings plots that were affected by day or sampling site or both were revealed as lipid compounds, that is, bile acid, cholesterol, glycerol, phosphatidyl, sphingomyelin, or acylglycerol derivatives. In conclusion, the intermediary metabolism of sows, especially for fat, changed during transition, and a deeper understanding and detection of involved metabolites are needed to optimize sow feeding during transition.

Diarrhea-like condition and intestinal mucosal responses in susceptible homozygous and heterozygous F4R+ pigs challenged with enterotoxigenic Escherichia coli.

Enterotoxigenic Escherichia coli (ETEC) F4 is a major cause of diarrhea in both neonatal and young pigs. Indeed, only pigs having F4 receptors are susceptible. Among the susceptible pigs, it is yet unknown if spontaneous E. coli postweaning diarrhea (PWD) occurrence and intestinal mucosal responses to ETEC differ between genotypes. This study investigated a diarrhea-like condition and intestinal mucosal responses in F4 homo- and heterozygous susceptible weaner pigs. Sixteen weaned pigs (28 d of age) were used in a 2 × 2 factorial study with genotype (homo- or heterozygous F4R(+)) and inoculation with E. coli F4 or not as the 2 factors. Within genotype, 4 pigs were inoculated with E. coli F4 and the other 4 pigs received saline buffer on days 7 and 8 after weaning. Fecal score and DM and bacterial counts were conducted from days 7 to 12 after weaning. Blood was obtained on days 3 and 10 after weaning and at the time of killing. Four pigs were killed per day on days 14, 15, 16, and 17. Small intestine (SI) was divided into 3 parts of equal length for measurement of intestinal weight and the amount of mucosa. Lymphocyte subsets in jejunal Peyer's patches (jejPP) were analyzed using flow cytometry. Escherichia coli reduced (P = 0.05) total percentage of intestinal mucosa (on a dry basis) and had an impact on metabolomics profile of the plasma. No effect of genotype was seen on fecal score and DM, fecal shedding of hemolytic E. coli, mucosal responses, metabolomics profile, antibody responses, and lymphocyte subsets counts. This study suggests that both F4 homo- and heterozygous susceptible pigs have similar functional receptors for E. coli F4, which facilitate the adhesion of F4 to the intestinal tissue.

Gastrointestinal development of dairy calves fed low- or high-starch concentrate at two milk allowances.

The objective was to study the effect of type of concentrate with varying starch and fibre content on growth and gastrointestinal development in preweaned dairy calves. Thirty-two newborn Danish Holstein male calves were allocated to four treatment groups in eight blocks of four calves. An experimental low-starch, high-molasses, high-fibre (EXP) concentrate or a traditional high-starch (TRA) concentrate were fed either at a high (HIGH; 2 × 3.2 kg/day) or a low (LOW; 2 × 1.6 kg/day) whole milk allowance in a 2 × 2 factorial design. TRA contained 350 and EXP 107 g starch/kg dry matter (DM), whereas the NDF content was 136 and 296 g/kg DM, respectively. Metabolizable energy (ME) was 11.2 and 12.2 MJ ME/kg DM in EXP and TRA, respectively. All calves had free access to artificially dried grass hay (9.8 MJ ME/kg DM). Four calves were culled during the experiment. The calves were euthanized either at 38 (12 calves) or 56 days (16 calves) of age. Evaluated across both slaughter ages, there was no difference between TRA and EXP in concentrate and hay intake, rumen weight and papillation. EXP resulted in increased villi number in duodenum and jejunum compared with TRA. Concentrate intake and reticulo-rumen weight was higher for LOW compared with HIGH milk allowance, whereas live weight gain was 20% lower. The results show that a low-starch, high-molasses, high-fibre concentrate with 8% lower ME content tended to reduce daily gain compared with a traditional calf starter concentrate, but resulted in similar ruminal development in preweaned calves both on a high and a low milk allowance fed along with grass hay. Furthermore, the results suggest that the experimental concentrate stimulated intestinal villi growth over that of the traditional concentrate.

Changes in digestive enzyme activity, intestine morphology, mucin characteristics and tocopherol status in mink kits (Mustela neovision) during the weaning period.

Weaning of livestock mammals is often associated with digestive problems related to profound changes in the physiology of the gastrointestinal tract. This study was undertaken to study the developmental changes in the gastrointestinal tract of mink kits during the period of 34 to 59 days of age. Twenty-four mink kits from eight litters were included in the experiment. The dams and their litters were kept under standard farm conditions. The dams and the kits were fed a diet consisting of 48.1% protein, 40.7% fat and 11.1% carbohydrate of metabolizable energy. The mink kits were weaned at 42 days of age. At 34, 47 and 59 days of age, one male mink kit from each litter was euthanized. The activity of amylase, trypsin, chymotrypsin and lipase in the pancreatic tissue increased during the experimental period, whereas the activity of carboxyl ester hydrolase remained constant. The vitamin E concentration in plasma was stable from 34 to 59 days of age, whereas the concentration decreased in the liver. The stereochemical composition of α-tocopherol showed a steep decrease in the concentration of the biologically most active natural isomer in both plasma and liver through the whole weaning period, whereas the biologically less active 2S isomers showed a clear increase. The concentration of bile salts did not change during the experimental period. The villous height increased in the proximal part of the small intestine and decreased in the distal part, whereas the crypt depth was doubled in both the proximal and distal part of the small intestine. The mucin-staining area on the villi was markedly reduced during the experimental period but no change in the mucin-staining area in the crypts was observed.

Influence of dietary fiber on luminal environment and morphology in the small and large intestine of sows.

In this study, the effect of feeding different types and amounts of dietary fiber (DF) on luminal environment and morphology in the small and large intestine of sows was studied. Three diets, a low-fiber diet (LF) and 2 high-fiber diets (high fiber 1, HF1, and high fiber 2, HF2) were used. Diet LF (DF, 17%; soluble DF 4.6%) was based on wheat and barley, whereas the 2 high-fiber diets (HF1: DF, 43%; soluble DF, 11.0%; and HF2: DF, 45%; soluble DF, 7.6%) were based on wheat and barley supplemented with different coproducts from the vegetable food and agroindustry (HF1 and HF2: sugar beet pulp, potato pulp, and pectin residue; HF2: brewers spent grain, seed residue, and pea hull). The diets were fed for a 4-wk period to 12 sows (4 receiving each diet). Thereafter, the sows were killed 4 h postfeeding, and digesta and tissue samples were collected from various parts of the small and large intestine. The carbohydrates in the LF diet were well digested in the small intestine, resulting in less digesta in all segments of the intestinal tract. The fermentation of nonstarch polysaccharides in the large intestine was affected by the chemical composition and physicochemical properties. The digesta from pigs fed the LF diet provided low levels of fermentable carbohydrates that were depleted in proximal colon, whereas for pigs fed the 2 high-DF diets, the digesta was depleted of fermentable carbohydrates at more distal locations of the colon. The consequence was an increased retention time, greater DM percentage, decreased amount of material, and a decreased tissue weight after feeding the LF diet compared with the HF diets. The concentration of short-chain fatty acids was consistent with the fermentability of carbohydrates in the large intestine, but there was no effect of the dietary composition on the molar short-chain fatty acid proportions. It was further shown that feeding the diet providing the greatest amount of fermentable carbohydrates (diet HF1, which was high in soluble DF) resulted in significant morphological changes in the colon compared with the LF diet.

Lectin histochemical characterisation of the porcine small intestine around weaning.

The present study was undertaken to characterise the carbohydrate profile of the porcine small intestine using lectin histochemistry during the period from 3 days prior to weaning to 9 days post-weaning. A total of 56 piglets weaned at 4 weeks of age were included in the experiment. The most prominent changes in the glycosylation pattern were observed in the goblet cells. The highest lectin reactivity of the goblet cells in the crypts was observed 7 days post-weaning which suggests that the protective effect of the mucus layer against pathogenic bacteria is increasing during the postweaning period. The staining pattern of the apical membrane remained unchanged during the experimental period. This indicates that the glycosylation process in the goblet cells is rapidly inducible whereas changes in the glycosylation pattern of the apical membrane requires more time. The glycosylation pattern of both goblet cells and apical membrane differed between the positions of the small intestine. As glycoconjugates can act as attachment sites for microorganisms, these differences in the distribution of sugar residues may be one explanation for the site-specificity of certain pathogens.

Influence of dietary zinc and copper on digestive enzyme activity and intestinal morphology in weaned pigs.

The current study was conducted to investigate the effects of high dietary concentrations of Zn as zinc oxide and Cu as copper sulfate on the activity of digestive enzymes in the pancreas and the intestinal mucosa, intestinal morphology, and mucin histochemistry in pigs after weaning. Thirty-two pigs were weaned at 4 wk of age. The pigs were fed standard weaning diets supplemented with Zn (100 or 2,500 ppm) and Cu (0 or 175 ppm) in a 2 x 2 factorial arrangement of treatments for a 14-d period. In pancreatic tissue, the activity of amylase, carboxypeptidase A, chymotrypsin, trypsin, and lipase increased (P < 0.01) in pigs fed 2,500 ppm of Zn, whereas the activity of carboxypeptidase B and carboxylester hydrolase was unaffected. Copper had no effect on the activity of pancreatic enzymes. In small intestinal contents, the total activity of amylase and carboxypeptidase A was greater in pigs fed 100 ppm of Zn (P < 0.05), whereas feeding 2,500 ppm of Zn increased the chymotrypsin activity (P < 0.001). The remaining enzymes were unaffected by dietary Zn concentration. The villi were longer in the cranial small intestine (P < 0.001) in pigs fed 100 ppm of Zn than in pigs fed 2,500 ppm of Zn, but otherwise there were no clear effects of Zn and Cu supplementation on intestinal morphology. In the cranial small intestine, the activity of maltase (P < 0.001), sucrase (P < 0.001), and lactase was greater in pigs fed 100 ppm of Zn, even though there was a Zn x Cu interaction (P < 0.05) in lactase activity. In the middle and caudal small intestine, no clear differences between dietary treatments were observed. The activity of gamma-glutamyl transpeptidase in the intestinal mucosa was not affected by dietary Zn or Cu. In pigs fed 100 ppm of Zn, the activity of aminopeptidase N was greater in the caudal small intestine, but dietary Zn or Cu had no effect on aminopeptidase N in the cranial and middle small intestine. No effect of dietary Zn or Cu supplementation was found on carbohydrate histochemistry in the caudal small intestine, whereas high dietary Zn increased the area of neutral, acidic, and sulfomucins in the cecum (P < 0.01) and in the colon (P < 0.001). In summary, high dietary Zn increased the activity of several enzymes in the pancreatic tissue and increased the mucin staining area in the large intestine, whereas Cu had no clear effect on these variables. However, no definite answers were found as to how the growth promoting and diarrhea reducing effects of excess dietary Zn are exerted.

The effect of dietary carbohydrates and Trichuris suis infection on pig large intestine tissue structure, epithelial cell proliferation and mucin characteristics.

Two experiments (Exps. 1 and 2) were performed to study the influence of Trichuris suis infection and type of dietary carbohydrates on large intestine morphology, epithelial cell proliferation and mucin characteristics. Two experimental diets based on barley flour were used; Diet 1 was supplemented with resistant carbohydrates from oat hull meal, while Diet 2 was supplemented with fermentable carbohydrates from sugar beet fibre and inulin. In Experiment 1, 32 pigs were allocated randomly into four groups. Two groups were fed Diet 1 and two groups Diet 2. Pigs from one of each diet group were inoculated with a single dose of 2000 infective T. suis eggs and the other two groups remained uninfected controls. In Experiment 2, 12 pigs were allocated randomly into two groups and fed Diet 1 or Diet 2, respectively, and inoculated with a single dose of 2000 infective T. suis eggs. All the pigs were slaughtered 8 weeks post inoculation (p.i.). The worm counts were lower in pigs fed Diet 2 in both experiments, but not significantly so. Both diet and infection status significantly influenced the tissue weight of the large intestine. In both experiments, pigs fed Diet 2 had heavier large intestines than pigs fed Diet 1 and in Experiment1 the infected pigs of both diets had heavier large intestines than their respective control groups. Diet and infection also significantly affected the morphological architecture and mucin production in both experiments. Pigs fed Diet 1 had larger crypts both in terms of area and height than pigs fed Diet 2 and T. suis infected pigs on both diets in Experiment 1 had larger crypts than their respective control groups. The area of the mucin granules in the crypts constituted 22-53% of the total crypt area and was greatest in the T. suis infected pigs fed Diet 1. Epithelial cell proliferation was affected neither by diet nor infection in any of the experiments. The study showed that both T. suis infection and dietary carbohydrates significantly influence the morphological architecture and the production and composition of mucins in the large intestine of pigs and suggests that both factors are important in large intestine function and that carbohydrates may play a role in the susceptibility to intestinal helminth infections.

Intestinal morphology and enzymatic activity in newly weaned pigs fed contrasting fiber concentrations and fiber properties.

The main objective of this study was to determine the effect of fiber source and concentration on morphological characteristics, mucin staining pattern, and mucosal enzyme activities in the gastrointestinal tract of pigs. The experiment included 50 pigs from 10 litters weaned at 4 wk of age (BW 8.6 +/- 1.4 kg) and divided into 5 treatment groups. Diets containing fiber of various physico-chemical properties and concentrations were formulated to contain 73, 104, or 145 g of dietary fiber/kg of DM. The diets were based on raw wheat and barley flours. Pectin and barley hulls, representing soluble and insoluble fiber sources, respectively, were used to increase the fiber concentration. The pigs were fed the experimental diets for 9 d, and then the pigs were euthanized and the entire gastrointestinal tract was removed. Tissue samples were taken from the mid and distal small intestine and from the mid colon. Inclusion of pectin in the diets significantly decreased (P < 0.001) ADFI and ADG compared with pigs fed no pectin. The villi and the crypts were shorter in pigs fed pectin-containing diets, but the villous height/crypt depth ratio was unaltered. Pectin significantly decreased the area of mucins in the crypts of the small intestine, indicating that the pigs fed the pectin-containing diet would probably be more susceptible to pathogenic bacteria, although this cannot be separated from the impact on ADFI. The lectin-binding pattern of the intestinal mucosa was unaffected by diet. The activity of lactase and maltase was increased in pigs fed diets with high fiber content, whereas sucrase activity was increased in pigs fed the pectin-containing diets. The activity of the peptidases, aminopeptidase N and dipeptidylpeptidase IV, was increased when feeding high fiber diets, whereas the activity of gamma-glutamyl transpeptidase remained unaffected by the experimental diets. In conclusion, the reduced feed intake observed with the pectin-containing diets could explain the lower villous height and crypt depth observed in this study. However, direct effects of pectin also are possible, and thus further study is warranted. Feeding pigs high insoluble fiber diets improved gut morphology by increasing villi length and increased mucosal enzyme activity when compared with pigs fed pectin-containing diets. The mucin content as determined by staining characteristics suggests that pigs fed high insoluble fiber diets might be better protected against pathogenic bacteria than pigs fed diets high in soluble fiber.

Effect of feed particle size and feed processing on morphological characteristics in the small and large intestine of pigs and on adhesion of Salmonella enterica serovar Typhimurium DT12 in the ileum in vitro.

A 2 x 2 factorial experiment with pigs was undertaken to investigate the effect of particle size (fine and coarse) and feed processing (pelleted and nonpelleted) on morphological characteristics in the small intestine, cecum, and colon of pigs and on the adhesion of Salmonella enterica serovar Typhimurium DT12 to the ileum in vitro. Ninety-six pigs (average BW = 33 +/- 7 kg) were fed the experimental diets. After 4 wk, 24 pigs were selected (six pigs per diet) and euthanized, and tissue samples were taken from the mid and distal small intestine, cecum, and distal colon. The effects of particle size and feed processing on villus height and crypt depth in the small intestine were minor. Feeding coarse diets increased (P = 0.05) the crypt depth in the colon. The crypt depth was 420 +/- 12 and 449 +/- 12 microm in pigs fed finely and coarsely ground feed, respectively. Pigs fed pelleted diets had a larger (P = 0.01) staining area for neutral mucins, as well as for acidic and sulfomucins on the villi of the distal small intestine than pigs fed nonpelleted diets. The area was 41, 46, and 33% larger for neutral, acidic, and sulfomucins, respectively. The mucin-staining areas of the crypts in the cecum and the colon were not affected by the experimental diets. Examination of lectin binding characteristics of the distal small intestine and the cecum did not reveal any differences between the experimental diets. Using a pig intestine organ culture model, Salmonella adhered less (P < 0.05) to the ileal tissue of pigs fed the nonpelleted diets than to those fed pelleted diets; the adherence was 60% less in these pigs. Results of this study suggest that pigs fed pelleted diets secrete mucins that are capable of binding Salmonella enterica serovar Typhimurium DT12 and thereby allowing for colonization. Therefore, pigs fed a nonpelleted diet are better protected against Salmonella infections than pigs fed a pelleted diet.

Influence of whole wheat and xylanase on broiler performance and microbial composition and activity in the digestive tract.

An experiment was carried out to study the effect of different forms of wheat (airtight silo stored whole wheat, conventionally stored whole wheat, and ground wheat included in pellets) and dietary xylanase addition on production results and gastrointestinal characteristics of broiler chickens. Ileal viscosity, pancreatic digestive enzyme activities, and the composition and activity of the intestinal microflora were considered as response parameters. Differences between the 2 types of whole wheat with respect to the various measured parameters were marginal, whereas distinct differences were found between pellet-fed birds and birds receiving whole wheat. Whole wheat feeding improved feed conversion ratio and reduced water consumption (P < 0.001). Compared with pellets, whole wheat increased the relative weight of pancreas and gizzard and the dry matter concentration of gizzard content (P < 0.001). Whole wheat feeding reduced the pH in the gizzard contents (P < 0.01) and increased ileal viscosity. The addition of xylanase reduced ileal viscosity in birds receiving whole wheat to the same level as in pellet-fed birds. Whole wheat feeding resulted in lower activities of amylase in pancreatic tissue (P = 0.054), whereas xylanase addition increased chymotrypsin (P = 0.030) and lipase activities (P = 0.052). Whole wheat feeding resulted in lower intestinal numbers of lactose-negative enterobacteria (P < 0.05) and tended to reduce the ileal and cecal numbers of Clostridium perfringens (P < or = 0.08). It is concluded that whole wheat feeding stimulates gizzard function, which in turn prevents potentially pathogenic bacteria from entering the intestinal tract.

Variations in enzyme activity in stomach and pancreatic tissue and digesta in piglets around weaning.

A study was performed to investigate the effect of weaning at 4 weeks of age on the activity of digestive enzymes in the stomach and pancreatic tissue and in digesta from 3 days prior to weaning to 9 days postweaning in 64 piglets. In stomach tissue the activity of pepsin and gastric lipase was determined. Pepsin activity declined abruptly after weaning but 5 days postweaning the weaning level was regained and in the gastric contents no change in pepsin activity was observed. Weaning did not influence the activity of gastric lipase. The activity of eight enzymes and a cofactor was measured in pancreatic tissue. The effect of weaning on the enzyme activity was highly significant for all enzymes except elastase. The activity of all enzymes remained at the weaning level during day 1-2 postweaning followed by a reduction of the activity. The activity of trypsin, carboxypeptidase A, amylase and lipase exhibited minimum activity 5 days postweaning. Trypsin activity increased to the preweaning level on day 7-9 whereas the activity of the others increased but did not reach the preweaning level. The activity of chymotrypsin, carboxypeptidase B and carboxyl ester hydrolase decreased during the entire experimental period. In digesta no effect of weaning was observed on the activity of amylase and trypsin. The activity of chymotrypsin was reduced after weaning in the proximal third of the small intestine and lipase and carboxyl ester hydrolase activity was reduced in the middle and distal parts of the small intestine after weaning. The present study shows that the activities of the digestive enzymes in the pancreatic tissue are affected by weaning. Even though the pancreatic secretion cannot be judged from these results they show that the enzymes respond differently to weaning. In general the activity of the digestive enzymes in pancreatic tissue is low on day 5 postweaning which in interaction with other factors may increase the risk of developing postweaning diarrhoea.