低聚壳聚糖对断奶仔猪血清生化指标、抗氧化性能和粪便微生物的影响

研究在断奶仔猪饲粮中添加不同水平的低聚壳聚糖对其血清生化指标、抗氧化性能及粪便菌群的影响.结果显示:与未添加低聚壳聚糖组相比,低聚壳聚糖组断奶仔猪血清总蛋白、白蛋白、球蛋白、总胆固醇和低密度脂蛋白胆回醇差异不显著(P＞0.05);100mg/kg低聚壳聚糖组的谷草转氨酶活性极显著提高(P＜0.01),碱性磷酸酶活性极显著降低(P＜0.01);50、100mg/kg低聚壳聚糖组过氧化氢酶活性提高显著(P＜0.05);低聚壳聚糖对血清中的三碘甲状腺原氨酸、甲状腺素均有提高趋势,其中添加25 mg/kg可显著提高血清中生长激素含量(P＜0.05);低聚壳聚糖组断奶仔猪粪便中大肠杆菌、乳酸杆菌数量均呈下降趋势,其中添加50 mg/kg低聚壳聚糖可显著降低大肠杆菌的数量(P＜0.05).低聚壳聚糖适宜的添加水平为50 mg/kg.     

低聚壳聚糖对蛋鸡脂类代谢及鸡蛋品质的影响

试验旨在研究低聚壳聚糖对蛋鸡脂类代谢及鸡蛋品质的影响。结果表明,低聚壳聚糖使第4周蛋鸡血清甘油三酯、低密度脂蛋白胆固醇和极低密度脂蛋白胆固醇含量分别降低了40.90%(P<0.05)、49.02%(P<0.01)和34.76%(P<0.05),脂蛋白脂肪酶、肝脂酶和总酯酶活性分别提高了10.38%(P>0.05)、42.89%(P<0.05)和30.24%(P>0.05);第8周脂蛋白代谢酶活性也有所提高。低聚壳聚糖对蛋鸡腹脂率、鸡蛋脂肪含量和鸡蛋品质无影响(P>0.05)。     

植物甾醇对肉鸡血清胆固醇、蛋白质水平和抗氧化酶活性的影响

目的:研究植物甾醇对肉仔鸡生产性能、血液胆固醇、蛋白质水平和抗氧化酶活性的影响。方法:试验设6组,日粮中分别添加0、5、10、20、40和80mg/kg的植物甾醇,测定肉仔鸡生产性能及血液生化指标。结果:与对照组相比:植物甾醇可提高肉仔鸡的生产性能;20mg/kg植物甾醇添加组能显著降低肉仔鸡血清总胆固醇(TC)水平(P<0.05),极显著降低血清低密度脂蛋白胆固醇(LDL-C)水平(P<0.01),10、40和80mg/kg组均能显著降低LDL-C水平(P<0.05);40mg/kg组能显著提高血清白蛋白水平(P<0.05);80mg/kg组能显著提高肉鸡前期和后期血清总超氧化物歧化酶(T-SOD)活性(P<0.05)。结论:40mg/kg为植物甾醇在肉仔鸡日粮中的适宜添加水平。     

凹凸棒石黏土对生长育肥猪生产性能、金属含量及肉品质的影响

研究凹土原土及热改性凹土对生长育肥猪生产性能、金属含量和肉品质的影响。选用体重约47kg健康"杜×长×大"三元杂交的生长育肥猪60头,随机分为3组,每组4个重复。对照组饲喂基础日粮,试验组饲喂在基础日粮中添加2%凹土原土、2%热改性凹土的试验日粮。结果表明:1)凹土原土和热改性凹土对生长育肥猪生产性能无显著影响(P0.05);2)凹土原土和热改性凹土降低血液中As、Pb、Cr含量和腿肌中Cr的含量(P0.05),热改性凹土显著提高血液中Mg含量(P0.05);3)凹土原土降低眼肌MDA(P0.05),凹土原土和热改性凹土降低眼肌中T-AOC的活性(P0.05);4)凹土原土提高眼肌p H45 min、a*45 min(P0.05),降低L*45 min、b*24 h和压力损失(P0.05)。添加凹土原土和热改性凹土能降低重金属在动物机体中的沉积、提高抗氧化能力进而改善肉品质,热改性凹土效果优于原土。     

壳聚糖对肉仔鸡生长性能及血清生化指标的影响

探讨在基础日粮中添加不同水平的壳聚糖替代抗生素对内仔鸡生长性能及脂类代谢的影响.结果表明:100 mg/kg壳聚糖组肉仔鸡平均日增重提高显著,料肉比降低显著;在血清生化指标方面,100 mg/kg壳聚糖组相比对照组降低了血清中总胆固醇(TC)、总甘油三酯(TG)含量(P<0.05),提高了总蛋白(TP)、类胰岛素生长因子(IGF-1)和生长激素(GH)含量(P<0.05),而对葡萄糖和尿酸含量无影响(P>0.05).壳聚糖的适宜添加水平为100 mg/kg.     

人参不定根皂苷对小鼠脂质代谢的影响研究

目的 研究人参不定根皂苷对小鼠脂质代谢的影响。方法 将小鼠随机分成5个实验组(共50只, 每组10只), 分别为正常组(生理盐水)、对照组(生理盐水)、人参不定根皂苷低(50 mg/kg)、中(100 mg/kg)、高(200 mg/kg)剂量组, 连续灌胃30 d, 测定小鼠血脂、肝损伤和抗氧化指标。结果 与高脂对照模型组相比, 人参不定根皂苷高剂量组甘油三酯、总胆固醇显著降低(P<0.05)、低密度脂蛋白胆固醇极显著降低(P<0.01); 中、高剂量组谷草转氨酶和谷丙转氨酶含量极显著降低(P<0.01); 中、高剂量组总超氧化物歧化酶活性极显著升高(P<0.01)、丙二醛含量极显著降低(P<0.01)。结论 人参不定根皂苷能够促进高脂饲料诱导高脂血症小鼠机体代谢, 降低血脂, 修复肝损伤, 降低过氧化损伤, 增强抗氧化能力。     

低聚壳聚糖对鸡白痢沙门氏菌的体外和体内抑菌效果研究

研究旨在评价低聚壳聚糖对沙门氏菌的体外和体内抑菌效果的影响。结果表明:低聚壳聚糖的体外抑菌效果随其添加水平的提高和取样时间的延长而增强。低聚壳聚糖组肉鸡平均日增重相比感染对照组提高了13.52%(P<0.05),比抗生素组降低7.34%(P>0.05)。低聚壳聚糖组在4、7、14和21日龄时肉鸡盲肠沙门氏菌数显著低于感染对照组(P<0.05),在21日龄时也极显著低于抗生素组(P<0.01)。     

姜黄素对皖江黄鸡脂肪代谢的影响

选择健康的1日龄皖江黄鸡(公鸡)216只,随机分成4个处理组,每组设3个重复,分别在基础日粮中添加0、150、250、350 mg/k的姜黄素,研究其对皖江黄鸡脂肪代谢的影响.结果表明,添加250、350 mg/kg姜黄素显著地降低了皖江黄鸡腹脂率(P<0.05)、肝脂率(P<0.05),添加350 mg/kg姜黄素显著地降低了皖江黄鸡皮下脂肪厚度和肌间脂肪宽度(P<0.05).添加250、350 mg/kg姜黄素显著地降低了血清中胆固醇含量(P<0.05)、甘油三酯浓度(P<0.05),提高了血清中高密度脂蛋白胆固醇水平和游离脂肪酸浓度(P<0.05),使腹脂中激素敏感脂酶活性增强(P<0.05),苹果酸脱氢酶活性降低(P<0.05);添加350 mg/kg姜黄素显著地降低了血清中低密度脂蛋白胆固醇水平(P<0.05).上述结果提示姜黄素通过调节血脂代谢和改变皖江黄鸡体内脂肪代谢相关酶的活性,以降低皖江黄鸡脂肪沉积.     

胍基乙酸对育肥猪肉品质和抗氧化能力的影响

本试验旨在研究日粮添加不同浓度胍基乙酸（GAA）对育肥猪生长性能、肉品质和抗氧化能力的影响。140头健康的体重相近的育肥猪,随机分为4个处理,分别饲喂在基础日粮中添加0（对照组）、300、500和700 mg/kg的GAA,饲养期为35天。饲养过程中记录体重和采食量,屠宰时采集背最长肌和血浆样品用于肉品质和抗氧化指标分析。日粮添加GAA对育肥猪日采食量、日增重均有提高的趋势,对料重比也有降低的趋势（P>0.05）,显著降低平均背膘厚（P<0.05）;添加GAA可以显著提高育肥猪背最长肌宰后45 min的pH值,降低滴水损失、蒸煮损失和剪切力值（P<0.05）,对肉色影响不显著（P>0.05）;添加GAA显著提高血浆中谷胱甘肽过氧化物酶活性和总抗氧化能力,降低丙二醛含量（P<0.05）;添加GAA显著提高背最长肌中超氧化物歧化酶活性和总抗氧化能力,降低丙二醛和羰基含量（P<0.05）。育肥猪日粮中添加GAA可以改善背最长肌肉品质,增强机体的抗氧化能力。     

1-脱氧野尻霉素对高脂饮食肥胖小鼠脂代谢的改善作用

探讨1-脱氧野尻霉素(DNJ)对高脂饮食肥胖小鼠脂代谢的影响及作用机理,为DNJ降脂机理研究提供理论依据。通过喂饲高脂饲料建立小鼠肥胖模型,在持续饲喂高脂饲料的同时灌胃不同剂量的DNJ,40 d后测定实验小鼠一般生理指标,血清及肝脏的相关指标。结果表明,与高脂对照组相比,灌胃8.0 mg/kg bw/d DNJ可显著降低高脂饮食肥胖小鼠的体重、腹腔脂肪系数及肝脂肪含量(P<0.05);显著降低血清中总胆固醇(TC)、甘油三脂(TG)、低密度脂蛋白胆固醇(LDL-C)、游离脂肪酸(FFA)、内脂素水平,显著增加高密度脂蛋白胆固醇(HDL-C)、脂联素(ADP)含量(P<0.05);8.0 mg/kg bw/d DNJ可显著降低肝脏组织中促进脂肪合成的相关酶脂肪合成酶(FAS)、乙酰辅酶A羧化酶(ACC),显著增加分解相关酶酰基辅酶A氧化酶(ACO)、肉毒碱脂酰转移酶Ⅰ(CPT-1)的酶活(P<0.05)。结论:DNJ可能通过控制脂肪因子分泌及脂代谢相关酶活性来抑制脂肪合成,促进脂肪分解,达到调控高脂饮食肥胖小鼠脂代谢的目的。     

摄入有机硒与亚麻籽油对猪肉及其肉制品品质的影响

研究日粮添加有机硒和亚麻籽油对猪背长肌中硒含量、脂肪酸组成、肌原纤维蛋白特性及加工肉制品的影响。选取192头"杜×长×大"三元杂交猪,随机分为4组,设为C组(0.3 mg/kg亚硒酸钠+1.5%大豆油),S1组(0.3 mg/kg酵母硒+1.5%大豆油),S2组(0.5 mg/kg酵母+1.5%大豆油)及SL组(0.3 mg/kg酵母硒+1.5%亚麻籽油)。研究发现有机硒能显著提高猪背长肌中的硒贮存量(P0.05);亚麻籽油能改善肉品的n-6/n-3比例;亚麻籽油相比大豆油能显著提高肌原纤维蛋白的溶解性和凝胶强度(P0.05);0.5mg/kg有机硒在7~12d的储藏期内能减少香肠的脂质氧化(P0.05),但是香肠的微观结构和感官评价不受有机硒和亚麻籽油的影响。因此在日粮中添加亚麻籽油和有机硒有益于富硒富n-3PUFA猪肉的生产和加工。     

亚麻籽和茶多酚对肉鸭生长性能、屠宰性能、血液抗氧化能力和肌肉不饱和脂肪酸含量的影响

研究以亚麻籽为n-3 PUFA来源的肉鸭饲粮中添加茶多酚(TP),对其生长性能、屠宰性能、抗氧化能力和肌肉不饱和脂肪酸含量的影响。选用240只1日龄樱桃谷肉鸭,随机分为4组,其中对照组饲喂基础饲粮,实验组一、二、三分别饲喂含3%亚麻籽、3%亚麻籽+100 mg/kg TP、3%亚麻籽+200 mg/kg TP的实验饲粮。实验期为40d。结果表明:实验组一的平均日采食量(ADFI)和料重比(F/G)显著高于对照组(P 0.05);实验组二、三的ADFI和F/G与对照组差异不显著(P 0. 05)。屠宰率、半净膛率和全净膛率各组间均差异不显著(P 0. 05)。实验组三血浆的总抗氧化能力(T-AOC)、总超氧化物歧化酶(T-SOD)活力显著高于对照组(P 0. 01),丙二醛(MDA)含量显著低于对照组(P 0. 01)。各实验组腿肌中n-3 PUFA的含量均显著高于对照组(P 0. 05)。因此,饲粮中添加3%亚麻籽会显著增加樱桃谷肉鸭的料重比,以及肌肉中n-3PUFA的含量,但对屠宰性能无显著影响。在肉鸭饲粮中添加3%亚麻籽用于生产富含n-3 PUFA肉产品时加入200 mg/kg TP对肉鸭生长性能及机体抗氧化效果最佳。     

鼠李糖脂对肉鸡腿肌肉品质、常规化学成分和抗氧化功能的影响

本试验旨在研究日粮中添加鼠李糖脂（Rhamnolipid）对肉鸡腿肌肉品质、常规化学成分和抗氧化功能的影响。选取1日龄爱拔益加（AA）公肉仔鸡600只,随机分为5组,每组8个重复,每个重复15只,空白对照组饲喂基础饲粮,抗生素组饲喂基础饲粮中添加75 mg/kg金霉素,试验组饲喂基础饲粮中分别添加250、500、1000 mg/kg鼠李糖脂的试验饲粮,试验为期42 d。与空白对照组相比,日粮中添加250、500、1 000 mg/kg鼠李糖脂和抗生素提高了肉鸡腿肌重和腿肌GPx活性,增加了腿肌24 h的pH值,降低了腿肌24 h和48 h滴水损失和蒸煮损失,减少了腿肌MDA含量,上调了腿肌SOD1和GPx的基因表达水平（P＜0.05）;此外,日粮中添加250、500、1 000 mg/kg鼠李糖脂降低了肉鸡腿肌24 h亮度值（P＜0.05）;日粮中添加500、1 000 mg/kg鼠李糖脂提高了肉鸡腿肌45 min的pH值和粗脂肪含量,增加了腿肌T-SOD活性,上调了腿肌Nrf2和HO-1的基因表达水平（P＜0.05）;日粮中添加1 000 mg/kg鼠李糖脂上调了肉鸡腿肌SOD2的基因表达水平（P＜0.05）。鼠李糖脂组和抗生素组肉鸡腿肌重和腿肌肉品质、常规化学成分、抗氧化酶活性和抗氧化相关基因表达水平均无显著差异（P＞0.05）。综上所述,鼠李糖脂可作为抗生素替代品添加于肉鸡饲料中,提高肉鸡腿肌重,改善腿肌肉品质,增加腿肌粗脂肪含量,提高腿肌Nrf2信号通路相关抗氧化基因表达水平,提高腿肌抗氧化能力。     

胍基乙酸对建鲤生产性能、体成分及肌肉能量代谢关键酶的影响

研究胍基乙酸(guanidinoacetic acid,GAA)对建鲤生产性能、体成分及肌肉能量代谢的影响。选取600尾平均体重为(23.23±0.14)g的建鲤随机分为4组,每组5个重复,每个重复30尾,分别投喂基础饲料(对照组)和在基础饲料中添加250、500和1 000 mg/kg GAA的试验饲料,试验为期42 d。结果表明:与对照组相比,添加250、500 mg/kg GAA可显著降低饵料系数(P0.05),但对体重、特定生长率、增重率、平均日采食量和成活率均无显著影响(P0.05)。添加GAA可显著提高脏体指数(P0.05),对肝体指数无显著影响(P0.05)。GAA对肌肉中粗脂肪、粗蛋白和粗灰分含量无显著影响(P0.05)。250 mg/kg GAA组可显著降低肌肉中丙酮酸激酶活性(P0.05);250、500 mg/kg GAA组显著降低琥珀酸脱氢酶活性(P0.05);1 000 mg/kg GAA组显著降低肌酸激酶活性(P0.05);GAA组均显著提高肌糖原含量(P0.05)。结果表明,饲料中添加胍基乙酸可降低肌肉中能量代谢关键酶的活性来改善其能量代谢,提高饲料转化率,以添加250 mg/kg GAA效果较好。     

Effect of supplementation of two sources and two levels of copper on lipid metabolism in Nellore beef cattle

This study was conducted with 35 Nellore beef cattle to determine the effect of supplementation of two levels and two copper sources (organic and inorganic) on metabolism of lipids and cholesterol of meat. The five treatments used were: Control: without copper supplementation, I10 or I40: 10 or 40 mg/kg DM (as Cu sulfate), O10 or O40: 10 or 40 mg/kg DM (as Cu proteinate). In general, the copper supplementation changed the fatty acid profile of meat (p<0.05), with a higher proportion of unsaturated fatty acids and reduction of saturated fatty acids. There was no effect of supplementation on blood cholesterol and triglycerides, however; in general, there was a reduction in cholesterol concentration in the L. dorsi (p<0.05) compared to the control treatment through the reduction (p<0.05) in the concentrations of GSH and GSH/GSSG ratio. The Cu supplementation did have an influence on metabolism of lipids. The production of healthier meat is beneficial to public health by reducing the risk of cardiovascular disease.     

Carcass quality,physico-chemical parameters,muscle fibre traits and myosin heavy chain composition of m. longissimus lumborum from Puławska and Polish Large White pigs

In 54 Puławska pigs and 60 Polish Large White pigs (PLW), slaughtered at 30 and 100 kg body weight, carcass and meat quality of m. longissimus lumborum were studied. Analysis revealed that in both examined body weight groups, hot carcass weight, carcass yield percentage, meat content, and weight of ham and carcass ham percentage were significantly lower and backfat thickness higher for Puławska pigs compared to PLW pigs, while PLW pigs exhibited significantly longer carcasses, greater loin eye area, and, in the case of lighter pigs, smaller proportion of loin in the carcass. Muscles of Puławska pigs, in the lighter group, had higher IMF content and a* value, while in the heavier group they exhibited higher pH₄₅, pH₂₄ and a* values, lower L*, drip loss, WHC, and thermal loss compared with PLW pigs. PLW pigs had higher WB and hardness values and more glycolytic muscles characterised by higher TNF.     

Effect of antioxidants on stabilization of meat products fortified with n-3 fatty acids

The effects of an n-3 oil emulsion, with and without added antioxidants, on lipid oxidation in n-3 polyunsaturated fatty acid (PUFA)-fortified meat products were studied. An emulsion of n-3 PUFAs was prepared (25% algal oil, 2.5% whey protein isolates, 10mM sodium citrate, 0.2% potassium sorbate, 500ppm of 70% mixed tocopherols, 100μM EDTA, pH 3, pasteurized at 75°C for 30min) and incorporated into fresh ground turkey, and fresh pork sausage (20% fat) to achieve a concentration of 500mg n-3 PUFA/110g meat. An antioxidant combination containing rosemary (0.2% w/w; radical quencher), citrate (0.5% w/w; sequestrant) and erythorbate (1g/kg product; reductant) was prepared and incorporated into ground turkey patties (5cm dia, 1.5cm thick) or fresh pork sausages (5cm dia, 1.5cm thick). Meat products were stored at 4°C or -18°C and analyzed for color (L*, a*, b* values), lipid oxidation (TBARS and lipid hydroperoxides) and n-3 PUFA profile. a* Values of refrigerated ground turkey patties decreased with storage, and an antioxidant combination effect was observed after 4 days (P<0.05). For fresh pork sausages at 4°C, control+antioxidant (CON+ANTI), and n-3+antioxidant (n-3+ANTI) groups showed greater a* values than controls (CON) indicating that the antioxidant combination stabilized meat color. TBARS and lipid hydroperoxides of both n-3 PUFA-enhanced meat products increased with storage (P<0.05); there were no significant changes in TBARS or lipid hydroperoxides for treatments containing the antioxidant combination (P<0.05). The actual level of n-3 PUFA incorporation in both meat products was greater than 87%; n-3 PUFA concentrations did not change within any treatment during storage (P>0.05). These results provide support for including antioxidant protection in n-3 PUFA fortified meat products.     

Effects of vitamin E supplementation on performance and meat quality traits of Morkaraman male lambs

This research was carried out to determine the effects of vitamin E supplementation on meat quality traits of approximate 8 months of age Morkaraman male lambs. The lambs were divided into two groups-control (CG, n=7) and experimental (VG, n=6)-at the beginning of fattening period. The diet given to the CG and VG consisted of concentrate and grass hay. In addition, the VG received a supplement of 45 mg vitamin E per lamb in a day during a 75-day fattening period. At the end of the study, average daily weight gain and feed conversion efficiency values as to feed basis were found to be 208 g and 6.3 for CG and 223 g and 6.0 for VG groups, respectively. Vitamin E supplementation resulted in 8.8% improvement in feed conversion efficiency. In the same way, vitamin E supplementation resulted in 6.7% increase in daily weight gain. Slaughter and carcass characteristics of lambs were also determined, but fattening performance, slaughter and carcass characteristics were not significantly different between groups. The effects of vitamin E on meat characteristics, meat colour (L*, a* and b*), thiobarbituric acid reactive substances content (TBARS), drip loss and pH were determined using m. longissimus dorsi (LD) muscles obtained from CG and VG. Though the effect of vitamin E supplementation on most of the meat quality traits was not statistically significant (P>0.05), L* and a* values in LD muscle from VG were preserved for a period of 12 days of maturation. In addition, a* (redness) tended to increase slightly. TBARS values in samples from CG were found to be higher than those of vitamin E treatment group. In this study, it was also concluded that drip loss was relatively preserved by vitamin E supplementation. In conclusion, vitamin E supplementation of Morkaraman male lambs at an inclusion rate over the amount of nutritional recommendations, significantly reduced lipid oxidation, drip loss and tended to maintain meat redness.