影响仔猪胃肠道发育的因素

仔猪胃肠发育的情况直接影响了营养物质的消化、吸收及利用,及时找到影响其发育的因素对仔猪的营养管理是非常有意义的。目前发现的诸多因素中,生长因子及营养物质对其发育起到促进作用,而抗营养因子往往对其发育不利。本文从生长因子、营养物质到抗营养因子角度出发,分析了它们对仔猪肠道发育影响,为今后合理配制仔猪饲养阶段的日粮提供依据。     

早期断奶对湖羊羔羊生长性能及胃肠道发育的影响

为研究湖羊羔羊28日龄断奶是否可行,本试验选用48只初生重[(3.51±0.57)kg]接近的湖羊公羔,随机均分为2组,分别为早期断奶组(28日龄断奶)和对照组(56日龄断奶)。从7日龄开始补饲开食料,60日龄同时逐渐换生长料。分别在42、56、70、84日龄测定羔羊体重,每组屠宰6只,测定各胃室重量、容积以及各肠段重量、长度。结果表明:1)42、56、70、84日龄2组羔羊体重差异不显著(P0.05),各时间段平均日增重2组差异不显著(P0.05);2)瘤网胃、瓣胃的重量、容积,瘤网胃相对重量(占活体重、胃肠道重、胃重百分比),瘤网胃相对容积(占胃容积百分比)在42、56日龄早期断奶组显著高于对照组(P0.05);3)除70日龄结肠重外,其余各肠段重量、长度在各日龄2组间无显著差异(P0.05)。综合以上各项指标认为,本试验条件下,28日龄断奶可促进湖羊羔羊胃肠道早期发育,28日龄断奶可行。     

丁酸钠对犊牛胃肠道发育的研究进展

丁酸钠是一种绿色新型饲料添加剂,目前在动物饲料中应用广泛,且效果良好。作者主要介绍了丁酸钠的生物学功能、对犊牛胃肠道发育的影响及其在犊牛日粮中的应用效果。重点总结了丁酸钠促进犊牛胃肠道发育的影响机制,包括作为胃肠道组织的能量来源调控激素和生长因子的分泌,提高消化和吸收相关酶的分泌及活性,提高肠道免疫细胞保护性蛋白的分泌等。现有研究表明,日粮干物质中添加0.3%丁酸钠就能达到促进犊牛生长和胃肠道发育的效果,但具体添加水平、添加阶段和方式等尚不明确。此外,日粮粗饲料水平、精料发酵所产生的内源丁酸对外源丁酸钠的作用效果是否有影响也鲜有报道,有待进一步开展研究。     

新型发酵豆粕对断奶仔猪生长性能及胃肠道发育的影响

为了研究新型发酵豆粕对断奶仔猪生长性能和胃肠道发育的影响,根据胎次、体重相近原则,选用26日龄断奶体重为(4.75±0.38)kg的90头杜枫姜仔猪分为对照组、试验Ⅰ组(日粮+17.5%发酵豆粕)和试验Ⅱ组(日粮+35%发酵豆粕),每组3个重复,每个重复10头,试验为期20 d。结果:与对照组相比,试验Ⅰ(P<0.05)、Ⅱ组(P<0.01)仔猪日增重效果均显著;料重比分别降低4.21%(P>0.05)、19.47%(P<0.05);腹泻率均显著低于对照组;两试验组仔猪胃内容物pH值均显著降低(P<0.01);而胃黏膜厚度及胃壁厚度显著增加(P<0.01)。试验Ⅱ组的肠绒毛高度、绒毛高度/隐窝深度比值显著高于对照组(P<0.05),隐窝深度和肠壁厚度显著降低;试验Ⅰ组肠道发育也有所改善。表明新型发酵豆粕可提高断奶仔猪生长性能,降低腹泻率,促进仔猪胃肠道发育,且完全替代普通豆粕时效果最佳。     

IUGR新生仔猪胃肠道发育早期营养调控的研究进展

宫内发育迟缓(IUGR)是猪胚胎发育过程中的一种常见的病理现象,常导致胎儿在围产期的死亡与器官发育障碍,对养猪生产造成巨大危害。通过调整仔猪日粮营养水平、新生期口服胰岛素和酪蛋白酶解物等营养调控方法可在一定程度上改善IUGR仔猪胃肠道的发育,提高其消化吸收能力。本文在总结国内外对于IUGR新生仔猪胃肠道发育特点的研究基础上,综述了对IUGR仔猪胃肠道进行早期营养调控的一些措施。     

不同蛋白质来源对早期断奶犊牛胃肠道形态发育的影响

本试验研究代乳品中不同蛋白质来源对早期断奶犊牛胃肠道形态结构发育的影响。选取15头2-8周龄的新生荷斯坦犊牛随机分为3组,分别饲喂乳蛋白和植物性蛋白比例分别为80：20、50：50及20：80的代乳品,记为S20、S50、S80组。结果表明：蛋白质来源影响犊牛胃肠道器官与犊牛体重的比值,其中瘤网胃相对比重随日粮植物性蛋白含量升高而上升,皱胃则与之相反,但差异均不显著（P〉0．05）;肝脏、胰脏的相对比重随植物性蛋白含量升高而降低。日粮植物性蛋白含量增加可促进犊牛瘤网胃的发育,     

发酵豆粕对断奶仔猪生长性能、养分消化率和胃肠道发育的影响

本试验旨在研究发酵豆粕对断奶仔猪生产性能、养分消化率和胃肠道发育的影响.根据胎次、体重相近原则,选择90头26日龄体重为(4.75±0.38)kg的杜枫姜断奶仔猪,分为对照组、试验Ⅰ组(日粮中添加17.5%发酵豆粕)和试验Ⅱ组(日粮中添加35%发酵豆粕),每组3个重复,各重复10头.结果表明:试验Ⅰ、Ⅱ组仔猪日增重分别增加13.90%(P<0.05)、50.55%(P<0.01),料重比分别降低4.21%(JP>0.05)、19.47%(P<0.05).试验Ⅱ组、试验Ⅰ组仔猪腹泻率均极显著(P<0.01)、(P<0.05)低于对照组.试验Ⅰ、Ⅱ组仔猪粗脂肪、粗蛋白质的消化率均显著高于对照组(P<0.05),钙、磷的消化率差异不显著.两试验组仔猪胃内容物pH、胃黏膜和胃壁厚度极显著优于对照组(P<0.01),试验Ⅱ组的肠绒毛高度和绒毛高度/隐窝深度比值显著高于对照组(P<0.05),隐窝深度和肠壁厚度显著降低.     

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。     

芽孢杆菌制剂对断奶仔猪生长性能、胃肠道发育的影响

本试验在断奶仔猪日粮中添加不同比例的芽孢杆菌制剂,研究其对断奶仔猪生长性能、胃肠道pH、小肠形态发育及盲肠和结肠内容物中VFA的影响。选择35日龄断奶仔猪96头,按性别比例一致的原则,随机分为4个处理,每个处理3个重复,每个重复8头仔猪,每个重复为1栏。对照组饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ组在基础日粮中分别添加0.75%、1.50%、3.00%的芽孢杆菌制剂(即每千克日粮中含有的活菌数为0.66×1010、1.32×1010、2.64×1010 cfu),试验期35d。试验结束时,每个重复选取1头接近平均体质量的仔猪进行屠宰,迅速结扎各胃肠段分界处,测定各段pH;取十二指肠、空肠前、中、后段及回肠做肠道组织切片;收集盲肠和结肠内容物测定挥发性脂肪酸含量。结果显示:(1)芽孢杆菌制剂对断奶仔猪生长性能无显著影响(P>0.05);(2)空肠及盲肠部分,0.75%组的pH显著低于对照组(P<0.05);盲肠部分,1.50%组的pH较对照组显著降低6.86%(P<0.05);(3)与对照组相比,0.75%组显著提高了十二指肠、空肠中段的绒毛高度(P<0.05),显著降低了空肠前段、后段的隐窝深度(P<0.05),同时,显著提高了空肠中段、后段的绒毛高度与隐窝深度的比值(P<0.05);(4)盲肠部分,0.75%组的丙酸和总挥发性脂肪酸含量较对照组显著升高(P<0.05)。试验结果提示:在断奶仔猪日粮中添加0.75%的芽孢杆菌制剂可降低胃肠道pH,增加盲肠中挥发性脂肪酸的含量,促进小肠形态发育,进而说明芽孢杆菌制剂可优化胃肠道环境,促进断奶仔猪健康生长。     

湖羊羔羊早期断奶前后胃肠道发育、酶活性及发酵参数的变化研究

试验旨在研究湖羊羔羊早期断奶前后的胃肠道结构和功能发育的变化,为羔羊的早期培育提供理论依据。选择初生重相近的22只双羔湖羊公羔(初生重3.81 kg±0.55 kg),1~7日龄饲喂母乳,8日龄与母羊分离,开始饲喂代乳粉(按8日龄体重的2%,分3次等量饲喂)和开食料(自由采食),35日龄停止饲喂代乳粉。于8、21和42日龄分别屠宰6只羔羊,检测瘤胃、网胃、瓣胃、皱胃的重量及十二指肠、空肠、回肠、盲肠、结肠、直肠的长度和重量;采集瘤胃和小肠组织,切片后进行伊红和苏木精染色,检测瘤胃乳头长度、宽度、环形肌厚度、小肠绒毛高度、宽度和隐窝深度,并计算绒隐比(绒毛高度/隐窝深度);采集瘤胃、十二指肠和空肠内容物,检测淀粉酶、纤维素酶、乳糖酶、胰蛋白酶和脂肪酶活性及氨态氮(NH₃-N)、挥发性脂肪酸(VFA)浓度。结果显示,瘤胃、网胃、瓣胃重和瘤胃占总胃重的比例随日龄的增加而显著增加(P<0.05),皱胃重占总胃重的比例随着日龄的增加而减小(P<0.05);十二指肠、空肠、回肠、盲肠、结肠和直肠的长度、重量随日龄的增加而增加(P<0.05),42日龄十二指肠、回肠绒隐比均显著高于8和21日龄(P<0.05),瘤胃乳头高度、乳头宽度和肌层厚度均随日龄的增加而显著增加(P<0.05),十二指肠的绒毛高度、绒毛宽度、隐窝深度及空肠的绒毛高度、隐窝深度均随着日龄的增加而减小;十二指肠淀粉酶、胰蛋白酶、脂肪酶及空肠淀粉酶、胰蛋白酶活性均随着日龄的增加而显著增加(P<0.05);42日龄羔羊瘤胃中淀粉酶活性及乙酸、丙酸和丁酸浓度均显著高于21日龄羔羊(P<0.05)。以上结果说明,和断奶(21日龄)前相比,断奶后羔羊的瘤胃发育增强,皱胃和小肠组织形态变小,瘤胃和小肠中主要消化酶的活性均增强。     

仔猪色氨酸研究新进展

<正>色氨酸(Trp)是仔猪日粮中排于赖氨酸、苏氨酸、蛋氨酸之后的第4限制性氨基酸。它除了有助于蛋白质沉积,最重要的作用就是对适口性和采食量的调     

Effect of segregated early weaning on postweaning small intestinal development in pigs

The effect of segregated early weaning (SEW) on postweaning small intestinal development was investigated in SEW and control (CON) pigs. Small intestines were collected from a total of 15 pigs killed at 11 (preweaning), 15 (3 d postweaning), and 34 d of age. At 3 d postweaning, the SEW and CON pigs had shorter villi (P<.01), deeper crypts (P<.01), and reduced (P<.01) ratios of villus height:crypt depth (V:C) compared with preweaning. Weaning also reduced specific activities of lactase (P<.01) in duodenum and ileum and alkaline phosphatase (ALP) (P<.05) in duodenum and jejunum. Sucrase activity in the three regions of the small intestine marginally decreased in both groups at 3 d postweaning. The mucosal protein:DNA ratio in duodenum and jejunum increased (P<.05) in SEW and CON pigs at 3 d postweaning compared with preweaning pigs. The SEW and CON treatments resulted in differences in postweaning gut development. At 15 d of age in SEW pigs, the mucosal protein:DNA ratio in duodenum and jejunum were 20 and 25.5% (P<.05) less, respectively, than those in CON pigs. However, at 34 d, these ratios in duodenum, jejunum, and ileum were 43.5 (P<.05), 24.3, and 32.9% (P<.05) greater, respectively, in SEW pigs than in CON pigs. Longer villi, shorter crypts (P<.01), and higher V:C ratios (P<.01) in jejunum and ileum were observed in SEW pigs vs CON pigs at 34 d of age. The specific activities of lactase in duodenum (P<.01) and jejunum (P<.05) and of ALP in duodenum (P<.01) were higher in SEW pigs. Sucrase activity in duodenum, jejunum, and ileum was 21.7, 46.3 (P<.05), and 11.2% greater in SEW pigs at 34 d of age. These results demonstrate differences in postweaning gut development between SEW and CON pigs. Furthermore, the number of intraepithelial lymphocytes in jejunum was greater (P<.001) in 34-d-old SEW pigs compared with CON pigs. Microscopy revealed a thick mucus coating over epithelial cells in the ileum of 34-d-old CON pigs that was not apparent in the SEW pigs. These observations are consistent with reduced pathogen exposure associated with SEW. We suggest that segregated early weaning advances postweaning gut maturation, which is consistent with improved growth and feed efficiency observed in SEW pigs.     

近期猪低蛋白日粮研究进展

低蛋白日粮具有节省成本、提高能量水平、降低氮污染等经济的和环境的优势。利用猪的理想蛋白比例、采用可消化氨基酸和净能系统等技术配制以玉米和豆粕为主要原料的猪日粮时,可以不对日粮粗蛋白水平做最低限制。研究表明,猪日粮的粗蛋白水平在NRC推荐标准上降低4%,其饲养效果与限制最低粗蛋白水平的日粮相同,而且能使氮的排出量显著减少。     

绒山羊毛囊发育规律及毛囊发育调控因子的研究进展

针对绒山羊毛囊发育规律及调控毛囊发育相关因子的研究进展进行了介绍.     

苏氨酸对畜禽肠道健康影响的研究进展

<正>W.C.Rose于1935年在纤维蛋白质水解物中首次分离出苏氨酸,因其空间结构与苏糖相似而命名为苏氨酸。在大多数植物性饲料(尤其是谷     

布氏杆菌病致病因子及防治研究进展

布氏杆菌是引起动物布氏杆菌病的病原。这类胞内病原菌表达一系列的因子,包括脂多糖类、毒力调节蛋白和磷酸卵磷酯等来保证其毒力。有些毒力因子是侵袭宿主所必须的,而其他的毒力因子对逃脱宿主的清除是必须的。它们允许布氏杆菌在复制泡内生存和增殖,逃脱宿主免疫系统的检测。了解其毒力可为疫苗研制提供依据,也可促使新的抗生素研制。在动物布病防治中生产兽用疫苗来预防该病,但还没有合适的疫苗防治人布病,可能是人布病复杂的病理生理学不同于动物模型。本文就布氏杆菌毒力因子以及如何操纵在宿主细胞中运输进行综述。     

Prevalence and risk factors associated with intestinal parasites in pigs in Chongqing, China

From 2007 to 2009, the prevalence of intestinal parasites was investigated in intensive and extensive pig farms in Chongqing, China. A total of 2971 samples from both sexes and five age categories (breeding boars, breeding sows, fatteners, growers and weaners) were evaluated by standard methods for the presence of helminth ova and protozoan oocysts, cysts and/or trophozoites. Of the 2971 pigs sampled, 362(12.18%) were infected with Ascaris suum, 301(10.13%) with Trichuris suis, 301(10.13%) with Oesophagostomum spp., 491(16.53%) with Eimeria spp., 149(5.02%) with Isopora suis, 677(22.79%) with Balantidium coli and 196(6.60%) with Cryptosporidium spp. Growers had the highest infection rate while breeding boars had the lowest among the five age categories. B. coli was the most common protozoan in all pig age groups. Pigs infected with multiple parasites were common. Risk factors such as management methods, seasons, ages, etc. can influence the infection rate to a certain degree. This investigation provides relevant data about risk factors for pig farmers, thus allowing them to make more appropriate antiparasitic treatments according to farm conditions and local climate in Chongqing.     

Effects of pregelatinized vs. native potato starch on intestinal weight and stomach lesions of pigs housed in barren pens or on straw bedding

In a 2 × 2 factorial arrangement, 16 groups of 12 pigs (approximately 25 kg) were assigned to either barren or straw housing and to native or pregelatinized potato starch included in the diet (35%) to investigate effects on intestinal weight and gastric lesions. Pigs were fed restrictedly (2.5 × MEm) for 5 weeks. At slaughter, weights of empty small intestine and stomach were determined. Stomachs were inspected for incidence of lesions in the pars oesophagea. No starch type × housing interactions were found. In pigs fed pregelatinized starch, weight of the small intestine (26.8 ± 0.4 g/kg BW) and stomach (7.6 ± 0.1 g/kg BW) were higher than in pigs fed native starch (24.9 ± 0.4; 7.1 ± 0.1 g/kg BW, respectively; P < 0.01). Straw bedding increased empty stomach weight (7.9 ± 0.1 vs. 6.8 ± 0.1 g/kg BW; P < 0.001), but not small intestine weight. Starch type did not affect stomach scores, but straw bedding reduced the incidence of gastric lesions to a very low level (scores 0.5 and 3.0 for straw and barren housing, P < 0.001). In conclusion, straw bedding reduced gastric lesions, reflecting either reduced environmental stress or a positive effect of physical stimulation. Pregelatinization of starch increased the empty weight of the proximal GI tract, possibly reflecting increased nutrient uptake.     

A defined intestinal colonization microbiota for gnotobiotic pigs

Maximising the ability of piglets to survive exposure to pathogens is essential to reduce early piglet mortality, an important factor in efficient commercial pig production. Mortality rates can be influenced by many factors, including early colonization by microbial commensals. Here we describe the development of an intestinal microbiota, the Bristol microbiota, for use in gnotobiotic pigs and its influence on synthesis of systemic immunoglobulins. Such a microbiota will be of value in studies of the consequences of early microbial colonization on development of the intestinal immune system and subsequent susceptibility to disease. Gnotobiotic pig studies lack a well-established intestinal microbiota. The use of the Altered Schaedler Flora (ASF), a murine intestinal microbiota, to colonize the intestines of Caesarean-derived, gnotobiotic pigs prior to gut closure, resulted in unreliable colonization with most (but not all) strains of the ASF. Subsequently, a novel, simpler porcine microbiota was developed. The novel microbiota reliably colonized the length of the intestinal tract when administered to gnotobiotic piglets. No health problems were observed, and the novel microbiota induced a systemic increase in serum immunoglobulins, in particular IgA and IgM. The Bristol microbiota will be of value for highly controlled, reproducible experiments of the consequences of early microbial colonization on susceptibility to disease in neonatal piglets, and as a biomedical model for the impact of microbial colonization on development of the intestinal mucosa and immune system in neonates.     

奶牛氧化应激研究进展及其影响因素

<正>氧化应激由机体自由基的产生和清除失衡所造成,当机体产生的自由基超过机体防御能力时,过多的自由基可破坏蛋白质、核酸等生物大分子,使机体正常的代谢发生紊乱(Trevisan等,2001)。机体的各种生物膜(如红细胞膜)富含PUFA,产生的过多自由基易攻击细胞膜上的必需脂肪酸,造成细胞损害,影响