饲粮能量、蛋白质水平对 肉鸡肉质的影响

近年来,随着肉鸡业对提高肉鸡生长速率和饲料效率的遗传选育,以及为充分发挥肉鸡遗传潜力在营养配方上的不断完善,使得肉用仔鸡生产水平得到提高,但同时肉质变得粗老、腹脂沉积增多,缺少风味,降低了消费者对肉质的满意度。肉鸡生长率不仅受遗传因素的影响,还受能量、蛋白质水平(以下简称能、蛋水平)的影响(Ｃｈｅｒｒｙ,1978;Ｍａｒｏｈ,1977)。1　能、蛋水平对肉鸡肉质的影响11　直接影响　饲粮能、蛋水平影响肉鸡腹脂沉积,直接影响肉质。许多研究表明,营养因素对肉鸡体成分(包括体脂)有显著影响,影响脂肪沉积的主要营养因素有能量、蛋白质…     

饲粮粗蛋白质水平对肉鸡消化酶活性及能量、蛋白质代谢的影响

本试验旨在研究饲粮粗蛋白质（CP）水平对肉鸡生长性能及消化功能的影响,并探讨由此是否引起了对饲粮表观代谢能（AME）测定的差异。试验包括2个部分。第1部分考察饲粮CP水平对肉鸡生长性能及消化酶活性的影响。采用完全随机区组设计,以7日龄体重为区组,饲粮设置2个CP水平,即高CP水平（HP）饲粮（8～21日龄饲粮CP水平为22.57%,22～35日龄饲粮CP水平为20.65%）和低CP水平（LP）饲粮（8～21日龄饲粮CP水平为19.29%,22～35日龄饲粮CP水平为17.49%）,每个处理6个重复,其中8～21日龄每个重复24只鸡,22～35日龄每个重复17只鸡。第2部分考察饲喂不同CP水平饲粮的肉鸡对排泄物中可消化养分及饲粮能量和蛋白质代谢的影响。采用2×2两因素完全随机设计,试验鸡的来源设2个处理,即饲喂HP饲粮的肉鸡和饲喂LP饲粮的肉鸡;经肉鸡消化代谢的饲粮设2个处理,即HP饲粮（21～28日龄,CP水平为22.57%;35～42日龄,CP水平为20.65%）和LP饲粮（21～28日龄,CP水平为19.29%;35～42日龄,CP水平为17.49%）,每个处理6个重复,其中21～...     

肉鸡饲粮能量水平对植酸酶作用效果的影响

试验选用324只1日龄AA肉鸡(公鸡),采用3×2因子设计,研究在不同能量水平的饲粮中添加植酸酶对肉鸡生长性能和养分利用率的影响。试验设3个能量水平(12.33、12.13、12.03MJ/kg)和2个酶水平(0、500FTU/kg),共计6个处理组,每个处理组6个重复,每个重复9只鸡,试验期42d。结果表明:饲粮添加植酸酶显著(P<0.05)或极显著(P<0.01)提高了肉鸡日增重、采食量,改善了饲料利用率,提高了干物质、粗蛋白、钙、磷的利用率,但对能量利用率没有明显影响(P>0.05);降低饲粮能量水平极显著降低了肉鸡对干物质、能量、钙的利用率(P<0.01),显著降低了其对磷的利用率(P<0.05),但对生产性能和粗蛋白利用率没有显著影响(P>0.05);植酸酶和能量对肉鸡饲料利用率、干物质和钙的利用率存在显著的交互作用(P<0.05),表现为处理2组能量水平条件下添加植酸酶在生长性能和养分利用率上改善幅度最大,表明植酸酶在适宜降低能量水平的饲粮中的作用效果更好。试验中,以能量水平为12.13MJ/kg的肉公鸡饲粮中添加500FTU/kg植酸酶(处理5组)为最佳组合。     

饲粮能量、蛋白质水平对生长猪生产性能的影响

采用2×2因子设计,能量和蛋白质各设2个水平,分别在NRC推荐水平上提高或降低10%,以考察饲料能量、蛋白质水平对生长猪生产性能的影响.试验以NRC水平为对照,共5个处理,每个处理4个重复,每个重复4头猪.将80头生长猪随机分为5个处理.试验结果:与对照组相比,高能高蛋白组(15.6MJ/kg,18.7%)日增重显著降低(P<0.05),其他处理组差异都不显著(P>0.05);低能低蛋白组(12.78MJ/kg,15.3%)日增重显著低于其他两个处理组;高能和高蛋白均显著降低采食量,料肉比有所降低,但差异不显著.结果表明适宜能量和蛋白质水平为NRC水平.     

不同能量、蛋白质水平饲粮对蛋公鸡肥育效果的影响

不同能量、蛋白质水平饲粮对蛋公鸡肥育效果的影响王成章王志祥刘刚聂芙蓉韩彪（河南农业大学牧医工程学院郑州４５０００２）随着生活水平的提高，人们对肉食品的品质，风味越来越重视。肥育小公鸡以其鲜美的肉质，良好的风味而倍受我国广大人民的青睐，特别是中小城市及...     

日粮蛋白质与能量水平对肉鸡痛风症的影响

现有资料表明:鸡痛风是一种代谢紊乱的综合性禽病,发病因素多达20多种,如日粮中高钙低磷等矿物质因素可引起痛风;维生素A、D等缺乏可引起痛风;甚至运动不足、光照不够、水源缺乏、长期或大量使用碳酸氢钠、饲料中氨基酸超量等因素都可引起痛风。但在蛋白质水平能否引起痛风方面     

饲粮不同能量、蛋白质水平对生茸期梅花鹿的影响

本研究采用 2 (CP:2 4和 2 2 % )× 2 (GE:4.1 5和 1 6.74MJ/kg)二因子交叉设计 ,选用1岁 (毛桃 )梅花公鹿 69头 ,分为四个试验组 ,进行了饲养试验和消化试验。试验结果表明 ,饲粮能量、蛋白质水平对鹿体增重的互作效应显著 (P<0 .0 5) ,饲粮粗蛋白质水平对蛋白质消化率有极显著的影响 (P<0 .0 1 )。 1岁梅花鹿生茸期饲粮中能量、蛋白质适宜水平分别为1 7.37MJ/kg GE、2 2 .44% CP。平均每头鹿每天对能量和蛋白质的需要量分别为 36.84MJGE和 478g CP     

饲粮不同蛋白质、能量水平对大白鼠生长发育及体成分的影响

本试验所用动物为53—57日龄雄性大白鼠(sprague——Dawley品系),初始体重为121.73±3.95g,试验期为大白鼠生长发育旺期的21天。试验拟研究不同粗蛋白水平(10％、15％、20％、25％和30％)及两个能量水平(消化能:3.6和3.9kcal/g)的饲粮对大白鼠生长发育及各种体成分的影响。结果表明,当饲粮蛋白质供应充分时,大白鼠生长随饲粮能量浓度的提高而改善;而当饲粮蛋白质供应感觉不足时,提高能量浓度对生长无益。机体各项成分指杯中,以蛋白质、脂肪、水分沉积受饲粮蛋白质,能量浓度影响显著;而蛋白质、脂肪沉积在很大程度上受饲粮能朊比的影响,饲粮中添加脂肪可使大白鼠机体肥胖。     

饲粮不同蛋白质原料和水平对黄鳝生长性能与肉质的影响

以进口鱼粉、膨化豆粕为主要蛋白源,配制4种不同蛋白水平的全价配合饲料,分别饲喂野生健康黄鳝苗(体重37.83～39.75g,P>0.05)110d,以探讨饲粮不同蛋白质原料和水平对黄鳝生长性能与肉质的影响。结果表明:饲粮不同蛋白质原料和水平对黄鳝的增重、体长、腹肌嫩度、净膛率有极显著影响(P<0.01);对背肌嫩度具有显著的影响(P<0.05)。根据屠宰率、肥满度、肝胆指数、肌肉蒸煮损失、肌肉成分、饵料系数、养殖效益等指标判断,黄鳝饲粮粗蛋白质最佳水平为42%,其次为40%。     

饲粮能量水平对热带地区瘦肉型猪生产性能及胴体肉质的影响

试验选用体重约65kg的三元杂交[杜×(大×长)]猪96头,按性别和体重随机分为3组,分别饲喂能量水平为14.21、13.59、12.96MJ/kg的试验饲粮并在饲养试验结束时进行了屠宰试验。结果表明:在热带地区冷季节气候条件下(约平均温度为19.7℃,平均相对湿度为75.4%),瘦肉型育肥猪饲粮的消化能需要参数定为14.21MJ/kg时其日增重和饲料转化率最佳;随着饲粮消化能水平的提高,瘦肉型猪屠宰率和三点平均值有着提高的趋势,瘦肉率和腿臀比例有下降的趋势,但肉色评分和肌肉pH值无明显变化;当饲粮消化能水平为13.59MJ/kg时,试验猪背最长肌干物质、粗脂肪和蛋白质含量最高,肌肉大理石花纹和眼肌平均面积较理想,但饲粮消化能水平对肌肉pH1和pH24的影响不显著(P>0.05)。     

Effect of L-carnitine supplementation on utilisation of energy and protein in broiler chicken fed different dietary fat levels.

Effects of a supplementation of 80 mg L-carnitine per kg diet were studied in broiler chicken at two dietary levels of fat (4 and 8%) and different feeding levels (ad libitum in a growth trial, 95 and 85% of ad libitum in a balance trial). A low-carnitine basal diet adequate in amino acid concentration was used. In the growth trial, each diet was fed to 9 groups of 10 birds each for 16 days from day 5 of live onwards. Growth and feed intake were determined. At the end of the trial, birds were killed and homogenised for subsequent empty body analysis. Accretion of protein and energy was determined using a representative blank group killed at the beginning of the trial. In the balance trial, 8 individual birds were used per treatment. Birds were offered the feed at approximately 85 and 95% of ad libitum intake, which was determined with separate birds for both fat levels. Excreta were quantitatively collected three times daily for 8 consecutive days beginning on day 17 individually for each bird. Supplemented L-carnitine did not significantly affect any response criterion. However, growth and feed conversion tended to be improved by about 5% in the carnitine supplemented diets when fed ad libitum. An interaction between carnitine and fat level occurred with regard to feed conversion, indicating that carnitine had a positive effect at the high fat level, but not at the low fat level. L-carnitine did not positively affect the metabolisability of energy (ME/GE) and the efficiency of energy utilisation (RE/GE or RE/ME). Similarly, no significant carnitine effect was determined with regard to N accretion and the efficiency of utilisation of dietary protein in both trials. It is concluded that endogenous carnitine synthesis is not the limiting factor for energy utilisation in broiler chicken, even at high dietary fat concentration. Occasionally reported positive effects of supplemental carnitine were likewise caused by reasons other than improved energy or protein utilisation. Further studies on amino acid utilisation and catabolism should consider marginal amino acid supply.     

日粮蛋白质和能量水平对猪肉品质的影响研究

猪肉品质的调控是一个复杂的生理生化过程,受诸多因素的影响,而日粮蛋白质和能量水平是影响肉质的关键因素。本文综述了蛋白质（氨基酸）、能量以及两者的比例对猪胴体肉品质的影响。     

The effects of the dark house system on growth,performance and meat quality of broiler chicken

Meat production with minimum animal suffering is a humanitarian concern. Thus, the objective of this work was to observe the performance of Cobb broiler chickens from 7 to 46 days of age when raised under different installations: dark house system (DHS), conventional yellow system (CYC) and conventional blue system (CBC). The feed conversion ratio for the birds raised on the DHS was 3.8% and 2.7% lower than those for the CYC and CBC systems, respectively. Compared with the CYC and CBC systems, average daily gain under the DHS was 11.4% and 9.3% higher, respectively, and body weight at 46 days was 11.4% and 9.3% higher, respectively (P ≤ 0.05). The birds' welfare was assessed based on their stress by determining the amount of pale, soft and exudative (PSE) meat in the breast fillets. The CYC and CBC birds had 24.3% and 25.3% PSE meat, respectively, whereas the DHS birds had 37.0%. We concluded that the DHS has a greater potential to produce broiler chickens, with superior performance to conventional systems, despite the higher stress faced by the birds during the maneuvers just before slaughter.     

Effect of reduced dietary protein and supplementation with a docosahexaenoic acid product on broiler performance and meat quality

1. Chicken breast meat is a lean meat due to its low content of intramuscular fat (IMF) resulting in an overall lower acceptability by consumers due to a decrease in juiciness, flavour and increased chewiness. Recently, studies performed in pigs suggested the possibility of increasing IMF by decreasing dietary crude protein (CP) content, an effect possibly mediated through an increased lipogenesis.

2. Dietary supplementation with lipids rich in omega 3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) may modulate an increase in the content of these fatty acids in meat from monogastric animals and, thus, promote the daily intake of n-3 LC-PUFA by humans.

3. LC-PUFA are very susceptible to oxidation, resulting in off-flavours that affect meat quality and consumers’ acceptability.

4. This trial was conducted to assess the effect of reducing dietary CP, from 21% to 17%, on chicken’s meat IMF content and, simultaneously, to evaluate if a complementary supplementation with a proprietary n-3 LC-PUFA source (DHA Gold?) could improve meat quality. These effects were assessed by measuring productive performance and meat quality, oxidative stability, sensory traits and fatty acid profile.

5. A reduction in CP content of broiler diets, from 21% to 17%, balanced for lysine, improved performance while it was not sufficient to increase IMF content in chicken meat. In contrast, DHA Gold? supplementation had a positive impact both in broiler productive parameters and in meat fatty acid profile.

6. In addition, incorporation of 7.4% of DHA Gold? in the diet promoted carcass yield but negatively affected chicken meat acceptability by consumers, due to a decrease of meat oxidative stability.

7. Overall the data suggest that neither a dietary supplementation with DHA Gold? nor a reduction in CP have a direct positive effect in the levels of IMF present in broiler meat.     

The effect of dietary energy:protein ratio,protein quality and food allocation on the efficiency of utilisation of protein by broiler chickens

1. Various theories have been proposed to explain the reduced performance of broilers when given feeds excessively high in protein, but a satisfactory solution to this problem had, up to now, not been found. Three experiments were conducted to test the hypothesis that the efficiency of utilisation of protein (e_p) is a linear–plateau function of the ratio between the feed apparent metabolisable energy and digestible crude protein contents (AMEn:DCP) and that dietary protein quality, feed allocation and sex do not influence this relationship.

2. A ‘linear–plateau’ model successfully described the efficiency of protein utilisation (e_p) as a function of AMEn:DCP in all three experiments. In Experiment 1, with both sexes being both ad libitum and control fed, the breakpoint was at 58.6 MJ AMEn/kg DCP. In Experiment 2, both sexes were fed balanced and unbalanced protein series, and at different rates, the slopes of the ascending part of the linear–plateau relationships for the different treatments were the same for all treatments (0.0204), and the inflection point was at 71 MJ AMEn/kg DCP. Using similar treatments in Experiment 3, the breakpoint for the balanced protein was 72 MJ/kg and for the unbalanced, 64, with a combined slope of 68 MJ AMEn/kg DCP.

3. The three experiments provide adequate evidence that e_p is a linear–plateau function of the dietary AMEn:DCP ratio with a breakpoint of around 66.2 ± 1.98 MJ AMEn/kg DCP. Below this critical ratio, food intake declines as does protein and lipid retention.

4. That broilers, like pigs, exhibit an energy-dependent phase when high-protein feeds are offered is of practical importance when formulating pre-starter feeds for broilers and starter feeds for turkey poults as the e_p of such feeds may well fall below the maximum due to the lack of dietary energy required to process the high dietary protein contained in such feeds resulting in poorer performance than expected.     

育雏期不同能量蛋白质水平对肉鹅生产性能影响

我国过去养鹅,大多参照美国和前苏联的饲养标准。这些标准是根据美国和前苏联的饲养条件制定,并且数据大都非常陈旧,已经不适应我国鹅的饲养。近年来,我国鹅养殖量不断增加,规模也在逐渐加大,迫切需要制定鹅的饲养标准。1材料与方法1.1试验设计试验以能量和蛋白质为因子,日粮的蛋白质设为20.0%、18.0%2个水平;能量设为11.29、11.70、12.12MJ/kg3个水平。试验动物为0～4周龄莱茵鹅420只(公鹅300只,母鹅120只),分成6组,每组5重复,每个重复14只。试验日粮组成及营养水平见表1。1组2组3组4组5组6组麸皮(%)7.8--12.66.2-豆粕(%)27.628.534222426…     

Comparison of effects of dietary olive oil,tallow and vitamin E on the quality of broiler meat and meat products

1. The effect of dietary fat and vitamin E supplementation on quality attributes (drip loss, oxidative stability, sensory quality) in chicken meat and meat products was investigated. Broiler chicks were fed on diets containing tallow (60 g/kg) or olive oil (60 g/kg) at a basal (30 mg/kg diet) or supplemental (200 mg/kg diet) concentration of alpha-tocopheryl acetate for 8 weeks. The alpha-tocopherol content and fatty acid composition of breast and thigh meat was determined. Drip loss was determined in breast fillets. Lipid oxidation (thiobarbituric acid-reacting substances/TBARS) and sensory quality (warmed-over flavour development/WOF) were assessed in minced thigh meat during storage. 2. Dietary olive oil increased the ratio of monounsaturated to saturated fatty acids (MUFA/SFA) in the diets. In breast and thigh, this resulted in approximately a two-fold increase in the MUFA/SFA ratio. Supplemental alpha-tocopherol increased the alpha-tocopherol content of muscles. 3. Dietary fat did not influence drip loss in thawed breast fillets during refrigerated storage, but supplemental alpha-tocopherol reduced drip loss. 4. TBARS and WOF development in minced thigh meat patties were also reduced by supplemental alpha-tocopherol following frozen storage, or cooking and refrigerated storage. Storage stability was not adversely affected by dietary fat. 5. Overall, the results showed that increasing the monounsaturated profile of chicken meat lipids did not adversely affect quality characteristics. Dietary alpha-tocopherol supplementation was a more important factor in the determination of broiler meat quality.     

Effects of dietary supplementation with carnosine on meat quality and antioxidant capacity in broiler chickens

1. This study aimed to investigate the effects of carnosine supplementation on meat quality, antioxidant capacity and lipid peroxidation status in broiler chickens.

2. A total of 256 1-d-old male Arbor Acres broilers were randomly assigned to 4 treatments consisting of 8 replicates of 8 chickens each. The birds were supplied with 4 different diets: a basal diet or a basal diet supplemented with 100, 200 or 400 mg/kg carnosine, respectively. The whole experiment lasted 42 d.

3. The results showed that dietary supplementation with carnosine linearly increased the values of pH_45 min and redness and reduced drip loss of breast meat. Dietary carnosine increased the activity of antioxidant enzymes in liver, serum and breast meat and decreased the contents of lipid peroxides at 21 and 42 d of age.

4. These findings indicated that dietary supplementation with carnosine was beneficial to enhance meat quality, antioxidant capacity and decrease lipid peroxidation status of breast meat.