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.     

Effect of thermal treatment of potato products on nutrient decomposition in the digestive tract of swine. 2. Nutrient content and bacterial activity in various parts of the intestine

Dry matter (DM), starch, crude protein (CP), amino acids (AA) and diaminopimelic acid (DAPA) were estimated in the contents of the digestive tract of slaughtered pigs, which were fed a basal diet with raw (rKSt) or with cooked (QuSt) potato starch. When fed rKSt, there was larger quantities of starch and DAPA in the content of the distal small intestine and also of DM, CP, AA and DAPA in the contents of caecum and proximal colon, compared to QuSt. The bacterial breakdown of the raw potato starch granules in the proximal large intestine is shown by microscopic examinations. It is suggested, that the quantity of bacterial protein excreted in the faeces did not allow to quantify the extent of the bacterial activity in the different segments of the digestive tract.     

DEVELOPMENT OF REFERENCE INTERVALS FOR THE LARGE INTESTINAL TRANSIT OF RADIOPAQUE MARKERS IN DOGS

Ten healthy dogs were fed 30 1.5 mm and 10 5 mm radiopaque markers (BIPS, MedID, Grand Rapids) mixed with sufficient quantities of a high fibre diet to meet 25% of their estimated daily caloric requirements. Abdominal radiographs were made at two hour intervals until 90% of the small and large markers had left the colon. The mean residence times (MRT) of each size of marker in the proximal, distal and total colon were calculated using kinetic analysis. The MRT's of the small markers were 4.9 hours (SD 4.4), 7.1 hours (SD 3.3) and 12.0 hours (SD 7.1) respectively. The MRT's of the large markers were not significantly different from the small markers except in the proximal colon where they were significantly shorter (3.2 hours, SD 2.3). Reference colonic filling and colonic transit curves for both sizes of markers were constructed. These may be useful to detect abnormal colonic transit in dogs.     

The influence of xylanase on the fermentability,digestibility, and physicochemical properties of insoluble corn-based fiber along the gastrointestinal tract of growing pigs

In theory, supplementing xylanase in corn-based swine diets should improve nutrient and energy digestibility and fiber fermentability, but its efficacy is inconsistent. The experimental objective was to investigate the impact of xylanase on energy and nutrient digestibility, digesta viscosity, and fermentation when pigs are fed a diet high in insoluble fiber (>20% neutral detergent fiber; NDF) and given a 46-d dietary adaptation period. A total of 3 replicates of 20 growing gilts were blocked by initial body weight, individually housed, and assigned to 1 of 4 dietary treatments: a low-fiber control (LF) with 7.5% NDF, a 30% corn bran high-fiber control (HF; 21.9% NDF), HF + 100 mg xylanase/kg (HF + XY [Econase XT 25P; AB Vista, Marlborough, UK]) providing 16,000 birch xylan units/kg; and HF + 50 mg arabinoxylan-oligosaccharide (AXOS) product/kg (HF + AX [XOS 35A; Shandong Longlive Biotechnology, Shandong, China]) providing AXOS with 3–7 degrees of polymerization. Gilts were allowed ad libitum access to fed for 36-d. On d 36, pigs were housed in metabolism crates for a 10-d period, limit fed, and feces were collected. On d 46, pigs were euthanized and ileal, cecal, and colonic digesta were collected. Data were analyzed as a linear mixed model with block and replication as random effects, and treatment as a fixed effect. Compared with LF, HF reduced the apparent ileal digestibility (AID), apparent cecal digestibility (ACED), apparent colonic digestibility (ACOD), and apparent total tract digestibility (ATTD) of dry matter (DM), gross energy (GE), crude protein (CP), acid detergent fiber (ADF), NDF, and hemicellulose (P < 0.01). Relative to HF, HF + XY improved the AID of GE, CP, and NDF (P < 0.05), and improved the ACED, ACOD, and ATTD of DM, GE, CP, NDF, ADF, and hemicellulose (P < 0.05). Among treatments, pigs fed HF had increased hindgut DM disappearance (P = 0.031). Relative to HF, HF + XY improved cecal disappearance of DM (162 vs. 98 g; P = 0.008) and NDF (44 vs. 13 g; P < 0.01). Pigs fed xylanase had a greater proportion of acetate in cecal digesta and butyrate in colonic digesta among treatments (P < 0.05). Compared with LF, HF increased ileal, cecal, and colonic viscosity, but HF + XY decreased ileal viscosity compared with HF (P < 0.001). In conclusion, increased insoluble corn-based fiber decreases digestibility, reduces cecal fermentation, and increases digesta viscosity, but supplementing xylanase partially mitigated that effect.     

Changes in gastric contents in pigs fed a finely ground and pelleted or coarsely ground meal diet.

The objective was to characterize the change in stomach contents in relation to time after feeding between pigs consuming a restricted amount of a finely ground and pelleted (FGP) or coarsely ground meal (CGM) diet. Particular interest was placed on the concentration of organic acids and ammonia, the products of microbial fermentation. Thirty barrows were ranked by weight and assigned to a postfeeding time of 2, 4, 6, 8, or 12 h and either the FGP or CGM diet. Initiation and termination of the experiment were staggered over a 2-wk period. The treatment period was 42 d. Percentage of dry matter was higher (P<.01) in the stomach contents of pigs on the CGM diet. Concentrations of pepsin and protein were higher (P<.05) and ammonia tended to be higher (P = .10) in the proximal stomach of pigs fed the FGP diet. In contrast, concentrations of acetate and L-lactate were higher (P<.05) in the proximal stomach of pigs fed the CGM diet. All pigs on the CGM diet had stomachs that graded as normal on visual inspection. There was variable damage to the stomachs of pigs on the FGP diet. Measurement of chromium concentration in the stomach after an oral dose of Cr-EDTA clearly demonstrated the mixing that occurs between the proximal and distal stomach by 2 h after feeding in pigs consuming the FGP diet, whereas a gradient was maintained in pigs consuming the CGM diet. Thus, components normally secreted in the distal stomach return to the proximal stomach. These data show that components secreted in the distal region, such as acid and pepsin, may play a role in initiating damage to the stratified squamous mucosa. High concentrations of organic acids in the stomach of pigs on the CGM diet were not associated with damage to the stratified squamous mucosa in the esophageal region.     

饲粮蛋白质水平对早期断奶仔猪大肠蛋白质腐败作用和腹泻的影响

选５７头２８日龄断奶仔猪（平均体重约４．５ｋｇ），研究饲粮粗蛋白质（ＣＰ）水平对早期断奶仔猪大肠蛋白质腐败作用和腹泻的影响。结果显示：（１）饲粮ＣＰ水平分别与仔猪的ＣＰ、未消化ＣＰ日摄入量，结肠内容物中大肠杆菌、挥发性盐基氮（ＶＢＮ）和氨氮（ＡＮ）含量，以及腹泻指数之间存在显著（Ｐ＜０．０５）或极显著（Ｐ＜０．０１）的正相关。（２）结肠内容物中ＶＢＮ和ＡＮ含量分别与仔猪腹泻指数呈显著（Ｐ＜０．０５）的正相关。（３）饲粮ＣＰ水平分别与盲肠内容物中ＶＢＮ和ＡＮ含量之间的相关关系不显著（Ｐ＞０．０５）。（４）随着饲粮ＣＰ水平的升高，仔猪结肠组织病理变化亦增加。（５）与ＣＰ２０．４％的全植物蛋白型饲粮和ＣＰ１９．２％的复合蛋白型饲粮比较，低蛋白质氨基酸平衡饲粮（ＣＰ１６．５％）可有效地降低仔猪结肠内容物中ＶＢＮ和ＡＮ含量及腹泻指数。试验表明，饲粮ＣＰ水平对结肠蛋白质腐败作用可产生显著的影响。随着饲粮ＣＰ水平的升高，结肠内蛋白质腐败、结肠组织病理变化和仔猪腹泻指数均有增加。平衡饲粮氨基酸使ＣＰ水平降低可减少结肠内蛋白质的腐败和仔猪断奶后腹泻。     

地方猪种对纤维饲料利用的研究——Ⅱ.消化道形态与大肠内容物重量的变化

以三元杂种猪为对照,研究了东北民猪在3种NDF水平(0、10、20％)下消化道形态及后肠内容物鲜重的变化。试验从活重30千克开始,80千克结束时,每组在最后一次给食后的2、4、8、12或16小时随机屠宰2头。电击晕死后立即开膛取出内脏,分为胃、小肠、盲肠和结肠4段进行测量。结果表明猪对饲粮纤维含量的增加从胃肠道形态上发生明显的适应性变化,消化道长度、鲜重增加,尤其结肠长度增加明显,胃、小肠和结肠的鲜重显著地高于基础饲粮组。民猪胃重和结肠鲜重及长度的增加比对照杂种猪明显,消化道总鲜重及其占空体重的比例显著地高于对照杂种猪。随NDF水平的提高,大肠内容物鲜重明显增加,其中民猪更为突出,后肠是吸收水分的主要场所。     

Gastrointestinal volatile fatty acid concentrations and pH in cats

OBJECTIVE: To measure volatile fatty acid (VFA) concentrations and pH in the gastrointestinal tracts of healthy adult cats fed a commercial dry cat food. ANIMALS: 14 cats. PROCEDURE: The gastrointestinal tracts were excised immediately after euthanasia and divided into 6 sections (stomach, duodenum, jejunum, ileum, proximal portion of the colon, and distal portion of the colon). Luminal contents were collected from each segment, pH was measured, and contents were centrifuged. The supernatant was analyzed for acetate, proprionate, butyrate, isobutyrate, valerate, and isovalerate concentrations by use of gas chromatography. RESULTS: Mean total VFA concentrations were lowest in the stomach (20 mmol/L); increased through the duodenum, jejunum, and ileum (30, 29, and 41 mmol/L, respectively); and were greatest in the proximal and distal portions of the colon (109 and 131 mmol/L, respectively). Estimated mean total VFA amounts were low (<600 micromol) throughout all segments of the gastrointestinal tract; pH values increased from the stomach through the ileum and subsequently decreased in the colon. CONCLUSIONS AND CLINICAL RELEVANCE: Total VFA concentrations in the colon were comparable to values reported for the forestomach of ruminants and large intestines of monogastric animals, whereas values in the small intestine were higher than reported for other species. Total VFA amounts were low, consistent with the short, nonvoluminous gastrointestinal tract of carnivores. Luminal pH varied throughout the gastrointestinal tract in a pattern similar to other monogastric animals. Volatile fatty acids probably contribute minimal metabolic energy in cats but may be important in the maintenance of local mucosal health.     

Influence of Diet on Experimental Swine Dysentery. 1. Effects of A Vitamin E and Selenium Deficient Diet Supplemented with 6.8 % Cod Liver Oil

Sixteen growing pigs were fed a vitamin E and selenium deficient diet; half of the animals (Group 2) were given a daily supply of vitamin E and selenium. After having been fed these diets for 53 days, the pigs were infected orally with minced colonic material from cases with typical swine dysentery. This exposure resulted in outbreaks of swine dysentery in both groups. The incubation times were, however, distinctly shorter and the clinical symptoms much more pronounced in Group 1 than in Group 2. The patho^morphological lesions in the colon also differed between the 2 groups. In the pigs of Group 1 evident pseudomembraneous lesions were observed in the spiral colon. In Group 2, the colonic alterations consisted predominantly of a catarrhal enteritis; pseudomembranes occurred in a minor part of colon in only 4 pigs. Both the clinical and the chemical observations and the pathological findings indicated a much better vitamin E and selenium balance in the pigs of Group 2. It is concluded that the treatment with vitamin E and selenium in Group 2 greatly increased resistance to swine dysentery.     

Effects of feed and water restriction and receiving diet crude protein on feeder pig performance

Two experiments were conducted to determine the effects of feed and water restriction and receiving diet crude protein level on feeder pig performance. In Exp. 1, a total of 239 commingled feeder pigs transported over 1,000 km were used in two trials. Pigs given access to feed and water (FW) at the market weighed more (P less than .0001) following marketing and transport than pigs given no feed and water (N) for the comparable 25-h market period (20.7 vs 19.6 kg). While FW pigs weighed less (P less than .02) than N pigs at the conclusion of the trials (93.9 vs 96.6 kg), there was no effect (P greater than .1) on overall average daily gain (.32 vs .35). There were no effects of receiving diets containing 12, 16 or 20% crude protein on daily gain, daily feed intake or feed efficiency for the overall growing-finishing period. Scour scores on d 8, 9, 10, 11, 13 and 14 post-arrival increased (P less than .01) with increased levels of protein in the receiving diets. In Exp. 2, a total of 360 crossbred feeder pigs was mixed and moved from a nursery to grower-finisher facilities in three trials, given feed and water access immediately (FWG) or denied access for 44 h (NG). At the end of the 44-h period, FWG pigs were heavier than NG pigs (P less than .0001; 18.3 vs 16.7 kg). There was no treatment effect on overall pig weight, daily gain or feed efficiency.     

Necessity for end colostomy with transection of the descending colon in guinea pigs

Surgical procedures for resection and transection of the descending colon in the guinea pig were studied. Wedge resection with removal of less than 1 cm diameter of tissue resulted in an 80% (8 of 10 guinea pigs) survival rate. Colonic transection with restorative anastomosis, either end-to-end or side-to-side, resulted in a 94% (35 of 37 guinea pigs) death rate due to colonic impaction proximal to the site of anastomosis. A modified procedure for ventral end colostomy resulted in a 79% (19 of 24 guinea pigs) survival rate. These results indicated that caution should be taken in surgical manipulations intended to treat or study diseases of the colon in the guinea pig.     

Effects of carprofen on the integrity and barrier function of canine colonic mucosa

OBJECTIVE: To measure effects of carprofen on conductance and permeability to mannitol and histologic appearance in canine colonic mucosa. SAMPLE POPULATION: Colonic mucosa from 13 mature mixed-breed dogs. Procedures-Sections of mucosa from the transverse colon and proximal and distal portions of the descending colon were obtained immediately after dogs were euthanized. Sections were mounted in Ussing chambers. Carprofen (400 microg/mL) was added to the bathing solution for treated sections. Conductance was calculated at 15-minute intervals for 240 minutes. Flux of mannitol was calculated for three 1-hour periods. Histologic examination of sections was performed after experiments concluded. Conductance was graphed against time for each chamber, and area under each curve was calculated. Conductance X time, flux of mannitol, and frequency distribution of histologic findings were analyzed for an effect of region and carprofen. RESULTS: Carprofen significantly increased mean conductance X time, compared with values for control (untreated) sections for all regions of colon. Carprofen significantly increased mean flux of mannitol from period 1 to period 2 and from period 2 to period 3 for all regions of colon. Carprofen caused a significant proportion of sections to have severe sloughing of cells and erosions involving >or= 10% of the epithelium, compared with control sections. CONCLUSIONS AND CLINICAL RELEVANCE: Carprofen increased in vitro conductance and permeability to mannitol in canine colonic mucosa. Carprofen resulted in sloughing of cells and erosion of the colonic mucosa. These findings suggested that carprofen can compromise the integrity and barrier function of the colonic mucosa of dogs.     

Impact of betaine on pig finishing performance and carcass composition

Two experiments were conducted to evaluate the effect of betaine supplementation of finishing diets on growth performance and carcass characteristics of swine. Experiment 1 included 288 pigs in a 2 x 2 x 3 factorial arrangement of treatments consisting of barrows and gilts of two genetic populations fed diets with 1.25 g/kg supplemental betaine from either 83 or 104 kg to 116 kg and control pigs fed betaine-devoid diets. Pigs were housed three pigs per pen with eight replicate pens per treatment. Diets were corn-soybean meal-based with 300 ppm added choline. Genetic populations differed (P < 0.05) in fat depth (2.24 vs 2.93 cm) and longissimus muscle depth (53.8 vs 49.1 mm) at 116 kg. Betaine reduced feed intake (P < 0.05); however, real-time ultrasound measurements were not affected. In Exp. 2, 400 pigs were used in a 2 x 2 x 2 factorial arrangement of treatments to evaluate the effect of sex (barrow or gilts), betaine (0 or 1 g/kg of diet), and crude protein (CP) (0.70% lysine = 12.7% CP or 0.85% lysine = 15.0% CP) when fed from 60 to 110 kg live weight. Pigs had been assigned to either a high- or low-protein feeding regimen at an average initial weight of 11.3 kg and were maintained on their respective protein levels throughout the experiment. For a 56-d period from 61.7 kg to 113.6 kg, pigs were fed diets with 300 ppm added choline. Within each protein level, pigs were randomly assigned to diets containing 0 or 1 g/kg betaine. Pigs were group-housed (four to five pigs per pen). Pig weight and feed intake were recorded every 28 d. Real-time ultrasound measurements were recorded initially and at d 28 on 64 pigs, and on all pigs prior to slaughter. Growth rate was fastest and feed intake greatest for barrows (P < 0.05) and for pigs receiving 12.7% crude protein. A crude protein x betaine interaction (P < 0.05) was observed from d 28 to 56 with pigs fed the 15% CP diet growing fastest when supplemented with 1 g/kg betaine, and pigs receiving the 12.7% CP diet growing fastest when the diets contained 0 g/kg betaine. Gilts more efficiently (P < 0.05) converted feed into body weight gain, as did pigs receiving the 12.7% CP diet (P < 0.05). Longissimus muscle area and fat measurements were unaffected by betaine or dietary protein on d 28. However, by d 56 betaine reduced average fat depth in barrows (P < 0.05; 3.21 vs 3.40 cm), but not in gilts. Betaine may be more effective at altering body composition in barrows than in gilts.     

Goblet cells and mucus layer in the gut of young pigs: Response to dietary contents of threonine and non‐essential amino acids

Mucins secreted by goblet cells (GC) are the major components of mucus layer coating and protecting gut epithelium. The study aimed at determining the effect of non‐essential amino acids (NEAA) and threonine (Thr) levels on GC number and mucus layer thickness measured in different parts of the gut. A two‐factorial experiment was conducted on 72 pigs (initial BW 12.5 kg) using as factors: Thr level (5.1, 5.7, 6.3 and 6.9 g standardized ileal digestible [SID] Thr/kg) and wheat gluten (WG) level used as a source of NEAA (20.4, 40.4 and 60.4 g WG protein in WG20, WG40 and WG60 diets respectively). All diets covered the requirement for essential AA, except for Thr, and they were fed to six pigs for 20 days. Thr level affected only the count of GC containing acidic mucins in the proximal colon, which was higher in pigs fed a diet with 5.1 g SID Thr/kg in comparison with diet containing 6.3 g SID Thr/kg. In the villi, WG40 and/or WG60 increased the GC number containing acidic mucins and lowered that with neutral mucins in the middle jejunum. In the crypts, higher WG levels decreased the GC number with acidic mucins in the duodenum, ileum and proximal colon and increased that with neutral and mixed mucins in the duodenum and ileum. The mucus layer was thicker in the proximal and middle jejunum in WG20 pigs, whereas in the proximal colon it was thicker in WG60 pigs. The lowest GC count was found in the middle jejunum and the highest in the duodenum and proximal colon. The mucus layer was the thinnest in the proximal and middle jejunum and the thickest in the ileum. The results did not show the negative effect of a moderate Thr deficiency and the positive effect of non‐essential AA supplementation on GC functions.     

Effects of oligosaccharides on functional parameters of the intestinal tract of growing pigs.

Feeding experiments were carried out in growing pigs using topinambur powder or inactivated yeasts as prebiotic additives with an application period of at least 3 weeks. At the end of the experimental periods the animals were killed and segments of the intestinal tract were used for measuring transport physiological parameters and for mucin histochemistry. Jejunal epithelia were mounted in Ussing chambers for measuring electrical tissue parameters, paracellular permeability and short circuit current response to mucosal glucose. Both prebiotics had no effects on basal or forskolin stimulated short circuit currents. Total tissue conductances tended to be higher in response to both prebiotics. Topinambur increased mucosal-to-serosal fluxes of mannitol in the proximal and distal jejunum, which could only be demonstrated for the distal jejunum when inactivated yeasts were fed. Mucosal application of glucose induced higher current responses in jejunal tissues. From histochemistry it could be demonstrated that both prebiotics increased the number of ileal goblet cells and the thickness of the colonic mucosa.     

Enhancement of phosphorus utilization in growing pigs fed phytate-rich diets by using rye bran.

Some cereal by-products, such as bran, exhibit a high phytase activity that may enhance phytate P digestibility. This was studied in growing pigs fed a phytase-rich (1,200 IU/kg) diet containing 20% rye bran. The trial involved 12 animals; six were fed a control diet and six were fed a diet containing rye bran for 2 mo. Both diets contained the same levels of energy, protein, Ca (.7%) and total P (.4%). No inorganic P was added; thus, the dietary P was mainly phytic. Pigs fed the control diet, in contrast to those fed the diet containing rye bran, developed a P deficiency, as indicated by hypophosphatemia, hypophosphaturia, hyperhydroxyprolinuria, hypercalcemia, and hypercalciuria. Phosphorus from the rye bran diet was more completely absorbed (55 vs 36%) and retained (50 vs 36%) than that from the control diet. Calcium absorption was equal for the two diets, but Ca retention was higher in pigs fed rye bran than in controls. Pigs fed the rye bran diet showed greater bone density, ash content, and bending moments than controls. In conclusion, high dietary phytase levels or phytase-rich by-products increased phytate P availability and consequently improved bone scores.     

Effects of stachyose on performance, diarrhoea incidence and intestinal bacteria in weanling pigs.

A three-week trial was conducted to evaluate the effects of the oligosaccharide stachyose on performance, diarrhoea incidence and intestinal bacterial populations in weaned pigs (7.96 +/- 0.2kg). A total of 144 crossbred (Landrace x Large White x Duroc) pigs weaned at 28 days were allotted to one of four treatments with six pens per treatment and six pigs per pen. The experimental diets were based on maize, dried whey and whole-fat milk and were supplemented with 0, 1 or 2% stachyose. A fourth diet contained no milk but instead contained 20% soybean meal to provide 0.78% stachyose and 0.21% raffinose. Inclusion of 1 or 2% stachyose in the diet depressed growth compared with pigs fed the control diet. Pigs fed the soybean meal diet gained weight at a rate similar to pigs fed the diet containing 1% added stachyose. Diarrhoea incidence was highest for pigs fed the soybean meal diet and lowest for pigs fed the control diet, with pigs fed the diets containing stachyose being intermediate. Pigs fed 1% stachyose had more lactobacilli in the ileum as well as more bifidobacteria in the caecum and colon than control pigs. They also had fewer enterobacteria in the colon. In contrast, pigs fed the diet containing 2% stachyose had fewer lactobacilli and bifidobacteria in the jejunum, ileum and caecum than did control pigs. Volatile fatty acids in the ileum, caecum and colon were highest for pigs fed 1% stachyose and lowest for pigs fed 2% stachyose. Volatile fatty acid concentrations were not significantly different between pigs fed the soybean meal diet and those fed the control. The overall results of this experiment indicate that the oligosaccharide stachyose had a negative effect on pig performance and its presence may partially explain the poorer performance observed when soybean meal is used as the sole source of supplemental protein in cereal-based diets fed to weaned pigs.     

饲喂脆茎全株水稻对生长肥育猪生长性能、养分消化和胴体品质的影响

体重相近的杜洛克生长母猪54头，随机分成3组（每组3个重复），研究脆茎全株水稻（3个水平0、10％和20％）用于生长肥育猪日粮，对猪的生长性能、养分消化、胴体品质和肉质的影响。结果表明，生长猪阶段（29～52kg）对照组、10％组和20％组的采食量、平均日增重和料重比均无显著差异（P〉0．05）。肥育猪阶段（54～85kg）采食量和平均日增重，20％组显著低于对照组（P〈0．01），10％组与对照组之间无显著差异（P〉0．05）；各组料重比均无显著差异（P〉0．05）。生长猪阶段10％组和20％组各种养分的消化率都低于对照组；而肥育猪阶段，两组NDF消化率显著低于对照组（P〈0．01），其它养分消化率与对照组无显著差异。与对照组相比，10％组和20％组屠宰率有所下降，而瘦肉率提高，眼肌面积增大，背膘厚降低，但差异均不显著（P〉0．05）。10％组和20％组的背最长肌蛋白含量增加，脂肪含量降低，其中20％组与对照组差异显著（P〈0．05）；滴水损失和大理石纹及肉色评分各组之间均无显著差异（P〉0．05），20％组宰后24h的pH，显著高于对照组（P〈0．01）。     

Motility of the large intestine and flow of digesta in pigs

The motor function of the large intestine of pigs is incompletely understood. Here the ileo-caecal-colonic motility is investigated by means of chronically implanted extraluminal strain gauge transducers and simultaneous videofluoroscopy in six pigs. Motility parameters were evaluated by computer and manually. The dominant feature of the ileal motility were aborally propagating giant contractions (velocity: 3.9 (0.7) cm sec(-1)) occurring at intervals of 7-12 minutes. They pushed the ileal digesta into the caecum. Despite a fed-state, migrating motor complexes occurred at intervals of 131.5 (8.1) minutes consisting of repetitive peristaltic waves. The motility of the caecum showed clustered contractions representing haustral movements. Transfer of caecal digesta and gas into the colon was caused by peristaltic contractions. The motility of the proximal colon was characterised by long peristaltic waves resulting in a rapid aboral transport of gas and a slow aboral flow of digesta. The propagation velocities along the centripetal and centrifugal loops of the colonic coil were 2.8 (0.6) and 5.7 (0.8) cm sec(-1), respectively. About half of the colonic waves were coordinated with the ileal giant contractions and the caecal peristaltic waves. The contraction parameters showed pronounced differences between the ileum and large intestine. The contraction rise time of the caecal and colonic contractions was about twice that of the ileal contractions (5.1 (0.2) and 4.4 (0.6) seconds versus 2.2 (0.1) seconds). Consequently, the maximal frequencies of the caecal and colonic contractions were about half compared with the ileal contractions (5.3 (0.4) and 6.1 (0.1) contractions min(-1) versus 11.8 (0.3) contractions min(-1)). Results show that the contractile patterns and motor functions of the individual intestinal segments differ markedly.     

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.