Effects of different rearing systems on muscle and meat quality traits of slow- and medium-growing male chickens

1. This experiment was conducted to evaluate the effect of production system on the meat quality of slow- and medium-growing chickens. A total of 1075 1-d-old male chicks were equally divided into 6 experimental groups, represented by three strains (SG: TETRA-H, MG1: TETRA HB Color, MG2: Shaver Farm) and were reared in a poultry house in floor pens (12 males/m²).

2. On d 49, 150 healthy birds (50/genotype) were placed in a free-range family farm while the rest of the birds remained indoors. All birds were fed ad libitum and consumed the same diet. On d 70, 20 birds of each experimental group were slaughtered and muscle samples were taken from the left breast and thigh muscles.

3. Thigh muscle of SG males kept on free range was darker (L* = 75.12 vs. 78.33) with lower frying loss (45.9% vs. 55.9%) compared with the indoor group. Similar results were obtained from the MG1 group. Free-range MG2 males had lighter thigh meat (L* = 50.7 vs. 57.8) and lower frying loss compared to the indoor group.

4. In general, the indoor treatment had a lower impact on breast meat than the outdoor system. Regardless of the rearing system, genotypic differences were more pronounced in thigh than in breast muscle.

     

硒代甲硫氨酸对肉仔鸡肉品质和抗氧化性能的影响

试验采用单因子随机化设计,将400只AA肉仔鸡随机分为5个组,每个组设4个重复,每个重复20只鸡。第1组为对照组,饲喂玉米-豆粕型基础日粮,并添加亚硒酸钠0.30 mg/kg;第2~5组为试验组,在基础日粮的基础上,分别添加0.15、0.30、0.45、0.60 mg/kg的硒代甲硫氨酸。通过42 d的饲养试验和测试,综合日增重、采食量和料重比3项生长性能指标,当硒代甲硫氨酸添加量为0.30 mg/kg时肉仔鸡生长性能最佳,且与对照组差异显著(P0.05);与0.30 mg/kg无机组相比,相同剂量的硒代甲硫氨酸在改善肉鸡的屠宰性能方面,可显著提高半净率、腿肌率(P0.05),对胴体率、全净率、胸肌率也有改善作用(P0.05),对改善肉品的滴水损失、嫩度和肉色作用显著(P0.05),但对屠宰24 h后胸肌pH值差异不显著(P0.05);硒代甲硫氨酸添加浓度为0.15 mg/kg、0.30 mg/kg时,对提高肉仔鸡机体抗氧化效应显著(P0.05)。综合各项指标,对于1~42日龄肉仔鸡最适的硒代甲硫氨酸添加量为0.30 mg/kg。     

不同寡糖对肉仔鸡生产性能和肉品质的影响

<正>寡糖为饲料中的天然成分,不会带来污染,并能提高动物机体的抗病潜力,由于其结构和理化性质的特殊性(不能被家禽的胃和小肠分泌的酶消化),可以直接到达消化道后段,具有调节畜禽胃肠道微生态平     

不同饲喂方式对育肥水牛胴体特征和肉品质的影响

文章旨在研究不同饲喂方式对育肥水牛生长性能、胴体特征、肉品质及抗氧化的影响.试验将36头平均初始体重为(207.67±12.81)kg的水牛随机分为4组,每组3个重复,每个重复3头.处理1组和处理2组水牛采用放牧的形式,即分别在象草及象草与柱花草间作的牧场放牧,处理3组和处理4组饲喂浓缩饲料的同时补充2％和4％的象草,...     

牛磺酸对肉仔鸡屠宰性能和肌肉品质的影响

本研究旨在探讨牛磺酸对肉仔鸡屠宰性能和肌肉品质的影响。选用240只1日龄艾维茵肉仔鸡,随机分为5组,每组3个重复。对照组饲喂玉米-豆粕型基础日粮,试验组在基础日粮中添加0.05%、0.10%、0.15%和0.20%的牛磺酸,试验期42 d。结果表明:(1)日粮中添加0.10%牛磺酸能够显著降低42日龄肉仔鸡胸肌失水率和粗脂肪含量(P<0.05),显著提高胸肌pH和粗蛋白质含量(P<0.05);(2)添加0.15%的牛磺酸显著提高42日龄肉仔鸡胸肌率和瘦肉率(P<0.05),显著降低皮脂厚(P<0.05),显著提高胸肌pH和粗蛋白质含量(P<0.05),显著降低胸肌粗脂肪含量(P<0.05);(3)0.20%的牛磺酸显著提高胸肌pH、肉色和粗蛋白质含量(P<0.05)。     

肉鸡品种对胴体性状和肉质的影响

本研究将清远麻鸡的两个纯系(A和B)与快速生长型AA肉鸡(C)杂交,在3个月的生长时间中测定了杂交品对肉鸡胴体性状、肌肉成分及氨基酸组成的影响.结果:杂交品系肉鸡的体重、屠体重、半净膛重、全净膛重、胸肌和腹脂重量均显著高于纯种品系(P<0.05).杂交品系肉鸡的肌纤维密度和剪切力较纯种品系显著提高了6.94％和7.98...     

红车轴草异黄酮对肉鸡生产性能及肉品质的影响

为了研究红车轴草（Trifolium pratense）异黄酮对肉鸡生长、屠宰性能及肉品质的影响,将180羽1日龄AA肉仔鸡分成3组,即对照组、试验Ⅰ组、试验Ⅱ组,分别饲喂基础日粮、基础日粮+红车轴草异黄酮(10 mg/kg)、基础日粮+红车轴草异黄酮(20 mg/kg)。结果显示,红车轴草异黄酮可以提高肉鸡的日增体质量（P<0.05）和屠宰性能（P>0.05）,降低血清中甘油三酯、总胆固醇和腹脂率（P<0.05）,减少了储存第6天肉中丙二醛含量（P<0.05）,降低了肉品滴水损失和剪切力（P>0.05）。表明红车轴草异黄酮能够提高肉鸡生长性能和屠宰性能,改善肉品品质,添加20 mg/kg时肉鸡日增长速度最快。     

Shackling of broilers: Effects on stress responses and breast meat quality

1. Experiments were conducted to study the welfare and meat quality effects of shackling. In experiment 1, broilers with or without leg problems were shackled (S) for 4 min on a moving line and blood sampled; or handled (H), returned to the crate and sampled after 4 min; or sampled immediately after removal from the crate (control, C).

2. Plasma corticosterone (CORT) concentrations, as measured by radioimmunoassay, were highest in S and lowest in C, while the H group was intermediate. Leg problems had no effect on CORT.

3. In experiment 2, tonic immobility (TI) was induced in broilers after 2 min inverted handling to determine fear responses. One week later, the birds were fasted, transported and then shackled on a moving shackle line for 0, 1, 3 or 4 min, then unshackled and blood sampled. Wing flapping during shackling was also quantified.

4. Shackling time did not influence CORT concentrations. There was a negative correlation (r= ? 0.714) between CORT and wing flapping duration in the 1 min shackling treatment. There was no relationship between TI and wing flapping or CORT.

5. In experiment 3, broilers were exposed to two food withdrawal (FW) times (food withdrawn overnight or during crating only) and held for 4 h prior to processing, shackled (0, 2 or 4 min shackling time, ST), and then killed by exsanguination. Blood samples were collected during the neck‐cut. Pectoralis superficialis and Supracoracoideus samples were either collected after 15 min and individually quick frozen (IQF) in liquid nitrogen or collected at 4 h post mortem from carcases chilled on slush ice (COI).

6. CORT increased significantly with increased ST. There was a FW × ST interaction effect on the initial pH of fillets. ST influenced the b*, chroma and Hue values of the COI fillets. FW influenced the L* and Hue values of both IQF and COI fillets as well as the a* value of the COI fillets.

7. In summary, CORT increased with shackling time when birds were held after transport. FW and ST also influenced the colour of fillets, although it is not clear whether these changes are perceptible to the consumer. The duration of wing flapping during shackling did not appear to be related to fearfulness, although it was influenced by properties of the shackle line. We suggest that there be a maximum time lapse between shackling and stunning or killing of 2 min to minimise stress and meat quality changes.     

中国地方鸡与肉鸡的肉质比较

测定并比较了中国地方鸡与肉鸡的肌肉化学成分与物理特性及屠宰率。结果中国地方鸡胸肌较细嫩 ,色泽诱人 ,肌间脂肪与胶原含量较高和水分较低。肉鸡腿肌较嫩 ,熟肉率及屠宰率较高和价格较低。在中国地方鸡中 ,清远麻鸡和龙岗鸡之间无显著差异。而它们和三黄鸡之间在净膛率 ,pH值和腿肌的熟肉率、脂肪与水分含量方面则存在显著差异。     

二氢吡啶对鸡肉品质的影响

二氢吡啶的化学名称是2,6-二甲基-3,5-二乙酯基-1,4-二氢吡啶。二氢吡啶作为一种新型的抗氧化剂及动物促生长剂,具有天然抗氧化剂维生素E的某些功能。而维生素E作为动物体内重要的抗氧化剂,可阻止多不饱和脂肪酸及胆固醇的氧化,改善肉的品质。本试验以1日龄AA肉仔鸡为对象,研究     

不同限喂方法对肉用种鸡育成期体重均匀度的影响

本试验采用隔日限喂、每日限喂、“周五·二”限喂三种不同限时饲喂方法，观察对ＡＡ父母代肉用种鸡（６—１７周龄）体重均匀度的影响。结果表明，隔日限喂的肉种鸡体重均匀度最好，趋于标准均匀度，而每日限和“周五·二”限喂的体重均匀度差距较大。三种限时饲喂方法，其体重均匀度差距较大，分别是８０％、５９．５％和６０．０％。可见，对６—１７周肉种鸡而言，隔日限饲法不失为理想限饲法     

不同肉质改良剂在肉猪肥育阶段的试验效果

随着国民经济发展和人民生活水平不断提高 ,人们对畜产品质量的要求也越来越高 ,对优质无公害放心肉的需求量越来越大 ,这种趋势将会持续增长。随着我国规模化养猪业的发展 ,在高产、高效的同时 ,如何生产符合国家有关标准和确保消费者健康安全的优质猪肉是养猪者所面临的重要问题。各科研单位开发研制的肉质改良剂 ,正是在国家安全生产猪肉的有关政策法规基础上生产出的高科技产品 ,对发展安全、高效、优质的放心肉和促进养猪业可持续发展都具有重要的现实意义。肉质改良剂具有促进生长、降低料耗、提高肉的持水性和改善肉色、提高饲料利用…     

日粮不同动植物油配比对黄羽肉鸡血清学指标和抗氧化特性的影响

试验选用25日龄黄羽肉公鸡1 600羽,随机分成5组,每组4个重复,日粮中添加由猪脂和大豆油组成的混合油脂,各处理组猪脂占混合油脂的比例分别为0(I组)、25%(II组)、50%(III组)、75%(IV组)和100%(V组),试验分前期(25～45日龄)和后期(46～65日龄)两个阶段,各阶段结束时屠宰取样,测定相关血清生理生化和抗氧化指标。结果发现:(1)45日龄黄公鸡血清尿素氮含量I组比V组显著提高79.97%(P0.05);碱性磷酸酶活性II组显著升高(P0.05)。65日龄时黄公鸡尿素氮含量各组差异不显著(P0.05);碱性磷酸酶活性III组、IV组显著降低(P0.05)。(2)45日龄黄公鸡血清中SOD活性IV组比I组高32.70%(P0.05),65日龄时各抗氧化指标各组差异不显著(P0.05)。总之,日粮中猪脂与大豆油的比例为1～3∶1时,对黄鸡肝胆系统功能、蛋白质代谢和抗氧化特性有一定的改善作用,且3∶1比1∶1更适宜,此时日粮中不饱和脂肪酸与饱和脂肪酸之比为1.60(25～45日龄)和1.58(46～65日龄)。     

饲粮中植酸酶、钙、磷不同水平组合对肉仔鸡生长和屠宰性能的影响

利用正交实验[L(934)]把270只艾维茵肉仔鸡随机分为9组,研究植酸酶、非植酸磷和钙水平的不同组合对艾维茵肉仔鸡生长性能、死淘率、屠宰性能及肉品质的影响。结果表明,添加非植酸磷0.18%+钙0.8%组肉仔鸡生长最差,全部发生腿病,并于试验中期死亡或被淘汰;在非植酸磷0.18%+钙0.65%组的饲粮中添加植酸酶600FTU/kg,一定程度上改善了肉仔鸡的生长发育,但日增重仍较差,且死淘率较高;而添加植酸酶1200FTU/kg+非植酸酶0.18%+钙1.00%的组合显著降低了肉仔鸡的食欲与生长发育速度,腿病发生率和死淘率仍较高。饲粮中添加非植酸磷0.28%+不添加植酸酶+钙1.00%组仔鸡生长很差、死淘率较高;添加植酸酶600FTU/kg+非植酸磷0.28%+钙0.80%的组生长效果良好,而非植酸磷0.28%+钙0.65%+植酸酶1200FTU/kg组并未进一步提高生长效果。饲粮非植酸磷为0.38%时的3个组合都表现出较佳的日增重,说明非植酸磷0.38%能满足仔鸡需要。试验处理对仔鸡屠宰性能与肉品质未产生明显影响。饲粮中添加非植酸磷0.28%+钙0.80%+植酸酶600FTU/kg时,肉仔鸡的综合效益较佳。     

天门冬氨酸镁添加水平对肉仔鸡生长性能及肉品质的影响

试验研究天门冬氨酸镁(MgAsp)添加水平对肉仔鸡生长性能及肉品质的影响。选用240只22日龄的艾维茵肉仔鸡,随机分成5组,每组6个重复,每个重复8只鸡。试验期为3周。分别添加MgAsp使镁的添加水平分别为0、0.06%、0.12%、0.20%、0.30%。结果表明,饲料中添加镁对肉仔鸡的日平均增重和料重比无显著影响(P>0.05);0.20%镁能显著改善肉质,提高胸肌蛋白和腿肌蛋白含量;降低脂肪、总胆固醇、甘油三酯和低密度脂蛋白含量(P<0.05),对腿肌脂肪含量影响不显著(P>0.05)。研究结果表明,日粮中添加天门冬氨酸镁对肉仔鸡的生产性能无显著影响;添加0.20%镁水平可以显著提高鸡肉肉品质。     

不同剂量枯草芽孢杆菌对肉鸡生长性能、肉品质和肠绒毛形态的影响

文章旨在评估日粮添加不同剂量枯草芽孢杆菌对肉鸡生长性能、肉品质、肠绒毛形态和肠道菌群的影响.试验将刚孵化的528只1日龄肉鸡随机分为3组,每组8个重复,每个重复22只.在为期5周的饲养试验中,对照组肉鸡饲喂基础日粮,处理1组和处理2组肉鸡饲喂基础日粮+1和2?g/kg枯草芽孢杆菌(1.5×109 CFU/g).结果:处...     

五味子提取物对低脂系肉仔鸡肉质的影响

本试验采用单因子试验设计,将144羽1日龄健康、体重均一的低脂系肉仔鸡随机分为两组,每组6个重复,每个重复12羽。对照组饲喂基础日粮,试验组饲喂添加0.125%五味子提取物组的基础日粮,试验期为8周,研究五味子提取物对低脂系肉仔鸡肉质的影响。结果表明:(1)与对照组相比,五味子提取物组肉仔鸡胸肌纤维密度显著提高,腿肌直径显著降低(P0.05),腿肌纤维密度有升高趋势,胸肌直径有降低趋势;(2)与对照组相比,五味子提取物组胸肌和腿肌的水分、蛋白质与脂肪含量无显著差异(P0.05);(3)五味子提取物显著降低了肉仔鸡胸肌和腿肌剪切力(P0.05),胸肌和腿肌pH、红度(a*)、黄度(b*)有升高趋势(P0.05),滴水损失和蒸煮损失有降低趋势(P0.05)。     

Effect of less intensive rearing conditions on litter characteristics, growth performance, carcase injuries and meat quality of broilers

1. The objective was to compare the effect of two litter types (wheat straw and wood shavings) and two different rearing conditions (Treated and Control) on welfare indicators, broiler performance, carcase injuries, particularly hock and foot pad dermatitis (FPD), litter characteristics and meat quality. 2. Treated conditions were characterised by a low stocking density (11 birds/m(2)), short photoperiod (16 h light: 8 h dark) and a large amount of litter (3 to 4.5 kg/m(2), respectively, for wheat straw or wood shavings). Control conditions were a high stocking density (14 birds/m(2)), long photoperiod (23 h light:1 h dark) and small amount of litter (2.3 to 3 kg/m(2), respectively, for wheat straw or wood shavings). In addition, the effects of two widely used litter materials, wheat straw and wood shavings, were investigated. 3. The combined effects of lower stocking density, greater amount of litter material and a photoperiod similar to the natural one, reduced the occurrence of FPD in Treated groups keeping the FPD score under the European threshold. 4. Improved rearing conditions led to faster growth rate associated with inferior feed efficiency, whereas litter type exerted negligible effects on broiler performance. 5. Litter moisture content, nitrogen and ammonia released by the litter were lower in Treated groups than Control groups. The use of wood shavings resulted in lower moisture and nitrogen concentrations in the litter.