乌骨鸡日粮蛋氨酸、赖氨酸、苏氨酸需要量的研究

单因子试验设计,将1日龄丝毛乌骨鸡雏200只,随机分为10组,每组20只,逐只带翅号,研究0～12周龄乌骨鸡对日粮蛋氨酸、赖氨酸、苏氨酸的营养需要。以乌骨鸡生产性能和经济效益为判断依据,乌骨鸡几种氨基酸营养需要(%)为:0～4周龄蛋氨酸0.32,赖氨酸0.90,苏氨酸0.87;5～8周龄蛋氨酸0.29,赖氨酸0.77,苏氨酸0.78;9～12周龄蛋氨酸0.28,赖氨酸0.76,苏氨酸0.77。     

乌骨鸡日粮氨基酸消化率的研究

选用96只150日龄体重1．4kg的成年乌骨公鸡，进行代谢试验，测定了玉米、麸皮、豆粕、肉骨粉、菌糖蛋白等饲料氨基酸的表观消化率和真消化率，为乌骨鸡日粮的合理配制提供了科学依据。     

过量赖氨酸对产蛋鸡日粮氨基酸消化率影响的研究

赖氨酸是产蛋鸡日粮的第一限制性氨基酸，其含量的高低和同其他氨基酸的比例直接影响着本身和其他氨基酸的消化吸收，对产蛋鸡的生产性能发挥起着重要的作用。Antis等（１９８０）报道，过多的赖氨酸使蛋鸡的产蛋率显著下降。蒋辉等（２００１）产蛋鸡的试验表明，０．８％的赖氨酸处理组产蛋率显著低于０．７％的赖氨酸水平处理组，０．８％赖氨酸水平处理组破蛋率显著高于０．７％处理组（P＜０．０５）。翟少伟（２００２）用优质蛋白玉米日粮饲喂产蛋鸡也有类似的报道。可见，赖氨酸对产蛋鸡生产性能的影响主要体现在产蛋率和软破蛋率…     

瘦肉猪饲养：赖氨酸和蛋氨酸及其他氨基酸营养进展

养猪生产者在不断寻求较快速、较经济的方法生产瘦肉率更高、品质更优的胴体。由于消费者抵制使用生长促进剂,猪肉生产者将注意力集中在遗传学方法上。但最近研究表明,通过日粮蛋白质的调控和特定地平衡日粮氨基酸以维持肌肉最佳生长需要,可以获得瘦肉率高的猪肉。最近Supersweet饲料公司生产出一种专供瘦肉率高的猪使用的猪饲料,这种饲料能够满足生长猪前五种限制性氨基酸(赖氨酸、蛋氨酸、色氨酸、苏氨酸和异亮氨酸)的需要。饲喂这种氨基酸平衡日粮猪的肥育期,比饲喂高赖氨酸、高脂肪含量的猪缩短了15天,并且试验猪的平均日增重和饲料效     

日粮蛋氨酸水平对泰和乌骨鸡生长性能影响研究

中国泰和鸡，又名白毛乌骨鸡、武山鸡、药鸡，原产江西泰和县，具有丛冠、缨头、绿耳、胡须、白丝毛、毛脚、五爪、乌皮、乌肉、乌骨等十大特征，是我国特有的珍贵家禽。1874年被列为国际标准品种。2001年已列为农业部首批公布确定的87个国家级畜禽保护品种之一。并曾搭乘“神舟3号”进行空间试验，这充分说明国家对泰和鸡的研究、保护和利用十分重视。     

日粮蛋白质、赖氨酸水平对生长猪生产性能及蛋白质、氨基酸消化率的影响

试验旨在研究日粮蛋白质和赖氨酸水平对生长猪生产性能及蛋白质、氨基酸消化率的影响.90头平均体重为(44.0±2.0)kg的杜长大三元阉公猪随机分为5个组,每组3个重复,每重复6头猪;1组为对照组(粗蛋白为17.47%、可消化赖氨酸为0.80%),2组～5组为试验组,试验组采用2×2因子设计,蛋白质水平为15.46%和1...     

肉鸡日粮中赖氨酸和蛋氨酸是独立发挥作用的

由于赖氨酸被定为“理想蛋白质”概念中的参考氨基酸，有些人就错误地认识这一原理，他们在配合日粮时只是简单地使其它氨基酸保持与赖氨酸的理想比率，即使日粮中赖氨酸的含量超过了实际需要量也是如此。本研究的结果表明，当日粮中赖氨酸和蛋氨酸的含量等于或高于NRC(1994)的推荐量时两之间并无显的相互作用。     

日粮赖氨酸、蛋氨酸水平对不同性别肉鸡生长性能的影响

本试验研究日粮赖氨酸或蛋氨酸水平对不同性别肉鸡生长性能的影响以及与血清总蛋白和尿酸含量之间的关系。试验１日粮采用３个赖氨酸水平（１．２％，１．３％和１．３５％）。试验２日粮采用３个蛋氨酸水平（０．２５％，０．４５％和０．５５％）。结果表明，公鸡比母鸡生长速度快（１４％～１６％），饲料报酬高。公鸡随着日龄的增长，对日粮赖氨酸的需求降低，从１．３５％降至１．２％。采食较低水平的赖氨酸（１．２％），母鸡就可达到较快的生长速度。母鸡比公鸡较早地可以降低其日粮中的蛋氨酸水平。本试验的结论是，公母肉鸡对日粮赖氨酸或蛋氨酸的需求与利用具有不同的特点。母鸡对日粮中赖氨酸或蛋氨酸的需求比公鸡低，利用效率比公鸡高。母鸡的生长速度与其血清中尿酸水平呈显著的负相关。母鸡的生长速度越快，其血清中的尿酸水平越低。     

低蛋白质蛋鸡日粮添加蛋氨酸和赖氨酸的效果

在低蛋白质日粮中,添加两种限制性氨基酸蛋氨酸和赖氨酸,研究其对蛋鸡生产性能及产品质量的影响,以期为蛋氨酸和赖氨酸在蛋鸡饲料中应用提供依据。试验于2000年9月至11月在北华大学农业技术学院畜牧实验养殖场进行。 1.材料与方法 1.1试验动物与分组 试验选用高峰期海赛克斯蛋鸡384只,随机平均分成4组:一个对照组,三个试验组,每组2个重复,每个重复48只鸡。     

Ileal amino acid digestibility assay for the growing meat chicken--comparison of ileal and excreta amino acid digestibility in the chicken

1. The apparent and true amino acid digestibilities in sorghum, wheat, soyabean meal, meat-and-bone meal, fish meal and blood meal for growing meat chickens were determined using an assay based on the collection of digesta from the terminal ileum and comparison was made with digestibility values determined using an excreta-based assay. 2. Five-week-old meat chickens were given maize-soyabean meal basal diet or mixtures of the basal diet and test diets containing the 6 ingredients as the sole source of dietary protein (50:50 on weight basis). Apparent amino acid digestibility values of assay diets at ileal and excreta levels were calculated using chromic oxide as the indigestible marker. True digestibility values were calculated using endogenous outputs determined by feeding a protein-free diet. Amino acid digestibilities of the ingredients were calculated by difference. 3. The site of measurement had no influence on endogenous amino acid output, the exceptions being aspartic acid and glutamic acid. The output of these two amino acids was higher in the excreta. 4. Significant differences were found between ileal and excreta-based digestibility of certain amino acids in some ingredients, with excreta values being usually higher than the ileal values, indicating a net catabolism of amino acids in the large intestine. The degree of net amino acid disappearance was found to be variable among amino acids and ingredients. In general, threonine had the lowest digestibility at the ileal level and, compared with other amino acids, the highest degredation during passage through the hindgut. 5. The results showed that digestibility determination based on excreta collection will overestimate the uptake for some amino acids in some feeds. The degree of overestimation was often considerable, ranging from 8.9% (apparent digestibility of threonine in soyabean meal) to 56% (apparent digestibility of aspartic acid in wheat). It is concluded that digestibility values measured at the terminal ileum provide a more reliable measure of amino acid availability than those measured in the excreta.     

Sulphur amino acid requirement of laying hens and the effects of excess dietary methionine on laying performance

1. Individually‐caged laying hens were fed on maize‐soya bean meal diets containing 11.50 or 12.35 MJ ME/kg with sulphur amino acid (SAA) contents varying from 5.0 to 7.0 g/kg in period 1 (0 to 20 weeks); from 5.0 to 8.0 g/kg in period 2 (21 to 36 weeks) and from 5.0 to 10.0 g/kg in period 3 (37 to 52 weeks).

2. A SAA requirement of about 750 mg/hen d, of which about 425 mg was methionine, was found to be adequate for birds producing on average 51 g egg mass per hen d over 52 weeks. The SAA requirement was found to be higher for maximum efficiency of food utilisation than for maximum egg yield.

3. A diet containing 140 g protein/kg adequately supplemented with methionine and lysine, could sustain laying performance almost identical to that achieved on a diet containing 167 g protein/kg.

4. In diets with 140 g protein/kg the addition of 0.5 to 3.5 g dl‐methionine/kg diet in excess of the requirement did not affect egg production adversely, but food conversion efficiency was decreased.     

An estimate of the methionine requirement and its variability in growing pigs using the indicator amino acid oxidation technique

Although AA requirements for the mean of a population of growing pigs have been established using traditional methods, there are no estimates of the variability within the population and whether this variation differs among AA. With the increased use of supplemental Lys in pig diets, there will be an increased need to supplement Met, commonly the second or third limiting AA in corn-soybean diets. The indicator AA oxidation method allows repeated measurements in a short period of time so that the AA requirement can be determined for individual pigs at a similar physiological stage. The objective of this study was to determine the mean Met requirement in individual gilts and to estimate the related variability. Six individually housed female pigs (initial BW = 8.8 kg, SD 1.5) each received diets providing 6 levels of dl-Met. The isonitrogenous and isoenergetic diets contained 0.187, 0.250, 0.290, 0.320, 0.350, and 0.377% Met (analyzed, as-fed basis). Cysteine (0.48%) and Lys (1.44%) concentrations were similar for all diets. Pigs were adapted for 6 d to the basal corn-soybean meal diet (0.187% Met), which was offered at 95 g/kg(0.75) of BW to ensure complete consumption of the test diets. During 4-h oxidation studies, 313.4 kBq, (SD 35.6) of L-[1-(14)C]Phe was mixed with each of 8 half-hourly meals, and expired CO(2) was collected. The breakpoint in Phe oxidation, representing the Met requirement, and its variability, was determined using 2-phase linear regression. Phenylalanine oxidation decreased as the Met content increased from 0.187 to 0.29%. Phenylalanine oxidation was not different (P > 0.2) for diets ranging from 0.320 to 0.377% Met. The dietary Met requirement varied from 0.320 to 0.373% for individual pigs. The mean Met requirement for individual pigs was determined to be 0.340% of diet (SD = 0.024%, CV= 7.1%), with 0.340, 0.364, and 0.388% covering the requirement of 50, 66, and 95% of the population, respectively. The present mean population estimate was similar to the recommended dietary Met concentration of 0.325% for pigs of this BW and feed intake. To maximize profitability, Met levels in starter pig diets should be determined, depending on the cost of crystalline Met and the fraction of the population whose requirement is to be met.     

Activity of and requirement for selected amino acids in growing female pigs. 1. Lysine

In N balance experiments with a total 59 growing female pigs in the live weight range of 33 to 55 kg the lysine efficiency (bc-1 value) and the lysine efficiency coefficient (kLys) of various cereal proteins were ascertained under the consideration of various charges and varieties. The range of kLys = 0.65 ... 0.96 shows a wide spectrum of lysine efficiency, which results in an analogous differentiation of the derived lysine requirement values. Assuming kLys = 1.0 (lysine efficiency 100%, i.e. the maximum value for bc-1 found as yet for native proteins) a daily lysine requirement (efficient amino acid) of 8.9, 10.8 and 12.6 g resp. was ascertained for 100 g daily protein retention at 30, 40 and 50 kg live weight resp.     

家禽蛋白质和氨基酸的维持代谢

蛋白质及氨基酸的维持代谢比较复杂,一直是动物营养学研究的难点之一。维持需要作为一项基础研究,对于探索具有普遍意义的营养需要规律,比较不同动物或同一种类动物在不同的条件下的营养需要特点具有重要作用。文章就家禽氨基酸维持代谢的意义、途径,维持氨基酸需要量的研究方法及研究现状等几方面作以简单阐述。