大豆低聚糖及其功能组分对体外条件下肉仔鸡盲肠内容物粪臭素产量及菌群组成的影响

本试验旨在研究大豆低聚糖(SBO)及其功能组分对体外条件下肉仔鸡盲肠内容物粪臭素产量及菌群组成的影响。试验采用单因素完全随机设计,以42日龄肉仔鸡盲肠内容物为菌源,将厌氧培养液分装于无菌培养瓶中,分成5个组,每组3个重复。对照组添加250μmol/L的L-色氨酸,蔗糖(SUC)、水苏糖(STA)、棉籽糖(RAF)和SBO组分别在对照组的基础上添加1%的SUC、STA、RAF和SBO。另外,每组均设1个不加L-色氨酸但其他成分都相同的空白对照。利用ANKOM RFS体外产气系统,39℃厌氧培养24 h。采用PCR-变性梯度胶凝电泳(DGGE)技术研究了发酵液菌群组成的差异。结果表明:1)SUC、STA、SBO组24 h发酵液累积产气量极显著高于对照组和RAF组(P0.01);SBO、SUC和STA组吲哚浓度分别比对照组降低了98.15%、97.72%和94.17%(P0.01),粪臭素浓度分别比对照组降低了79.04%、71.88%和70.28%(P0.05);SUC组乳酸浓度极显著高于其他各组(P0.01);对照组p H极显著高于除RAF组之外的其他各组(P0.01)。2)SBO组菌群均匀度显著低于对照组(P0.05);SUC、STA、RAF、SBO组菌群丰富度显著高于对照组(P0.05);SBO、STA、RAF组菌群相似性高于对照组;试验组有3条特异性条带,相似菌分别为延长布劳特氏菌(Blautia producta)、迪氏副拟杆菌(Parabacteroides distasonis)、路氏乳杆菌(Lactobacillus reuteri)。综上,在本试验条件下,添加1%的SUC、STA和SBO显著降低了肉仔鸡体外盲肠内容物培养液中L-色氨酸代谢生成吲哚和粪臭素的浓度,提高了菌群丰富度,并促进了特异性菌的增殖。降低粪臭素效果优劣依次为SBO、SUC、STA。     

Impact of dietary chitosan oligosaccharide and its effects on coccidia challenge in broiler chickens

ABSTRACT

1. Two experiments were conducted, the first to determine the optimum inclusion of chitosan oligosaccharide (COS) in broiler diets to support growth performance, digestive functions, intestinal morphology, and immune organs. The second experiment evaluated the immune-protective properties of COS on broiler chickens during coccidia challenge (CC).

2. Experiment 1 investigated the effect of graded dietary concentration of COS in the diets of broiler chickens using eight cage replicates for each of the six diets. A corn-soybean meal-based diet was used as the basal diet and supplemented with 0.0, 0.5, 1.0, 1.5, 2.0, or 2.5 g of COS/kg feed to form the six treatments.

3. The diet supplemented with 1.0 g COS/kg of feed provided the optimal inclusion level for broiler chickens regarding body weight (BW) gain, jejunal villus height, villus height to crypt depth ratio, and ileal energy digestibility at d 22 of age.

4. Experiment 2 investigated the immune-protective properties of COS in broiler chickens during CC. A total of 224 male broiler chicks were randomly assigned to eight replicate cages in a 2 × 2 factorial arrangement of treatments with two COS concentrations (0 or 1 g of COS/kg of diet), with or without CC.

5. On d 18 of age, birds in the CC group received twice the recommended coccidia vaccine dose of 30 doses/kg BW.

6. Coccidia challenge reduced (P < 0.05) and dietary COS increased (P < 0.05) BW gain, and feed intake. Dietary COS mitigated (P < 0.05) the CC-induced effects on gain:feed. Dietary COS supplementation attenuated the CC-induced effects (P < 0.05) on the expression of occludin genes.

7. In conclusion, dietary COS improved performance, and the immune-related beneficial impact of COS supplementation was associated with reduced expression of pro-inflammatory cytokine genes.     

壳寡糖对断奶仔猪回肠养分消化、小肠形态及隐窝细胞增殖的影响

本研究旨在探讨日粮添加壳寡糖对断奶仔猪生长性能、营养物质消化率和小肠功能的影响,评估其作为断奶仔猪日粮中抗生素替代品的效果。试验选择21 d断奶的三元仔猪280头,随机分为5组,每组4个重复,每个重复14头猪,各组猪只分别饲喂在基础日粮中分别添加0、80、160、240 mg/kg壳寡糖和45 mg/kg盐霉素的日粮,试验分为1~28 d和29~56 d两个阶段,共进行8周。结果显示,日粮添加160 mg/kg壳寡糖显著提高回肠粗蛋白质、粗脂肪、灰分、钙和磷的表观消化率(P <0.05),显著提高小肠绒毛高度及绒毛高度与隐窝深度的比值(P <0.05),同时显著提高56 d十二指肠和空肠隐窝细胞增殖活力(P <0.05)。结论:日粮添加160 mg/kg壳寡糖可以通过提高回肠养分表观消化率、绒毛高度和肠上皮细胞的数量来促进消化吸收能力,进而提高断奶仔猪生长性能和健康状态,其作用与盐霉素的效果相当。     

Involvement of PKA signalling in anti‐inflammatory effects of chitosan oligosaccharides in IPEC‐J2 porcine epithelial cells

Weaning is characterized by intestinal inflammation, which is a big challenge in pig industry. Control of intestinal inflammation is important for improvement of growth performance and health. Therefore, the study was focused on the anti‐inflammatory activity of low‐molecular‐weight chitosan oligosaccharide (LCOS) in a porcine small intestinal epithelial cell line (IPEC‐J2). The results showed that TNF‐α, as inflammation inducer, significantly upregulated the mRNA expression of IL‐8 and MCP‐1. Afterwards, LCOS significantly attenuated mRNA expression of IL‐8 and MCP‐1 induced by TNF‐α in the cells. Mannose (MAN), as ligand of mannose receptor, had no effect on the anti‐inflammatory activity of LCOS, which suggested that mannose receptor may not involve in the anti‐inflammatory activity of LCOS in IPEC‐J2 cells. Interestingly, N‐[2‐(p‐bromocinnamylamino)ethyl]‐5‐isoquinolinesulfonamide 2HCl hydrate (H89), as PKA (protein kinase A)‐specific inhibitor, reversed the mRNA expression of IL‐8 when co‐cultured with LCOS. Furthermore, LCOS concentration dependent downregulated the mRNA expression of claudin‐1 compared with TNF‐α treatment. However, the trans‐epithelial electric resistance (TEER) was not affected by LCOS when co‐cultured with TNF‐α in 3 hr. In conclusion, LCOS have a potent anti‐inflammatory activity, and as a feed additives, may be useful for the inhibition of inflammatory process in weaning period of pigs with intestinal inflammation occurring.     

Effect of adjuvants on in ovo vaccination against Newcastle disease on hatchability,performance and antibody titres in commercial pullets

This study was conducted to investigate the efficacy of in ovo administration of aluminium hydroxide (AH) and/or mannan oligosaccharide (MOS) adjuvants along with lentogenic VG/GA strain‐Avinew to alleviate the embryonic pathogenicity of Newcastle disease virus. Six hundred and thirty fertilized Bovans eggs were divided into nine groups of 70 each incubated in a commercial hatchery and administered with eight types of in ovo injections in a factorial design of 2 × 2 × 2 including with/without AH, MOS and Newcastle disease vaccine (NDV), and one uninjected group on day 18 of incubation. Hatchability was higher in the eggs received MOS and/or AH adjuvants plus NDV compared those injected with NDV alone which confirmed the attenuation of NDV. However, the average daily feed intake and feed conversion ratio of pullets hatched from NDV‐injected eggs were significantly reduced, but did not affect growth performance during 0‐42 days of age. The performance of pullets hatched from eggs injected with AH, MOS or their mixture with NDV was not significantly different during all growth periods. Pullets from MOS + vaccine injected eggs had significantly higher antibody titres against NDV compared to those hatched from either injected with saline or uninjected on d 28 (p < .05). In addition, AH plus vaccine and MOS significantly improved total anti‐SRBC and IgG respectively. Histological observation revealed that injection of MOS adjuvant into eggs led to increase crypt depth, whereas AH injection caused a reduction in villus surface area of jejunum in chicks on d 14 post‐hatch. It is concluded that in ovo MOS injection as compared to AH may be more effective to attenuate the embryonic pathogenicity of in ovo NDV injection.     

基于液滴微流控的壳寡糖植物免疫诱导剂荧光检测

为了建立基于液滴微流控芯片平台的植物免疫诱导剂的荧光信号检测技术,该文设计制作了具有液滴生成结构的芯片,制备包裹烟草(BY-2)细胞的液滴,并对包裹了细胞的液滴数目进行统计分析。将包裹细胞的液滴孵育一氧化氮探针后使用质量浓度为50μg/m L壳寡糖处理,在荧光显微镜下观测其产生的荧光,利用荧光酶标仪对比采用96孔板和液滴承载的细胞的荧光变化趋势。结果显示,水相流速为100μL/h,油相流速为300μL/h时,微流控芯片产生的液滴尺寸适合包裹细胞,其中液滴包裹单细胞的比例达22.9%。经壳寡糖处理后的细胞在生成的液滴中产生了明显的荧光,且用96孔板和液滴承载的细胞的荧光变化趋势一致。研究结果为开发基于液滴微流控技术的植物免疫诱导剂的高通量筛选平台提供参考。     

不同取代度羧甲基壳聚糖的抗氧化性能研究

[目的]为了研究羧甲基壳聚糖的取代位置、取代度及其抗氧化功能之间的关系。[方法]低聚壳聚糖经醚化得到3种取代度不同的N,O-羧甲基壳聚糖-NOA,NOB和NOC,并对其结构和取代度进行了表征,考察了它们对羟自由基的清除作用。[结果]NOA,NOB和NOC清除羟自由基的半抑制浓度分别为0.15,0.29和0.23 mg/ml。而NOA,NOB和NOC在氨基上的取代度分别为0.51,0.29和0.38,羟基取代度分别为0.74,0.84和0.97[结论]随着氨基位置取代度的升高,N,O-羧甲基壳聚糖清除羟基自由基的能力逐渐增强。     

20%寡聚酸碘田间防治黄瓜炭疽病的效果

对20%寡聚酸碘WP防治黄瓜炭疽病(病原Colletotrichum lagenarium)的田间效果进行了测定。结果表明,该药剂对黄瓜炭疽病有较好的防治效果且有较好的增产效果。20%寡聚酸碘1 000倍、1 500倍、2 000倍稀释液对黄瓜炭疽病的防效分别为88.60%、84.38%、78.76%,与不施药对照相比其增产率分别为13.39%、9.11%、8.14%。防效及产量均高于对照药剂20%咪鲜胺可湿性粉剂1 000倍稀释液。     

复合寡糖对肉鸡生产性能和免疫器官指数的影响

试验选用1日龄AA肉用仔鸡640羽,随机分为4组,每组设8个重复,每个重复20羽。第1组为对照组,第2~4组分别在基础日粮中添加250 mg/kg、500 mg/kg、750 mg/kg复合寡糖,研究其对肉鸡生产性能和免疫器官指数的影响。结果表明:复合寡糖对肉鸡前期生产性能有明显促进作用(P<0.01),后期趋于平缓,但对肉鸡的免疫器官指数影响不明显。