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.     

Morphology of the small intestine of weaned piglets and a novel method for morphometric evaluation

The intestinal morphology of 7-week-old pigs was investigated by light (LM) and scanning electron microscopy (SEM). The piglets were fed either a semisynthetic or a cereal-based diet. The shapes of the intestinal villi and crypts of the duodenum, jejunum and ileum were examined. The villi were predominantly tongue-shaped. In the duodenum they were also ridged, branched and folded, and in the jejunum they were also leaf-like and ridged. At places with lymph follicles, the surface of the ileum was rugged with meandering fold-like villi. The crypts of the three segments of the small intestine were mainly coiled and sometimes branched. A novel morphometric evaluation method was introduced using the enlargement factors of each villus and crypt surface. The enlargement factor for the villus surface of the duodenum, jejunum and ileum was 3.13, 3.72 and 2.71, respectively. The factor for the crypt surface of the duodenum, jejunum and ileum was 9.07, 8.94 and 6.53, respectively. Furthermore, the relative proliferation rate and the epithelial renewal index were calculated for the first time. The relative proliferation rate of the duodenum, jejunum and ileum was 32.88, 34.78 and 50.77 proliferations per mm crypt perimeter, respectively. The diets consumed had an influence on the epithelial renewal index being higher for piglets fed the cereal-based diets.     

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.     

不同来源纤维饲粮对福建黄兔表观消化率、十二指肠组织形态及盲肠纤维消化酶活性的影响

本试验旨在研究不同来源纤维饲粮对福建黄兔表观消化率、十二指肠组织形态及盲肠纤维消化酶活性的影响。试验选用200只健康、体重接近的断奶福建黄兔,随机分为4组,每组5个重复,每个重复10只。4组分别饲喂由添加比例为25%的苜蓿草粉、甜菜渣、燕麦草、大麦糠为纤维饲料原料配制而成的饲粮。试验期为60 d,于试验第54天以全收粪法进行消化试验,屠宰后测定十二指肠绒毛高度、隐窝深度及二者比值,盲肠纤维素酶、半纤维素酶和果胶酶活性。结果表明：①苜蓿草粉与甜菜渣组的中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）、不溶性纤维（IDF）、可溶性纤维（SDF）的消化率均极显著高于大麦糠与燕麦草组（P<0.01）。其中,甜菜渣组不溶性纤维、可溶性纤维的消化率最高,与苜蓿草粉组差异显著（P<0.05）。②苜蓿草粉与甜菜渣组的绒毛高度极显著高于大麦糠组（P<0.01）,但显著低于燕麦草组（P<0.05）,隐窝深度显著低于大麦糠和燕麦草组（P<0.05）,其中甜菜渣组隐窝深度最低。甜菜渣组的绒毛高度/隐窝深度（V/C）最高,极显著高于其他组（P<0.01）。③苜蓿草粉与甜菜渣组盲肠3种纤维消化酶活性均极显著高于大麦糠和燕麦草组（P<0.01）,其中甜菜渣组的3种酶活均极显著高于苜蓿草粉组（P<0.01）。综上所述,对比4种纤维饲粮,在饲粮配方中添加25%的甜菜渣能提高肉兔的表观消化率与盲肠纤维消化酶活性,并能改善十二指肠组织形态。     

Spray-dried plasma improves growth performance and reduces inflammatory status of weaned pigs challenged with enterotoxigenic Escherichia coli K88

We investigated whether spray-dried plasma (SDP) improved growth and health of piglets challenged with enterotoxigenic Escherichia coli K88 (ETEC). Forty-eight pigs weaned at 21 d (BW = 4.88 +/- 0.43 kg) received one of four diets containing 6% SDP or fish proteins (as-fed basis) either nonmedicated (SDP-NM and FP-NM diets) or medicated with 0 or 250 mg/kg of colistine + 500 mg/kg of amoxycycline (SDP-M and FP-M diets), for 15 d. On d 4, pigs were orally challenged with ETEC. On d 15, eight pigs per dietary group were killed, blood and saliva were collected for analysis of K88 fimbriae-specific immunoglobulin (Ig)-A, and jejunum was removed for villi preparation, histological analysis, and cytokine expression. The presence or absence of K88 receptors (K88+ and K88- pigs respectively) was determined by villous adhesion assay. Effects of protein source on ADG (P = 0.04) and ADFI (P < 0.01), as well of medication on ADFI (P < 0.02), of all pigs were observed. In sacrified pigs, there was an effect of protein source on ADG (P = 0.03) and ADFI (P < 0.001), as well an interaction between medication and presence of K88 receptor (P = 0.02) for feed:gain ratio. Plasma K88 specific IgA were low in all K88 pigs and higher in K88+ pigs fed FP-NM compared with all the other groups (P < 0.05), except SDP-M. An interaction was found among protein source, medication, and presence of K88 receptors (P = 0.04). Saliva IgA concentrations were high in all pigs fed FP-NM and low in all other pigs. Jejunum of pigs fed FP-NM showed some ulcerations, edema, and mild inflammatory cell infiltration (ICI). In pigs fed FP-M, edema was reduced. Conversely, only a mild ICI was observed in pigs fed SDP-NM and SDP-M. Crypt depth was increased in K88+ pigs fed SDP-NM and an interaction between protein source and presence of K88 receptors was observed (P < 0.05). Expressions of tumor necrosis factor-alpha and interleukin (IL)-8 were lower in pigs fed SDP-NM and SDP-M than in those fed FP-NM and FP-M, either K88- or K88+ (P < 0.01). In pigs fed FP diets, expression of IL-8 tended to increase (P = 0.08) in K88+ compared with K88- subjects. Expression of interferon-gamma increased in K88 and K88+ pigs fed FP-M as compared with other pigs (P < 0.01). These results indicate that feeding with SDP improved growth performance and protected against E. coli-induced inflammatory status, and suggest that use of SDP-NM can be considered a valid antibiotic alternative.     

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.     

Resistant starch for weaning pigs — Effect on concentration of short chain fatty acids in digesta and intestinal morphology

We investigated the effect of potato starch, a source of resistant starch (RS), in diets for newly weaned pigs on production of short chain fatty acids (SCFA) and intestinal morphology. At weaning, at 4 weeks of age, 24 pigs were divided into 3 groups and fed diets containing 0 (C), 80 (P80) or 160 (P160) g raw potato starch per kg feed for 12 days. Pigs fed P160 had the longest villi whereas pigs fed P80 had the deepest crypts. Villous height at the mid-small intestine and average daily gain were positively correlated (r = 0.59, P < 0.01). The daily gain tended to be lower (P = 0.08) for pigs fed P80 than for pigs fed C or P160. The colon weight increased in pigs fed RS which coincided with an increased crypt depth in the colon. The concentration of SCFA increased in the large intestine with increasing amount of RS. The proportion of acetic acid decreased and the proportion of butyric acid increased in pigs fed P80 and P160. The increased SCFA production, especially of butyrate, may explain the colonic growth.     

Absorption of carbohydrate-derived nutrients in sows as influenced by types and contents of dietary fiber

The current investigation was undertaken to study the absorption and plasma concentration of carbohydrate-derived nutrients [glucose, short-chain fatty acids (SCFA), and lactate] and the apparent insulin production in sows fed diets containing contrasting types and contents of dietary fiber. Six sows were fed 3 experimental diets, low fiber (LF; 177 g of dietary fiber and 44 g of soluble fiber/kg of DM), high soluble fiber (HF-S; 429 g of dietary fiber and 111 g of soluble fiber/kg of DM), and high insoluble fiber (HF-I; 455 g of dietary fiber and 74 g of soluble fiber/kg of DM), in a repeated crossover design. Variations in dietary concentration and solubility of dietary fiber were obtained by substituting starch-rich wheat and barley in the LF diet with dietary fiber-rich co-products (sugar beet pulp, potato pulp, pectin residue, brewers spent grain, pea hulls, and seed residue, which have distinct physicochemical properties). The main carbohydrate component of the LF diet was starch and nonstarch polysaccharides (cellulose and noncellulosic polysaccharides) for the 2 high dietary fiber diets. Consumption of the LF diet resulted in increased and rapid glucose absorption at 0 to 4 h postfeeding. With the HF-I diet, the glucose absorption pattern was similar but at a decreased rate, whereas it was decreased and delayed with the HF-S diet (diet, P < 0.001; time, P < 0.001). These differences were also reflected in the insulin response. The quantitative absorption of SCFA at 0 to 10 h postfeeding was greater when feeding the HF-S diet compared with the LF diet (P < 0.001) and intermediate when feeding the HF-I diet (P < 0.001). The study showed that feeding the high dietary fiber diets resulted in a increased and more uniform uptake of SCFA than when feeding the LF control. Moreover, the HF-S diet reduced diurnal variation in glucose and insulin concentrations.     

Dietary fibre and indigestible protein increase ileal glycoprotein output without impacting colonic crypt goblet cells in weaned piglets

Mucus plays an important role in gut health by favouring colonisation resistance. The aim of this study was to quantify the impact of fibre and protein on mucin recovery in ileal digesta and on goblet cell histochemistry in the proximal colon. A control diet with highly digestible protein and low fibre and three complex diets containing indigestible protein associated with low, soluble or insoluble fibre sources were tested for 14 days in piglets weaned at 28 days of age. Mucin concentration was determined by ethanol precipitation. Goblet cell subtypes in colonic crypts were analysed by histochemistry. The ileal mucin output was higher with the complex diets than with the control diet (31.6 on average vs 21.7 g/kg DM intake). Increases observed with the low and soluble fibre diets were similar (34 g/kg DM intake). This suggests a limited effect of soluble fibre in presence of indigestible protein. Surprisingly, the observed increase was lower with insoluble fibre (27.2 g/kg DM intake). DM and N output and digestibility were not affected by the diets, but a linear relationship was found between DM and mucin output. In proximal colon, crypt depth, goblet cell numbers per crypt and glycosylation subtypes were not affected by the diet suggesting no change in the capacity of mucus to protect the gut. To conclude, introducing highly indigestible protein in the diet increased ileal mucin output, without effects of these factors on crypt goblet cell patterns in the proximal colon. Introducing fibre in a diet containing highly indigestible protein had a marginal effect.     

Assessment of Hull-less Barley as a Locally Grown Swine Feed Ingredient in the Mid-Atlantic Region of the United States

Crossbred pigs (six replicate pens of four pigs per treatment, avg. initial BW = 38 kg) were used in a 6-wk growth and digestibility trial to assess a hull-less barley adapted for the mid Atlantic region of the U.S. as the primary ingredient in pelleted diets for growing pigs. There were five experimental diets: 1) a corn-soybean meal-based diet, 2) a diet containing 46% hull-less barley and 1.6% added fat, 3) a diet containing 41% hulled barley and 4.1% added fat, 4) a diet containing 46% hulled barley and 1.6% added fat, and 5) a diet containing 46% wheat and 0.68% added fat. For diets based on small grains, a fixed inclusion rate of 25% corn was used. With the exception of Diet 4, all diets were formulated to be iso-lysinic and iso-caloric. Diet type had no effect (P>0.10) on ADFI or ADG. Pigs fed the hulled barley, high-fat diet (Diet 3) had slightly improved feed efficiency (P<0.05) relative to pigs fed the corn, hull-less barley or hulled barley, low-fat diets. Only minor differences in digestibility of DM, energy, and protein were observed among the corn, hull-less barley, hulled barley, high-fat, and wheat diets. The digestibility of these components in the hulled barley, low-fat diet (Diet 4) was 3.9 to 6.9 percentage units less (P<0.05) than in the other diets. These results demonstrate that good quality hulled and hull-less barley adapted for the mid-Atlantic region of the U.S. can be used at a relatively high inclusion rate in pelleted grower pig diets and produce growth performance comparable with similar diets based mainly on corn or wheat.     

Feeding high fibre diets changes luminal environment and morphology in the intestine of sows

Sows were fed three diets varying in type and level of dietary fibre (DF). The low fibre diet (LF; 17% DF) was based on wheat and barley. In the two high DF diets (HF1, high in soluble DF and HF2, high in insoluble DF;  44% DF), the cereal part of the diet was substituted with different co-products (sugar beet pulp, potato pulp, pectin residue, pea hull, brewer's spent grain, and seed residue). The diets were fed for a four-week period to 12 sows (4 for each diet). Sows were stunned 4 h post-feeding, and digesta and tissue samples were collected from various parts of the small and large intestines. The carbohydrate load to the large intestine was 538–539 g/d when feeding the high DF diets and 190 g/d when feeding diet LF. Feeding sows the high DF diet containing large proportion of soluble DF resulted in a lower dry matter content of digesta (23 contra 28%), a higher tissue weight (2.9 contra 2.0 kg), and a higher crypt depth (492 contra 330 μm) and area (23,201 contra 15,751 μm²) in the colon compared with the low DF diet. In conclusion, increasing the amount of DF in the diet for sows resulted in an increased amount of digesta entering the large intestine which influences the functional properties of digesta. Furthermore, a high DF diet with a high proportion of soluble DF increases tissue weight, crypt depth and crypt area in the midcolon compared to a low fibre diet.     

Neutral detergent-soluble fiber improves gut barrier function in twenty-five-day-old weaned rabbits

The effect of neutral detergent-soluble fiber level on gut barrier function and intestinal microbiota was examined in weaned rabbits. A control diet (AH) containing 103 g of neutral detergent-soluble fiber/ kg of DM included alfalfa hay as main source of fiber. Another diet (B-AP) was formulated by replacing half of the alfalfa hay with a mixture of beet and apple pulp resulting in 131 g of soluble fiber/kg of DM. A third diet (OH) was obtained by substituting half of the alfalfa hay with a mix of oat hulls and a soybean protein concentrate and contained 79 g of soluble fiber/kg of DM. Rabbits weaned at 25 d and slaughtered at 35 d were used to determine ileal digestibility, jejunal morphology, sucrase activity, lamina propria lymphocytes, and intestinal microbiota. Suckling 35-d-old rabbits were used to assess mucosa morphology. Mortality (from weaning to 63 d of age) was also determined. Villous height of the jejunal mucosa increased with soluble fiber (P = 0.001). Rabbits fed with the greatest level of soluble fiber (BA-P diet) showed the highest villous height/ crypt depth ratio (8.14; P = 0.001), sucrase specific activity (8,671 mumol of glucose/g of protein; P = 0.019), and the greatest ileal starch digestibility (96.8%; P = 0.002). The opposite effects were observed in rabbits fed decreased levels of soluble fiber (AH and OH diets; 4.70, 5,848 mumol of glucose/g of protein, as average, respectively). The lowest ileal starch digestibility was detected for animals fed OH diet (93.2%). Suckling rabbits of the same age showed a lower villous height/crypt depth ratio (6.70) compared with the B-AP diet group, but this ratio was higher than the AH or OH diet groups. Lower levels of soluble fiber tended (P = 0.074) to increase the cellular immune response (CD8+ lymphocytes). Diet affected IL-2 production (CD25+, P = 0.029; CD5+CD25+, P = 0.057), with no clear relationship between soluble fiber and IL-2. The intestinal microbiota biodiversity was not affected by diets (P >/= 0.38). Rabbits fed the B-AP and AH diets had a reduced cecal frequency of detection compatible with Campylobacter spp. (20.3 vs. 37.8, P = 0.074), and Clostridium perfringens (4.3 vs. 17.6%, P = 0.047), compared with the OH diet group. Moreover, the mortality rates decreased from 14.4 (OH diet) to 5.1% (B-AP diet) with the increased presence of soluble fiber in the diet. In conclusion, increased levels of dietary soluble fiber improve mucosal integrity and functionality.     

Utilization of spray-dried blood cells and crystalline isoleucine in nursery pig diets

Three experiments were conducted to evaluate spray-dried blood cells (SDBC) and crystalline isoleucine in nursery pigs. In Exp. 1, 120 pigs were used to evaluate 0, 2, 4, and 6% SDBC (as-fed basis) in a sorghum-based diet. There were six replicates of each treatment and five pigs per pen, with treatments imposed at an initial BW of 9.3 kg and continued for 16 d. Increasing SDBC from 0 to 4% had no effect on ADG, ADFI, and G:F. Pigs fed the 6% SDBC diet had decreased ADG (P < 0.01) and G:F (P = 0.06) compared with pigs fed diets containing 0, 2, or 4% SDBC. In Exp. 2, 936 pigs were used to test diets containing 2.5 or 5% SDBC (as-fed basis) vs. two control diets. There were six replicates of each treatment at industry (20 pigs per pen) and university (six pigs per pen) locations. Treatments were imposed at an initial BW of 5.9 and 8.1 kg at the industry and the university locations, respectively, and continued for 16 d. Little effect on pig performance was noted by supplementing 2.5% SDBC, with or without crystalline Ile, in nursery diets. Pigs fed the 5% SDBC diet without crystalline Ile had decreased ADG (P < 0.01), ADFI (P < or = 0.10), and G:F (P < 0.05) compared with pigs fed the control diets. Supplementation of Ile restored ADG, ADFI, and G:F to levels that were not different from that of pigs fed the control diets. In Exp. 3, 1,050 pigs were used to test diets containing 5, 7.5, or 9% SDBC (as-fed basis) vs. a control diet. There were six replicates of each treatment at the industry (20 pigs per pen) location and five replicates at the university (six pigs per pen) locations. Treatments were imposed at an initial BW of 6.3 and 7.0 kg at the industry and university locations, respectively, and continued for 16 d. Supplementation of 5% SDBC without crystalline Ile decreased ADG and G:F (P < 0.01) compared with pigs fed the control diet, but addition of Ile increased ADG (P < 0.01) to a level not different from that of pigs fed the control diet. The decreased ADG, ADFI, and G:F noted in pigs fed the 7.5% SDBC diet was improved by addition of Ile (P < 0.01), such that ADG and ADFI did not differ from those of pigs fed the control diet. Pigs fed diets containing 9.5% SDBC exhibited decreased ADG, ADFI, and G:F (P < 0.01), all of which were improved by Ile addition (P < 0.01); however, ADG (P < 0.05) and G:F (P = 0.09) remained lower than for pigs fed the control diet. These data indicate that SDBC can be supplemented at relatively high levels to nursery diets, provided that Ile requirements are met.     

Efficacy of partially hydrolyzed corn syrup solids as a replacement for lactose in manufactured liquid diets for neonatal pigs

Feeding manufactured liquid diets to early-weaned pigs improves growth performance and reduces days to market weight compared with pigs receiving pelleted dry feed. Few alternative dietary ingredients are utilized in manufactured liquid diets other than byproducts of the dairy industry, especially for sources of carbohydrates. This experiment was designed to evaluate the efficacy of starch from partially hydrolyzed corn syrup solids (CSS), at two different levels of hydrolyzation, as a replacement for lactose in manufactured liquid diets. Forty-eight pigs were removed from sows at 1 d of age and randomly assigned to one of three treatments: 1) control with lactose as the carbohydrate source, 2) lactose replaced (gram for gram) with CSS (dextrose equivalent [DE]-20), and 3) lactose replaced with DE-42. In addition, 10 pigs were randomly removed from several litters to provide estimates of initial body composition and small intestinal variables. Twenty-four pigs were removed from the study on d 10 of treatment, and the remaining 24 pigs were removed on d 20 of treatment. Pigs averaged 9,845 +/- 191 g at d 20 of treatment regardless of dietary treatment (P > 0.20). No differences in ADG, ADFI, or feed efficiency were detected between treatment groups from d 0 to 20 (P > 0.19). Whole-body water, protein, lipid, and ash accretion rates were unaffected by dietary treatment from d 0 to 10 or from d 0 to 20 (P > 0.20). The replacement of lactose with CSS did not affect intestinal villi height or width, or crypt depth (P > 0.10). Pigs fed lactose tended to have greater lactase activity on d 10 than pigs fed CSS (P < 0.07). Also, pigs fed lactose tended to have lower oligosaccharidase activity than pigs fed the DE-20 diet on d 20 (P < 0.07). No other differences in lactase, maltase, or long oligosaccharidase specific activity on d 10 or 20 of treatment were detected (P > 0.12). Plasma urea nitrogen concentrations were unaffected by diet on d 10 and 20 of treatment. In addition, dry matter digestibility of the diets averaged approximately 85.6 +/- 0.8% and was unaffected by dietary treatment or day of treatment. These results suggest that partially hydrolyzed CSS can be used as a replacement for lactose in manufactured liquid diets for neonatal pigs.     

An evaluation of barley in starter diets for swine

Four growth trials and one digestibility trial were conducted to determine the effects of substituting barley for grain sorghum in weanling pig diets on pig performance and nutrient digestibility. Experiments 1 and 2 were 35-d growth trials in which barley was substituted for gain sorghum at levels of 0, 10, 20, 30 and 40% of the diet. Average daily gain (ADG), average daily feed intake (ADFI) and feed conversion (F/G) were not affected by dietary barley level (P greater than .50). Experiment 3 was a digestibility trial conducted to determine the apparent digestibility of dry matter (DMD), gross energy (GED), and N (ND) and percentage of N retained (%NRT) of pigs fed the 0, 20 and 40% barley diets. As dietary barley level increased, DMD and GED decreased linearly (P less than .05), whereas %NRT increased linearly (P less than .10). Apparent N digestibility was not affected by dietary treatment (P greater than .12). Experiments 4 and 5 were 35-d growth trials with treatments arranged in a 2 x 3 factorial design to determine the effects of barley particle size (fine, 635 microns or medium, 768 microns) and dried whey level (0, 10 or 20%) on pig performance. Average daily gain and ADFI increased linearly (P less than .01) as whey level increased. Pigs fed diets containing fine-ground barley grew faster and were more efficient (P less than .05) than those fed medium-ground barley diets.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of chito-oligosaccharide on growth performance, intestinal barrier function, intestinal morphology and cecal microflora in weaned pigs

A total of 180 weanling pigs (21 ± 3 d of age; 5.98 ± 0.04 kg) were used to investigate the effect of chito-oligosaccharide (COS) on growth performance, intestinal barrier function, intestinal morphology, and cecal microflora. Based on initial BW, gender and litter, the pigs were given 5 treatments during a 14-d feeding experiment, including a basal diet (control), 3 diets with COS supplementation (200, 400, or 600 mg/kg), and a diet with colistin sulfate (CSE) supplementation (20 mg/kg). Six randomly selected pigs from each treatment were used to collect serum, duodenal, jejunal, ileal, and cecal samples on d 7 and 14 postweaning. From d 1 to 7 postweaning, pigs fed COS or CSE had greater ADG and ADFI compared with the control pigs. From d 1 to 14, diets with either 400 or 600 mg/kg COS, or 20 mg/kg CSE increased (P < 0.05) ADG and G:F compared with the control diet. No significant differences were observed in ADG, ADFI, and G:F between the pigs fed COS and CSE. Pigs fed either 400 or 600 mg/kg COS, or 20 mg/kg CSE had less (P < 0.05) diamine oxidase (DAO) in the serum, but greater concentration of (P < 0.05) DAO in jejunal mucosa, than the control pigs on d 7 postweaning. Treatments did not affect villous height and crypt depth of the duodenum, jejunum, or ileum. Pigs fed COS at 400 mg/kg had greater (P < 0.05) concentration of Bifidobacteria and Lactobacilli in the cecum than pigs fed the control diet and CSE diet on d 7 postweaning. Supplementation of COS or CSE decreased (P < 0.05) the population of cecal Staphylococcus aureus compared with the control diet on d 7 postweaning. The number of cecal Bifidobacteria in pigs fed 600 mg/kg COS was greater (P < 0.05) than that of pigs fed the control diet or CSE diet on d 14 postweaning. No significant differences were observed in Escherichia coli counts in the cecum among treatments. The present results indicate that dietary supplementation of COS at 400 or 600 mg/kg promotes growth performance and improves gut barrier function, increases the population of Bifidobacteria and Lactobacilli, and decreases S. aureus in the cecum of weanling pigs.     

Pathologic changes of the small intestinal mucosa of pigs after feeding Phaseolus vulgaris beans

The jejunal mucosa of pigs fed diets containing Phaseolus vulgaris beans was characterized grossly as mucosal atrophy and microscopically as atrophy and blunting of the villus in association with elongation of crypts with cells with increased mitotic activity. These morphologic findings were most severe in the proximal and middle parts of the jejunum. Compared to controls, goblet cells were significantly decreased in the villus but markedly increased in the crypt region. The activity of aminopeptidase and sucrase-isomaltase in the test animals was also significantly lower than in the controls. The findings in this study suggested that feeding Phaseolus vulgaris beans reduced the digestive and absorptive capacity of the mucosa, resulting in weight loss and diarrhea of affected pigs.     

Effects of dietary fiber of young adult genetically lean, obese and contemporary pigs: rate of passage, digestibility and microbiological data

Twenty-one genetically lean, obese or contemporary slaughter weight castrated male pigs (6 mo old; seven of each genotype) were assigned to individual tether stalls and fed either a control diet (low fiber) or a diet containing 80% alfalfa meal (high fiber) at 1.50% of initial body weight for 71 d (1.75% for d 1 to 4). Apparent dry matter digestibility of the diets was estimated by determining acid insoluble ash in fecal samples. Fecal cellulolytic bacteria and total viable bacteria were enumerated at d 0, 14, 35, 49 and 70. Fecal inocula were used to determine 48-h in vitro digestibility of alfalfa meal fractions on the same days. Digesta rate of passage was determined by feeding a pulse dose of chromium-mordanted alfalfa fiber to the pigs fed the high-fiber diet. In vivo digestibility of both diets was less for the obese pigs than for the lean or contemporary genotypes. In vitro digestibility of alfalfa fiber fractions was not different between the genotypes fed either diet. When the high-fiber diet was fed, in vitro digestibility increased for all genotypes from d 0 to d 14, but not thereafter. The numbers of cellulolytic bacteria for all three genotypes were greater when pigs were fed the high-fiber diet (23.0 X 10(8), 51.6 X 10(8), 37.2 X 10(8) per gram fecal dry weight; obese, lean and contemporary, respectively) compared to the low-fiber diet (3.0 X 10(8), 3.2 X 10(8), 3.4 X 10(8), respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Age-dependent resistance to transmissible gastroenteritis of swine. III. Effects of epithelial cell kinetics on coronavirus production and on atrophy of intestinal villi.

Coronavirus titers in small intestine, degree of villous atrophy and apparent rates of regeneration of intestinal villi were compared in newborn, 3-week-old and adult pigs for 1 week after they were exposed to the transmissible gastroenteritis virus of swine. The response within the newborn group was homogeneous, resulting in high virus titers, maximal villous atrophy and comparatively slow regeneration. In general, virus titers were lower, villous atrophy was less severe and regeneration more rapid in both older groups than in the newborn pigs. However, the response varied greatly in the older groups. The 3-week-old group was divided into two populations. The major population had low virus titers and developed partial villous atrophy, whereas the minor population had marked villous atrophy and virus titers comparable to those of the newborn pigs. These observations support the hyposthesis that the accelerated replacement of villous epithelium in the small intestine of pigs during the first 3 weeks contributes to the innate age-dependent resistance to transmissible gastroenteritis. The accelerated replacement of villous epithelial cells in older pigs contributes to resistance in two ways. The increased proliferative capacity of crypt epithelium results in a more rapid regeneration of atrophic villi; and the comparatively young villous absorptive cells resulting from accelerated replacement produce less virus per cell than the older ones of the newborn pig.     

The effect of pectin on amino acid digestibility and digesta viscosity, motility and morphology of the small intestine, and on N-balance and performance of young pigs

Two experiments were carried out using a balanced feed mixture composed of wheat, corn, soyabean meals, casein, and crystalline amino acids (AA) and supplemented with 0, 4, or 8% of apple pectin. The daily dietary allowance provided pigs with the same level of nutrients, apart from the pectin. One experiment was conducted on pigs (within 25 to 40 kg BW) with the post valve T-caecum (PVTC) cannula to determine AA digestibility and ileal digesta viscosity. In the second experiment, the N-balance was measured twice on male pigs at about 20 and 28 kg BW using 6 animals per diet and feed intake and body weight were measured twice during the 28 d. After 40 d of feeding the diets, the pigs were sacrificed and the small intestines were weighed and sampled. The added pectin decreased standardized ileal AA digestibility (on average up to 5% dig. units) and increased digesta viscosity from about 1 to 88 mPa s. The higher pectin level did not affect motility of the duodenum and mid-jejunum, measured as responses to electrical field stimulation and to acetylcholine. However, the response of the duodenum to electrical field stimulation was after feeding the diet with 4% pectin increased compared with other diets. Pectin supplementation did not alter the weight and the length of the small intestine, but induced changes in the intestinal morphology. Muscle layer width increased significantly in the duodenum, the mid-jejunum, and the ileum while villi length increased in the duodenum and ileum. The addition of pectin decreased N retention and increased the F/G ratio but did not affect significantly the ADG of the pigs.