低聚壳聚糖对肉仔鸡生产性能的研究

<正>甲壳素的化学名称是—(1,4)苷键连接的直链状多糖,是唯一含氨基的均态多糖,结构与纤维素相似。壳聚糖是由甲壳素脱去乙酰基后的产物,一般来讲,甲壳素的N-乙酰基脱去55%以上就可以称为壳聚糖。壳聚糖存在于虾、蟹和昆虫的外壳及藻类、菌类的细胞壁中。低聚壳聚糖可以直接溶于水中,其溶液黏度较低;由于分子上     

低聚壳聚糖在断奶仔猪生产上的应用研究

甲壳素是唯一含氨基的均态多糖．结构与纤维素相似．是纤维素第二位上的羟基被酰胺基置换的产物。甲壳素与浓碱反应生成壳聚糖。壳聚糖是由甲壳素脱去乙酰基后的产物。一般来讲．甲壳素的N-乙酰基脱去55％以上就可以称为壳聚糖。壳聚糖存在于虾、蟹和昆虫的外壳及藻类、     

甲壳素、壳聚糖在畜牧业中应用的研究

甲壳素（chitin）,是一种天然高分子聚合物,在自然界中,是仅次于纤维素的第二大生物资源.甲壳素分子脱乙酰基后称为壳聚糖（chitosan,CS）.多年的研究表明,甲壳素、壳聚糖具有抗微生物活性、激活淋巴细胞、提高免疫力、调节脂肪代谢、降低血脂胆固醇等多种生理功能.由于具有以上特性,甲壳素、壳聚糖广泛应用于畜牧业中.现将甲壳素、壳聚糖在畜牧业的应用及应用前景作一报道.     

甲壳素、壳聚糖在动物营养中的研究进展

甲壳素 (Ｃｈｉｔｉｎ)是天然的高分子多聚糖 ,广泛存在于甲壳类动物、节枝类动物的壳体及蕈类、藻类的细胞壁。自然界中甲壳素的年生物合成量约 10 0 0亿吨 ,是地球上除纤维素以外的第二大有机资源。甲壳素分子脱乙酰基后称为壳聚糖 (Ｃｈｉｔｏｓａｎ ,ＣＳ) ,是迄今为止唯一发现的阳离子动物纤维 ,唯一的碱性多糖。甲壳素和壳聚糖在动物体内具有多种生理作用而成为糖生物学的研究热点。本文在目前已有的研究基础上 ,就甲壳素、壳聚糖的研究历程、理化性质及在动物营养中的作用做一综述。1　甲壳素和壳聚糖的研究历程甲壳素首先是由法国学…     

壳聚糖对动物脂肪代谢及生长性能的影响

壳聚糖(chifosan)，是甲壳素的衍生物．又名可溶性甲壳素、脱乙酰甲壳素、甲壳胺、几丁聚糖．是通过甲壳素一定程度的脱乙酰而得到．通常将脱乙酰度55％以上的甲壳素称作壳聚糖，化学名称是(1．4)-2-氨基-2-脱氧-β-D-葡聚糖。在众多的天然多糖中，甲壳素及其主要衍生物壳聚糖是唯一的碱性多糖．具有生物相容性、可食用性、可抗菌性、     

壳聚糖及其在家禽饲料中的应用

壳聚糖又称脱乙酰甲壳素聚氨基葡萄糖,是甲壳素脱乙酰后的产物。甲壳素是自然界中产量仅次于纤维素的天然产物,广泛存在于虾、蟹等甲壳动物外壳中。壳聚糖因具有优良的生物相容性,可被溶菌酶溶解,可生物降解,其代谢产物无毒,且能被生物体完全吸收等独特的理化特性,在医药、食品、化妆品、农业及环境等方面应用较为广泛。而壳聚糖作为一种极有潜力的饲料添加剂只是在近几年才开始进行研究开发的,本文将对近年有关壳聚糖在家禽饲料中的应用效果进行总结分析。1壳聚糖结构与理化性质壳聚糖是甲壳素脱乙酰后的产物,化学名称为β-(1,4)-2脱氧-D-…     

蚕蛹壳聚糖的制备及应用研究进展

壳聚糖是甲壳素的脱乙酰化产物,具有安全无毒、抗菌、吸湿透气、吸附性强、成纤性好以及良好的化学反应活性和生物活性等特点。蚕蛹壳中含有丰富的甲壳素,是提取壳聚糖的优质原料。介绍了蚕蛹壳聚糖的制备工艺技术,着重讨论了蚕蛹原料预处理、脱无机盐、脱蛋白质、脱色、脱乙酰等工艺流程采用的技术方法;简述了蚕蛹壳聚糖在农业、纺织、食品加工、医用材料、环保、生物工程等领域的应用状况;分析了蚕蛹壳聚糖产业化生产存在的问题,提出了解决办法。     

蛹壳中提取甲壳素及微晶化晶体结构的研究

采用两段碱煮法从蚕蛹壳中提取甲壳素 ,NaOH的质量分数分别为 10 %和 5 % ,甲壳素的提取率为 4 5 %。分析了微晶甲壳素与甲壳素的反应活性 ,并对微晶甲壳素 ,原甲壳素及壳聚糖的溶解性、差示热、热重等进行了比较 ,依据两种甲壳素的红外光谱和差示量热分析的不同 ,提出了微晶化甲壳素可能的晶体结构模型。用甲壳素制备微晶甲壳素的得率为 89 6 %。     

壳聚糖在家禽养殖中的应用

甲壳素（chitin）又名甲壳质、几丁质、壳多糖、明角质，于1881年由法国学者布拉克诺首次从菌类提取出来，是自然界中产量仅次于维生素的天然产物，广泛存在于昆虫、甲壳类动物虾、蟹等外壳及真菌、藻类细胞壁中。壳聚糖（chitosan）又称可溶性甲壳素、甲壳胺，是甲壳素有效成分之一。壳聚糖因具有优良的生物相容性，     

壳聚糖在水产养殖上的应用

美国食品卫生组织在1983年已批准壳聚糖作为饲料添加剂应用,而在我国壳聚糖方面的研究较晚,但在近年已取得了很好的研究成果。本文对壳聚糖在水产养殖中的应用进行综述。1壳聚糖的来源及其安全性壳聚糖(Chitosan)又称甲壳质、壳多糖,主要来源于甲壳素,是甲壳素脱乙酰基程度达70%以上的产物。甲壳素是一种十分丰富的自然资源,广泛存在于藻类、真菌、节肢动物如虾、蟹、昆虫的外壳、贝类等软体动物的外壳和软骨以及低等植物菌类、高等植物的细胞壁中。它是地球上仅次于植物纤维素的第二大可再生资源,由于其原材料来源广泛、成本低以及优良的…     

甲壳素和壳聚糖营养研究进展

甲壳素、壳聚糖是一种新型绿色饲料添加剂,具有降脂、抗菌抑菌和免疫调节等多种生物学活性,本文综述了甲壳素、壳聚糖的生理生化功能以及在畜禽日粮中添加的生物学效应,为进一步促进其开发利用提供理论依据。     

Mechanism of macrophage activation by chitin derivatives

In order to analyze the detailed mechanisms responsible for macrophage activation by chitin derivatives, resident peritoneal macrophages were prepared and stimulated with chitin, chitosan and low-molecular weight chitosan. Our findings were as follows: (i) chitosan induced apoptosis of peritoneal macrophages, but this did not occur when chitin or water soluble low-molecular weight chitosan were used; (ii) chitosan treatment induced activation markers, such as the major histocompatibility complex (MHC) class I, class II, Fc receptors, transferrin receptor, mannose receptor, Fas, and macrophage inflammatory protein (MIP)-2, whereas chitin and low molecular weight soluble chitosan induced only the expression of MHC class I and II molecules; (iii) apoptosis induced by chitosan was mediated by the Fas signaling pathway, in response to phagocytosis via the mannose receptor. We conclude that since chitosan activates macrophages, this may be the mechanism by which it accelerates wound healing.     

Effects of chitin and chitosan from cricket and shrimp on growth and carcass performance of broiler chickens

Tropical Animal Health and Production - Majority of the studies on the effect of chitin and chitosan on growth and carcass characteristics of broiler chickens has concentrated more on shrimp chitin...     

Chitosan and D-glucosamine induce expression of Th1 cytokine genes in porcine spleen cells

Chitosan, a polymer of D-glucosamine, is a polysaccharide derived from the chitin found in the exoskeleton of shellfish, such as shrimp or crabs. The effects of chitosan has been recognized that chitosan-fed farm animals demonstrated higher weight gains but less incidence of diseases than the unfed ones. However, these beneficial effects has not been elucidated clearly. In this study, we examined the modulatory effect of chitosan and D-glucosamine on the expression of porcine cytokines in vitro. Porcine spleen cells were cultured in the presence of chitosan and D-glucosamine, and the effects of chitosan on the cytokine mRNA expression were evaluated. Expressions of IL-2 and IFN-gamma were increased in the chitosan-treated porcine spleen cells. Expressed cytokines in the D-glucosamine-treated cells were IL-2, IFN-gamma, and IL-12 p40 subunit. In particular, IFN-gamma was expressed more efficiently, and D-glucosamine was more effective for expressing the cytokine gene. These results suggest chitosan as well as D-glucosamine could induce the expression of cytokines as Th1 subset such as IL-2, IFN-gamma.     

Effects of chitin and chitosan on collagen synthesis in wound healing

Collagen synthesis was evaluated by measuring prolyl hydroxylase (PHL) activity induced within rat granulation tissue by a polyester non-woven fabric (NWF, 1 x 1 cm, 0.6 mm in thickness) impregnated with a chitin or chitosan suspension ranging in concentration from 0.1 to 10 mg/ml. In addition, PHL activity induced in rat granulation tissue by a NWF impregnated with a phosphate buffer solution was examined as a control. The PHL activity in each group remained low until 4 days post-implantation (Day 4). However, in the 10 mg chitin group, the PHL activity increased rapidly without scatter of the data at Day 7 and remained at a plateau until Day 14. In other groups, PHL activity increased linearly until Day 14. The data varied widely at Day 7. Compared to chitosan, chitin at the higher concentration was found to induce stable collagen synthesis in the early wound healing process.     

Chitosan and its oligosaccharide derivatives (chito‐oligosaccharides) as feed supplements in poultry and swine nutrition

Chitosan is a non‐toxic polyglucosamine, widespread in nature, which is deacetylated to varying degrees form of chitin, a component of exoskeleton of shrimps, crabs and insects. Because chitosan contains reactive functional groups, that is, amino acids and hydroxyl groups, it is characterised by antimicrobial, anti‐inflammatory, anti‐oxidative, antitumor, immunostimulatory and hypocholesterolemic properties when fed as dietary additive for farm animals. This article reviews and discusses the results of studies on the effects of dietary chitosan and its oligosaccharide derivatives on performance and metabolic response in poultry and pigs, that is, haematological, biochemical and immunological blood characteristics, microbiological profile of intestines, intestinal morphology and digestibility of nutrients, as well as on the quality of meat and eggs. The results of most of the experiments presented in this review indicate that chitosan used as a feed additive for poultry and pigs has some beneficial, biological effects, including immunomodulatory, anti‐oxidative, antimicrobial and hypocholesterolemic properties. These properties of chitosan, unlike many other kinds of feed additives, were often reflected in improved growth performance (body weight gain and/or feed conversion ratio) of young animals, that is, broiler chickens and weaned pigs.     

Effects of dietary chitosan on fat deposition and lipase activity in digesta in broiler chickens

1. The effect of dietary chitosan on fat deposition and lipase activity in the small intestinal contents was investigated in broiler chickens fed an adequate or high metabolisable energy (ME) diet. 2. Male broiler chickens at 14 d old were fed on the adequate or high ME diet supplemented with 0 or 50 g/kg chitosan, which has a low viscosity, for 3 weeks. 3. Dietary chitosan did not affect food intake, body weight gain or food efficiency in either dietary ME groups. 4. Dietary chitosan reduced the excessive abdominal fat deposition induced by the high ME diet. 5. Dietary chitosan increased the weight of intestinal contents irrespective of dietary ME concentration. 6. Dietary chitosan decreased the lipase activity per g of small intestinal contents. 7. These results suggest that dietary chitosan with low viscosity decreases lipase activity and fat absorption in the small intestine, consequently resulting in a reduction of fat deposition in broiler chickens. 8. It was concluded that dietary chitosan with low viscosity can decrease body fat deposition without reducing food intake and body weight gain in broiler chickens.     

甲壳素生产废水提取虾青素及水解蛋白的工艺研究

以小龙虾壳为原料,按酸碱交替法生产的甲壳素,蛋白质和虾青素等物质流失于废水中,采用壳聚糖作絮凝剂,可将虾青素与蛋白质絮凝沉淀。试验结果表明:调节pH值6.0,每升废水中添加40 ml 1%壳聚糖醋酸水溶液,静置3 h,废水中溶液的透光率最低,絮凝物蛋白质回收率达88.6%。使用几种蛋白酶水解絮凝物,其中风味蛋白酶水解度最大,在初始pH值6.5,水解温度55℃,试验确定:选用风味蛋白酶1.5 g/kg絮凝物,固液比1:2时,保温酶解时间4 h,虾青素提取率可达4.49%。该条件下絮凝物蛋白质的水解度为23.8%。提取虾青素并将水解后的蛋白浓缩,喷雾干燥,制成水解动物蛋白,产品不苦,具有良好的风味。