Penetration in vitro of newly excysted juvenile flukes of Japanese Fasciola sp. through ligated intestines of rabbits, mice, rats and chickens.

Ligated intestines of rabbits, mice, rats and chickens were used to examine the penetration of newly excysted juvenile flukes of Japanese Fasciola sp. in vitro. In rabbit intestines, the penetration rate was relatively high in the rectum and duodenum. Penetration rates in the jejunum, ileum, cecum and colon were comparable to those in the rectum and duodenum, although it was lower in the appendix. In the case of mouse, juvenile flukes penetrated the duodenum, jejunum, cecum, and rectum at considerably high rates. In rat intestine, penetration by flukes was less in the duodenum and rectum, although flukes were detected in the jejunum. In chicken intestine, flukes barely penetrated the duodenum, jejunum and rectum. Consequently, newly excysted flukes of Fasciola sp. seem to penetrate any region of the intestine in rabbits and mice. In rats, the middle small intestine may be the site suitable for flukes to penetrate. In chickens, the difficulty in penetration of the intestinal wall may be one of the reasons why chickens are scarcely infected with Fasciola sp.     

Ultrasonography of the gastrointestinal tract of toco toucans (Ramphastos toco)

Baseline data for wall thickness in healthy toucans can be used to diagnose disease in sick individuals. This study aimed to evaluate the use of ultrasonography for the examination of the gastrointestinal tract of healthy toco toucans (Ramphastos toco). Ten non-anaesthetized healthy adult toco toucans were evaluated. Food was withheld for 3 h prior to the ultrasound examination. Longitudinal and transverse images of the gastrointestinal tract were obtained using ventromedian cranial and ventromedian caudal approaches to evaluate the morphology and stratification. The wall thickness of the sections was measured: proventriculus and ventriculus, duodenum, jejunum/ileum, and cloaca. Additionally, the thickness of the mucosal layer of the duodenum and jejunum/ileum was also measured. Subsequently, the ratios of the duodenal wall thickness to the duodenal mucosa layer and the total wall thickness of the jejunum/ileum to the jejunum/ileum layer mucosa were stablished. The wall thickness of the proventriculus was significantly higher than the wall thickness of ventriculus. The wall thickness of the duodenum was significantly higher than the wall thickness of jejunum/ileum. The mean ratios of the duodenal wall thickness to the duodenal mucosa layer and the wall thickness of the jejunum/ileum to the jejunum/ileum layer were 83.15% and 80.07%, respectively. In conclusion, it was possible to assess the stomach and intestines using ultrasound examination in healthy toco toucans, due to their medium body size and no interference by surrounding air sacs.     

Effects of Lactobacillus plantarum on the intestinal morphology,intestinal barrier function and microbiota composition of suckling piglets

This study investigated the effect of Lactobacillus plantarum strain 299v on gut health in suckling piglets. Sixty newborn piglets were assigned to control and probiotic treatments, with three litters per treatment (ten piglets/litter). From days 1 to 20 of life, piglets were orally administered a placebo of 0.1% peptone or 1.0 ×  10¹⁰ CFU L. plantarum 299v daily. Six piglets per treatment were sacrificed on day 20, and intestinal tissues (including duodenum, jejunum, ileum and colon) and the intestinal contents from colon segments were collected. The results demonstrated that piglets treated with L. plantarum 299v had a lower diarrhoea incidence than the controls. L. plantarum 299v administration significantly increased the ratio of the villus height to the crypt depth in the jejunum and ileum, as well as the mRNA expression of jejunal occludin and ileal zonula occludens 1 (ZO‐1). The L. plantarum treatment also increased the mRNA abundance of porcine β‐defensin 2 (pBD2) and pBD3 in the jejunum and ileum and of toll‐like receptors (TLRs), such as TLR2, TLR4, TLR6 and TLR9 in the ileum, and significantly upregulated the mRNA abundances of ileal pBD1 and colonic TLR4. Additionally, the L. plantarum 299v treatment significantly changed the structure of the colonic microbiota, as evidenced by the obvious increases in the relative abundances of the phyla Firmicutes and Actinobacteria and of the genus Lactobacillus. Our findings indicate that L. plantarum 299v facilitates the gut health of suckling piglets, probably by improving the intestinal morphology and intestinal barrier function and by modifying the structure of the gut microbiota.     

Effect of colibacillosis or coccidiosis on expression of breast cancer resistance protein in small intestine and liver of chickens

Breast cancer resistance protein (BCRP, ABCG2) is a member of ABC (ATP‐binding cassette) transporter superfamily that occurs in a variety of tissues including liver and small intestine of animals. As BCRP is involved in drug absorption, distribution, and elimination, modulation of its expression may affect the clinical efficacy of drugs. However, little is known about the effects of coccidiosis or colibacillosis infection on the levels of BCRP expression in chickens. Here, we studied the effect of infection with Escherichia coli (E. coli) or Eimeriida mixture (E. necatrix and E. tenella) on the expression levels of ABCG2 mRNA and BCRP in the different segments of small intestine and liver in chickens. Expression of ABCG2 mRNA or BCRP was detected in the entire small intestine and liver of healthy chickens, and the expression levels in liver and ileum were significantly higher than duodenum and jejunum. Infection with E. coli or Eimeriida mixture resulted in significant decrease in ABCG2 mRNA and BCRP expression in liver, ileum, and jejunum, but not in duodenum, in comparison with noninfection control. The results indicate that coccidiosis or colibacillosis infection inhibits BCRP expression in chickens, which may consequently influence drug distribution and therapeutic efficacy.     

Ontogenetic development of proline intestinal transport in the domestic fowl

1. The proline disappearance from the jejunal and ileal lumen of chickens aged from 1 day to 15 weeks were studied using a perfusion method "in vivo”.

2. A decrease in proline transport was observed from younger to older animals. The 2 intestinal segments showed different behaviours, the 1‐day and 1‐week‐old animals showed the same value in the jejunum, whereas in the ileum a progressive decrease in proline transport was observed from the first week of life.

3. The differences observed in the 2 segments could be attributed to the different rates of growth of the jejunum and ileum with age; the jejunum showed a peak of growth in the second week of life whereas the ileum showed a peak of growth in the first week. Proline transport in the jejunum decreased until the fifth week and remained constant thereafter.     

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.     

Estimating danofloxacin withdrawal time in broiler chickens based on physiologically based pharmacokinetics modeling

In this study, a physiologically based pharmacokinetics (PBPK) model was firstly developed for danofloxacin in healthy broiler chickens after a single oral administration at 5 mg/kg bw. Then, the model extrapolation from healthy chickens to those infected with Pasteurella multocidaones was performed. The healthy model was validated through a comparison of predicted and previously published concentrations, which indicated that the healthy PBPK model had good predictive ability in plasma, lung, muscle, liver, and kidney, especially at the later sampling time points. Multiple dosing of administration was incorporated into the healthy and infected models. In addition, a Monte Carlo simulation (MCS) included 1000 iterations was further incorporated into both models to predict the withdrawal times of danofloxacin in healthy and infected chickens, which were estimated to be 3 and 2 days, respectively.     

粗酶制剂对雏鹅小肠食糜粘度和pH的影响

18只 7日龄雏鹅 ,随机分成对照和试验两组。饲以大麦 (占 45 % )基础日粮 ,试验组添加 0 .1%的Biokyowa粗酶制剂。实验期为 7～ 2 1日龄 ,2 1日龄屠宰 ,测定小肠食糜中的粘度和pH值。结果显示 :对照组雏鹅小肠各段食糜粘度依十二指肠、空肠和回肠次序向后逐渐显著增加 (P <0 .0 1) ,十二指肠食糜的粘度较空肠和回肠食糜分别低 17.6 1%(P <0 .0 1)和 37.15 % (P <0 .0 1) ,而十二指肠食糜pH值则较空肠和回肠分别低 0 .75 % (P >0 .0 5 )和 5 .92 % (P >0 .0 5 )。试验组各段小肠食糜上清的粘度变化趋势与对照一致 ,十二指肠、空肠和回肠食糜的粘度较对照组分别低 17.6 1%(P <0 .0 1)、37.15 % (P <0 .0 1)和 5 9.46 % (P <0 .0 1) ;十二指肠、空肠和回肠食糜的pH值与较对照组分别低 4.2 1%、4.18%和 3 .79% ,但差异不显著 (P >0 .0 5 )。以上结果表明 :酶制剂通过解除饲料中β -葡聚糖等抗营养因子对消化的负面作用 ,改变了小肠食糜中理化特性 ,从而影响其化学性消化和吸收 ,提高了机体饲料的转化效率 ,有利于雏鹅的生长。     

三种营养需要模式对断奶仔猪生产性能胴体品质和瘦肉生长的影响

试验研究 3种营养需要模式对 8～ 2 0kg断奶仔猪生产性能、胴体品质和胴体瘦肉生长的影响。结果表明 ,采用建议的营养需要模式配制的饲粮饲养仔猪 ,获得的生产性能、胴体品质、胴体瘦肉增重和无脂瘦肉增重以及胴体瘦肉成分优于或接近于采用NRC( 1998)营养需要模式配制的饲粮、极显著优于采用中国 ( 1987)营养需要模式配制的饲粮。根据本试验结果认为 ,建议的营养需要模式更适合杜× (大×长 )断奶仔猪的需要。     

Analysis of Microbiota Structure and Bacteroides Distribution in Different Intestinal Segments in Duck

This study aimed to analyze the microbiota composition and diversity and the distribution of Bacteroides in duodenal, jejunal, ileal and caecal contents in healthy ducks. The contents of duodenum, jejunum, ileum and cecum were collected aseptically from 20 healthy adult Gaoyou ducks (70-day-old, half male and female), and the bacterial DNA of intestinal contents were extracted. The IonS5TMXL platform was used for 16S rRNA high-throughput sequencing, the microbiota structure and abundance, as well as the distribution of Bacteroides were analyzed. The results showed that the microbiota abundance in duodenal and jejunal contents was significantly higher than that in ileal and caecal contents (P<0.05), the microbiota diversity in ileal contents was the lowest. The microbiota structure in duodenal and jejunal contents was similar, they were different from that in ileum, and especially cecum. The dominant phyla in the intestinal contents of healthy duck were Bacteroidetes, Firmicutes, Proteobacteria and Fusobacteria. The relative abundance of these phyla were different in different intestinal segment contents. The different microbial species were colonized in different intestinal segments, and the differential phyla in duodenum, jejunum, ileum and cecum were Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes, respectively. There were 28 kinds of Bacteroides species in duck intestine, among them, B. acidifaciens, B. barnesiae, B. caccae, B. caecicola, B. coprocola, B. sp and B. luti were significantly clustered in the cecum, and B. caecigallinarum, B. plebeius and B. barnesiae were dominantly colonized in duck cecum. The results indicate that intestinal space significantly affects the microbiota abundance and diversity, and different intestinal segments were colonized by differential microorganism, which is consistent with the intestinal segment niche and function. In the cecum, the dominant colonization of Bacteroides may be related to its physiological and biochemical functions.     

鸭不同肠段内菌群结构分析与拟杆菌分布研究

旨在分析健康鸭十二指肠、空肠、回肠和盲肠内容物菌群组成、多样性特征以及拟杆菌分布。本研究选择健康高邮鸭20只,公母各半,70日龄时无菌采集十二指肠、空肠、回肠和盲肠内容物,提取肠道内容物细菌基因组,利用IonS5TMXL平台进行高通量测序,分析肠道内容物菌群结构与丰度特征以及拟杆菌的分布。结果表明,十二指肠、空肠内容物菌群丰度显著高于回肠和盲肠内容物（P<0.05）,回肠内容物菌群多样性最低;十二指肠和空肠内菌群群落结构较为相似,与回肠,特别是盲肠的相似度较小。健康鸭肠内优势菌门为拟杆菌门（Bacteroidetes）、厚壁菌门（Firmicutes）、变形菌门（Proteobacteria）和梭杆菌门（Fusobacteria）,上述菌门在各肠段内容物中相对丰度不同;不同肠段内容物中定植了不同差异微生物物种,十二指肠、空肠、回肠和盲肠内容物中差异菌门分别是变形菌门、放线菌门（Actinobacteria）、厚壁菌门和拟杆菌门。鸭肠道中共分析到28种拟杆菌种,其中B.acidifaciens、B.barnesiae、B.caccae、B.caecicola、B.coprocola、B.sp和B.luti在盲肠内容物中显著聚类,且B.caecigallinarum、B.plebeius和B.barnesiae在鸭盲肠中优势定植。结果显示,鸭肠段空间显著影响了其内容物中菌群丰度与多样性,不同肠段内定植了差异的优势微生物物种,这可能与肠段小环境以及功能一致,在盲肠内容物中优势定植拟杆菌,推测可能与鸭盲肠生理生化功能相关。     

Necrotic Enteritis in Broiler Chickens II. Pathology and Proposed Pathogenesis

The intestines from 124 dead, sick and normal broiler chickens from 24 cases of necrotic enteritis were subjected to histological examination. Tissue sections from the duodenum, jejunum, ileum and ceca from each broiler were examined histologically for lesions of necrotic enteritis and the presence of coccidia. Lesions of necrotic enteritis were present in one or more areas of the intestine in all but six of 94 dead or sick birds and they were most common and severe in the jejunum. Coccidia were found in only small numbers in both diseased and normal birds.

Brown and Brenn stained sections showed Gram-positive bacilli intimately associated with early necrotic lesions on the tips of villi. Tissue sections from the intestines of sick birds permitted a proposed pathogenesis for this disease with the lesion starting at the tips of villi.

The similarity in pathogenesis and pathological lesions in this disease of broilers and Clostridium perfringens type C enteritis in baby pigs is discussed.

     

毒害艾美耳球虫感染对雏鸡肠道组织热休克蛋白-90mRNA表达的影响

将90只海蓝褐雏鸡随机分为对照组、毒害艾美耳球虫(E.necatrix)一次感染组和毒害艾美耳球虫两次感染组,应用二重PCR方法,通过对肠道组织热休克蛋白-90 (HSP-90) mRNA表达的检测,较全面系统地研究了毒害艾美耳球虫感染对雏鸡肠道组织HSP-90 mRNA表达的影响。结果发现,14日龄雏鸡经口第一次感染毒害艾美耳球虫后0~14 d,其肠道组织HSP-90 mRNA表达虽然不同程度的低于对照雏鸡,但总体呈上升趋势;上述雏鸡于28日龄时再次攻击性感染毒害艾美耳球虫,其十二指肠、空肠和回肠HSP-90 mRNA表达均呈先下降后上升,而盲肠HSP-90 mRNA表达始终呈下降趋势。28日龄雏鸡一次性大剂量感染毒害艾美耳球虫后,其十二指肠、空肠、盲肠HSP-90 mRNA表达均下降,而回肠HSP-90 mRNA表达先下降后上升。结果表明毒害艾美耳球虫感染雏鸡初期,肠道组织HSP-90 mRNA表达受到一定抑制,其表达量与肠道组织细胞损伤程度密切相关。     

Effect of Heat Shock Protein-90 (HSP-90) mRNA Expression in Intestinal Tissuse of Chickens Infected with E.necatrix

The 90 chickens were randomly divided into control group, E.necatrix one time infection group and E.necatrix two times infection group.We used duplex PCR method to test the expression changes of HSP-90 mRNA in intestinal tissue of chickens infected with E.necatrix and researched the effects of it comprehensively and systematically.The results were showed that after 0 to 14 days the expression of HSP-90 mRNA in intestinal tissues of 14-day-old chickens infected with E.necatrix presented a upward trend though it was lower than the control chickens.These chickens were infected with E.necatrix again at 28 days, HSP-90 mRNA expressions of duodenum, jejunum and ileum decreased and then increased.However, it always showed a downward trend in appendix.When 28 days chickens were infected with high-does E.necatrix once, HSP-90 mRNA expressions of duodenum, jejunum and appendix were in a declining curve.While it was increased originally and then decreased in ileum.This study indicated that HSP-90 mRNA expressions in intestinal tissue of chickens infected with E.necatrix were inhibited at first, and the expression quantity was closely related to the degrees of intestinal tissue damage.     

Phase 1 and phase 2 metabolic activities along the small intestine in adult male sheep

Maté, L., Virkel, G., Lifschitz, A., Sallovitz, J., Ballent, M., Lanusse, C. Phase 1 and phase 2 metabolic activities along the small intestine in adult male sheep. J. vet. Pharmacol. Therap. 33 , 537–545. Metabolic activities of several xenobiotic metabolizing enzymes were evaluated in both hepatic and enteric subcellular fractions obtained from Corriedale × Merino crossbreed rams by using a biochemical approach. Microsomes obtained from the different segments of sheep small intestinal mucosa displayed cytochrome P450 (CYP)‐dependent N‐demethylations but not O‐deethylase activities apparently occurred. CYP‐mediated N‐demethylations neither decreased nor increased along the small intestinal mucosa. Percentages of activity for erythromycin N‐demethylase in the small intestine were between 29% (duodenum) and 45% (ileum) from that measured in the liver, whereas those determined for triacetyl‐oleandomycin N‐demethylation ranged between 10% (duodenum) and 15% (jejunum) of the same hepatic activity. Conversely, metabolic rates for aminopyrine and chlorfeniramine N‐demethylations in the gut mucosa ranged between 3% and 7% compared to their respective hepatic enzyme activities. Sheep enteric mucosa also displayed metabolic reactions typically mediated by flavin‐containing monooxygenases (FMOs), carbonyl reductases (CBRs), carboxylesterases (CES), glutathione S‐transferases (GSTs) and uridine diphosphoglucuronyltransferases (UGTs). The FMO‐mediated sulfoxidation of methimazole was 2.6‐fold higher (P < 0.01) in the ileal compared to the duodenal mucosa. Percentages of activity for the microsomal CBR‐dependent biotransformation of menadione were between 12% (ileum) and 19% (duodenum–jejunum) of the total activity measured in the liver; metabolic rates measured in duodenum and jejunum were ～1.7‐fold higher (P < 0.05) than that observed in the ileum. The microsomal CES activity (using p‐nitrophenyl acetate as substrate) was around twofold higher in duodenum (P < 0.05) and jejunum (P < 0.01) in comparison to the ileum. Cytosolic GST‐dependent activities (toward 1‐chloro, 2,4‐dinitrobenzene) were similar in the mucosa of duodenum, jejunum and ileum. Microsomal UGT activities (toward 1‐naphthol) in duodenum and jejunum were three‐ and fourfold higher, respectively, compared to that measured in the ileum. The small intestinal mucosa may play a critical defensive role due to its involvement in the detoxification of toxic compounds prior to absorption. In addition, gut metabolic reactions may contribute to the presystemic metabolism of orally administered drugs. These results are a further contribution to the understanding of the relevance of the extra‐hepatic metabolism of xenobiotics in ruminant species.     

凝结芽孢杆菌BC-HYI改善脂多糖损伤蛋雏鸡肠道作用的研究

本试验旨在探究凝结芽孢杆菌BC-HYI调节脂多糖(LPS)损伤蛋雏鸡肠道作用。选取1日龄京红蛋雏鸡180只,随机分为5组,每组6个重复,每个重复6只,重复之间体重接近。空白对照组(CON组)和模型组(LPS组)饲喂基础饲粮,连续灌服生理盐水;3个益生菌组饲喂基础饲粮,同时分别连续灌服低、中、高剂量的凝结芽孢杆菌BC-HYI (浓度分别为106、107、108CFU/mL),连续灌服28 d,28 d后灌服LPS,灌服浓度为2 mg/kg,灌服剂量为200μL/只,试验周期为6 h,分别记为LOW+LPS、MID+LPS、HIGH+LPS组。6 h后采血,剖检、收集蛋雏鸡十二指肠、空肠、回肠肠道组织及空肠黏膜。结果表明：与空白对照组相比,LPS灌服后,蛋雏鸡十二指肠、空肠、回肠的绒隐比以及空肠黏膜黏液蛋白2(MUC2)、闭合蛋白(Occludin)和闭锁小带蛋白-1(ZO-1)mRNA相对表达量显著降低(P<0.05),血清二胺氧化酶(DAO)活性及D-乳酸(D-Lac)、肿瘤坏死因子-α(TNF-α)含量,空肠黏膜分泌型免疫球蛋白A(SIgA)和白细胞介素-10(IL-10)的含...     

益生菌发酵棉粕对黄羽肉鸡小肠黏膜形态、血清T淋巴细胞亚群及肠道菌群的影响

本试验旨在研究添加不同比例益生菌发酵棉粕对黄羽肉鸡小肠黏膜形态、血清T淋巴细胞亚群及肠道菌群的影响。选用14日龄健康黄羽肉鸡320只,随机分成4组,每组4个重复,每个重复20只鸡,Ⅰ组为空白对照组,Ⅱ、Ⅲ、Ⅳ组分别添加3%、6%和9%发酵棉粕,研究不同添加量对肉鸡生长前期(14～28日龄)、中期(29～45日龄)、后期(46～65日龄)各阶段小肠黏膜形态,中、后期血清T淋巴细胞亚群及后期肠道菌群的影响。研究结果显示:①与Ⅰ组相比,Ⅲ组黄羽肉鸡前、中、后期的十二指肠绒毛高度极显著提高31.90%、25.17%、49.41%(P<0.01),隐窝深度极显著降低9.42%、11.31%、10.83%(P<0.01),V/C极显著提高45.65%、41.19%、67.84%(P<0.01);空肠绒毛高度极显著提高28.72%、28.38%、27.61%(P<0.01),隐窝深度显著或极显著下降6.65%(P<0.05)、6.18%(P<0.01)、7.37%(P<0.01),V/C极显著提高37.84%、36.69%、37.82%(P<0.01);回肠绒毛高度极显著提高76.64%、40.36%、67.20%(P<0.01) ,隐窝深度显著降低4.09%、6.07%、6.02%(P<0.05),V/C极显著提高83.79%、49.27%、78.26% (P<0.01)。②中、后期Ⅳ组黄羽肉鸡CD4⁺/CD8⁺显著提高42.86%、34.95%(P<0.05)。③随着发酵棉粕添加量的增多,黄羽肉鸡的十二指肠、空肠、回肠中乳酸菌的数量逐渐增多,且差异越来越明显,除Ⅱ组十二指肠和空肠段外,其余各组的各肠段差异均显著或极显著(P<0.05;P<0.01)。大肠杆菌和沙门氏菌的数量逐渐减少,且差异越来越明显,除Ⅱ组十二指肠段外,其余各组各肠段差异均显著或极显著(P<0.05;P<0.01)。综上所述,6%发酵棉粕组在提高十二指肠、空肠、回肠绒毛高度、V/C,降低其隐窝深度方面都优于3%、9%发酵棉粕组,而9%发酵棉粕组在提高CD4⁺/CD8⁺、肠道乳酸菌数量和降低大肠杆菌和沙门氏菌数量方面优于3%、6%发酵棉粕组。     

Developmental changes in morphometry of the small intestine and jejunal sucrase activity during the first nine weeks of postnatal growth in pigs

The objective of this study was to investigate the development of small intestinal size and digestive capacity of the jejunum in growing pigs. The weight, length, surface area, and mucosa weight of the small intestine were measured when pigs were 1, 3, 5, and 9 wk of age. Sucrase and alkaline phosphatase (ALP) activities of the jejunal brush-border membrane, prepared by differential centrifugation and Mg2+ precipitation, were determined at the respective postnatal stages. Body weights increased 7-fold from 2.7 kg at 1 wk to 23.32 kg at 9 wk postnatal. Body weight gains were greater (P < 0.05) from wk 3 to 5 than from wk 1 to 3. Weights of the small intestine and of the intestinal mucosa increased faster (P < 0.05) from 3 to 5 wk than from 1 to 3 wk; the slowest increase occurred from 5 to 9 wk. Weights of the duodenum, jejunum, and ileum, and mucosa from the respective sections increased (P < 0.05) as pigs grew from 3 to 9 wk. Mucosa weight relative to the weight of the section was greater (P < 0.05) for the duodenum and jejunum than for the ileum at 9 wk of age. Between the ages of 3 and 9 wk, the increase in mucosa weight was highest for the jejunum followed by the duodenum and the ileum. The increase was greatest for the duodenum followed by the jejunum and the ileum when mucosal weight was expressed per unit of appropriate intestinal section weight. There was a 55-fold increase in jejunal sucrase activity from 1 to 9 wk; the greatest rate of increase occurred between 5 and 9 wk. Total jejunal ALP activities in pigs at 9 wk was greater (P < 0.05) than at 5 wk, which in turn was greater than at 1 wk of age. In summary, increases in BW during the first 9 wk of postnatal growth in pigs are accompanied by significant developmental changes in digestive capacity including intestinal weights, length, and area as well as jejunal brush-border sucrase and ALP activities.     

A deficient or an excess of dietary threonine level affects intestinal mucosal integrity and barrier function in broiler chickens

The aim of this study was to investigate the effects of deficient or excess of dietary threonine (Thr) levels on intestinal integrity and barrier function of broilers. A total of 432 1‐day‐old commercial broilers (Arbor Acre) were assigned to four experiment groups consisting of six replicates of 18 birds. The treatments were designed as follows: 85%, 100%, 125% and 150% of NRC (Nutrient requirements of poultry (9th edn). Washington, DC: The National Academies Press, 1994) recommendations. The results indicated that expressions of jejunal and ileal secretory immunoglobulin A (sIgA) mRNA were increased linearly or quadratically by increasing Thr (p < .05), and the highest sIgA mRNA abundance was obtained in 125% Thr level. Likewise, the intestinal sIgA content showed similar increasing trend with the intestinal sIgA gene expression in this instance. The high level of Thr inclusion upregulated mucin 2 (MUC2) mRNA expression in the jejunum and ileum (p < .05). In addition, on day 21, the expression levels of jejunal zonula occludens‐2 (ZO‐2) and ileal zonula occludens‐1 (ZO‐1) decreased then increased with increasing Thr level (p < .05), whereas, the mRNA expressions of occludin in the jejunum and ileum had no significant difference amongst groups (p >.05). On day 42, Thr treatments did not affect the mRNA abundance of measured genes in the jejunum and ileum (p > .05). These findings suggested that Thr might be a nutrient immunomodulator that affects intestinal barrier function, moreover, 125% of the NRC (1994) recommendations Thr level was optimum.     

Problems involved in correlating changes of functional diffusive and anatomical surface areas of the upper and lower chicken small intestine during fasting

The anatomic villous surface area and the functional diffusive area (measured by the absorption of 64 mM thiourea) of the jejunum and ileum was estimated in fed and 3-d-fasted chickens. In the jejunum, fasting caused a 50% reduction of the anatomic villous surface area but only a 32% reduction in the functional diffusive area. The jejunal permeability to thiourea was unaltered. The ileal anatomic villous surface area was unaffected by fasting but the ileal functional diffusive area was decreased significantly by 26%, concomitant with a significant reduction of 34% in the permeability to thiourea. The passive absorption of thiourea cannot be used as a simple index of the functional diffusive surface area for dietary-induced changes in the small intestine of the domestic fowl.