Effects of lactulose supplementation on performance,blood profiles,excreta microbial shedding of Lactobacillus and Escherichia coli,relative organ weight and excreta noxious gas contents in broilers

This study was to evaluate the effects of lactulose supplementation on performance, blood profiles, excreta microbial shedding of Lactobacillus and Escherichia coli, relative organ weight and excreta noxious gas contents in broilers. A total of 720 ROSS 308 broilers with a body weight of 46 ± 0.1 g (1 day of age) were used in a 28‐d experiment. Broilers were randomly allotted to 4 experiment diets with 12 replicate pens and 15 birds per pen. Dietary treatments were as follows: NC, negative control (without antibiotic); PC, NC + 0.1% tiamulin; L1, NC + 0.1% lactulose; and L2, NC + 0.2% lactulose. Broilers were fed with phase 1 (1–8 day), phase 2 (9–18 day) and phase 3 (19–28 day) diets in the form of mash. During day 1–8, broilers fed the PC and L2 diets had higher (p < 0.05) body weight gain than those fed the NC diet. During day 19–28, broilers fed the L1 and L2 diets had lower (p < 0.05) feed intake than those fed the NC diet. The feed conversion ratio (FCR) was decreased (p < 0.05) in L1 treatment compared with NC treatment. Overall, the FCR was improved (p < 0.05) in all supplementation treatments compared with NC treatment. The apparently metabolizable nitrogen in L1 treatment was higher (p < 0.05) than that in NC treatment at day 28. The excreta Lactobacillus was increased and E. coli was decreased in PC and L2 treatments compared with NC treatment at day 28 (p < 0.05). The excreta NH₃, H₂S and acetic acid contents were decreased (p < 0.05) in L1 and L2 treatments compared with NC treatment. The relative weight of abdominal fat of broilers fed the PC diet was lowest (p < 0.05) compared with other treatments. In conclusion, this study indicated that dietary supplementation of 0.1% or 0.2% lactulose could improve growth performance, decrease excreta E. coli and excreta NH₃ and H₂S contents.     

乳果糖替代饲用抗生素对AA肉仔鸡生产性能和屠宰性能的影响

[目的]研究乳果糖替代饲用抗生素后对AA肉仔鸡生产性能和胴体品质的影响.[方法]选用180只1日龄AA肉仔鸡,随机分成5组,每组3个重复,每个重复12只.阴性对照组饲喂基础日粮;抗生素组添加0.3 g/kg那西肽和0.25 g/kg硫酸粘杆菌素预混剂;试验组分别添加0.5;、1.0;和1.5;乳果糖.测定生产性能及胴体指标.[结果]各组肉仔鸡活体重分别为2 164.22、2 057.58、2 101.43、2 208.86、2 172.00 g,差异不显著(P＞0.05).料重比分别为2.15、1.90、1.95、1.96、2.02,抗生素组显著低于阴性对照组13.16;(P＜0.05),但其它各组均差异不显著(P＞0.05).乳果糖组肉仔鸡平均日增重、平均日采食量较抗生素组均有所提高,但差异不显著(P＞0.05).添加抗生素、1.0;、1.5;乳果糖肉仔鸡的存活率显著提高.乳果糖在很大程度上改善了肉仔鸡的胴体品质,其中0.5;、1.0;乳果糖组比抗生素组腹脂率分别降低3.48;(P＞0.05)、17.24; (P ＞0.05).[结论]添加不同水平乳果糖替代饲用抗生素后均具有提高肉仔鸡生产性能、改善胴体品质的趋势,综合生产性能和胴体品质来看,1.0;乳果糖的替代效果较佳.     

高效液相色谱-蒸发光散射检测法与酶法检测UHT灭菌乳中乳果糖含量的对比研究

采用液相色谱法分离、蒸发光散射检测器检测,外标法定量测定超高温瞬时灭菌乳中乳果糖的含量。采用盐酸沉淀蛋白,氨基色谱柱分离,流动相为75％乙腈溶液。该方法能使乳果糖得到很好分离,精密度为0.77％(n=6),平均回收率为98.7％～102.6％。高效液相色谱-蒸发光散射检测法较酶法操作简便、省时、重复性好,可以根据实验需求选择使用。     

乳酮糖研究进展

乳酮糖是一种人工合成的双糖,在医学上一直用于治疗肝性脑病和便秘。由于乳酮糖还具有双歧杆菌的高增殖活性等独特功能,目前已作为一种新型的功能性低聚糖应用于食品领域。对乳酮糖的物化性质及生理功能、合成方法、应用研究等方面进行了综述。     

乳果糖对黄瓜枯萎病防效及其诱导抗性的作用

测试乳果糖对黄瓜枯萎病的防治作用,并通过黄瓜相关抗性酶活性的影响,明确乳果糖对黄瓜枯萎病的防治效果及初步作用机制。采用生长速率法测定乳果糖对黄瓜枯萎病菌的抑制率;采用胚根接种法、灌根接种法进行盆栽防效测试;相关抗性酶活性测试采用分光光度法。1 mg/L乳果糖的盆栽防效最好,胚根期浸种和子叶期喷雾处理的防治效果分别为43.87%和41.97%,其次是0.1 mg/L乳果糖的盆栽防效,分别为39.62%和37.21%,而离体抑菌活性测试结果显示乳果糖对黄瓜枯萎病菌无杀菌活性。对黄瓜防御反应酶系过氧化物酶(POD)、过氧化氢酶(CAT)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)活性进行测试,结果表明乳果糖处理后黄瓜内各防御酶系均比对照高,尤其1 mg/L乳果糖胚根浸种和子叶期喷雾处理黄瓜PAL比对照分别提高了97.5%和92.4%。综上,乳果糖对黄瓜的诱导抗性作用是防治黄瓜枯萎病的主要机制,并可作为新型药剂用于农业植物病害防治中,具有较大开发潜力。     

乳果糖替代饲用抗生素对黄羽肉鸡生产性能和屠宰性能的影响

[目的]研究基础日粮中添加乳果糖替代饲用抗生素对黄羽肉鸡生产性能和屠宰性能的影响.[方法]将180只1日龄的黄羽肉鸡随机分为5个处理组(每个处理组3个重复,每个重复12只).阳性对照组在基础日粮中添加饲用抗生素(0.3 g/kg的那西肽+0.25 g/kg的硫酸粘杆菌素预混剂);阴性对照组饲喂基础日粮;试验Ⅰ组、Ⅱ组、Ⅲ组在基础日粮中分别添加5、10、15 g/kg的乳果糖.[结果]81 d时各组平均体重分别为2.72、2.66、2.75、2.41、2.76 kg,差异不显著(P＞0.05).8～81 d料重比分别为2.67、2.66、2.59、2.76、2.65,差异不显著(P＞0.05),日粮中分别添加5、10、15 g/kg的乳果糖替代饲用抗生素,黄羽肉鸡81 d体重、饲料转化率、胴体品质等指标上各组间无显著差异(P＞0.05).[结论]从黄羽肉鸡81 d体重、料重比、死亡率等指标综合来看,用添加5 g/kg乳果糖替代黄羽肉鸡饲用抗生素是可行的.     

高效液相色谱法测定乳粉中异构化乳糖的含量

建立乳粉中异构化乳糖高效液相色谱的测定方法.采用盐酸沉淀蛋白,氨基色谱柱分离,流动相为80％乙腈溶液,示差检测器检测.每100 g乳粉中异构化乳糖添加量为0.3～2.0 g时,回收率97.4％～103.0％.定量检出限为0.3 g/100 g.该方法操作简便,检测准确,可用于乳粉中异构化乳糖的检测.     

乳果糖制备方法的研究进展

乳果糖又名乳酮糖、异构化乳糖,是以乳业副产物乳糖为原料制备的一种还原性二糖,其浓缩液形式是一种重要的非处方药物,对急慢性便秘、肝性脑病等疾病具有显著疗效。乳果糖的生产方法包括化学法、β-半乳糖苷酶法、差向异构酶法等。近年来差向异构酶法因其高转化率受到广泛关注,是极具潜力的新一代乳果糖制备方法,但目前存在副产物依匹乳糖比例高、酶活力偏低等瓶颈问题。本文针对乳果糖制备方法的研究历史与现状进行综述,为该领域的基础理论及产业化研究提供借鉴。     

New biomarkers for increased intestinal permeability induced by dextran sodium sulphate and fasting in chickens

Increased intestinal permeability (IP) can lead to compromised health in chickens. As there is limited literature on in vivo biomarkers to assess increased IP in chickens, the objective of this study was to identify a reliable biomarker of IP using DSS ingestion and fasting models. Male Ross chickens (n = 48) were reared until day 14 on the floor pen in an animal care facility, randomized into the following groups: control, DSS and fasting (each with n = 16), and then placed in metabolism cages. DSS was administered in drinking water at 0.75% from days 16 to 21, while controls and fasted groups received water. All birds had free access to feed and water except the birds in the fasting group that were denied feed for 19.5 h on day 20. On day 21, all chickens were given two separate oral gavages comprising fluorescein isothiocyanate dextran (FITC‐d, 2.2 mg in 1 ml/bird) at time zero and lactulose, mannitol and rhamnose (LMR) sugars (0.25 g L, 0.05 g M and 0.05 g R in 2 ml/bird) at 60 min. Whole blood was collected from the brachial vein in a syringe 90 min post‐LMR sugar gavage. Serum FITC‐d and plasma LMR sugar concentrations were measured by spectrophotometry and high‐performance ion chromatography respectively. Plasma concentrations of intestinal fatty acid binding protein, diamine oxidase, tight junction protein (TJP), d ‐lactate and faecal α‐antitrypsin inhibitor concentration were also analysed by ELISA. FITC‐d increased significantly (p < 0.05) after fasting compared with control. L/M and L/R ratios for fasting and L/M ratio for DSS increased compared with control chickens (p < 0.05). TJP in plasma was significantly increased due to fasting but not DSS treatment, compared with controls. Other tests did not indicate changes in IP (p > 0.05). We concluded that FITC‐d and LMR sugar tests can be used in chickens to assess changes in IP.     

乳制品中异构化乳糖的色谱法检测研究进展

异构化乳糖作为益生元在国际乳制品领域中广泛应用,特别是在婴幼儿配方乳粉中作为重要的组成成分.但是我国仅有GB 8816-1988《食品添加剂异构化乳糖液》,且原料的分析方法相对有些滞后.同时也没有相关的食品中异构化乳糖的检测标准.如何将异构化乳糖从其他碳水化合物中区别开来,尤其是与乳糖区分,是目前我国分析检测的一个难点,也是限制异构化乳糖在我国应用的一个障碍.本文主要介绍了国内外关于乳制品中异构化乳糖的色谱检测方法(薄层色谱法、液相色谱法和气相色谱法),以期能为乳制品中异构化乳糖的检测提供参考依据.