谷氨酰胺对早期断奶仔猪生长性能及肠道形态发育的影响

选21日龄断奶的杜大长仔猪72头,按试验要求分为2组,每组3个重复,每重复12头。分别饲喂基础日粮和含1%谷氨酰胺(Gln)日粮,试验期21 d,在断奶后0 d、7 d和14 d分别屠宰取小肠测重,并取十二指肠、空肠、回肠测定绒毛高度和隐窝深度。试验结果表明:断奶后7 d,日粮中添加Gln可显著提高仔猪的平均日增重和小肠相对重量,提高十二指肠和空肠绒毛的高度,降低十二指肠和空肠的隐窝深度;断奶后14 d,日粮中添加Gln对断奶仔猪的生长和肠道形态发育影响与基础日粮组相比差异不显著。     

Growth, nutrient utilization and intestinal morphology of pigs fed high-fiber diets

Two trials (24 and 48 pigs; 9.7 kg initial body weight) were conducted to determine the effects of dietary fiber on growth, nutrient utilization and intestinal morphology of young pigs. The four diets fed were: basal corn-soybean meal (B), 15% oat hulls (OH), 15% soybean hulls (SH), and 20% alfalfa meal (AM). Fiber source did not have major effects on performance in a 35-d feeding trial. Balance trials (7-d duration) were conducted 32 d (Trial 1) or 6 d (Trial 2) after completion of the feeding trials. Feed intakes were equalized at 8.7% (Trial 1) or 10.3% (Trial 2) of initial body weight (kg.75). All fiber sources decreased apparent digestibilities of N, energy and dry matter (P less than .05) with no effect on N retention. Apparent digestibilities of neutral and acid detergent fiber, cellulose, and hemicellulose were reduced by OH and AM (P less than .01), but not by SH. Fiber sources did not affect apparent Ca, P, Zn or Mn absorption or retention, or Mg absorption, but decrease Mg retention (P less than .05). Apparent Na absorption was decreased by OH and increased by AM (P less than .05) but was unaffected by SH. All fiber sources increased K intake, but only SH and AM increased apparent K absorption (P less than .05). Fiber sources did not affect Na or K retention. The OH increased Cu intake and balance (P less than .05). All fiber sources increased Fe intake, but only SH and AM increased (P less than .05) Fe balance. Villus shape and surface morphology in jejunum and ileum examined by scanning electron microscopy (Trial 1 only) appeared to be independent of diet. However, jejunum villus morphologies of two pigs fed AM were characterized by loss of epithelial cells and microvilli at the villus apex, and ileum villi were blunted and frequently folded in one pig fed SH. Fiber sources at the levels included in a corn-soybean meal diet fed in this study had only a minimal impact on performance and utilization of minerals and N and intestinal structure, although apparent energy utilization was decreased.     

Influence of dietary forage and feed intake on carbohydrase activities and small intestinal morphology of calves.

Twenty (12 Holstein, 8 Longhorn cross) calves (198 kg and 7 mo old) were used in a randomized complete block design to evaluate the effects of dietary forage concentration and feed intake on carbohydrase activities and small intestinal (SI) morphology. Calves were individually fed 90% forage (alfalfa) or a 90% concentrate (50% sorghum: 50% wheat) diet at either one or two times NEm for 140 d and slaughtered; tissues and small intestinal digesta were collected. Increased feed intake increased (P less than .05) pancreatic weight, alpha-amylase and glucoamylase activities in the pancreas, SI length and SI digesta weight. Forage-fed calves gained faster (P less than .01) and had greater (P less than .05) pancreatic protein concentrations, alpha-amylase and glucoamylase activities in the pancreas and greater SI digesta alpha-amylase activities than grain-fed calves did. Increased feed intake increased (P less than .01) mucosal weight/cm small intestine only in forage-fed calves and increased (P less than .05) SI surface/volume only in grain-fed calves. Mucosal weight was greatest (P less than .05) at the terminal ileum, surface/volume was greatest (P less than .05) in the duodenum, and mucosal protein concentration was highest (P less than .05) in the SI mid-section. Mucosal lactase was higher (P less than .05) in proximal segments, whereas mucosal isomaltase was higher in middle and distal segments of the small intestine. For mucosal maltase activity, there was a feed intake x SI sampling site interaction (P less than .05) and for trehalase, a diet x feed intake x SI sampling site interaction (P less than .05). The SI distribution patterns of maltase and isomaltase were similar, as were those of trehalase and lactase. The alpha-amylase activity in the pancreas and SI morphology were influenced greatly by diet composition and feed intake by calves.     

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.     

Granulated lysozyme as an alternative to antibiotics improves growth performance and small intestinal morphology of 10-day-old pigs

Lysozyme is a 1,4-β-N-acetylmuramidase that has antimicrobial properties. The objective of this experiment was to determine the effect of a purified granulated lysozyme, compared with antibiotics, on growth performance, small intestinal morphology, and Campylobacter shedding in 10-d-old pigs. Forty-eight pigs (n = 16 per treatment), with an initial BW of 4.0 ± 0.1 kg (P > 0.40), were weaned at 10 d of age, blocked by litter and sex, and assigned to pens (8 pigs/pen). Each block was randomly assigned to consume 1 of 3 liquid dietary treatments for 14 d: a control diet, the control diet + lysozyme (100 mg/kg of diet), or the control diet + antibiotics (neomycin and oxytetracycline, 16 mg/kg of diet). Pigs were weighed and blood was sampled on d 0, 7, and 14. Blood was analyzed for plasma urea N and IgA. After 14 d of treatment, pigs were killed and samples of the jejunum and ileum were collected and fixed to measure villus height and crypt depth. Rectal swabs were taken on d 0, 7, and 14 of treatment, and samples of ileal and cecal contents were taken at d 14 of treatment to determine the presence of Campylobacter. Pigs consuming lysozyme and antibiotics gained BW at a faster rate than did control pigs over the course of the study (402 ± 12 and 422 ± 14 g/d, respectively, vs. 364 ± 14 g/d; P < 0.02), resulting in heavier ending BW (9.9 ± 0.3, 9.9 ± 0.3, and 9.0 ± 0.2 kg for pigs in the lysozyme, antibiotic, and control groups, respectively; P < 0.03). Immunoglobulin A decreased and plasma urea N increased over the course of the study (P < 0.1), regardless of dietary treatment (P > 0.6). Crypt depth was increased in pigs fed lysozyme- and antibiotic-treated diets, compared with pigs fed the control diet, in both the jejunum (60.0 ± 2.8 and 62.2 ± 3.0 μm, respectively, vs. 50.7 ± 3.1 μm; P < 0.03) and ileum (76.0 ± 7.5 and 72.2 ± 5.0 μm, respectively, vs. 52.4 ± 3.5 μm; P < 0.02). Villus height did not differ in the jejunum (P > 0.2) but was increased in the ileum of pigs consuming the lysozyme- and antibiotic-treated diets, compared with pigs fed the control diet (312 ± 20 and 314 ± 10 μm, respectively, vs. 263 ± 15 μm; P < 0.4). Small intestinal total mucosa and mucosal protein concentrations, as well as disaccharidase-specific activities, were not altered by lysozyme or antibiotics (P > 0.05). Campylobacter was detected in 27% of control samples but in only 5% of samples from pigs fed antibiotics and 8% of samples from pigs fed lysozyme (P < 0.01). Thus, granulated lysozyme is a suitable alternative to antibiotics for 10-d-old pigs consuming manufactured liquid diets.     

Effect of dietary soybean meal on the microscopic anatomy of the small intestine in the early-weaned pig

Two experiments were conducted to determine the effect of soybean meal in postweaning diets on villus height (VH), villus shape and lamina propria depth (LPD) in the small intestine. Intestinal samples were taken at 25, 50 and 75% of the small intestine's length. The first experiment determined the normal effects of age on these structures in nursing pigs from 9 to 36 d of age. Villus height decreased (P less than .01 at the 50 and 75% locations) and LPD increased (P less than .01 at the 25% location) in a quadratic fashion with increasing age. In the second experiment, pigs were weaned at 21 d of age and fed one of three 20% protein diets: 1) protein from hydrolyzed casein (CAS), 2) soybean meal (SBM) or 3) a conventional corn-soybean meal diet (CSBM). Intestinal samples were taken 0, 3, 6, 9, 12 and 15 d post-weaning. Villus height decreased dramatically the first 3 d postweaning, with a continuing decline until 12 d post-weaning. Averaged over the d 3 to 15 interval, VH were generally greater for pigs fed CAS than for pigs fed CSBM or SBM. Pigs fed SBM or CSBM had deformed villi, and pigs fed SBM had greater (P less than .05) LPD at all intestinal locations, suggesting less mature enterocytes on the villi. These data suggest that feeding high concentrations of soybean meal to the pig post-weaning has a detrimental effect on the small intestine, but this effect was minimized when soybean meal was fed as part of a corn-based diet.     

丁酸钠对断奶羔羊胃肠道发育的影响

本试验旨在研究丁酸钠对断奶羔羊胃肠道发育的影响。选取24只42日龄的断奶羔羊,随机分成4组,每组6个重复。空白对照组饲喂基础饲粮,抗生素组饲喂在基础饲粮中添加250 mg/kg黄霉素的饲粮,丁酸钠A组和丁酸钠B组分别饲喂在基础饲粮中添加2和3 g/kg包膜丁酸钠的饲粮。各组分别在试验第14天、第28天选取3只羔羊屠宰取样。结果表明:试验第14天时,各组断奶羔羊的瘤胃相对质量和相对容积以及各胃肠道形态指标均无显著差异(P>0.05);试验第28天时,与空白对照组相比,丁酸钠B组瘤胃背囊的肌层厚度,瘤胃腹囊的肌层厚度、乳头高度,十二指肠、空肠和回肠绒毛高度,空肠绒毛表面积以及空肠和回肠绒毛高度/隐窝深度显著增加(P<0.05)。由此可见,在饲粮中添加3 g/kg包膜丁酸钠并持续饲喂28 d可以促进断奶羔羊瘤胃乳头和肌层以及肠道绒毛的生长,增加肠道绒毛高度与隐窝深度的比值,有利于胃肠道的发育。     

Histological alterations of the intestinal villi and epithelial cells in chickens fed dietary sugar cane extract

1. Sugar cane extract (SCE) is the residue after removing glucose, fructose and sucrose from sugar cane juice. To investigate the effects of dietary SCE on growth performance and alterations to intestinal histology, 36 male Sanuki Cochin chickens were divided into three groups: a control group was fed a commercial diet (180 g/kg CP, 13.59 MJ/kg ME) and the treatment groups were fed the commercial diet supplemented with 0.5 or 10 g/kg SCE ad libitum for 35 d. 2. Feed intake and weight gain tended to be higher in the 0.5 and 10 g/kg SCE groups than in the control group. No specific gross morphological alterations were observed in the visceral organs of chickens in any of the groups. However, intestinal villus height, villus area, epithelial cell area and cell mitosis in each intestinal segment had higher values in the SCE groups than in the control group. In the 0.5 and 10 g/kg SCE groups, but not in the control group, the cells on the villus apical surface protuberated and had larger cell clusters and some areas with cells with no microvilli. 3. The observed alterations to intestinal histology in chickens fed dietary SCE diets demonstrate that the function of villi and cells on the villus tip might be activated in all the intestinal segments and that cell turnover is also accelerated. These activated intestinal functions appear to promote growth and immuno-stimulation in chickens fed SCE diets, especially in the 0.5 g/kg group.     

Tributyrin and lactitol synergistically enhanced the trophic status of the intestinal mucosa and reduced histamine levels in the gut of nursery pigs

This study determined whether tributyrin and lactitol could synergistically facilitate the transition from milk to solid feed in nursery pigs. At 21 d after birth, 64 piglets were moved from the piggery to a production barn and fed a medicated diet. At 28 d after birth, the piglets were weighed and allotted into four groups and fed a standard nonmedicated diet (control) or the control diet with tributyrin (butanoic acid 1,2,3-propanetriyl ester; 10 g/kg), or with lactitol (beta-D-galactopyranosyl-(1-->4)-D-sorbitol; 3 g/kg), or with tributyrin (10 g/kg) plus lactitol (3 g/kg). On d 0, 14, and 42 after being fed the control or experimental diets, the animals were weighed, and animal health, feed intake, and feed conversion ratio were determined. On d 42, four piglets from each treatment were killed to measure the empty and full weight of the gut, as well as the weights of the liver and kidneys. The jejunum and cecum were sampled to analyze the luminal concentrations of lactic acid; short-chain fatty acids; and mono-, di-, and polyamines and to assess the mucosal status. Mortality after 42 d ranged from 19% for animals fed the control diet, to 6% for animals fed the tributyrin or lactitol diets, and to 0% for animals fed the tributyrin+lactitol diet. After 14 d, the ADG was 127% greater (P < 0.05) in animals fed the tributyrin+lactitol diet than in animals fed the control or tributyrin diets. After 42 d, animals fed the tributyrin+lactitol diet were heavier (P < 0.05) than animals fed the tributyrin diet. At slaughter, no differences (P > 0.05) in organ weights were observed. With the exception of animals fed the lactitol diet, wherein cecal lactic acid levels increased threefold (P < 0.01), the luminal concentrations of lactic acid and short-chain fatty acids were not different (P > 0.05). Among the various amines analyzed, the only response (P < 0.05) was a 66 and 49% decrease in histamine levels in the jejunum and cecum, respectively, in animals fed the tributyrin+lactitol diet compared to the control diet. In the jejunum of animals fed the lactitol or tributyrin+lactitol diets, the length of the villi was increased by 12% (P < 0.05) compared to animals fed the control diet, whereas the tributyrin diet did not have any effect on the villi (P > 0.05). In the cecum, the depths of the crypts were reduced (P < 0.001) by 18% in animals fed the lactitol diet and 45% in animals fed the tributyrin or tributyrin+lactitol diets compared to animals fed the control diet. In conclusion, a diet containing tributyrin and lactitol as nutribiotics resulted in lower histamine levels in the jejunum and cecum, as well as longer jejunal villi and shallower cecal crypts.     

Comparison of wheat gluten and spray-dried animal plasma in diets for nursery pigs

Five experiments were conducted to determine the effects of different wheat gluten (WG) sources (Source 1 = enzymatically hydrolyzed, Source 2 = nonmodified ring-dried, Source 3 = spray-dried, and Source 4 = flash-dried) on growth performance of nursery pigs compared with soybean meal (SBM), spray-dried animal plasma (SDAP), or other specialty protein sources. In Exp. 1, pigs (n = 220, initially 6.1 +/- 2.5 kg) were fed a control diet containing (as-fed basis) 6% SDAP or WG Source 1 or 2. The WG and l-lysine*HCl replaced 50 or 100% of the SDAP. From d 0 to 21, increasing WG (either source) decreased ADG and ADFI (linear, P < 0.01), but improved (linear, P < 0.02) G:F. In Exp. 2, pigs (n = 252, initially 6.2 +/- 3.0 kg) were fed a negative control diet containing no SDAP or WG, diets containing (as-fed basis) 9% WG Source 1 or 5% SDAP, or combinations of WG and SDAP where WG and l-lysine*HCl replaced 25, 50, or 75% of SDAP. From d 0 to 14, pigs fed increasing WG had decreased ADG (linear, P < 0.05). In Exp. 3, pigs (n = 240, initially 7.0 +/- 2.5 kg) were fed a negative control diet, a diet containing (as-fed basis) either 3, 6, 9, or 12% WG Source 3, or a positive control diet containing 5% SDAP. The diets containing 9% WG and 5% SDAP had the same amount of SBM. From d 0 to 7, pigs fed 5% SDAP had greater (P < 0.04) ADG than pigs fed the diet containing 9% WG. From d 0 to 14, increasing WG had no effect on ADG, ADFI, or G:F. In Exp. 4, pigs (n = 200, initially 6.0 +/- 2.4 kg) were fed a negative control diet, the control diet with (as-fed basis) 4.5 or 9.0% WG Source 1, or the control diet with 2.5 or 5.0% SDAP. Diets containing WG and SDAP had similar SBM levels. From d 0 to 7 and 0 to 14, increasing SDAP tended to improve (linear, P < 0.06) ADG, but increasing WG had no effect. In Exp. 5, 170 barrows and gilts (initially 7.5 +/- 2.8 kg) were used to determine the effects of WG Source 1 and 4 compared with select Menhaden fish meal or spray-dried blood cells and a negative control diet (SBM) on the growth performance of nursery pigs from d 5 to 26 postweaning (d 0 to 21 of experiment). No differences were found in ADG or G:F, but pigs fed the diet containing (as-fed basis) 2.5% spray-dried blood cells had greater ADFI than pigs fed the negative control from d 0 to 21. Wheat gluten source had no effect on ADG, ADFI, or G:F. The results of these studies suggest that increasing WG in diets fed immediately after weaning did not improve growth performance relative to SBM or SDAP.     

Xylanase and beta-glucanase supplementation improve conjugated bile acid fraction in intestinal contents and increase villus size of small intestine wall in broiler chickens fed a rye-based diet

This study was performed with growing chickens (4 to 22 d of age) to evaluate the effects of feeding a rye-based diet supplemented with commercial enzyme preparation containing xylanase and beta-glucanase (Quatrazyme HP, Nutri-Tomen, France) on small intestine wall morphology, bile acid composition, nutrient digestibility, and bird performance compared with unsupplemented rye- or corn-based diets. The rye-based diet decreased (P < or = 0.05) weight gain, feed intake, and feed efficiency and increased water intake compared with the corn-based diet. Moreover, rye consumption reduced crude fat and protein digestibility as well as apparent metabolizable energy (P < or = 0.05). The small intestine wall showed that villus length, width, and surface were decreased in broiler chickens fed the rye-based diet compared with those fed the corn-based diet. However, crypt morphometry parameters were not affected by diet type. The concentration of conjugated bile acids in the small intestine contents of broiler chickens fed the rye-based diet was decreased (P < or = 0.05) compared with those fed the corn-based diet. These findings suggest that feeding a rye-based diet reduces villus capacity for nutrient absorption and bile acid capacity for fat solubilization and emulsification, resulting in decreased bird performance. The addition of xylanase and beta-glucanase to the rye-based diet improved (P < or = 0.05) weight gain, feed intake, and feed efficiency, and decreased water intake. The digestibility of nutrients and apparent metabolizable energy were also increased (P < or = 0.05). Addition of xylanase and beta-glucanase increased (P < or = 0.05) villus size and the villus height-to-crypt depth ratio, as well as the concentration of conjugated bile acids (P < or = 0.05) in the small intestine contents. Exogenous enzymes improved nutrient digestibility and broiler chicken performance, probably by improving the absorption capacity ofthe small intestine through increased villus surface and intestinal concentration of conjugated bile acids.     

Effect of dietary high- and low-methylated citrus pectin on the activity of the ileal microflora and morphology of the small intestinal wall of broiler chicks.

1. A study was conducted with broiler chicks to evaluate the effects of dietary high-methylated citrus pectin (HMC) or low-methylated citrus pectin (LMC) on the performance, nutrient digestibility, morphology of the small intestinal wall and ileal microbial activity. 2. Both pectin products were tested at a dietary content of 30 g/kg using a diet based on maize and soya flour. 3. Inclusion of HMC in the diet depressed weight gain and food utilization significantly. With a dietary addition of LMC there were only small decreases in weight gain and food utilisation. 4. Digestibility of dry matter, organic matter, crude fat, starch and amino acids, nitrogen retention and metabolisable energy value were reduced significantly when HMC was added to the diet. The addition of LMC to the diet reduced fat and ash digestibility and metabolisable energy value significantly. 5. Inclusion of LMC in the diet increased ileal viscosity marginally, whilst HMC had such an effect that the supernatant could not be extracted. Microbial activity in the ileum, particularly that of Enterococci, Bacteroidaceae, Clostridia and E. coli, was increased significantly with dietary addition of HMC. Inclusion of LMC in the diet did not greatly affect microbial activity as only the number of Clostridia was increased. 6. The addition of HMC to the diet markedly affected the morphology of the intestinal wall and significantly increased the number of goblet cells per 100 villus cells and the sucrase isomaltase activity was increased significantly. However, the morphology of the intestinal wall was hardly affected by LMC, whereas the number of goblet cells per 100 villi cells was significantly increased. 7. Results of the present study indicate that the inclusion of water-soluble pectins in diets of chicks changes ileal microbial activity and the morphology of the small intestinal wall. The magnitude of these changes depends on the degree of methylation of the pectins.     

Histological intestinal alterations in chickens fed low protein diet

To demonstrate whether that hypotrophied histological alterations of intestinal villi and epithelial cells are observed in chickens fed low crude protein (CP) diet, 36 male chickens were allotted into 10%, 16% and 22% CP diets groups for 35 days. The 10% CP group showed a lower value of weight gain and feed efficiency than the other two CP groups (p < 0.05). On the relative weight of visceral organs, the 10% CP group showed a heavier gizzard than the 22% CP group, a heavier jejunum than the other two CP groups and a heavier value of ileum and caeca than the 22% CP group (p < 0.05). On the relative length of intestines, the 10% CP group showed a longer value of duodenum and caeca than the other two CP groups, a longer jejunum than the 16% CP group and a longer colon than the 22% CP group (p < 0.05). The villus height and villus area of all intestinal segments did not change in all groups. The duodenal cell areas and cell mitosis numbers tended to be lower in 10% CP group than in the other two protein groups, and the jejunal cell area and duodenal cell mitosis numbers were decreased in the 10% crude protein group (p < 0.05). In relation to the protuberated cells in the higher CP groups, the 10% CP group showed only faintly protuberated cells on the duodenal and jejunal villus apical surface. The ileal villi did not show specific alterations among each group. The chronic feeding of low CP diet induced a hypotrophied histological alteration. This suggests that the hypotrophied histological alterations can assess that the fed‐diet is not so well‐balanced diets, nutritionally.     

Glutamine,glutamate,and aspartate differently modulate energy homeostasis of small intestine under normal or low energy status in piglets

Weaning stress may cause reduced energy intake for maintenance of mucosal structure.Gln,Glu,and Asp are major energy sources for the small intestine.This study investigated whether Gln,Glu,and Asp improve the intestinal morphology via regulating the energy metabolism in weaning piglets.A total of 198 weaned piglets were assigned to 3 treatments:Control(Basal diet+1.59%L-Ala);T1(Basal diet+1%L-Gln+0.5%L-Glu+0.1%L-Asp);T2(Low energy diet+1%L-Gln+0.5%L-Glu+0.1%L-Asp).Jejunum and ileum were obtained on d 5 or 21 post-weaning.T1 enhanced growth performance.T1 and T2 treatments improved small intestinal morphology by increasing villus height,goblet cell number and decreasing crypt depth.Days post-weaning affected the efficacy of T2,but not T1,on energy metabolism.At normal energy supplementation,Gln,Glu,and Asp restored small intestinal energy homeostasis via replenishing the Krebs'cycle and down-regulating the AMPK(adenosine monophosphate activated protein kinase)pathway.As these are not sufficient to maintain the intestinal energy-balance of piglets fed with a low energy diet on d 5 post-weaning,the AMPK,glycolysis,beta-oxidation,and mitochondrial biogenesis are activated to meet the high energy demand of enterocytes.These data indicated that Gln,Glu,and Asp could restore the energy homeostasis of intestinal mucosa of weaning piglets under normal energy fed.Low energy feeding may increase the susceptibility of piglets to stress,which may decrease the efficacy of Gln,Glu,and Asp on the restoration of energy balance.These findings provide new information on nutritional intervention for insufficient energy intake in weaning piglets.     

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.     

Effects of enzymatic hydrolysate of locust bean gum on digestibility,intestinal morphology and microflora of broilers

To investigate the effects of different levels of enzymatic hydrolysate of dietary locust bean gum on nutrient digestibility, intestinal morphology and microflora of broilers, a total of 768 one-day-old Arbor Acres (AA) broiler chicks were randomly divided into 6 treatments with 8 replicates per treatment and 16 birds per replicate. The treatments were as follows: (1) CON, basal diet; (2) ANT, basal diet +62.5 mg/kg flavomycin; (3) LBG, basal diet +0.1% locust bean gum; (4) ELBG-0.1, basal diet +0.1% enzymatic hydrolysate of LBG; (5) ELBG-0.2, basal diet +0.2% enzymatic hydrolysate of LBG; and (6) ELBG-0.3, basal diet +0.3% enzymatic hydrolysate of LBG. The digestibilities of ether extract, crude protein and dry matter were increased (p < .01) in broilers fed the ELBG-0.3 diet compared with the CON and LBG diets on day 21. Duodenal villus height and the ratio of the villus height to crypt depth were greater (p < .01) in broilers fed the ELBG-0.3 diet than the CON, ANT and LBG diets. Jejunum villus height was higher (p < .05) in broilers fed the ELBG-0.2 and ELBG-0.3 diets than the CON diet. The number of caecal Escherichia coli was reduced (p = .01) in broilers fed the ELBG-0.2 and ELBG-0.3 diets compared with the CON diet. The number of caecal Lactobacilli was greater (p < .05) in broilers fed the ELBG-0.3 diet than the CON and ANT diets. In summary, the addition of 0.3% locust bean enzymatic hydrolysate can increase the surface area of intestinal villi and the number of beneficial bacteria, inhibit the proliferation of harmful bacteria, maintain the balance of intestinal microflora and improve the digestibility of nutrients.     

Growth and intestinal morphology of pigs from sows fed two zinc sources during gestation and lactation

An experiment was conducted to compare the effects of organic (Zn AA complex, ZnAA) and inorganic Zn (ZnSO4) sources on sows and their progeny during gestation and lactation and on the pigs during the nursery period. The dietary treatments were 1) a corn-soybean meal diet with 100 ppm Zn from ZnSO4 (control); 2) diet 1 + 100 ppm additional Zn from ZnSO4; and 3) diet 1 + 100 ppm additional Zn from ZnAA. Dietary additions were on an as-fed basis. Thirty-one primaparous and multiparous sows were allotted to the treatment diet beginning on d 15 of gestation and continuing through lactation. At weaning (d 17 of age), 202 pigs (63, 55, and 84 pigs for treatments 1 to 3, respectively) were allotted to the same dietary treatment as their dam. The pigs were fed a 3-phase diet regimen during the nursery period: d 0 to 7 (phase I); d 7 to 21 (phase II); and d 21 to 28 (phase III). At weaning and at the end of phase III, 1 gilt per replicate was killed, and the left front foot, liver, pancreas, and entire small intestine were removed. Diet had no effect (P > 0.10) on any response during gestation. During lactation, there was an increase (P < 0.10) in litter birth weight in sows fed ZnAA compared with those fed the control or ZnSO4 diets. The sows fed ZnAA nursed more pigs (P < 0.10) than sows fed the ZnSO4 diet, and they weaned more pigs (P < 0.05) than sows fed the control diet. Jejunal villus height of the weaned pigs from sows fed ZnSO4 was increased (P < 0.05) compared with those from the sows fed the control diet. During the nursery period, growth performance was not affected (P > 0.10) by diet. Pigs fed ZnSO4 had greater duodenal villus width (P < 0.05) than those fed ZnAA, and pigs fed ZnSO4 or the control diet had greater ileal villus width (P < 0.05) than those fed ZnAA. Pigs fed ZnSO4 or ZnAA had more (P < 0.05) bone Zn than those fed the control diet. Liver Zn concentration was greatest in pigs fed ZnSO4, followed by those fed ZnAA, and then by those fed the control diet (P < 0.05). Pancreas Zn was increased (P < 0.05) in pigs fed ZnSO4 compared with those fed the control diet. These results suggest that 100 ppm Zn in trace mineral premixes provides adequate Zn for optimal growth performance of nursery pigs, but that 100 ppm additional Zn from ZnAA in sow diets may increase pigs born and weaned per litter.     

紫茎泽兰对大鼠肠道结构和肠道黏膜免疫屏障的影响

为探究紫茎泽兰对动物肠道损伤及致毒机制,本试验选取16只7周龄雄性SD大鼠经7 d适应期后随机分为对照组（饲喂不含紫茎泽兰饲料,10 g·100 g^-1 BW）与试验组（饲喂含30%紫茎泽兰饲料,10 g·100 g^-1 BW）,试验周期为14 d,试验结束后取各肠段（取十二指肠、空肠、回肠、盲肠、结肠和直肠）组织样品,观察结构损伤,计数免疫细胞,测定sIgA（secretory immunoglobulin A,sIgA）和炎性细胞因子分泌量。结果表明：与对照组相比,紫茎泽兰可使十二指肠绒毛出血及顶端轻度坏死脱落,肠绒毛高度、隐窝深度及其比值极显著增加（P<0.01）;空肠充血并伴有绒毛顶端糜烂性坏死脱落,绒毛高度及绒毛高度与隐窝深度比值极显著增加（P<0.01）;回肠大量肠绒毛顶端凝固性坏死,并伴有出血与炎性浸润,绒毛高度、隐窝深度及其比值极显著增加（P<0.01）;盲肠水肿及充血;结肠淋巴细胞增多、直肠大量淋巴细胞浸润及淋巴细胞增生,其中以回肠和直肠机械损伤最为严重,回肠评分增加722.36%,直肠评分增加976.00%;试验组各肠段上皮内淋巴细胞（intestinal intraepithelial lymphocytes, IELs）、固有层淋巴细胞（lamina propria lymphocytes, LPLs）和杯状细胞（goblet cells, GCs）数量极显著增加（P<0.01）,同时还可极显著增加sIgA的分泌量（P<0.01）,极显著增加促炎因子IL-1β、IL-2、TNF-α和IFN-γ的表达量（P<0.01）,极显著降低抑炎因子IL-4、IL-10的表达（P<0.01）,激活肠道炎症反应,从而破坏肠道黏膜免疫屏障,造成肠道损伤。     

Effect of dietary cholesterol and carbohydrate on small intestinal structure and function in prematurely weaned rats

A study using the prematurely weaned rat as a model for the pig was undertaken to determine the effect of dietary cholesterol and carbohydrate source on small intestinal structure and function. Duodenal and jejunal samples were obtained at 18, 24, and 30 d of age from rats weaned at 15 d of age and from unweaned rats at 15, 18, 24, and 30 d of age. Four 20% CP diets were formulated: two diets used lactose and glucose as the carbohydrate source and two used sucrose and starch as the carbohydrate source; 1% cholesterol was substituted for either glucose or starch in one of each diet type. The unweaned rats consistently gained weight at a faster rate (P less than .01), had greater concentrations of Alcian blue (AB+) and periodic acid-Schiff (PAS+) goblet cells (P less than .03), and had more favorable villus height than did the weaned rats. The animals fed cholesterol tended to gain more weight, had more AB+ and PAS+ goblet cells (P less than .03), and had longer villi than did those not fed cholesterol. Lactase activities tended to be greater in the unweaned rats. Sucrase activities were greater in the weaned rats at 18 d (P less than .02). The data indicate that the addition of cholesterol to weaning diets is beneficial in maintaining small intestinal integrity.     

Effect of dietary copper on intestinal mucosa enzyme activity, morphology, and turnover rates in weanling pigs.

Twenty-four pigs from four litters weaned at 21 d of age (6.6 kg of BW) were used to evaluate the influence of 250 ppm of dietary Cu on intestinal mucosa glucose-6-phosphatase (GP), alkaline phosphatase (AP), and adenosine triphosphatase (ATPase) activity; mucosal morphology; and the turnover rate of the intestinal mucosa throughout the gastrointestinal tract. Pigs were allotted into four pens of six pigs each based on sex, litter, and weight. Pens were then assigned to one of two treatments: 1) corn-soybean meal-whey diet with no antimicrobials (CO), or 2) CO + 250 ppm of Cu. Pigs were fed twice daily an amount approximately equal to ad libitum intake for 14 d. On d 14, pigs were injected i.p. with [3H]thymidine (50 microCi/kg of BW) 10 h after the morning meal. One pig from each pen was euthanatized at 1, 6, 12, 20, 32, and 44 h postinjection, and intestinal tissue was collected from the duodenum, two jejunum sites (upper and lower), ileum, cecum, and colon. The activity of GP and AP in the lower jejunum tended to decrease in pigs fed Cu (P less than .11, P less than .08, respectively). The ATPase activity was not affected by treatment (P greater than .10). Crypt death, villus height, or epithelial cell size (P greater than .10) were not affected by feeding Cu. Migration rate of epithelial cells up the villus was also not affected by treatment (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)