凹凸棒石黏土对肉鸡生产性能、免疫指标和血液及肝脏镁含量的影响

360羽1日龄的AA肉鸡随机分成3组,即分别饲喂基础日粮的对照组及在基础日粮中添加5%凹凸棒石黏土和5%改性凹凸棒石黏土的试验组,研究凹凸棒石黏土对内鸡生产性能、免疫指标和血液及肝脏镁含量的影响.结果表明,与对照组相比,凹土组和改性凹土组肉鸡的平均体重、平均日增重、料肉比均无显著差异,但能降低单位增重成本.凹土组和改性凹土组的脾脏指数和胸腺指数均无显著差异,但42日龄胸腺指数比对照组分别增加26.3%和31.6%.凹土组和改性凹土组21日龄血浆镁含量极显著低于对照组(P＜0.01),肝脏镁含量无显著差异(P＞0.05);凹土组和改性凹土组42日龄血浆和肝脏镁含量均无显著差异(P＞0.05),但凹土组血浆镁含量比对照组增加12.1%,肝脏镁含量比对照组增加14.8%.     

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。     

宰前短期饮水中添加VC对育肥猪肉品质的影响

试验考察宰前48 h饮水中添加VC对育肥猪血液指标、肉品质的影响.结果表明:宰前饮水短期添加VC对育肥猪胴体品质无影响;与对照组相比,添加VC 500和1 000 mg/L组血浆VC含量提高(P＜0.05),肉的亮度L*24h降低(P＜0.05);添加500 mg/L组肉的红度(α*24h)增加(P＜0.05).添加V...     

低蛋白质 、无微量元素添加日粮对育肥猪生产性能 、氮利用及胴体性能的影响

试验选取平均初始体重(85.00±2.00)kg的杜×长×大育肥猪120头,随机分为3个组,每组5个重复,每个重复8头猪,预饲期5 d,试验期31 d。试验1组为基础日粮组(粗蛋白质质量分数为13.96%)、试验2组为低蛋白质-氨基酸平衡日粮组(粗蛋白质质量分数为9.87%)、试验3组为低蛋白质-氨基酸平衡、无微量元素添加日粮组(粗蛋白质质量分数为9.87%+不添加微量元素的预混料)。结果显示,与基础日粮组相比,试验2组和试验3组的平均日采食量、平均日增重有下降趋势(P0.05),耗料增重比升高(P0.05);试验2组和试验3组的摄入氮含量分别低于试验1组31.96%和30.84%(P0.05);各组粪氮百分含量无显著变化(P0.05);试验2组和试验3组的尿氮浓度分别低于试验1组23.93%和15.64%(P0.05);与试验1组相比,试验2组和试验3组的胴体重和背膘厚度有升高趋势(P0.05)、眼肌面积及屠宰率均无显著变化;所有组的肉品质性状均无显著差异。研究表明,基础日粮粗蛋白质水平降低4个百分点,微量元素降低14%～60%后,育肥猪的生长性能、胴体性能及肉品质性状均无显著变化,但是均能够显著降低氮摄入量和氮排放量。     

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。     

普通和乳化植物甾醇对育肥猪生长性能、血清生化指标和养分消化率的影响

本试验旨在研究普通和乳化植物甾醇对育肥猪生长性能、血清生化指标和养分消化率的影响。选用75头初始重为60 kg左右的杜长大育肥猪随机分为3组,其中对照组饲喂基础日粮,试验组在基础日粮中分别添加30 mg/kg普通植物甾醇(Ⅰ组)或乳化植物甾醇(Ⅱ组)。试验期为52 d。2种植物甾醇对育肥猪生产性能无显著影响,但显著降低血清总胆固醇(TC)、甘油三酯(TG)水平和白球比(A/G)(P0.05),显著提高血清总蛋白(TP)和球蛋白(GLO)水平(P0.05),Ⅰ组血清白蛋白(ALB)含量显著低于对照组(P0.05),而Ⅱ组无显著差异;显著提高育肥猪对干物质、有机物、粗蛋白的消化率(P0.05),Ⅱ组粗脂肪消化率亦显著高于对照组(P0.05)。结果显示,在育肥猪日粮中添加30 mg/kg 2种植物甾醇可改善养分消化率,调节血脂和蛋白质代谢,且从血清ALB和粗脂肪消化率数据来看,乳化植物甾醇的作用效果优于普通植物甾醇。     

天然植物提取物对猪肉品质的影响及机理探讨

80头70kg杜长大三元杂交猪分成对照和试验2个处理组,每个处理设4个重复栏,每栏10头猪.对照组饲喂含常用市售抗生素的饲粮,试验组饲喂含300mg/kg天然植物提取物的饲粮.结果表明,与对照组相比,饲粮中添加300m/kg天然植物提取物使试验组猪的胴体脂肪率降低了20.85%(P＜0.05),胴体瘦肉率提高了4.20%(P＜0.05);使试验组猪背最长肌中肌红蛋白、肌内脂肪和肌苷酸含量分别提高了15.48%(P＜0.05)、52.77%(P＜0.01)和16.72%(P＜0.05);使试验组猪背最长肌中磷酸肌酸激酶(CPK)和磷酸葡萄糖异构酶(GPI)的活力分别提高了30.54%(P＜0.01)和20.04%(P＜0.01);使试验组猪背最长肌肌纤维的直径降低了7.98%(P＜0.05),而密度增加了4.70%(P＜0.05).     

环境热应激对绵羊肉品质及血液生化指标的影响

为了解热应激对绵羊肉品质及血液生化指标的影响,选择鲁中肉羊作为实验对象,人工调控养殖环境对其施加热应激处理,比较组间羊肉品质和血液生化指标。结果显示：热应激对羊肉在45 min和贮藏24 h时的pH值以及蒸煮损失均无显著影响;滴水损失、剪切力以及在45 min和24 h的亮度值(L^*)、红度值(a^*)和黄度值(b^*)在2组间均存在显著差异(P<0.05);对照组在各方面感官评分均优于应激组;扫描电镜结果显示应激组肌肉纤维更为松散。应激组血液中促甲状腺素释放激素(thyrotropin-releasing hormone,TRH)、甲状腺素、皮质醇(cortisol,Cor)含量的全天平均水平相较于对照组均极显著降低(P<0.01);肾上腺素、胰岛素(insulin,Ins)含量显著上升(P<0.05);三碘甲状腺原氨酸、促肾上腺皮质激素含量无显著差异。免疫球蛋白A(immunoglobulin A,IgA)含量应激组相较于对照组显著下降(P<0.05),IgG、IgM和白细胞介素4水平无显著差异;...     

微量元素铬对猪肉质性状的影响

将18头70kg左右的杜长大三元杂交猪随机分为2个处理组,分别饲喂基础日粮和实验日粮,实验日粮为基础日粮中添加吡啶羧酸铬,铬在日粮中的添加浓度为200μg/kg.研究铬对肥育猪肉质性状的影响.结果表明:在猪肥育期日粮中添加铬,可以显著提高眼肌面积(LMA)、宰后24h肌肉pH和肌内脂肪(IMF)含量(P<0.05),减少滴水损失和血清游离脂肪酸(NEFA)含量(P<0.05).通过对H-FABP基因表达量的分析表明,铬显著提高了肌肉组织中H-FABP基因表达量(P<0.05),H-FABP基因表达量与IMF含量呈正相关,相关系数为0.826(P=0.042);与NEFA含量呈负相关,相关系数为-0.753(P=0.046).研究表明,铬能够显著提高肌肉组织中H-FABP基因表达量,减少血清NEFA含量,改善肉质性状.     

高粱原花青素对生长育肥猪抗氧化、免疫以及养分消化率的影响

研究高粱原花青素(sorghum procyanidins,SPC)对生长育肥猪生长性能、养分消化率、消化酶活性、免疫力和抗氧化能力的影响。160头70日龄、平均体重为(31. 28±1. 12) kg的杜×长×大三元杂交猪,按照单因素完全随机设计分为4个组,分别饲喂玉米-豆粕基础日粮,以及基础日粮中添加100、150、200 mg/kg SPC。实验期为14周,生长期和育肥期各7周。在每个实验阶段开始和结束时称重,每天记录采食量,计算各阶段平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G)。在每个实验阶段的最后3 d,收集粪样测养分消化率。在每个实验阶段结束时,采血测血清抗氧化指数和免疫参数,同时,每个重复随机屠宰2头猪,取胰腺组织,测消化酶活性。结果表明,日粮添加SPC对生长育肥猪的生长性能没有显著的促进作用(P 0. 05)。在生长猪阶段,日粮添加150 mg/kg和200 mg/kg SPC显著降低了消化酶的活性,对养分消化率有降低的趋势。在育肥猪阶段,日粮添加150 mg/kg显著提高了粗蛋白的表观消化率(P 0. 05),200 mg/kg SPC显著地抑制了消化酶的活性(P 0. 05)。与对照组相比,不论是在生长期还是育肥期,添加150 mg/kg或200 mg/kg的SPC均显著地增强了猪血清谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)的活性以及血清总抗氧化能力(T-AOC)(P 0. 05),降低了血清丙二醛(MDA)浓度(P 0. 05),提高了猪血清IgG、IgM和白细胞介素2(IL-2)的浓度(P 0. 05)。总之,SPC有利于提高生长育肥猪抗氧化能力,增强免疫力,但是对于生长育肥猪的生长性能及养分消化率没有显著的促进作用,相反,高浓度的SPC甚至抑制了消化酶的活性,从而影响养分的消化利用。     

Effect of replacing soybean meal by extruded chickpeas in the diets of growing-finishing pigs on meat quality

The main objective of this study was to evaluate the effect of the replacement of soybean meal by extruded chickpeas in diets of growing-finishing pigs on meat quality. In a 17wk study 48 growing-finishing crossbred pigs were fed ad libitum. The experimental design included four treatments, each one of 12 pigs; the ECKP0 treatment was fed with diet containing soybean meal and no chickpeas (control), while treatments ECKP100, ECKP200 and ECKP300 were fed with diets containing 100, 200 and 300kg/t of extruded chickpeas, respectively. The lean meat quality of the longissimus lumborum et thoracis muscle was evaluated by chemical analysis (moisture, protein, fat and ash), fatty acid profile, pH measurement, cooking loss, color evaluation, and sensory evaluation. Odor and taste, tenderness, juiciness, and overall acceptability were scored on 1-10 scales by a group of 10 experienced assessors after a standard cooking regime. Small differences were observed between control and experimental groups in chemical composition (P>0.05). Fatty acid profiles, pH measurements and color evaluation did not differ among treatments (P>0.05), while cooking loss was significantly lower in the control group (P<0.05). The taste panel gave slightly higher scores for the tenderness and juiciness for the control group compared with the chickpea treatments (P<0.05). No differences were observed between control and experimental groups in taste scores (P>0.05). It is concluded that the replacement of soybean meal by extruded chickpeas, when substituted isonitrogenously and isoenergetically at inclusion levels up to 300kg/t of pig, does not influence significantly meat quality.     

Effects of dietary supplementation of vitamins D(3) and E on quality characteristics of pigs and longissimus muscle antioxidative capacity

The effects of addition of vitamin D₃ and vitamin E to pig diets on blood plasma calcium concentration, meat quality (longissimus muscle) and antioxidative capacity were investigated. Two treatments consisted of supplementation with vitamin D₃ (500,000 IU/d) for 5 days separately (group D) and a combination of vitamin E (500 mg α-tocopheryl acetate/kg diet) for 30 days and vitamin D₃ (500,000 IU/d) for 5 days (group D + E) to growing-finishing pigs before slaughter. Pigs fed with vitamin D₃ had higher (P < 0.01) plasma calcium concentration compared with control pigs. Dietary supplementation of vitamin E significantly (P < 0.05) increased the concentration of α-tocopherol in meat (longissimus muscle). Vitamin D₃ supplementation resulted in higher (P = 0.07) a^∗ values of loin chops at 5 days of storage. Vitamin D₃ and vitamin E supplementation did not affect other meat quality characteristics or tenderness (quantified by Warner–Bratzler shear force). Antioxidative capacity (measured as MDA production after incubation of longissimus muscle homogenates with Fe²⁺/ascorbate) was improved by vitamin E and partly by vitamin D₃ supplementation.     

Comparing the histochemical characteristics and meat quality traits of different pig breeds

The purpose of this study was to compare the muscle histochemical characteristics and meat quality traits between Berkshire, Landrace, Yorkshire, and crossbred pigs. A total of 594 pigs were evaluated. A clear difference between histochemical properties was observed from the results for fiber type composition. In Berkshire pigs, the area percentage of type I fibers was higher (P < 0.001) and that of type IIb fibers was lower (P < 0.05) than those of other breeds. The muscle pH_45min and pH_24h were significantly higher in Berkshire pigs. Drip loss and color parameters were significantly different between the breeds (P < 0.001). The Berkshire pigs, which showed the highest muscle pH and lowest drip loss and L^* values, contained a significantly higher percentage of type I fibers than the other breeds. By comparing the fiber type compositions of the different breeds, the results imply that the longissimus dorsi muscle of Berkshire pigs is more oxidative than that of other breeds. A high pH value in Berkshire pigs is due to a high percentage of type I fibers and a low percentage of type IIb fibers. Based on these results, we conclude that muscle fiber composition can explain in parts the variation of meat quality across and within breeds.     

藏猪与大白猪食用品质与肌纤维类型的相关性研究

为了探究不同地区猪肉品质差异及形成原因,本研究选取不同地区（西藏林芝、甘肃甘南、四川阿坝）自然放养下的藏猪与平原大白猪为研究对象,测定其背最长肌的食用品质（pH、颜色、蒸煮损失、剪切力）、肌红蛋白含量、羟脯氨酸含量、不同的肌球蛋白重链（MyHC）mRNA相对表达量,并对各指标进行相关性分析。结果表明,藏猪的pH_{3 h}处于5.7~5.8,显著低于大白猪（6.05±0.20,P<0.05）,藏猪的红度值（a*）和肌红蛋白含量显著高于大白猪（白猪为2.12±0.87、0.004 μmol/g）,其中,阿坝藏猪的a*最高（8.10±0.99）（P<0.05）;藏猪的剪切力和羟脯氨酸含量显著高于大白猪（41.81±0.83、5.92%±0.52%）（P<0.05）;藏猪的IIa型肌纤维比例显著高于大白猪而IIb型肌纤维比例显著低于大白猪（P<0.05）;相关性分析表明,a*与L*、IIb型肌纤维呈极显著负相关（P<0.01),与肌红蛋白含量、I型和IIa型肌纤维呈极显著正相关（P<0.01）,剪切力与羟脯氨酸含量呈现极显著正相关（P<0.01）。综上所述,藏猪大白猪肉的食用品质差异很大,藏猪比大白猪的肉色更红、嫩度更差,不同地区藏猪肉色也存在一定差异,这与它们的肌肉纤维类型有很大相关性。     

Halothane genotype and pork quality. 1. Carcass and meat quality characteristics of three halothane genotypes

The carcass and meat quality characteristics of three halothane genotypes in pigs were evaluated. Sixty crossbred Landrace×Large White pigs (NN=25, Nn=19, nn=16) of ±86 kg live weight were slaughtered, the carcasses chilled for 24 h at 2°C, certain carcass and meat quality traits determined and the shoulder and leg cuts deboned and cut into primal cuts. Dressing percentage of the Nn pigs was higher (P<0.05) than that of the NN and nn pigs. Carcass length was the longest (P<0.05) for the nn pigs. Midline fat measurements as well as measurements at the 2nd-3rd last rib (45 mm from the midline) indicated that the nn pigs had less fat (P<0.05) and a larger eye muscle width (P<0.05), depth (P<0.001) and area (P<0.001) than the NN or Nn pigs. This resulted in the nn pigs having the highest (P<0.05) percentage predicted carcass lean content. Fat, bone and lean yield of the shoulder identified the nn pigs with the least bone (P<0.05) and fat (P<0.001) and the highest lean yield (P<0.05), expressed as a percentage of total shoulder weight. Yield from the legs identified the nn pigs as having the lowest fat (P<0.001) and highest lean (P<0.05), expressed as a percentage of total leg weight. The primal lean cuts (topside, silverside, thickflank and rump) from the legs showed that the nn pigs had the highest values (P<0.05) for lean as a fraction of cold carcass weight. This resulted from the higher weight of these cuts (P<0.05) in the nn pigs. Calculation of bone yield in the legs showed that the femur weights were highest (P<0.05) for the Nn pigs, also when expressed as percentage of leg weight (P<0.05) and as a fraction of cold carcass weight (P<0.05). Comparison of meat quality traits show that the nn pigs had poor quality with regard to pH(45) (P<0.001), pH(24) (P<0.05), drip loss (P<0.001) and reflectance values (P<0.05).     

荣昌猪和杜洛克猪肉质及营养价值的比较分析

以脂肪型的荣昌猪和瘦肉型的杜洛克猪为研究对象,比较分析2 个品种之间背最长肌的肉质、氨基酸、脂肪酸和微量元素含量差异。结果显示：荣昌猪的肌内脂肪含量、肉色和大理石纹显著高于杜洛克猪（P＜0.05）,剪切力显著低于杜洛克猪（P＜0.05）;荣昌猪背最长肌中丝氨酸、丙氨酸、精氨酸、异亮氨酸、酪氨酸、总氨基酸含量和呈味氨基酸总量显著高于杜洛克猪（P＜0.05）;荣昌猪背最长肌的饱和脂肪酸含量显著低于杜洛克猪（P＜0.05）;单不饱和脂肪酸含量显著高于杜洛克猪（P＜0.05）;荣昌猪背最长肌中微量元素Co、Mn、Cr、Se和Zn含量均显著高于杜洛克猪（P＜0.05）,微量元素As和Mo含量显著低于杜洛克猪（P＜0.05）。结果表明,脂肪型的荣昌猪在肉质及营养价值方面总体优于瘦肉型的杜洛克猪,为中国地方猪种遗传资源的保护及开发利用提供了理论依据。     

Oxidative and colour changes in meat from three lines of free-range reared Iberian pigs slaughtered at 90 kg live weight and from industrial pig during refrigerated storage

The oxidative stability and colour evolution during refrigerated storage (10 days at +4?°C) of Longissimus dorsi muscle from three lines of Iberian pigs and industrial genotype pigs were studied. The Iberian pigs were reared in an extensive system and fed on a commercial feed with access to pasture grazing, while industrial genotype pigs were reared in an intensive system. Fresh Longissimus dorsi of Iberian pig lines showed a more intense and redder colour, with a statistically significant higher CIE chroma and a*-value as well as a lower L*-value (P<0.05) compared with those of industrial genotype pigs. Pig genotype significantly affected the colour and lipid oxidation changes of m. Longissimus dorsi during refrigerated storage. The decrease in L*-value during the refrigerated storage was more intense in industrial pig's Longissimus dorsi than in those from Iberian pig lines. CIE a*-value decrease was more intense in 'Lampi?o' Iberian line and industrial Longissimus dorsi than in the other two Iberian pig lines, however CIE a*-value was significantly higher in muscles from Iberian pig lines than in muscle of industrial genotype (P<0.05) at the end of refrigerated storage. The Iberian and industrial pig's Longissimus dorsi did not show statistically significant differences in TBA-RS values (mg MDA/kg meat) at the end of the refrigerated storage period (P>0.05). To establish relationships between parameters measured in fresh meat and oxidation and colour changes during refrigerated storage, correlations and multiple regression models were calculated. CIE a*-values at day 10 were positively correlated with values of fresh muscles for a*, C18:1 percentages and negatively correlated with polyunsaturated fatty acids percentages of neutral and polar lipids. Inversely, TBA-RS values at day 10 showed a positive correlation with initial values for phospholipid content and polyunsaturated fatty acids of neutral and polar lipid fractions, while C18:1 percentage were negatively correlated.     

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.