酪蛋白酶解产物对仔猪肠道黏膜IGF-I及其受体基因mRNA水平的影响

研究了酪蛋白酶解产物对新生仔猪肠道黏膜胰岛素样生长因子I(IGF-I)及其受体基因mRNA水平的影响.从五窝仔猪中选出10头仔猪,每窝选2头,分剐分至酪蛋白饲喂组(对照组)和酶解酪蛋白饲喂组(试验组).两组仔猪均以牛乳为基础日粮,并分别加入1.5%的酪蛋白和酪蛋白酶解液取代10%体积的牛乳,人工饲喂3d后屠宰取样.试验结果表明,试验组仔猪空肠黏膜IGF-I受体基因和IGF-I基因mRNA水平分别显著(P＜0.05)和极显著(P＜0.01)高于对照组仔猪.说明酪蛋白酶解产物促进肠道发育可能与提高IGF-I及其受体基因的mRNA水平有关.     

添加酪蛋白酶解物对宫内生长迟缓仔猪肠道生长发育的影响

为研究酪蛋白酶解物对宫内生长迟缓（IUGR）仔猪肠道生长发育的影响，本试验选择15头IUGR新生仔猪，分为新生对照组（N组）、酪蛋白组（C组）和酪蛋白酶解物组（CH组），以牛乳为基础日粮，C和CH组分别加入10％的酪蛋白溶液和10％的酪蛋白酶解物溶液，人工饲喂3d后取样。结果显示，CH组仔猪小肠长度显著高于C组（P〈0．05），CH组空肠后段和回肠前段的绒毛高度／隐窝深度显著高于C组（P〈0．05）；CH组小肠黏膜的蛋白质含量显著高于C组（P〈0．05），同时其DNA含量显著高于C和N组（P〈0．05）；CH组的麦芽糖酶活性和相对活性均显著高于C和N组（P〈0．05或P〈0．01），CH组的碱性磷酸酶（AKP）活性显著高于C组（P〈0．05）。结果表明，酪蛋白酶解物有促进新生IUGR仔猪肠道组织生长的作用，同时能够刺激IUGR仔猪小肠黏膜上皮细胞的增殖和提高小肠黏膜麦芽糖酶和碱性磷酸酶的活性。     

哺乳期给母猪饲喂碘化酪蛋白对仔猪的影响

选用哺乳期杂交母猪54头，随机分4组，对照组饲喂基础饲粮，试验组在饲喂基础饲粮中添加200mg/kg碘化酪蛋白，为期31d，研究哺乳期母猪饲喂磺化酪蛋白对仔猪的影响。试验结果显示：初产、经产母猪的试验组仔猪分别与对照组相比，20日龄窝重分别提高11．72％（P＜0．05），6．79％（P＜0．01），断奶窝重分别提高2．95％和18．84％（P＜0．01），哺乳期乳活率分别提高1．595和11．9％（P＜0．01）。     

β-酪啡肽7对早期断乳仔猪消化道发育的影响

将12头体质量相近的三元杂交仔公猪分为试验组和对照组：2组饲喂相同的基础料，试验组仔猪于21日龄断乳后添喂β-酪啡肽7，对照组仔猪正常吃母乳到28日龄断乳，2组均于32日龄宰杀后测定相关指标。结果表明：与对照组相比，添喂β-酪啡肽7的仔猪胃窦粘膜厚度增加61．98％（P〈0．01），十二指肠、空肠和回肠的绒毛长度分别增长34．47％（P〈0．05）、43．38％（P〈0．01）和26．92％（P〈0．01），而绒毛宽度和肠壁肌层厚度变化不明显（除回肠的肠壁肌层厚度显著增厚外），隐窝深度没有明显加深，但空肠的绒毛长度／隐窝深度的比值显著地大于对照组23．78％（P〈0．05）；添喂β-酪啡肽7的仔猪消化道胃蛋白酶总活性、淀粉酶活性、脂肪酶活性均显著低于对照组，而胰蛋白酶总活性接近于对照组。结果提示：在体内，β-酪啡肽7能改善断乳应激引起的肠道形态结构的变化，能促进肠道绒毛的生长，对断乳应激引起的胃蛋白酶总活性、淀粉酶活性、脂肪酶活性降低没有改善作用，而对胰蛋白酶总活性略有改善。     

乳源性生物活性肽对新生IUGR仔猪肝脏抗氧化功能的影响

本试验选择苏太初生IUGR仔猪10窝共20头,配对分为4组:胰岛素组(I组)、牛乳组(M组)、酪蛋白酶解产物组(CH组)和酪蛋白组(C组),饲喂3d后宰杀。另选5只初生IUGR仔猪立即宰杀,作为0d对照组(A组)。M组喂牛乳,I组在牛乳中添加2.5mg/L胰岛素;C组用1.5%酪蛋白水溶液取代10%(V/V)的牛乳,CH组用1.5%酪蛋白酶解液取代10%(V/V)的牛乳。宰杀后分析肝脏和血浆中SOD活性和MDA含量以及血浆中GPT和GOT水平。试验结果显示:酪蛋白酶解物可显著降低肝脏和血浆MDA含量,提高SOD活性(P<0.05),胰岛素可显著降低血浆中MDA含量(P<0.05);3日龄仔猪GPT和GOT均高于初生仔猪,其中I组、C组和CH组GPT均显著高于M组(P<0.05)。结果提示:胰岛素和酪蛋白酶解物可提高IUGR仔猪肝脏的抗氧化功能,促进肝细胞的生长发育。     

蛋白酶解物对仔猪胃窦胃泌素分泌的影响

为研究食物蛋白源活性肽对仔猪胃窦胃泌素分泌的影响．通过模拟猪胃内消化环境，制备了大豆蛋白酶解产物、酪蛋白酶解产物和面筋蛋白酶解产物的溶液和对照液，对10日龄仔猪离体胃窦进行体外灌流。结果表明，3种蛋白的胃蛋白酶解物对4头试验仔猪的胃窦黏膜胃泌素的分泌均有促进作用，但以大豆蛋白酶解物的作用最强。其中大豆蛋白酶解物组的4头猪胃泌素分泌分别比相应的对照组增高99．98％、65．12％、30．45％和9．48％。面筋蛋白酶解物组的4头猪胃泌素分泌分别比相应的对照组增高34．66％、20．35％、5．56％和3．87％。酪蛋白酶解物组的4头猪胃泌素分泌分别比相应的对照组增高107．12％、56．26％、6．77％和0．72％。     

乳源性活性肽对新生仔猪肝脏抗氧化功能的影响

本试验选择10窝共20头初生仔猪,配对分为4组:胰岛素组(Y)、牛乳组(P)、酶解酪蛋白组(M)和牛乳酪蛋白组(L)。P组喂牛乳,Y组在牛乳中添加2.5mg/L胰岛素;L组用1.5%酪蛋白水溶液取代10%(v/v)的牛乳,M组用1.5%酪蛋白酶解液取代10%(v/v)的牛乳。仔猪饲喂3d后宰杀,分析肝脏中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量。试验结果表明:胰岛素可降低肝脏MDA含量(P<0.05),但酪蛋白酶解产物对MDA含量无显著影响(P>0.05)。胰岛素和酪蛋白酶解产物对初生仔猪肝脏SOD、GSH-PX和CAT活性均无显著影响(P>0.05)。     

乳源性胰岛素对新生仔猪肠道生长和组织形态学的影响

研究了乳源性胰岛素对新生仔猪小肠生长和组织形态学的影响。随机选择5头初生苏太仔猪,生后立即屠宰取样,作为新生对照组（N）。另外,从五窝初生仔猪中选10头仔猪,每窝选2头,分别分到饲喂牛乳组（M）和牛乳加入胰岛素组（Mr）（添加量为2．5mg／L）。M组和MI组仔猪出生后用牛乳人工喂养3天后屠宰取样。结果表明,MI和M组小肠长度分别极显著（P〈0．01）和显著（P〈0．05）高于N组。MI组的非粘膜重有高于M组的趋势（P=0．148）。MI组空肠后段和回肠前段绒毛高度分别极显著（P〈0．01）和显著（P〈0．05）高于M组。MI组各肠段绒毛高度／隐窝深度均高于N组（P〈0．01或P〈0．05）,其中空肠前段和后段分别显著（P〈0．05）和极显著（P〈0．01）高于M组。结果提示：乳派胜胰岛素能够刺激新生仔猪小肠生长并影响到小肠的组织形态。     

乳源性活性肽对新生仔猪肝脏抗氧化功能的影响

本试验选择10窝共20头初生仔猪,配对分为4组胰岛素组(Y)、牛乳组(P)、酶解酪蛋白组(M)和牛乳酪蛋白组(L).P组喂牛乳,Y组在牛乳中添加2.5 mg/L胰岛素;L组用1.5%酪蛋白水溶液取代10%(v/v)的牛乳,M组用1.5%酪蛋白酶解液取代10%(v/v)的牛乳.仔猪饲喂3 d后宰杀,分析肝脏中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量.试验结果表明胰岛素可降低肝脏MDA含量(P<0.05),但酪蛋白酶解产物对MDA含量无显著影响(P>0.05).胰岛素和酪蛋白酶解产物对初生仔猪肝脏SOD、GSH-PX和CAT活性均无显著影响(P>0.05).     

苦豆籽粕-两歧双歧杆菌-唾液乳杆菌合生元对早期断奶仔猪肠黏膜形态的影响

为观察苦豆籽粕-两歧双歧杆菌-唾液乳杆菌合生元对早期断奶仔猪不同时期小肠黏膜绒毛长度、隐窝深度和绒腺比的影响,试验选用60头（21±2）日龄体质量相近的杜长大三元杂交断奶仔猪,随机分为4组,每组3个重复,每个重复5头仔猪。试验组在饲喂基础日粮的基础上分别添加0．5％,1．0％,2．0％的合生元,对照组饲喂基础日粮,试验期4周。结果表明,合生元组可显著提高仔猪小肠绒毛的高度,其中2．0％舍生元组效果较好;对小肠黏膜隐窝深度方面的差异不显著;饲喂合生元可以提高小肠黏膜绒腺比,其中以0．5％合生元组和2．0％合生元组效果明显。在本试验饲养方式下,苦豆籽粕一两歧双歧杆菌一唾液乳杆菌合生元可以改善肠道黏膜形态结构,尤以2．0％剂量组效果较好,适宜于生产实践。     

N-乙酰半胱氨酸灌胃对超早期断奶仔猪血浆中游离氨基酸及小肠形态结构与功能的影响

本试验旨在研究N-乙酰半胱氨酸(N-acetylcysteine,NAC)灌胃对超早期断奶仔猪血浆中游离氨基酸、小肠形态结构及功能的影响。将22头体重为(2.99±0.41)kg的7日龄断奶仔猪随机分为对照组和NAC组,每组11个重复,每个重复1头猪。在饲喂人工乳的基础上,NAC组每天每头按50 mg/kg体重进行NAC灌胃,对照组每天每头进行同体积的生理盐水灌胃。于试验第11天按0.1 g/kg体重的剂量给仔猪灌服D-木糖溶液,1 h后前腔静脉采血,然后屠宰取小肠组织样,刮取肠黏膜及制作组织切片。结果表明:与对照组相比,NAC组显著提高了超早期断奶仔猪平均日增重(P0.05);提高了超早期断奶仔猪血浆中谷氨酰胺、胱氨酸、γ-氨基丁酸水平(P0.05),降低了血浆中尿素氮、半胱氨酸、色氨酸水平和二胺氧化酶活力(P0.05);NAC灌胃提高了哺乳仔猪十二指肠黏膜的绒毛高度/隐窝深度(P0.05),有降低十二指肠隐窝深度的趋势(P0.10),有提高空肠绒毛宽度和回肠绒毛高度的趋势(P0.10)。在本试验条件下,NAC灌胃可改善小肠形态结构与屏障功能,提高氨基酸的利用率,调节血浆中部分氨基酸的含量。     

α-酮戊二酸对LPS慢性应激仔猪小肠黏膜形态与功能的影响

为了探讨α-酮戊二酸(AKG)能否缓解LPS慢性应激导致的仔猪小肠黏膜损伤及其机理,本试验研究了AKG对LPS慢性应激仔猪的小肠黏膜形态、血浆D-木糖的含量、血浆和小肠黏膜二胺氧化酶(DAO)活性及小肠黏膜mTOR及磷酸化的mTOR表达量的影响.18头(24±1)日龄健康断奶仔猪随机分成3个处理组(空白对照组、应激对照组、AKG组),每个处理6个重复.各组基础日粮一致,空白对照组和应激对照组饲喂基础日粮+1%淀粉,AKG组饲喂基础日粮+1%AKG.试验期为16 d.应激对照组和AKG组仔猪分别于第10、12、14和16天腹膜注射80μg·kg~(-1)BW的LPS,空白对照组注射相应剂量的灭菌生理盐水.第16天注射LPS 2 h后,按0.1g·kg~(-1)BW的剂量给仔猪灌服D-木糖溶液,注射LPS 3 h后,前腔静脉采血.第17天屠宰取小肠组织样,刮取肠黏膜及制作组织切片.结果表明:(1)与空白对照组相比,应激对照组十二指肠、空肠和回肠黏膜绒毛高度/隐窝深度、空肠和回肠磷酸化mTOR/mTOR(P-mTOR/mTOR)显著降低(P<0.05),血浆DAO活性显著升高(P<0.05).(2)与应激对照组相比,AKG组十二指肠、空肠和回肠黏膜绒毛高度/隐窝深度、空肠黏膜DAO活性、血浆D-木糖及十二指肠、空肠和回肠黏膜P-mTOR/mTOR显著升高(P<0.05).结果显示,日粮中添加1%AKG可在一定程度上改善仔猪的小肠组织学形态和吸收功能,缓解LPS慢性应激导致的仔猪小肠黏膜损伤,这与mTOR信号通路有关.     

二花脸猪和大白猪睾丸IGF-I和IGF-IR基因表达发育变化的研究

为了研究生长轴激素对猪繁殖性能发育的影响,随机选取0、3、20、30、90、120、180日龄纯种二花脸公猪和大白公猪各4头,屠宰并采取睾丸组织样,以18S rRNA为内标,用相对定量RT-PCR法研究睾丸IGF-I和IGF-IRmRNA的表达及发育性变化。结果表明,二花脸猪与大白猪睾丸IG-FI mRNA表达的发育模式在30日龄前完全相同,即随着日龄的增加而呈极显著增加(P<0.01);二花脸猪睾丸IG-FI mRNA相对表达量在30~180日龄无显著变化;大白猪睾丸IGF-I mRNA相对表达量在90日龄有所下降,而在120和180日龄又恢复到30日龄水平。二花脸猪睾丸IG-FI mRNA相对表达量显著高于大白猪(P<0.05)。二花脸猪与大白猪睾丸IGF-IR mRNA表达的发育模式不同。二花脸猪睾丸IG-FIR mRNA相对表达量在90~120日龄呈显著下降趋势(P<0.05);大白猪IG-FIR mRNA相对表达量在0日龄较高,随后显著下降(P<0.05),并在观察期内持续保持较低水平。二花脸猪IG-FIR mRNA相对表达量显著高于大白猪(P<0.05)。睾丸IGF-I mRNA和IG-FIR mRNA相对表达丰度呈极显著正相关(r=0.575,P<0.01)。结论:(1)不同品种猪睾丸IGF-I和IG-FIR mRNA表达具有特定的发育模式;(2)猪睾丸中IGF-I和IG-FIR mRNA的协同表达可能对猪繁殖性能的发育有重要调节作用。     

酵母壁多糖对断奶仔猪生长性能和小肠黏膜形态结构的影响

本研究旨在探讨饲粮中添加酵母壁多糖对断奶仔猪生长性能和小肠黏膜形态结构的影响。试验采用单因素试验设计方法,选取180头遗传背景一致、健康状况良好、胎次和体重接近的21日龄断奶仔猪,随机分为4个组,每组5个重复,每个重复9头猪。4个组分别饲喂对照饲粮、0.15%酵母壁多糖饲粮、0.30%酵母壁多糖饲粮和0.45%酵母壁多糖饲粮。试验期21 d。结果表明:1)与对照组相比,饲粮中添加酵母壁多糖能够显著提高断奶仔猪平均日增重和平均日采食量(P0.05);酵母壁多糖有降低断奶仔猪腹泻率和料重比的趋势,但差异不显著(P0.05)。2)与对照组相比,饲粮中添加酵母壁多糖能够显著提高断奶仔猪空肠绒毛高度/隐窝深度值(P0.05),添加0.45%酵母壁多糖能够显著提高断奶仔猪空肠绒毛高度和十二指肠绒毛高度/隐窝深度值(P0.05)。由此可知,酵母壁多糖可提高断奶仔猪的生长性能,并改善小肠黏膜形态结构;综合生长性能、小肠黏膜形态及经济成本等指标,其在仔猪饲粮中的适宜添加量为0.30%。     

Morphological and molecular response of small intestine to lactulose and hydrogen-rich water in female piglets fed Fusarium mycotoxins contaminated diet

Background: Following the intake of Fusarium mycotoxin-contaminated feed, small intestines may be exposed to high levels of toxic substances that can potentially damage intestinal functions in livestock. It is well known that Fusarium mycotoxins will lead a breakdown of the normally impeccable epithelial barrier, resulting in the development of a "leaky" gut. H2 administration with different methods has been proved definitely potentials to prevent serious intestinal diseases. The goal of this study is to investigate the roles of lactulose(LAC) and hydrogenrich water(HRW) in preventing intestinal dysfunction in piglets fed Fusarium mycotoxin-contaminated feed.Methods: A total of 24 female piglets were evenly assigned to 4 groups: negative control(NC) group, mycotoxincontaminated(MC) feed group, MC feed with LAC treatment(MC + LAC), and MC feed with HRW treatment(MC +HRW), respectively. Piglets in the NC group were fed uncontaminated control diet, while remaining piglets were fed Fusarium mycotoxin-contaminated diet. For the NC and MC groups, 10 mL/kg body weight(BW) of hydrogen-free water(HFW) was orally administrated to piglets twice daily; while in the MC + LAC and MC + HRW groups, piglets were treated with the same dose of LAC solution(500 mg/kg BW) and HRW twice daily, respectively. On d 25,serum was collected and used for biochemical analysis. Intestinal tissues were sampled for morphological examination as well as relative genes and protein expression analysis.Results: Our data showed that Fusarium mycotoxins induced higher serum diamine oxidase(DAO) activities(P 0.05), D-lactic acid levels(P 0.01), and endotoxin status(P 0.01), lower villus height(P 0.01) and ratio of villus height to crypt depth(P 0.05) in small intestine, greater apoptosis index and higher mRNA expression related to tight junctions(P 0.05). In addition, the distribution and down-regulation of claudin-3(CLDN3) protein in the small intestinal was also observed. As expected, oral administrations of HRW and LAC were found to remarkably provide beneficial effects against Fusarium mycotoxin-induced apoptosis and intestinal leaking.Moreover, either HRW or LAC treatments were also revealed to prevent abnormal intestinal morphological changes,disintegrate tight junctions, and restore the expression and distribution of CLDN3 protein in the small intestinal mucosal layer in female piglets that were fed Fusarium mycotoxins contaminated diet.Conclusions: Our data suggest that orally administrations of HRW and LAC result in less Fusarium mycotoxininduced apoptosis and leak in the small intestine. Either HRW or LAC treatments could prevent the abnormal changes of intestinal morphology and molecular response of tight junctions as well as restore the distribution and expression of CLDN3 protein of small intestinal mucosa layer in female piglets that were fed Fusarium mycotoxins contaminated diet.     

Small intestinal morphology in weaned piglets fed a diet containing spray-dried porcine plasma

The hypothesis tested in this study was that the reported beneficial effects of spray-dried porcine plasma (SDPP) on piglet post-weaning performance and health are associated with a trophic effect on small intestinal mucosa. At 24 days of age, the piglets of seven sows were assigned to one of three treatment groups. One group continued to be suckled. The other two groups were weaned and offered a diet containing either 15 per cent SDPP or casein. From each treatment group, one piglet was anaesthetised and samples were taken from the small intestinal wall at 26, 28 and 31 days of age. There were no significant effects of SDPP versus casein on villus length. On average, there was less mitotic activity in the SDPP -fed piglets than in those fed casein on days 4 and 7 after weaning. As less mitotic activity leads to less immature enterocytes, this may provide a mechanism for the reported beneficial effects of SDPP on performance and health.     

酿酒酵母发酵液对断奶仔猪生长性能、小肠发育及小肠黏膜免疫功能的影响

本试验旨在探究酿酒酵母(S.cerevisiae)发酵液对断奶仔猪生长性能、小肠发育及小肠黏膜免疫功能的影响。选取平均体重为(6.57±0.13)kg的26日龄"长白×杜洛克"断奶仔猪60头(公母各占1/2),按体重和性别随机分为3个组,每组4个重复,每个重复5头仔猪。3个组分别为:对照组(基础饲粮+300 m L/kg空白培养液)、酿酒酵母发酵液组(基础饲粮+300 m L/kg酿酒酵母发酵液)和抗生素组(基础饲粮+20 mg/kg硫酸黏杆菌素+40 mg/kg杆菌肽锌)。试验期21 d。结果表明:1)与对照组相比,酿酒酵母发酵液组和抗生素组的平均日增重(ADG)和平均日采食量(ADFI)显著或极显著升高(P0.05或P0.01),料重比极显著降低(P0.01);但酿酒酵母发酵液组与抗生素组的以上生长性能指标均无显著差异(P0.05)。2)与对照组相比,酿酒酵母发酵液组和抗生素组的十二指肠、空肠和回肠黏膜总蛋白、DNA和RNA含量显著或极显著升高(P0.05或P0.01);但酿酒酵母发酵液组与抗生素组的以上指标均无显著差异(P0.05)。3)与对照组相比,酿酒酵母发酵液组和抗生素组的十二指肠和回肠绒毛高度显著升高(P0.05),十二指肠、空肠和回肠绒毛高度/隐窝深度(V/C)显著或极显著升高(P0.05或P0.01);但酿酒酵母发酵液组与抗生素组的以上指标均无显著差异(P0.05)。4)与对照组相比,酿酒酵母发酵液组和抗生素组的十二指肠、空肠和回肠黏膜免疫球蛋白A、免疫球蛋白G和免疫球蛋白M含量均显著或极显著升高(除空肠黏膜免疫球蛋白G外)(P0.05或P0.01);但酿酒酵母发酵液组和抗生素组的以上指标均无显著差异(P0.05)。结果显示,饲粮中添加酿酒酵母发酵液能够提高断奶仔猪的生长性能,促进小肠发育,提高小肠黏膜免疫功能,达到与抗生素相当的效果。提示酿酒酵母发酵液可有效缓解断奶应激,减少或者替代抗生素在断奶仔猪饲粮中的使用,这为研发无抗饲粮提供了有力的理论依据和数据支持。     

三丁酸甘油酯对乙酸刺激仔猪肠道屏障功能的影响

本试验旨在研究三丁酸甘油酯（TB）对乙酸（ACA）刺激仔猪小肠黏膜生长和肠道屏障功能的影响。试验选用18头体重接近、健康的28日龄断奶仔猪（杜×长×大）,随机分为3个处理：对照组、乙酸组和TB组,每个处理6个重复,每个重复1头猪。试验期为21 d。试验期内对照组和乙酸组饲喂基础日粮,TB组饲喂基础日粮+0.1% TB。于试验第15天清晨,乙酸组和TB组仔猪直肠灌注10 mL 10%乙酸,对照组直肠灌注相应剂量的灭菌生理盐水。于试验第18、21天清晨前腔静脉采血,测定血浆二胺氧化酶（DAO）活力;第21天屠宰取样,取空肠、回肠等组织样品,测定仔猪肠道形态结构、肠道黏膜损伤相关基因mRNA水平等指标。结果表明：①未用乙酸刺激前,与对照组相比,日粮中添加0.1% TB对仔猪平均日增重有一定程度提高（P=0.089）,且显著降低了仔猪料重比（P<0.05）;②与对照组相比,乙酸组显著降低了空肠黏膜绒毛高度、回肠黏膜绒毛高度与隐窝深度比值及空肠绒毛表面积（P<0.05）;③与乙酸组相比,TB组显著降低了血浆DAO活力（P<0.05）,极显著降低了回肠AREG基因的相对表达量（P<0.01）。综合上述结果,日粮中添加0.1% TB能缓解乙酸诱导的仔猪肠黏膜生长及肠道屏障功能的损伤。     

Effect of a short-term fast on intestinal disaccharidase activity and villus morphology of piglets suckling insulin-like growth factor-I transgenic sows

The objectives of this study were to use transgenic sows that overexpress IGF-I in milk to investigate the effect of a short-term fast on piglet intestinal morphology and disaccharidase activity and to determine how milk-borne IGF-I influences the response to fasting. After farrowing, litters were normalized to 10 piglets. On d 6, piglets (n = 30) suckling IGF-I transgenic (TG) sows and piglets (n = 30) suckling nontransgenic sows (control) were assigned randomly to three treatments: fed piglets (0 h), which remained with the sow until euthanized on d 7, or fasted piglets, which were removed from the sow at either 6 or 12 h before euthanasia on d 7. Serum IGF-I and IGFBP, intestinal weight and length, jejunal protein and DNA content, disaccharidase activity, and villus morphology were measured. Fasting for 12 h resulted in a negative weight change between d 6 and 7 (quadratic response to fasting; P < 0.001). Piglets suckling TG sows tended to have greater intestinal length (P = 0.068), but no effect of IGF-I overexpression was noted for intestinal weight. Fasting, however, resulted in linear (P < 0.001) and quadratic (P = 0.002) decreases in intestinal weight. Serum IGF-I did not differ between control and TG sows, but decreased linearly (P = 0.003) with fasting. Serum IGFBP-4 decreased (linear and quadratic; P < or = 0.02) with fasting, whereas IGFBP-1 increased quadratically (P < 0.001) with fasting. Jejunal villus height, width, and crypt depth were all increased with fasting (linear and quadratic; P < 0.04). Disaccharidase activity was not affected by fed state; however, piglets suckling TG sows had greater jejunal lactase-phlorhizin hydrolase (P < 0.01) and sucrase-isomaltase (P = 0.02) activities than control piglets. In summary, intestinal weight, villus morphology, serum IGF-I, serum IGFBP-1 and -4, and piglet BW change were altered (P < or = 0.02) in response to fasting. Thus, the duration of food deprivation before euthanization should be considered when designing experiments to assess intestinal development or the IGF axis, as the magnitude of differences between the fed and fasted state may exceed those expected as a result of experimental treatment.     

宫内发育迟缓仔猪小肠形态和屏障功能相关基因的表达特征

为了研究宫内发育迟缓(IUGR)仔猪小肠形态和屏障功能相关基因的表达特征,选取24窝"长白×大白"杂交新生仔猪,每窝选取1头IUGR仔猪和1头正常出生体重(NBW)仔猪,分别于7、21和28日龄屠宰8头IUGR仔猪和8头NBW仔猪,采集小肠样品进行分析.结果表明:1)与NBW仔猪相比,IUGR仔猪7日龄时空肠绒毛高度、...