Effect of amino acid deficiency on precaecal amino acid digestibility in broiler chickens

In this study, we determined whether deficient dietary amino acid (AA) concentrations influence the precaecal (pc) AA digestibility when determined using the regression approach. We mixed two basal diets. Basal diet 1 was deficient in essential AAs, whereas adequate AA concentrations were ensured in basal diet 2 by adding free AAs. Rapeseed cake and full‐fat soya beans as test ingredients were included in the basal diets at levels of 100 and 200, and 150 and 300 g/kg, respectively, at the expense of maize starch. Each diet was tested with six replicates of 10 broiler chickens each. The feed intake of the chickens that were fed diets based on basal diet 2 was similar, whereas the feed intake of the chickens that were fed diets based on basal diet 1 differed considerably. The numerical differences in pc AA digestibility determined with basal diet 1 or 2 ranged from 2.6 percentage points to 20.8 percentage points in rapeseed cake and from 0.5 percentage points to 15.2 percentage points in soya beans. Across all measured AAs, the average differences were 10.1 percentage points and 5.4 percentage points in rapeseed cake and soya beans, respectively. The differences in the estimated pc AA digestibility between the basal diets were probably caused by different basal endogenous AA losses in the digesta between treatments as a consequence of different feed intake. Adequate AA concentrations and test ingredient levels that are specifically adjusted to avoid a negative effect on feed intake are recommended for future studies.     

动物营养代谢中的酸碱平衡

动物维持正常的酸碱平衡,是发挥机体细胞整体功能效应的必要前提。当某种酶活性对微小ｐＨ值变化敏感时,许多中间代谢产物反应,调控着动物细胞酸碱平衡。酸碱平衡是氢离子浓度的一种功能。当难于测定细胞内液和亚细胞内ｐＨ变化时,一般测定细胞外液中氢离子浓度,大多数哺乳动物细胞外液氢离子浓度维持在低水平状态(40×10-9ｍｏｌ/Ｌ或40ｎＥｑ/Ｌ,ｐＨ74)。细胞内液氢离子浓度比细胞外液高,哺乳动物肌肉细胞胞液ｐＨ值67～71变化,这种差异是维持细胞内代谢产物浓度的重要因子。但在细胞内,亚细胞器与胞液间也存在氢离子浓度差异。线粒体内…     

CNCPS氨基酸模型评定奶牛氨基酸供给和需求

1　氨基酸供应量奶牛可吸收且最终能够利用的氨基酸是由瘤胃微生物合成的蛋白、日粮过瘤胃蛋白和分泌到消化道中的内源性蛋白来提供 (Richardson和Hatfield ,1978)。以Russell等 (1992 )和Sniffen等 (1992 )的模型作为基础而得出氨基酸供应模型 ,用其模型可估计由瘤胃微生物合成的蛋白和由日粮过瘤胃蛋白提供的氨基酸量。由于描述奶牛内源性分泌的氨基酸数量资料有限 ,模型不考虑由内源性分泌蛋白提供的氨基酸量 (Mantysaari等 ,1989)。因此 ,在模型中 ,依据由瘤胃微生物蛋白和日粮过瘤胃蛋白而得到的氨基酸量 ,来确定由特定日粮而获得的…     

蛋鸡理想氨基酸比率的研究

<正>产蛋母鸡的氨基酸需要量是美国国家科学研究委员会(NRC)在1994年公布的。然而,这些需要量现已过时,因而不能适应大约1990年以来所取得的遗传进展。     

The amino acid requirements of the growing chick. I. Determination of amino acid requirements

The amino acid requirements of the growing chick have been determined using a diet based on soybean meal and maize meal. The diet contained 18% protein (N% x 6.25, dry matter basis) made up to 14% contributed by conventional ingredients and 4% protein equivalent in the form of amino acids. Starting with a diet formulated to meet the reference levels recommended by Dean and Scott (1965) a programme of experiments was carried out to improve this amino acid balance. The results indicated that the growing chick requires not more than 0.53% threonine, 0.61% glycine, 0.79% valine, 0.62% isoleucine, 1.34% leucine, 0.75% phenylalanine (or 1.3% phenylalanine plus tyrosine), 0.85 % lysine, 0.4% histidine, 0.86% arginine, 0.17% tryptophan and 0.39% methionine (or 0.79% methionine plus cystine).     

Modeling amino acid requirements of poultry

Poultry nutritionists should constantly evaluate their feeds and feeding programs in view of the changes that continue to be made to the potential growth rate of broilers and egg production in laying hens with the objective of providing the birds with the optimum economic level of nutrients at all times. In this review, the models generated at Universidade Estadual Paulista (UNESP) Jaboticabal, to estimate the optimum intake of amino acids (AA) for broilers and laying hens are presented. These models were used to estimate the variation in AA intake within a broiler population making use of coefficients of variation that represent the real situation in a commercial broiler operation. The range of AA intakes obtained was compared to some commonly applied feeding programs and recommendations. Based on results of our developed models and other feeding programs, feeds were formulated and growth was predicted using a growth simulation model (Avinesp). The prediction of growth showed that these models are reliable and useful tools to assist the nutritionists in decision making. In a study with laying hens, the Reading model (RM) was used to establish optimum economic AA intakes in a flock of hens. The input variables were the means and standard deviations of egg output and BW, and the relationship between the marginal cost of the AA and the marginal revenue for eggs. Based on this model, the optimum intake of each AA can vary with each of the variables considered. The models proposed in our study enable important decisions to be made regarding AA intakes to be used to obtain optimum economic performance from a population of broilers and laying hens.     

氨基酸转运载体的研究进展

氨基酸转运载体是介导氨基酸跨膜转运的膜蛋白,在医学、营养等生命科学领域有着重要的研究意义。本文就氨基酸转运载体家族成员及组织分布,生物学特征、生理功能和影响因素等方面进行了综述。     

我国饲用氨基酸市场现状分析

氨基酸种类主要有赖氨酸、蛋氨酸、谷氨酸盐、支链氨基酸及苯丙氨酸等,可用作饲料添加物、仪器添加剂、保健品及药物,畜禽养殖中常用的氨基酸是赖氨酸、蛋氨酸。近些年来氨基酸市场持续增长,最新的一项关于全球氨基酸市场发展的研究报告指出：直到2013年止,全球氨基酸市场将以每年6．8％的速度递增,中国是全球氨基酸市场的领导者,2006年其市场占有率达到了25％。报告还指出,至2013年,中国氨基酸领导地位仍可保持,但市场占有率可能会略有下降,占23．4％。而北美洲则是增长步伐最快的地区,由2000至2013年,估计年度增长率达8％,并可于2013年挑战中国的领导地位。     

Homeostatic responses to amino acid insufficiency

This article provides a brief overview describing how two key signaling pathways, namely the integrated stress response and the mammalian target of rapamycin complex 1, work together to facilitate cellular adaptation to dietary amino acid insufficiency. A deeper understanding of these mechanisms is leading to identification of novel targets which aid in disease treatments, improve stress recovery and increase health span through slowed aging and enhanced metabolic fitness.     

The amino acid taurine--physiology and pathophysiology]

In this review, the main aspects of our knowledge of the physiology and pathophysiology of the beta-amino sulfonic acid taurine will be summarized. After shortly considering the chemistry, the occurrence and the metabolism of taurine, the biological functions of taurine in the mammalian organism will be dealt with. With respect to taurine deficiency, this review will be limited to the cat since taurine is an essential nutrient for this species.     

Possibility of amino acid nutrition in broiler

The consumption of poultry meats exceeds 50% of total meat consumption. With the outbreak of bovine spongiform encephalopathy and foot and mouth disease, the consumption of poultry meat is set to increase. The use of meat bone meal derived from cattle and pigs is prohibited. Therefore, plant protein has to be used more frequently and the importance of the study of amino acid nutrition is increasing. In order to improve dietary efficiency, it is necessary to elucidate the exact amino acid requirements of poultry. The amino acid requirements are not constant and are affected by various factors. By using the plasma amino acid concentration as a parameter, it is possible to predict the amino acid requirements within a short period using a small number of animals repeatedly. By satisfying the amino acid requirements through supplementing crystalline amino acids, it is possible to reduce dietary protein and excretory nitrogen simultaneously. However, when the dietary protein is reduced, the abdominal fat tends to increase. This is solved by deciding the optimum dietary protein level, but it is difficult to control the taste of poultry meat by dietary amino acids.     

Plasma amino acid concentrations in aggressive dogs

Following the hypothesis that metabolic screens may be useful tools in the diagnosis of canine aggression we have investigated the blood plasma amino acid levels of dogs which have been found aggressive (N = 10) against dogs or men in comparison to non-aggressive dogs (N = 10). In summary, the aggressive dogs showed elevated plasma concentrations of the neurophysiological active aromatic amino acids tryptophan (46/171 micromol/l, p < 0,001), tyrosine (38/67 micromol/l, p < 0.01) and histidine (74/91 micromol/l, p < 0.01) and lower lysine concentrations (175/151 micromol/l, p < 0.05), which seems to point to a stress situation of these dogs. The nitrogen metabolism is impaired in the urea-cycle in the conversion of ornithine (17/34 micromol/l, p < 0.01) to citrulline (64/47 micromol/l). Higher levels of branched chain amino acids, especially leucine (122/150 micromol/l, p < 0.01), mainly metabolized in muscles, and isoleucin (60/71 micromol/l, p < 0.05) show a high energy potential.The acidose-stimulator methionine (48/78 micromol/l, p < 0.01) proved elevated. The results show that the changed behavior in the aggressive dogs is also reflected in their free amino acid plasma concentrations, independent of the question whether these data are the cause or the result of the aggressivity.     

瘤胃保护性氨基酸(RPAA)产品及其饲用效果的影响因素

<正>反刍动物蛋白质营养的实质和核心是氨基酸营养。国内外大量的研究表明,赖氨酸(Lys)和蛋氨酸(Met)是泌乳奶牛饲喂玉米为基础日粮合成蛋白质时的第一或第二限制性必需氨基酸。在制作日粮配方时,尤其对高产动物需要较高的瘤胃非降解蛋白(RUP)日粮时,只能通过饲料蛋白质添加物来达到预期的代谢蛋白质(MP)中Lys和Met的含量。而添加结品型的Lys和Met没有效果,因为它们在瘤胃中迅速     

肉鸡日粮的适宜氨基酸水平

<正>随着人们对肉鸡胸肌及其相关增值产品需求量的增加,肉鸡行业迅猛发展。与以前相比,肉鸡达到上市体重所需的时间更短。Fancher等[1]报道,过去十年,通过几家主要遗传育种公司的基因改良,肉鸡单位增重的耗料量更低。因此,为充分发挥生产性能,现代肉鸡对日粮氨基酸的需要量有所增加。在美国,日粮中氨基酸的增补有两个不同的营养策略:一是成本最低化导向的低氨基酸浓度;二是胸肌产量最大化导向的高氨基酸浓度。     

西藏冰川棘豆氨基酸含量的测定结果分析

应用Beckman 121MB型氨基酸自动分析仪测定了西藏冰川棘豆中氨基酸的含量。分析结果表明,冰川棘豆中含有天冬氨酸、谷氨酸、亮氨酸等17种氨基酸,总含量为8.409 g/100g。     

过瘤胃氨基酸在反刍动物饲料中的应用

本文综述了过瘤胃赖氨酸及蛋氨酸在反刍动物饲料中的应用,旨为过瘤胃氨基酸在反刍动物生产中的合理使用提供理论依据。     

洋虫氨基酸成分分析

本研究对洋虫Palembus dermestoides(Fairmaire)的幼、成虫氨基酸成分进行分析,结果表明,洋虫体内含有17种氨基酸,其中含有7种人体必需氨基酸,幼、成虫总氨基酸含量分别为51.15%和41.43%,幼、成虫必需氨基酸含量分别为18.36%和16.09%.洋虫是一种氨基酸种类齐全、营养丰富的资源昆虫.