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1.
本试验采用离体外翻肠囊法研究了蛋鸡小肠对Gly-L-Leu肽的吸收和转运.将6只206日龄的海兰褐蛋鸡的小肠分割为十二指肠、空肠前、中、后段和回肠5段,分别制备外翻肠囊.每3只鸡的肠囊为1个试验组,将灌注浆膜液(含Ca2+/Mg2+PBS缓冲液)的各肠囊置于相同的二肽培养液(含20mmoL/LGly-L-Leu的Ca2+/Mg2+PBS缓冲液)中进行培养.试验1组培养液添加了肽酶抑制剂(10μmoL/L Bestatin和Amastatin),试验2组浆膜液添加了等量的肽酶抑制剂.培养15分钟后测定培养液、浆膜液、肠组织匀浆液中二肽和游离氨基酸的含量.结果表明,鸡十二指肠、空肠前、中段对Gly-L-Leu有强烈的水解作用,空肠后段和回肠的水解能力相对较弱.鸡各肠段均能迅速吸收Gly-L-Leu,并将其转运到浆膜液中.吸收量和转运量有沿肠道延伸而增强的趋势. 相似文献
2.
用外翻肠囊法研究有机锰在肉仔鸡小肠中的吸收特点 总被引：8，自引：0，他引：8
用外翻肠囊法研究肉仔鸡十二指肠、空肠和回肠对无机锰和有机锰的吸收特点。共包括2个试验，试验1是以硫酸锰为锰源，根据单位时间锰的吸收率与外翻肠囊培养时间的曲线关系确定最佳培养时间，试验2是在此培养时间下比较不同形态锰在肉仔鸡小肠中的吸收特点。2个试验均采用单因子完全随机设计。试验1培养时间分别为20、40、60和80min 4个处理组，将48只28日龄商品代AA肉公鸡随机分到4个处理组，每组6个重复，每个重复2只鸡(为了扣除内源影响，其中1只鸡作为零添加锰水平处理)，每只鸡的十二指肠、空肠和回肠分别用作相应部位肠段外翻肠囊的1个重复。在试验2中共设8个处理组，分别为：硫酸锰、甘氨酸锰螫合物、蛋氨酸锰螫合物、弱络合强度的蛋氨酸锰(Mn—Met E)、中等络合强度的氨基酸锰(Mn—AA A)和强络合强度的氨基酸锰(Mn—AA B)、硫酸锰与甘氨酸混合物及硫酸锰与蛋氨酸混合物的处理组。为了扣除内源影响，另设1组作为零添加锰水平处理。用于试验1中日龄相同的AA肉公鸡72只，随机分到9个处理组，每组8个重复，每个重复1只鸡，每只鸡的十二指肠、空肠和回肠分别用作相应部位肠段外翻肠囊的1个重复。结果表明：(1)锰的吸收率和培养时间在40min内呈线性关系，因此选择30min为试验2的培养时间；(2)体外培养回肠肠囊对无机锰的吸收率一般是十二指肠和空肠肠囊的2～6倍；(3)回肠中锰的吸收率受到添加锰源的显著影响，其中合成蛋氨酸锰组锰的吸收率明显高于硫酸锰和合成甘氨酸锰，中等和强络合强度的氨基酸锰组锰的吸收率也明显高于无机锰和合成甘氨酸锰。试验结果提示，在体外简单缓冲溶液培养的肉仔鸡小肠各段外翻肠囊中，回肠是肉仔鸡小肠吸收锰的主要部位；络合或螫合的有机态锰在体外培养的小肠外翻肠囊中的吸收率比无机形态的锰高；作为配体而言，蛋氨酸比甘氨酸更有利于促进锰的吸收。 相似文献
3.
谷氨酰胺和牛磺酸对仔猪肠黏膜形态的影响 总被引：1，自引：0，他引：1
甘氨酰谷氨酰胺( Gly-Gln)和牛磺酸(Tau)对早期断奶仔猪小肠各段黏肠DNA和形态的影响.以28日龄杜×长×大断奶仔猪为研究对象,通过饲养和屠宰试验,研究Gly-Gln和Tau对早期断奶仔猪十二指肠、空肠和回肠黏肠DNA及形态的影响.结果表明:饲粮中分别或同时添加Gly-Gln和Tau均可提高小肠各段黏膜DNA的含量.Gly-Gln组能显著提高空肠和回肠段的黏膜DNA含量,Tau组和复配组对小肠各段黏膜DNA含量影响不显著;Gly-Gln组极显著增加了十二指肠和回肠的黏膜厚度(MT),显著提高了十二指肠和回肠后段的绒毛高度(VH),显著或极显著降低了空肠前段和中段的隐窝深度(CD),极显著提高了空肠前段和中段的VH/CD,显著提高了回肠段的VH/CD;Tau组极显著提高了十二指肠段的VH并降低了CD,极显著提高了十二指肠段和空肠中段的VH/CD;复配组显著或极显著降低了十二指肠段和空肠中段的CD,极显著提高了空肠前段、中段和回肠段的VH/CD.这说明,在早期断奶仔猪饲粮中分别或同时添加0.25%Gly-Gln和0.1% Tau能有效提高仔猪肠黏膜的发育及功能. 相似文献
4.
采用蛋鸡离体外翻肠段培养法,将小肠分为十二指肠、空肠前段、中段、后段和回肠五个部位肠段,洗净外翻。2种二肽培养液(Gly-Gly肽和Gly-L-Leu肽溶液)作为两组对照培养液,每种二肽培养液中添加肽酶抑制剂(Bestatin和Amastatin),作为试验培养液,39.5℃培养25min,每5min取样一次,测定培养液中的二肽含量。结果表明,培养5min后,含Gly-Gly肽的对照和试验培养液中均未能检测到完整Gly-Gly肽。而含Gly-L-Leu肽的对照培养液Gly-L-Leu肽的含量降低到16.75％,试验培养液则下降到43.40％。而试验培养液中Gly-L-Leu肽的含量10min后无显著降低(P>0.05)。各培养时段试验培养液Gly-L-Leu含量均显著高于对照培养液(P<0.05)。由此认为,离体肠囊在培养过程中能够迅速释放肠肽酶及一些生物活性物质,快速水解2种二肽。肽酶抑制剂(Bestatin和Amastatin)能抑制Gly-L-Leu的水解,但不能抑制Gly-Gly的水解。 相似文献
5.
断奶仔猪赖氨酸需求参数的研究 总被引：9，自引：1，他引：8
试验选取体重约８千克的杜×大×长三元杂交断奶仔猪（公母各半）７２头，随机分为６组，每组２个重复，每个重复６头猪，分别喂以含赖氨酸（Ｌｙｓ）水平为０．８５，０．９５，１．０５，１．１０，１．１５，１．２０％的饲粮。通过测定饲粮Ｌｙｓ水平对断奶仔猪生产性能和血清氮浓度的影响，探讨断奶仔猪Ｌｙｓ的需求参数。结果表明，随着饲粮中Ｌｙｓ水平的提高，仔猪的平均日增重增加，饲料转化率显著改善（Ｐ＜０．０５），并且在１．１５％的Ｌｙｓ组生产性能达到最佳，进一步提高Ｌｙｓ水平，生产性能反而下降。各组采食量差异不显著（Ｐ＞０．０５）。当饲粮Ｌｙｓ水平由０．８５％升至１．１５％，血清氮浓度无显著差异（Ｐ＞０．０５），但１．２％组极显著地高于其他各组（Ｐ＜０．０１），反映该组猪对蛋白质利用较差，这与该组猪生产性能差相符。以上结论提示，８～１９千克断奶仔猪Ｌｙｓ需求参数为饲粮的１．１５％，按ＡＥＣ（１９８９）有关饲料Ｌｙｓ可消化率数据，折算其相应真可消化和表观可消化Ｌｙｓ为１．０３２％和０．９６７％。 相似文献
6.
培养液磷含量和pH值对鸡离体小肠磷吸收的影响 总被引：1，自引：0，他引：1
本研究主要探讨了培养液不同pH值和磷含量对鸡离体小肠磷吸收的影响,为体外培养鸡小肠合理选择培养液pH值和用外翻肠囊法评定饲料有效磷时合理选择培养液磷浓度提供参考依据。采用2个单因子随机试验,每个因子4个处理。48只30日龄体重相近的三黄肉公鸡的十二指肠、空肠和回肠肠囊随机分配到8个处理中,每个处理6个重复,每个重复1个肠囊,39℃培养50min。结果表明：pH5．0～7．0时,肠囊的磷吸收量线性增加;pH8．0时,肠囊的磷吸收量降低;与pH5．0比较,pH7．0时,肠囊的磷吸收量极显著增加（P〈0．01）。培养液磷含量在50～200μg／mL时,肠囊的磷吸收量与磷含量呈正相关;当磷含量增加到400μg／mL,十二指肠肠囊和空肠肠囊的磷吸收量开始降低;磷吸收率与培养液磷含量之间呈负相关,不同处理之间差异极显著（P〈0．01）。结果显示：以肉仔鸡为动物模型,用外翻肠囊法评定饲料有效磷时,培养液适宜pH为6．0～7．0;有效磷含量不能超过200μg／mL,以50μg／mL左右为宜。 相似文献
7.
采用三因素二次回归正交组合设计 ,每组两个重复 ,公母各半 ,研究了能量（ＤＥ :３．０～３．８Ｍｃａｌ／ｋｇ） ,粗蛋白质水平（ＣＰ：１５ %～２５ %）与赖氨酸／能量比（Ｌｙｓ：ＤＥ） :０．６～１．２ｇ．Ｌｙｓ／ＭＪ．ＤＥ对２８日龄断奶仔猪（长白×汉梅）的日增重（ＡＤＧ）、饲料转化率（Ｆ／Ｇ）、日采食量（ＡＤＦＩ）、血浆尿素氮（ＰＵＮ）及血浆游离赖氨酸的影响 ,试验期４２天。试验结果表明 :能量、蛋白质水平及赖氨酸／能量比对仔猪生产性能均有影响（Ｐ＜０．０１） ,其中以赖氨酸／能量比的作用最重要。仔猪２８～６０… 相似文献
8.
本试验用外翻肠囊法研究高钙对肉仔鸡不同肠段(十二指肠、空肠和回肠)吸收不同形态锰的影响,以比较有机锰和无机锰在高钙条件下吸收特点的差异。采用单因子完全随机设计,培养液中添加的4种锰源分别为:硫酸锰、弱络合强度的蛋氨酸锰(Mn-MetE)、中等络合强度的氨基酸锰(Mn-AAA)和强络合强度的氨基酸锰(Mn-AAB)。为了扣除内源的影响,设置1个零添加锰水平处理。将40只31日龄AA肉公鸡随机分到以上5个组,每组8个重复,每个重复1只鸡,每只鸡的十二指肠、空肠和回肠分别作为相应肠段外翻肠囊的一个重复。结果表明:1)体外培养回肠肠囊对锰的吸收率显著高于十二指肠(P<0.01);2)回肠肠囊对强络合强度的Mn-AAB中锰的吸收率显著高于硫酸锰或中等络合强度的Mn-AAA(P<0.05)。本试验结果表明:在高钙条件下,络合形态的有机锰在体外培养的肉仔鸡肠囊中的吸收率显著高于无机形态的锰;强络合强度有机锰源中的锰能更强地抵抗小肠内的解离,比弱或中等络合强度的有机锰源更有利于锰的吸收。 相似文献
9.
为研究深海鱼肽对肉仔鸡肠道氨基酸(苏氨酸、甘氨酸、脯氨酸、异亮氨酸、亮氨酸、组氨酸、赖氨酸)吸收的影响,选取健康体重差异不显著的6周龄爱拔益加肉仔公鸡10只,随机分为两个处理,分别是深海鱼肽处理组和游离氨基酸处理组,每个处理5个重复.采用外翻肠囊法,将肠段进行离体培养.结果显示:在深海鱼肽系统中,7种氨基酸回肠中的总吸收高于游离氨基酸系统;对苏氨酸、甘氨酸、脯氨酸、组氨酸,深海鱼肽能很好的促进它们在小肠的吸收,且在小肠后段效果更明显;深海鱼肽系统中异亮氨酸、亮氨酸、赖氨酸的吸收相对于游离氨基酸系统要低.结果表明,深海鱼肽对不同肠段不同氨基酸作用效果不同. 相似文献
10.
11.
J Wünsche H D Bock U Hennig F Kreienbring E Borgmann 《Archives of Animal Nutrition》1979,29(4):221-234
Growing pigs with ileum and ileocecal re-entrant canulae were given 5 different rations (pig fattening feed 1 and 2, rations with dried skim milk, wheat gluten + lysine and wheat + wheat gluten + lysine). The crude protein and amino acid excretion was quantitatively determined with ileum chyme and feces. The calculation of the amino acid balances (apparent and true digestibility) at the end of the small intestine, at the end of the wholedigestive tract and the isolated colon showed characteristic differences for the individual amino acids. On ileum level the amino acids with relatively high endogenous quotas, threonine, tryptophane, alanine, aspartic acid and glycine showed a distinctly lower, the amino acids arginine, methionine, phenylalanine, glutamic acid, proline and tyrosine a distinctly higher digestibilityhan crude protein. In comparison of the values on the feces level, including the true digestibility, these differences are largely balanced out. At the end of the small intestine the absorption of the amino acids is in the main completed. The disappearance rate of amino acids from the colon shows large differences with reference to the different rations as well as the individual amino acids. They were particularly high for various rations as far as proline, tryptophane, glycine and cystine are concerned. If wheat gluten + lysine rations were given, a net synthesis of methionine in the colon could be proved. 相似文献
12.
OBJECTIVE: To measure nutrient absorption by the intestine during postnatal development of dogs. ANIMAL: 110 Beagles ranging from neonatal to adult dogs. PROCEDURE: Rates of absorption for sugars (glucose, galactose, and fructose), amino acids (aspartate, leucine, lysine, methionine, and proline), a dipeptide (glycyl-sarcosine), and linoleic acid by the proximal, mid, and distal regions of the small intestine were measured as functions of age and concentration (kinetics) by use of intact tissues and brush-border membrane vesicles. Absorption of octanoic acid by the proximal portion of the colon was measured in intact tissues. RESULTS: Rates of carrier-mediated transport by intact tissues decreased from birth to adulthood for aldohexoses and most amino acids but not for fructose and aspartate. Kinetics and characteristics of absorption suggest that there were changes in the densities, types, and proportions of various carriers for sugars and amino acids. Saturable absorption of linoleic acid in the small intestine and octanoic acid in the proximal portion of the colon increased after weaning. CONCLUSIONS AND CLINICAL RELEVANCE: Rates of absorption decreased between birth and adulthood for most nutrients. However, because of intestinal growth, absorption capacities of the entire small intestine remained constant for leucine and proline and increased for glucose, galactose, fructose, aspartate, and proline but were less than predicted from the increase in body weight. Although postnatal ontogeny of nutrient absorption was consistent with changes in the composition of the natural and commercial diets of growing dogs, rates of amino acid and peptide absorption were lower than expected. 相似文献
13.
Sigurdardóttir OG Bakke-McKellep AM Djønne B Evensen O 《Comparative immunology, microbiology and infectious diseases》2005,28(3):223-230
The main lesions of paratuberculosis in ruminants are in the small intestine. Previous studies have shown that the bacterium enters the small intestine through M cells found in the follicle-associated epithelium lining the domes of the Peyer's patches. The everted sleeve method, devised for the in vitro study of intestinal absorption, was used in this study to investigate the uptake of Mycobacterium avium subsp. paratuberculosis in goat intestine. Everted small intestinal sleeves of goat kids, prepared from areas with and without Peyer's patches, were incubated for 60 min in 3H-labeled bacterial solution. The results of this study imply that the bacteria can enter the intestinal mucosa of the jejunum, both in areas with and without Peyer's patches. These findings indicate, therefore, that M. avium subsp. paratuberculosis bacteria not only enter through M cells but also through enterocytes. 相似文献
14.
Reza Barekatain Peter V. Chrystal Saad Gilani Clive J. McLaughlan 《Journal of animal physiology and animal nutrition》2021,105(1):90-98
Reducing crude protein and supplementation with synthetic amino acids in poultry nutrition is a recent trend to avoid wastage of protein and ammonia in production systems. Stress has been shown to impair intestinal barrier and increase inflammatory response. This study was performed on intestinal tissues of broiler chickens to understand the mechanism of stress induced by a synthetic glucocorticoid, dexamethasone (DEX) and the effect of supplementation of arginine, glutamine and glycine in reduced protein diets. Intestinal tissue samples from a previous study were utilized. Male Ross 308 chickens received a basal diet for the first seven days and then fed with crude protein that was reduced to 194 g/kg in grower experimental diets supplemented with glutamine, glycine and additional arginine at 10, 10 and 5 g/kg respectively. Half of the 96 individual birds were injected with DEX (0.5 mg/kg body weight) or saline on days 14, 16, 18 and 20 of age. mRNA expression for jejunum and ileum for amino acid transporters (y+LAT-1, Bo,+AT, EAAT-3 and CAT-1), mechanistic genes (SGLT-1, mTOR, IAP and FABP-2) and pro-inflammatory genes (MUC-2, NF-κB, iNOS, IL-8 and IL-1β) were analysed using real-time PCR. The results showed that DEX decreased y+ LAT1 in jejunum, Bo,+AT and EAAT-3 in ileum. Arginine increased CAT-1 in the jejunum and ileum under DEX treatment. Through an interaction, DEX reduced IAP in jejunum of glycine and arginine supplemented group and reduced mTOR in jejunum independently. DEX reduced MUC-2 and iNOS in jejunum and increased iNOS and IL8 in the ileum. Amino acid supplementation did not appear to ameliorate these effects; however, there were some positive effects of glycine on NF-κB and arginine through increased CAT-1. Mechanistic understanding of amino acid supplementation in broiler diets warrants further research particularly when dietary protein is reduced below the level tested in the present study. 相似文献
15.
本试验旨在研究仔猪出生后10~20 d,早期断奶仔猪小肠谷氨酸转运载体基因表达情况与哺乳仔猪的差异。试验分别从40头不同母猪的仔猪中各选出体重相近,10日龄的"杜×长×大"三元杂交仔猪1头,共40头仔猪,随机不配对分为2组,每组20头仔猪,对照组(哺乳组)为哺乳仔猪,随母猪喂养;试验组(断奶组)为断奶仔猪,隔离断奶饲养;试验期10 d。饲养结束,每组随机取12只仔猪,宰杀取空肠和回肠,测定谷氨酸转运载体兴奋性氨基酸转运载体1(EAAC1)蛋白质表达情况和游离氨基酸含量。结果显示,断奶显著降低了仔猪空肠和回肠EAAC1(57和73 ku)及其相关蛋白谷氨酸转运联合蛋白(GTRAP3-18)(50 ku)的蛋白质和mRNA表达量(P0.05)。断奶提高了仔猪空肠游离谷氨酸和总氨基酸含量,却降低了仔猪回肠游离谷氨酸和总氨基酸含量,差异显著(P0.05)。结果提示,早期断奶降低EAAC1和GTRAP3-18的蛋白质含量,这可能与早期断奶仔猪遭受营养谷氨酸缺乏导致的肠道氨基酸吸收转运障碍有关。 相似文献
16.
Developmental changes in morphometry of the small intestine and jejunal sucrase activity during the first nine weeks of postnatal growth in pigs 总被引：1，自引：0，他引：1
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. 相似文献
17.
Incubations of bovine intestinal mucosa were characterized for location of maximal uptake of amino acid, steady-state accumulation time of the amino acids, methionine and lysine. Photomicrographs validated that cattle intestinal mucosa was isolated by the technique described. Methionine and lysine uptake was expressed as micromoles of amino acid per milliliter of cell water. The most active site of methionine and lysine uptake was the mid-ileum, while the proximal jejunum was the least active site. Both methionine and lysine uptake showed high correlation relative to intestinal region. Methionine uptake was shown to be saturated with concentrations greater than 1 mM. Lysine transport appeared to be approaching saturation at concentrations between .5 mM to 1 mM, revealing that cattle intestinal mucosa has a lower transport capacity for lysine than methionine. These results indicate the usefulness of a technique through which substrate uptake (amino acid, carbohydrate, etc.) can be characterized in cattle small intestine. 相似文献
18.
Body and intestinal growth of broiler chicks on a commercial starter diet. 1. Intestinal weight and mucosal development 总被引：1，自引：1，他引：0
1. A study was conducted on the pattern of development of the intestinal mucosa of the Steggles x Ross (F1) strain of broiler chickens reared on a commercial starter diet. The mechanisms underlying the structural changes were also assessed. 2. In relation to body weight, small intestinal weight peaked at 7 d of age and declined subsequently. There was also a reduction in the relative weights of the gizzard and yolk sac with age. The length of the small intestine and its regions increased with age. 3. Crypt depth increased with age in the duodenum and jejunum while villus height increased significantly with age in all three regions of the small intestine. There were also significant changes in apparent villus surface area in the three regions, while interactions between age and intestinal region were significant in the case of crypt depth and villus height. 4. There were significant differences between the age groups in the mucosal protein content of jejunal and ileal homogenates, both tending to peak at 7 d of age. The DNA content of the intestinal mucosa declined with age in the three regions of the small intestine. While there was an increase in RNA content in the duodenum and ileum, there was a reduction in the jejunum. 5. Protein: DNA ratio increased between hatch and 21 d of age in all intestinal regions. Protein: RNA ratio decreased with age in the duodenum and ileum but increased in the jejunum. There were significant increases in RNA: DNA ratio in the duodenum and ileum but no changes were observed in the jejunum. The interactions between age and intestinal region were significant for all biochemical indices assessed. 6. At all ages, enterocyte proliferation at the jejunum was completed and quantifiable within 1 h of administration of 5-bromo-2'-deoxyuridine (BrDU). Subsequent assessment revealed an increase in crypt column count and number of BrDU-labelled cells. The rate of cell migration increased with age while there was a decline in the distance migrated in proportion to mucosal depth. The estimated life-span of enterocytes and time spent by enterocytes in the crypt varied with age. In d-old and 7-d-old chicks, migration was complete or nearly complete within 96 h of cell birth. 7. Although the intestinal mucosa of the strain was structurally developed at hatch, there was much change in structure with age, especially over the first 7 d post hatch. The rate of development was most rapid in the jejunum but the other regions are also important, on account of villus height or relative length of the region. 相似文献
19.
Appearance of 15N-labeled intestinal microbial amino acids in the venous blood of the pig colon. 总被引：2，自引：0，他引：2
Two experiments were done to determine whether pigs possess the ability to absorb amino acids synthesized from urea nitrogen by indigenous microbes in the large intestine. Incorporation of [15N]urea into amino acid fractions of bacterial cells from the rectum and of the deproteinized incubated medium were examined in an experiment in vitro. The isotope was incorporated into 17 amino acids and the ammonia fraction of these samples. The absorption of the microbial amino acids from the colon was investigated by determination of the 15N concentration of the free amino acids in the venous blood of the colon after infusion of the 15N-labeled microorganisms into the cecum. The increase of 15N concentration was also observed in the plasma-free amino acids (threonine, isoleucine, phenylalanine, lysine, histidine, arginine, aspartic acid, serine, alanine, cystine) of the blood from the colic branch of the ileocolic vein. The results of these experiments indicated that pigs have the ability to utilize the microbial amino acids synthesized from urea nitrogen in the large intestine. 相似文献
20.
1. Absorption, secretion of digestive enzymes and intestinal morphology were determined in poults from hatching to 19 d. 2. Oleic acid was approximately 80% absorbed at hatch and this changed little with age and was not influenced by fasting. In contrast, glucose and methionine were 48 to 56% absorbed at hatch and this increased to 75 to 80% at 4 d; however, this increase in absorption was inhibited by fasting. Percentage absorption of protein did not change between 5 and 19 d, whereas absolute uptake of fat and protein and net secretion of digestive enzymes and fatty acids and N to the duodenum increased with age and body weight (BW). 3. The length and diameter and villus size in the small intestines increased rapidly after hatch whereas the number of villi per cross section did not change with age. Duodenum and ileum surface area reached a plateau after 11 d whereas jejunal surface area continued to increase until 19 d. Duodenal and ileal surface area were not related to BW, but jejunal surface area was significantly correlated. 4. While the major part of the absorption occurred in the duodenum and upper jejunum, uptake of both protein and fat increased in the distal segments of the small intestine with age. Overall absorption of both fat and protein was correlated with BW. 5. It appears that in the posthatch poult intestinal surface area is not a limiting factor in growth, which was correlated with digestive secretions, fat and protein uptake. 相似文献