乳源性活性肽在仔猪胃肠道适应性变化中的作用

仔猪出生以后，尤其是在出生与断奶时，其胃肠道面临着众多挑战与应激性变化，为了适应这些挑战，消化道发生了明显的变化，包括出生后消化道组织的快速生长与成熟以及断奶后小肠绒毛萎缩，隐窝深度增加，这些变化明显与出生后食入初乳以及断奶后停止供乳有关，猪乳不仅营养丰富，而且含有众多生物活性物质，包括各种生长因子，如ＥＧＦ、ＩＧＦ－Ⅰ、ＩＧＦ－Ⅱ、胰岛素与ＴＧＦ－β等，许多试验资料显示，这些乳源性生长因子在促进     

乳源性生长因子在新生反刍动物胃肠道生长发育中的作用

乳中含有大量具生物活性的多肽类生长因子。这些生长因子对新生反刍动物的胃肠道生长发育和完善有深刻影响 ,对刺激组织细胞生长、促进胃肠道吸收、调控消化酶和增强免疫力有明显作用     

乳源性生长因子和初生动物胃肠道生长发育的关系

对３ 种主要乳源性生长因子： 表皮生长因子, 胰岛素样生长因子和胰岛素的结构、性质、主要功能、可能的作用机制及目前的研究进展进行了综述。３ 种生长因子都可以在初生动物胃肠道中相对稳定地存活, 对动物胃肠道生长发育、消化道粘膜细胞的增殖和分化及消化酶的产生均有不同程度的促进作用。     

表皮生长因子对胃肠道的作用

综述了表皮生长因子(EGF)基础研究方面的进展、EGF与胃肠道之间的关系及其可能的作用机制,同时提出EGF在防制仔猪早期断奶综合征方面起了一定的作用。     

胰岛素和酶解配方乳对初生仔猪胃肠道生长发育影响的研究

为研究胰岛素和酶解配方乳是否促进初生仔猪胃肠道的生长发育 ,本试验比较了饲喂配方乳、配方乳补加胰岛素(60mIU/ml)或酶解(胰蛋白酶和糜蛋白酶)配方乳3天后仔猪胃肠的重量 ,肠道长度 ,肠粘膜DNA、RNA和蛋白质含量 ,血浆中皮质醇、胰岛素和胃泌素的水平。饲喂配方乳补加胰岛素或酶解配方乳的仔猪与饲喂配方乳的仔猪相比 ,胃、小肠、结肠的重量 ,小肠和结肠的长度 ,小肠粘膜DNA、RNA含量和结肠粘膜DNA、RNA、蛋白质含量均无显著变化(P>0.05) ;血浆中皮质醇、胰岛素水平也无显著差异(P>0.05)。但饲喂配方乳补加胰岛素的仔猪小肠粘膜尤其是回肠后段粘膜的重量(P<0.05)和蛋白质含量(P<0.01)显著高于饲喂配方乳的仔猪 ;饲喂酶解配方乳仔猪血浆的胃泌素水平均显著(P<0.01)高于饲喂配方乳的仔猪 ,酶解配方乳中可能含有刺激初生仔猪胃泌素释放的物质     

仔猪的胃肠道健康

最佳功能状态的胃肠道对于猪生长发育各阶段中的代谢、生理、疾病状态和生长性能具有重要意义。最近,猪胃肠道健康吸引了众多关注,而对胃肠道健康及其病因缺乏明确的定义。从广义上讲,“胃肠道健康”涵盖了大量的生理和功能特性(营养素的消化和吸收、宿主代谢和能量生成、稳定和适当的微生物区系)、防御机制(屏障功能和黏膜免疫机制)以及它们之间的互作。尤其是刚断奶仔猪的胃肠道健康受到了广泛关注,这是因为在断奶后的过渡阶段其胃肠道结构和功能发生了改变。最近,由于世界上许多地区禁止或减少某些抗生素的使用,人们对使用不同饲料添加剂替代日粮中抗生素的兴趣高涨。在仔猪断奶后出现胃肠道疾病的情况下,胃肠道健康的恶化可能影响着猪只整体健康状况。虽然在猪的生长性能、饲料利用率以及胃肠道健康之间人们能感知到一些直接联系,但是这种关系有时比较微妙而不太明显,尤其是在没有明显的胃肠道疾病情况下。影响胃肠道健康的因素和条件是多方面的、复杂的。尽管很明显胃肠道状态的波动会导致机体不平衡,并干扰广义上的内稳态,但目前对这方面的报道很少,有时还存在错误的解释。除了任何胃肠道疾病或者引发胃肠道紊乱的因素,其他因素也会对猪胃肠道健康产生影响,比如仔猪断奶后一段时期内胃肠道发生的应答反应,日粮改变后可能发生的任何变化“胃肠道健康”基本上代表着胃肠道代谢功能,它反映了胃肠道应对和适应损伤和感染的能力。     

生物活性物质对断奶仔猪胃肠道和生长性能的影响

欧盟饲用抗生素的禁用激发了人们对断奶仔猪日粮方面的研究,旨在减少仔猪断奶后肠道功能紊乱和生长受阻。目前,已有多种生物活性成分用于研究,但只有几种显示有效。有机酸(OA)通过非离解酸和降低胃pH产生的杀菌作用,促进肠道和胰腺酶的分泌,并改善肠道的形态学结构。丁酸盐及丁酸前体物已引起人们特别的重视,但其效果受剂量、处理时间、仔猪日龄、胃肠道位置和其他因素的影响。像谷氨酰胺、色氨酸和精氨酸等氨基酸通过影响组织代谢、应激和免疫,有助于改善营养成分的消化吸收和沉积。血浆蛋白粉(SDP)通过免疫球蛋白和其它生物活性成分特异性及非特异性的作用,对肠道的形态结构和炎症产生积极的影响,并减少获得性特异免疫反应。牛初乳与血浆蛋白粉作用可能多少相似。植物精油对青年猪的应用效果依据产品和使用剂量的变化差异很大。本文对有机酸和氨基酸、蛋白源(特别是血浆蛋白粉、牛初乳)以及植物提取物对肠道的抗菌活性进行了细致的分析。     

表皮生长因子与胃肠道的关系及其在早期断奶仔猪上的应用前景

表皮生长因子(EGF)在乳中丰富的含量及其受体在消化道内的广泛分布,提示其在初生动物的胃肠道发育中具有重要作用(Menard,1988;Schaudies,1990;Xu,1996,1998)。据研究,EGF是中、外胚层细胞一种强有力的有丝分裂原,在促进肠道粘膜上皮细胞的增殖和分化,增加刷状缘酶活性,增强粘膜对养分的利用,减轻多种因素对胃肠道形态的损害,维持胃肠道结构和功能的完整等方面,均表现出良好的效果(Ebert,1995;Xu,1996,1998)。目前,EGF与动物消化道关系方面的研究受到人们的普遍关注,已成为研究的热点之一。本文主要就EGF基础研究方面的进展及其与胃…     

新生动物肠道的生长发育及乳源性生长因子的影响

肠道是新生动物生长发育最迅速的组织，其功能的失调常被认为是引发新生动物高发病率和高死亡率的主要诱因。就新生动物肠道的生长发育特点及乳源性生长因子对它的影响做一综述。     

乳源性生长因子及其生理功能

乳,尤其是初乳中含有一类对细胞起调控作用的活性多肽--生长因子.本文着重介绍了其中的胰岛素样生长因子、表皮生长因子的种类,功能及其研究现状,并列举了近年来乳源性生长因子在医药领域的应用情况.     

Effect of bran diet on organic acids in the gastrointestinal tract and apparent digestibility in weanling piglets

Over a period of four weeks 88 piglets of an average weaning weight of 9.5 kg received rations with 2.1, 3.1 and 5.5% crude fibre in the original substance in the form of wheat bran. Between the 42nd and 49th day of life a digestibility investigation was carried out by means of Cr2O3, and on the 42nd and the 63rd day of life the organic acids in the complete gastro-intestinal tract could be ascertained, the causes of which are to be found in the lack of easily soluble carbohydrates (increased passage rate, bran quota). Due to crude fibre, the apparent digestibility of all nutrients decreased, which resulted in a lower live weight on the 63rd day of life. The effect of a bran diet in the alimentary prophylaxis of coli enterotoxaemia is thus furthermore substantiated.     

阿维菌素对藏猪胃肠道寄生线虫的驱杀试验

将自然感染的藏仔猪12头随机分为2组,第1组用阿维菌素注射液治疗,第2组用盐酸左旋咪唑治疗作为对照.结果表明：注射阿维菌素试验藏仔猪用药5 d后对线虫虫卵减少率为84.6%,10 d后对线虫虫卵减少率为100%;注射左旋咪唑试验组用药5 d后对线虫虫卵减少率为8 3.7%,10 d后对线虫虫卵减少率为98.0%.二者差异不显著（P＞0.05）。     

淫羊藿对贵妃鸡胃肠道发育的影响

研究不同剂量的淫羊藿对贵妃鸡胃肠道的影响,为生产应用提供试验依据。选用400只贵妃鸡随机均分4组,每组设2个重复,分别为饮用淫羊藿提取物大剂量组(2 g/l),中剂量组(1 g/l),小剂量组(0.5 g/l),对照组饮用自来水,14日龄开始给药,连续饮用6周。每周末各组随机抽样8只,公母各半,空腹称重,心脏采血处死,解剖取消化器官:十二指肠、空肠、回肠、盲肠、直肠、肌胃、腺胃测定其平均器官重、长度及器官指数。淫羊藿5～8周龄十二指肠相对肠重均较对照组低,6周龄十二指肠单位肠重均较对照组低;6周龄空肠相对肠重均较对照组低,8周龄空肠相对肠重及单位肠重均较对照组低;4周龄回肠单位肠重较对照组高,8周龄回肠相对肠重及单位肠重均较对照组低;7周龄盲肠相对肠重及单位肠重较对照组高;6周龄直肠相对肠重较对照组高,7、8周龄直肠相对肠重及单位肠重较对照组低。淫羊藿能够促进贵妃鸡胃肠道的早期发育,并能有效防止贵妃鸡生长中期的肠增厚,有利于营养物质的吸收。     

Effect of bovine colostrum supplementation on cytokine mRNA expression in weaned piglets

The aim of this study was to evaluate the influence of bovine colostrum supplementation on the immune Th1/Th2 response in weaned piglets. After weaning at 21 d, 3 groups of 7 piglets were fed ad libitum with a starter diet and received daily 0, 1 or 5 g of spray-dried bovine colostrum. Spleen and gut-associated lymphoid tissues (GALT): ileal Peyer's patch (iPP), jejunum wall (JW) and mesenteric lymph node (MLN)) biopsies were collected on each piglet after 3 wk of treatment and analysed for their cytokine mRNA expression (IL-2, IL-4, IL-10, IL-12 and IFNγ) by RT-PCR. The supplementation with bovine colostrum induced an increase (P < 0.05) in IL-12 in the JW, in IL-2, IL-10 and IL-12 in the MLN and in IL-4, IL-10 and IL-12 in the iPP. In the latter, bovine colostrum also decreased IFN-γ production (P < 0.01). Finally, no effect of the treatments was recorded in the spleen. These results suggest an immunomodulatory effect of bovine colostrum on the GALT, which responded by producing at different levels both Th1 pro-inflammatory cytokines (IL-2, IFN-γ and IL-12) and Th2 anti-inflammatory cytokines (IL-4 and IL-10). This Th1/Th2 bipolar response protects the weaned piglets from both allergic (food) and infectious (pathogens) diseases.     

The perinatal development of the gastrointestinal tract in piglets can be modified by supplementation of sow diet with bioactive substances

Dietary bioactive substances involving taurine, l-carnitine, polyunsaturated fatty acids, flavonoids and antioxidants were shown to control the perinatal development in mammals. A blend of bioactive substances was used to supplement the diet of sows according to the optimal needs of their offspring. Our study aimed to examine the development of gastrointestinal tract in their offspring as compared to the offspring from control sows fed with standard diet. The supplemented diet was given from the gestation day 80 until the end of lactation period. One piglet from each litter was sacrificed on postnatal days 1 (i.e., unsuckling neonates), 2, 4, 7, 14, and 28 for tissue sampling. At birth, the stomach relative weight was larger in the supplemented group, and the small intestine relative weight was smaller as compared to control. These differences disappeared within 1–4 postnatal days. The stomach weight was larger at postnatal day 28 in the supplemented group as compared to control. Gastric protein content and the proteolytic activity in the offspring of the supplemented sows showed after birth a tendency to increase as compared to control, though the differences disappeared after the fourth postnatal day. In conclusion, the supplementation of sow diet with dietary bioactive substances affected primarily the prenatal development of the stomach and small intestine in their offspring.     

肠膜蛋白粉对早期断奶仔猪生产性能及消化道发育的影响

豆粕中含有的大豆球蛋白和ｂｅｔａ -ｃｏｎｇｌｙｃｉｎｉｎ等抗原 ,可导致断奶仔猪肠粘膜细胞发生过敏反应 ,进而降低其生产性能 (谯仕彦等 ,1 995,1 996) ,因此人们试图用其他原料替代或降低日粮中的豆粕用量。研究表明 ,日粮中添加乳清粉和血浆蛋白粉能够提高断奶仔猪日采食量和日增重 (管武太 ,1 994) ,但昂贵的价格限制了其广泛的应用。最近试验表明 ,用ＤＰＳ(肠膜蛋白粉 ,其中ＤＰＳ30 、ＤＰＳ50 的粗蛋白质含量分别为 30 %、50 % )全部或部分替代乳清粉或血浆蛋白粉 ,能够在降低饲料成本的同时 ,保持甚至提高断奶仔猪的生产性能。…     

Effect of feeding fermented liquid feed and fermented grain on gastrointestinal ecology and growth performance in piglets

To investigate the microbial and nutritional characteristics of dry feed, liquid feed containing fermented liquid cereal grains, and fermented liquid feed, and their effect on gastrointestinal ecology and growth performance, 120 piglets from 40 litters were used and housed in pens with 5 animals in each. The 3 dietary treatments (all nonheated and nonpelleted diets) were: a dry meal diet (DRY); a fermented, liquid cereal grain feed (FLG); and a fermented liquid feed (FLF). The FLG diet was prepared by storing the dietary cereals (barley and wheat) and water (1:2.5, wt/wt) in a closed tank at 20 degrees C and adding the remaining dietary ingredients immediately before feeding. The FLF diet was prepared by storing compound feed and water (1:2.5, wt/wt) in a closed tank at 20 degrees C. Three times daily, 50% of the fermented cereals or compound feed and water stored in the tanks was removed and replaced with an equal amount of fresh cereals or feed and water. On d 14, 1 piglet from each pen was killed and samples from the gastrointestinal tract were obtained. The pH of the fermented cereals was 3.85 (SD = 0.10), that of the FLG diet was 5.00 (SD = 0.18), and the pH of the FLF diet was 4.45 (SD = 0.11). The dietary concentration of lysine (g/16 g of N) pointed to a decreased concentration in the FLF (5.46, SD = 0.08) compared with the DRY (6.01) and FLG (6.21, SD = 0.27) diets, and the concentration of cadaverine was greater in the FLF diet (890 mg/kg, SD = 151.3) than in the DRY (32 mg/kg) or FLG (153 mg/kg, SD = 18.7) diets. Fermenting only the cereal component of the diet (FLG) promoted the growth of yeasts to a greater extent than fermenting the whole diet (FLF). Terminal RFLP profiles of diets and digesta from the stomach and midcolon showed differences among dietary groups. The number of yeasts able to grow at 37 degrees C in the stomach and caudal small intestine was greatest in the FLG group compared with the other 2 dietary groups (P < 0.01). In the cecum and colon, the differences were only significant between piglets fed the FLG and the FLF diets (P < 0.05). The greatest number of yeasts able to grow at 20 degrees C was detected in the animals fed the FLG diet. However, the values were different from the FLF-fed piglets only in the stomach (P < 0.05) and midcolon (P < 0.05). There was a tendency (P < 0.10) for greater ADG of the piglets fed the FLG compared with the FLF diet. Feeding liquid feed containing fermented, liquid cereal grains as a means of avoiding microbial decarboxylation of free amino acids in the feed and increasing feed intake by improving palatability seems promising but requires further investigation.     

Effect of dietary nucleotide supplementation on performance and development of the gastrointestinal tract of broilers

1. Two experiments were conducted to determine the effects of dietary nucleotide supplementation on broiler performance, and physical and morphological development of the gastrointestinal tract.

2. Experiment 1: A total of 180 one-d-old male chicks were placed in battery brooders in 3?×?6 replicate pens containing 10 chicks each. Chicks were randomly assigned to one of the three dietary treatments; a maize-soyabean meal based diet supplemented with 0, 0·25, and 0·50% Torula yeast RNA (as a source of nucleotides) from 0 to 16?d of age.

3. Experiment 2: A total of 1344 one-d-old male chicks were placed in floor pens and reared on recycled wood shavings (two flocks) under a high stocking density (0·068?m²/bird). Chicks were randomly assigned to one of the 4 dietary treatments (0, 0·25% Torula yeast RNA, 2% and 6% Nupro®) for the starter period (0 to 14?d of age) with 6 replicate pens containing 56 chicks each. All the birds were fed on the same common grower diet with no supplementation of nucleotides from 15 to 32?d of age.

4. Experiment 1: Supplementing the diets with up to 0·50% Torula yeast RNA did not affect broiler performance, or relative intestinal tract weight and length of broilers at any periods measured.

5. Experiment 2: From 0 to 14?d of age, broilers fed on the diets supplemented with 0·25% Torula yeast RNA and 2 and 6% Nupro® were significantly heavier and had improved feed conversion (feed:gain) ratios as compared with the birds fed on the control diet. Supplementing the starter diet only with 2% Nupro® supplementation significantly improved body weight (BW) gain as compared with the control diet over the entire experiment (0 to 32?d of age). Broilers fed on the diets supplemented with 2 and 6% Nupro® from 0 to 14?d of age had better feed conversion (feed:gain) ratios over the entire experiment (0 to 32?d of age) as compared with the birds fed on the control diet, even though the birds were only fed on the diets supplemented with Nupro® from 0 to 14?d of age. The broilers fed on the diets supplemented with 0·25% Torula yeast RNA and 2% Nupro® had higher villus height and an improved villus height-to-crypt depth ratio as compared with birds fed on the control or 6% Nupro® diet at 14?d of age.

6. It is generally assumed that nucleotides are not an essential nutrient; thus there is no need to supplement the diets of broilers reared under normal conditions. However, dietary nucleotide supplementation may be important to maintain maximum growth performance when birds are exposed to stress conditions, such as high stocking density combined with dirty litter.     

Effect of cow colostrum on the performance and survival rate of local newborn piglets in Benin Republic

The effect of bovine colostrum, including its thermally labile compounds, on the survival and growth performance of local breed piglets reared by their mother, in Benin, was evaluated over a 49-day trial. Three groups of 16 piglets, stemming from two primiparous sows belonging to a unique traditional farm, were respectively fed for the first 48 h of life with either bovine colostrum heated to 85 °C for 30 min, or thawed bovine colostrum, or colostrum from the mother. Thereafter, the animals that received bovine colostrum turned back to their mother. At day 21, almost all piglets from the group that received heated colostrum died. The highest total weight gain was obtained in the group that received thawed bovine colostrum (P???0.01), followed by the group left with the mother. Corresponding average daily gains (ADGs) were 56, 34 and 2 g/day, respectively (P???0.05). At the end of the trial, the treatment effect was highly significant on the survival of piglets (100% in the thawed colostrum group vs. 00 and 50%, respectively, in the heated colostrum group and in the group left with the mother). At day 49, numerically higher weight and ADGs were obtained in the group that received thawed cow colostrum. Thawed bovine colostrum improved the growth performance and piglet survival in the local pig breed in Benin, probably owing to thermally labile components. Bovine colostrum may be used in our farms in order to reduce pre-weaning mortality, improve the profitability of livestock farmers, and ensure survival of traditional farms. The use of bovine colostrum on farms could be facilitated by collaboration between pig farmers and bovine farmers. It could also be facilitated by the creation of a colostrum bank.