低聚壳聚糖对生长育肥猪抗氧化性能、脂类代谢和肌肉品质的影响

研究低聚壳聚糖对生长育肥猪抗氧化性能、脂类代谢和肌肉品质的影响。结果表明:与对照组相比,低聚壳聚糖组可显著提高血清总抗氧化能力,其中40mg/kg低聚壳聚糖组达到极显著水平(P<0.01);对血清过氧化氢酶活性、丙二醛浓度和谷胱甘肽过氧化物酶活性无显著影响(P>0.05);可降低血清中总胆固醇、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇的含量,但差异均不显著(P>0.05);20mg/kg低聚壳聚糖能显著提高宰后眼肌L*45min(P<0.05),显著降低眼肌a*45min和a*24h(P<0.05),40mg/kg低聚壳聚糖也能显著降低眼肌a*24h(P<0.05),但两者对眼肌熟肉率、蒸煮损失、失水率、滴水损失和pH值无显著影响(P>0.05)。低聚壳聚糖以40mg/kg添加量较好。     

不同类型植物甾醇对蛋鸡脂类代谢的影响

旨在研究不同类型植物甾醇对蛋鸡脂类代谢的影响。选用72只30周龄伊莎褐蛋鸡,随机分为3组,每组8个重复,每重复3只。试验分组如下:(1)对照组,饲喂基础日粮;(2)天然植物甾醇组(NP),饲喂基础日粮+22.2 mg/kg天然植物甾醇(纯度为90%,植物甾醇净含量为20 mg/kg);(3)水溶性植物甾醇组(WP),饲喂基础日粮+50 mg/kg水溶性植物甾醇(纯度为40%,植物甾醇净含量为20 mg/kg)。试验为期8周。结果表明,添加2种植物甾醇使第4周血清三酰甘油(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)含量较对照组均有降低的趋势(P<0.1);WP组第4周脂蛋白脂酶(LPL)、肝脂酶(HL)和总酯酶(TL)活性较对照组有提高趋势,NP组血清HL活性也有提高的趋势(P<0.1),但在第8周各组均无显著差异;WP组第8周的蛋黄胆固醇含量显著低于NP组(P<0.05),而NP组与对照组差异不显著。本试验结果提示2种植物甾醇均有降低血脂和提高脂蛋白代谢酶活性的趋势,且此趋势随着时间的延长而逐渐消失,但对蛋黄胆固醇沉积无显著影响,只有WP在饲喂一段时间后有一定降低作用。     

低聚木糖对鸡蛋中常规成分及胆固醇含量的影响

将 72 0只蛋鸡随机分为 4组 ,每组 4个重复 ,分别在各组日粮中添加 0 .0 0 0 %、0 .0 15 %、0 .0 2 0 %低聚木糖组以及 0 .1%低聚果糖。研究结果表明 :0 .0 15 %和 0 .0 2 0 %的低聚木糖对鸡蛋中水分、粗蛋白质、粗灰分以及钙、磷均无显著影响 ,但具有降低鸡蛋中粗脂肪含量的趋势 ;低聚木糖显著降低了鸡蛋中胆固醇的含量 (P <0 .0 5 )。     

酵母培养物对蛋鸡生产性能及鸡蛋品质的影响

试验采用2 000只21周龄海兰褐蛋鸡,研究添加酵母培养物对蛋鸡生产性能和鸡蛋品质的影响,试验期6个月.结果表明:日粮中添加酵母培养物对蛋鸡平均蛋重和平均只耗料有增加的趋势,平均产蛋率试验组比对照组相比提高了3.88%(P＜0.05);料蛋比试验组与对照组相比降低了2.48%(P＜0.05).同时,改善了鸡蛋的品质,鸡蛋中蛋白质和有益维生素(VA、VE、VB2等)与对照组相比分别提高了0.66%和10.27%.脂肪的含量较对照组降低了0.54%(P＞0.05),胆固醇的含量较对照组降低了26.10%(P＜0.05).试验期每只鸡试验组比对照组多赢利1.20元.     

壳聚糖涂膜对鸡蛋品质的影响

通过对新鲜鸡蛋涂擦不同质量浓度的壳聚糖溶液,旨在研究壳聚糖对鸡蛋品质的影响。试验将300 枚新鲜鸡蛋随机分成6 组,分别涂上0、0.5、1.0、1.5、2.0g/100mL 和2.5g/100mL 壳聚糖溶液,25℃条件下贮存5周。每周从每个处理中取10 枚鸡蛋测定鸡蛋失重率、哈夫单位、蛋黄指数和蛋清pH 值。结果表明,第5 周与第1 周相比,不涂壳聚糖的鸡蛋失重率和蛋清pH 值显著升高(P ＜ 0.05)、哈夫单位和蛋黄指数显著低(P ＜ 0.05) 。5 周时,与不涂壳聚糖的鸡蛋相比,所有涂壳聚糖的鸡蛋失重率显著降低(P ＜ 0.05),蛋黄指数显著升高(P ＜ 0.05);涂1.0、1.5、2.0g/100mL 和2.5g/100mL 壳聚糖的鸡蛋哈夫单位显著升高(P ＜ 0.05),蛋清pH 值显著降低(P ＜ 0.05);涂1.5、2.0g/100mL 和2.5g/100mL 壳聚糖的鸡蛋间比较,蛋质量损失率、哈夫单位、蛋黄指数和蛋清pH 值差异均不显著(P ＞ 0.05)。用0.5g/100mL 壳聚糖涂擦的鸡蛋5 周时降到C 级,相当于不涂壳聚糖的鸡蛋3 周时的级别;用1.0、1.5、2.0g/100mL 和2.5g/100mL 壳聚糖处理的鸡蛋5 周时降到B 级,相当于不用壳聚糖处理的鸡蛋2 周时的级别。该实验证明壳聚糖能够延长鸡蛋货架期。     

壳聚糖涂膜鸡蛋保鲜效果研究

利用不同的壳聚糖分别对鸡蛋进行涂膜处理,室温下储藏20d并观察壳聚糖的保鲜效果.通过鸡蛋感官评价、内部理化指标作为衡量鸡蛋鲜度变化的各种指标,研究其对鸡蛋保鲜效果的影响.结果表明:在室温条件下,n2系列壳聚糖涂膜的鸡蛋贮藏20d后,能够基本保持原有新鲜度和品质.     

复合酶对蛋鸡生产性能鸡蛋品质血液生化指标的影响

研究复合酶制剂对蛋鸡产蛋后期生产性能、鸡蛋品质及血液生化指标的影响。结果表明:添加复合酶制剂对产蛋率和料蛋比有一定的改善作用,但对蛋重和鸡蛋品质无显著影响;复合酶制剂3组总蛋白、球蛋白、血磷含量均显著增加(P0.05),各试验组白蛋白和甘油三酯含量均有不同程度的提高,而尿素含量均有不同程度的降低。     

低聚壳聚糖的制备及应用

本文介绍了低聚壳聚糖的制备方法，包括化学降解法、物理场降解法、合成法、酶解法等。并对低聚壳聚糖的功能及其在食品、医药、化妆品、农业等领域的应用作了综述。     

低聚壳聚糖对肉鸡肌肉发育的影响

480羽1日龄AA肉鸡,随机分为4组,每组120羽,设6个重复,对照组饲喂玉米-豆粕型基础日粮,抗生素组基础日粮添加50 mg/kg金霉素,试验Ⅰ、Ⅱ组分别添加20 mg/kg和40 mg/kg低聚壳聚糖,试验期42 天。分别于试验第21天和42天每组随机选取18羽肉鸡,每个重复3羽,禁食不禁水过夜,颈动、静脉放血致死,解剖取胸肌、腿肌,测定胸肌、腿肌重量及器官指数,显微测定胸肌纤维直径,切取胸肌适量,制作常规石蜡切片,HE染色,显微观察与摄影。结果显示,与对照组相比较,21日龄时,试验组Ⅰ、Ⅱ组胸肌和腿肌重量及器官指数、胸肌纤维直径均差异不显著（P > 0.05）;42日龄时,试验组胸肌和腿肌重量显著升高（P < 0.05）,腿肌器官指数极显著升高（P < 0.01）;21日龄和42日龄试验Ⅰ、Ⅱ组胸肌纤维直径增大、肌纤维间结缔组织减少、横断面肌原纤维排列紧密、结构清晰。试验结果表明,低聚壳聚糖能明显促进肉鸡饲养后期肌肉的生长发育,显著提高胸肌和腿肌重量,改善肌肉品质。     

壳聚糖涂膜鸡蛋贮藏中品质变化的动力学模型

为研究壳聚糖涂膜鸡蛋在贮藏过程中品质变化与贮藏时间的相关性,本文利用统计软件对5、10、15、20、35 ℃下贮藏的壳聚糖涂膜鸡蛋的气室直径、重量、蛋黄系数和哈夫单位随贮藏时间变化的数据进行拟合,建立动力学模型。结果表明,壳聚糖涂膜鸡蛋的气室直径可以建立零级动力学模型,重量、蛋黄系数和哈夫单位可以建立一级动力学模型。且根据建立的模型,计算得到预测值与实测值拟合曲线的决定系数R²分别为:0.9797(气室直径)、0.9601(重量)、0.9786(蛋黄系数)和0.991(哈夫单位),并且其平均相对误差w分别为1.95%、0.53%、7.66%和2.84%,均小于10%。说明本文建立的模型可分别预测壳聚糖涂膜鸡蛋的气室直径、重量、蛋黄系数和哈夫单位在5~35 ℃范围内的变化情况和壳聚糖涂膜鸡蛋的贮藏期,为壳聚糖涂膜鸡蛋的贮藏和销售提供参考。     

Effects of Lactobacillus cultures on performance of laying hens,and total cholesterol,lipid and fatty acid composition of egg yolk

BACKGROUND: The use of antibiotic growth promoters in animal feeds is not approved for laying hens in many countries, and economically feasible biological measures which include probiotics are developed to improve hen performance. The present study investigated the effects of probiotics on hen performance for a 48‐week period and the cholesterol, total lipid and fatty acid composition of egg yolk at 24, 28 and 32 weeks of age. RESULTS: Egg weight of Lactobacillus culture (LC)‐fed hens was significantly (P < 0.05) greater than that of control hens throughout the laying period. From 20 to 44 weeks of age, LC‐fed hens produced a significantly (P < 0.05) lower percentage of small eggs and a higher percentage of large eggs, and from 45 to 68 weeks of age a significantly (P < 0.05) lower percentage of medium eggs and a higher percentage of large and extra‐large eggs than control hens. Significantly (P < 0.05) less cholesterol was found in egg yolks of hens fed LC at 24 and 28 weeks of age, but not at 32 weeks of age. The total lipid content and the fatty acid composition of egg yolks were similar between the treatments at 24, 28 and 32 weeks of age, except for stearic acid (C_{18 : 0}), which was significantly reduced in the egg yolk of LC‐fed hens at 28–32 weeks of age. CONCLUSION: The greatest benefit of LC was in increasing egg weight and improving egg size by influencing a shift from small and medium to large and extra‐large eggs. Copyright © 2008 Society of Chemical Industry     

Rapeseed meal in rations for laying hens: A review of the effect on egg quality

The current role of rapeseed meal (RSM) as a source of protein for laying hens is discussed. The advantages of the use of meal from low glucosinolate rapeseed cultivars are emphasised. The effect of the inclusion of RSM in layer rations on egg quality is discussed with special reference to the problem of the fishy egg taint which occurs in the eggs of certain breeds of laying hen. The current understanding of the problem is outlined and potential solutions are offered, based upon plant and avian genetic manipulation or chemical treatment of the rapeseed meal.     

Influence of dietary rapeseed meals and selenium on egg production and egg tainting in laying hens

In 3 experiments 152 hens of differing strains were fed diets containing 0, 50 or 100 g Span, Canadian or European rapeseed meal per kg. Two strains, Shaver 288 and Babcock B300, laid white-shelled eggs while three other strains, Shaver 585, Warren 14 and Thomber 404 laid brown-shelled eggs. Egg production performance was not significantly affected by the inclusion of rapeseed meal in the diet. However the strains laying brown-shelled eggs laid a high proportion of tainted eggs when rapeseed meal was included in the diet. All rapeseed meals led to a similar degree of tainting. Supplementing the diets with 1 or 2 mg selenium per kg did not significantly affect the incidence of tainting. Shell thickness, albumen height and Haugh unit were unaffected by the presence of rapeseed meal in the diet, and yolk colour was improved by the inclusion of Canadian and European rapeseed meals. On the basis of these and other findings it is recommended that rapeseed meal be omitted from diets at least for hens that lay brown-shelled eggs until the taint problem has been solved.     

Influence of chitosan feeding of laying hens on egg vitamin and cholesterol content

Chitosan feeding (10 and 20 mg per 1 kg body mass) of 19 week-age laying hens during 1.5 months caused a decrease in whole egg content of vitamin A for 13% and 20% (p < or = 0.05), vitamin E--for 30%, lutein--17% and didn't effect on vitamin B2 level. Chitosan intake lead to cholesterol content 1.5-2 fold decrease and didn't influence on egg yolk lipids concentration. Low dose chitosan-receiving hens had eggs with 1.8-fold increased egg yolk phospholipids level. The most optimal dose of chitosan for the improvement of eggs nutritive value was 10 mg. Under minimal loss in vitamins its administration lead to the pronounced cholesterol decrease and marked phospholipids elevation.     

The effects of sources of supplemental fat on performance,egg quality,and fatty acid composition of egg yolk in laying hens

BACKGROUND: The objective of this study was to determine the effects of sources of supplemental fat on laying performance, egg quality, and fatty acid composition of egg yolk. RESULTS: Two hundreds Isa Brown layers were assigned randomly to be fed ad libitum a standard commercial layer feed (BD), basal diet plus 2% tallow (T), basal diet plus a mixture of 1% tallow and 1% flaxseed oil (MTFO), basal diet plus 2% sunflower oil (SO), or basal diet plus 2% flaxseed oil (FO), which were offered for 8 weeks. Each diet was given to five groups, each containing 10 hens. The feed efficiency and egg production were 2.78 and 53.51% for BD; 2.30 and 63.47% for T; 2.45 and 60.14% for MTFO; 2.29 and 64.30% for SO, and 2.62 and 61.18% for FO groups, respectively. Dietary fat supplementation affected the laying performance but had no significant effects on egg quality parameters. The fatty acid composition of egg yolk lipids were significantly affected by dietary fatty acid composition. The supplemental tallow increased palmitic fatty acid. The proportions of linoleic and arachidonic fatty acids in egg yolks for layers fed the SO diet were higher than in the BD group and those on diets containing other fats. Concentrations of oleic and omega‐3 fatty acids were the highest in layers fed the FO diet during the laying period. CONCLUSION: The results indicated that dietary animal and plant fats changed the fatty acid composition of egg yolk. Copyright © 2008 Society of Chemical Industry     

Ovarian autoimmunity in relation to egg production in laying hens

The aim of this study was to determine whether anti-ovarian autoantibodies appear in the circulation of laying hens and whether the concentrations of these antibodies change with respect to ageing and egg laying rate. Autoantibodies to ovarian tissues in the circulation of aged (aged approximately 670 days) White Leghorn hens with low (< 50%) and high (> 90%) egg laying rates were examined by ELISA and western blotting. Young laying hens (aged 185 days) with > 95% egg production were used as controls. The results of the ELISA indicated that IgG, which bound to the ovary and small white follicles, was present in the circulation of old laying hens. More hens that laid few eggs had circulatory autoantibodies to the ovary and small white follicles, as determined by the cut-off value in ELISA (mean absorbance + 2 SD of young laying hens), than did hens that laid greater numbers of eggs, and the concentration of IgG was significantly higher in the hens that laid few eggs. In contrast, when the muscle proteins were used as antigens there were no significant differences in the absorbance values among low and high laying frequency old hens or young hens. Western blotting revealed many bands of immunoprecipitates formed by ovarian antigens and antibodies in the serum of old hens, indicating the presence of many binding sites for circulatory IgG in ovarian tissues. These results indicate that antibodies to ovarian tissues appear in the circulation of laying hens during ageing, and that the concentration of these autoantibodies is related inversely to the rate of egg laying by hens.