精氨酸族氨基酸在猪营养与生产中的重要作用〈上篇〉

精氨酸、谷氨酰胺、谷氨酸、脯氨酸、天冬氨酸、天冬酰胺、鸟氨酸和瓜氨酸可在大多数哺乳动物（包括猪）体内通过复杂的器官间代谢进行相互转化。小肠、肾脏和肝脏是这些氨基酸代谢的主要场所,皮质醇则是这些代谢的一个重要调控激素。由于这些氨基酸（除鸟氨酸和瓜氨酸之外）通常大量地存在于植物和动物的组织蛋白中,所以养猪生产者习惯上不大关心猪日粮中精氨酸族氨基酸的添加问题。然而,最近的研究结果表明,这些氨基酸在养分代谢和免疫应答上起着重要的调控作用,从而会影响猪的饲料利用率。精氨酸和谷氨酸就是其中的典型代表,它们具有明确的功能,因此被广泛地应用于猪肉生产中。由瓜氨酸在小肠中合成减少所引起的精氨酸缺乏,是限制哺乳仔猪获得最佳生长性能的主要因素。酶学和代谢学研究结果均表明,对于7～21日龄哺乳仔猪而言,肠上皮细胞线粒体内N－乙酰谷氨酸的生物利用率低下应为通过谷氨酸和脯氨酸合成瓜氨酸受到阻碍负责：因此,无论在日粮中添加精氨酸还是口服N－胺基甲基麸胺酸（N—carbamylglutamate,N－乙酰谷氨酸的一种稳定的代谢类似物）都能提高哺乳仔猪的肌肉蛋白合成率和增重。此外,在早期断奶的仔猪日粮中添加谷氨酸已可防治其小肠萎缩,并且提高了仔猪的生长性能。值得注意的是,在妊娠30～114d的小母猪日粮中添加精氨酸,也会显著地提高产活仔数和窝初生重。大规模地使用饲料级精氨酸和谷氨酰胺为提高全球养猪生产的动物健康和养分利用率展现了广阔的前景。     

精氨酸营养(一):精氨酸族氨基酸在猪营养与生产中的重要作用<下篇>

上期回顾:上期主要介绍了母猪乳汁中精氨酸族氨基酸的含量及其在哺乳母猪乳腺组织中的代谢,和谷酰胺和胱氨酸在仔猪营养中的作用. 4 精氨酸在新生仔猪营养中的作用 4.1 精氨酸合成对维持其在哺乳仔猪体内的自动动态平衡所起的关键作用     

精氨酸族氨基酸在猪营养在生产中的重要作用〈下篇〉

4精氨酸在新生仔猪营养中的作用 4．1精氨酸合成对维持其在哺乳仔猪体内的自动动态平衡所起的关键作用 对于幼龄仔猪来说，精氨酸是一种必需氨基酸（Southern和Baker，1983；Roth等，1995；Urschel等，2006）。虽然精氨酸可经鸟氨酸循环在肝脏中合成，但由于能够快速水解精氨酸的胞质精氨酸酶具有极高的活性（Wu和Morris，1998），使肝脏不能实现精氨酸的净合成（Urschel等，2005）。     

猪的支链氨基酸营养

支链氨基酸是对亮氨酸、异亮氨酸和缬氨酸的统称,对提高猪（尤其是泌乳母猪）的生产性能有重要作用。本文重点从支链氨基酸的生物学作用、对猪生产性能的影响及其需要量等方面进行综述。     

含硫氨基酸在猪营养中的研究进展

养猪业是我国畜牧生产中的主要组成部分,发展养猪业势必要发展猪饲料,而由蛋氨酸、胱氨酸和半胱氨酸组成的含硫氨基酸是氨基酸的重要组成部分,其中蛋氦酸是猪的第二限制性氨基酸,是猪不可或缺的营养元素。本文主要介绍了含硫氨基酸的理化性质、代谢机制、生物学功能以及在猪营养中的研究进展。     

功能性氨基酸营养——精氨酸

近年来，人们对氨基酸在物质代谢和免疫功能调控中所起的作用越来越感兴趣，并提出了功能性氨基酸的概念。功能性氯基酸除了合成蛋白质外还具有其他特殊功能，不仅对动物的正常生长及维持是必需的，而且对多种生物活性物质的合成也是必需的，在日粮中添加功能性氨基酸可大大提高动物的营养状况和生产性能。鉴于此，《新饲料》杂志与现龙（长沙）生物科技有限公司合作在2009年第10期开办“特别关注”栏目，     

饲粮中锌的作用及其在猪生产上的应用

锌是动物体内重要的微量元素,在动物体内具有重要的生理作用.在猪生产上,缺乏锌元素容易造成猪采食量降低、生产性能下降、皮肤及被毛损害,严重时能够导致公猪生殖器官发育不良,导致母猪繁殖力下降等.     

氨基酸螯合锌在动物生产中的应用

氨基酸螯合锌是一种有机微量元素添加剂,与无机锌相比,氨基酸螯合锌具有其独特的优点,如能减轻锌对其他矿物元素的颉颃作用,促进锌和其他矿物元素的吸收,减少锌排出对环境造成的污染.实际生产中,氨基酸螯合锌能提高动物生产性能和饲料利用率,还具有抗生物氧化、抗应激和提高机体免疫等功能.     

Triennial Growth Symposium: important roles for L-glutamine in swine nutrition and production

L-Glutamine (Gln) has traditionally not been considered a nutrient needed in diets for livestock species or even mentioned in classic animal nutrition textbooks. This is due to previous technical difficulties in Gln analysis and the unsubstantiated assumption that animals can synthesize sufficient amounts of Gln to meet their needs. Consequently, the current (1998) version of NRC does not recommend dietary Gln requirements for swine. This lack of knowledge about Gln nutrition has contributed to suboptimal efficiency of global pig production. Because of recent advances in research, Gln is now known to be an abundant AA in physiological fluids and proteins and a key regulator of gene expression. Additionally, Gln can regulate cell signaling via the mammalian target of rapamycin pathway, adenosine monophosphate-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and nitric oxide. The exquisite integration of Gln-dependent regulatory networks has profound effects on cell proliferation, differentiation, migration, metabolism, homeostasis, survival, and function. As a result of translating basic research into practice, dietary supplementation with 1% Gln maintains gut health and prevents intestinal dysfunction in low-birth-weight or early-weaned piglets while increasing their growth performance and survival. In addition, supplementing 1% Gln to a corn- and soybean-meal-based diet between d 90 and 114 of gestation ameliorates fetal growth retardation in gilts and reduces preweaning mortality of piglets. Furthermore, dietary supplementation with 1% Gln enhances milk production by lactating sows. Thus, adequate amounts of dietary Gln, a major nutrient, are necessary to support the maximum growth, development, and production performance of swine.     

精氨酸在猪营养中应用的研究进展

内源合成以及传统日粮供给的精氨酸并不能完全满足猪的最佳营养需要,因此需外源添加精氨酸,其对猪的生长、发育及繁殖具有重要意义.本文综述了精氨酸在不同阶段猪营养中应用的研究进展.     

氨基酸对妊娠母猪繁殖性能的影响及其作用机理(续完)

<正>上期回顾:上期介绍了母猪窝产仔数受影响的因素、养猪生产中胎儿宫内发育迟缓问题、胎盘在胚胎发育中的作用主氨基酸在胎盘生长中的作用。5氨基酸对胎儿肌肉和脂肪组织生长发育的影响研究表明,妊娠期间母体的蛋白质营养会影响出生后仔猪的肌肉生长和肌内脂肪的含量(Rehfeldt等,2004)。肌细胞和脂肪细胞来源于普通的造血前体细胞     

Effects of excess arginine on swine growth and plasma amino acid levels

One hundred seventy-six crossbred weaned pigs (4 to 5 wk old) were used in two growth trials to determine the effect of excess arginine on pig growth and plasma amino acid levels. In the first 28-d growth trial, two lysine levels (1.03 and 1.26%) and three arginine levels (.94, 1.29 and 1.63%) were used in a nested treatment arrangement. Lysine supplementation improved daily gains (P less than .05), tended to improve feed efficiency (P less than .12) and caused a general reduction in plasma essential amino acid levels. Arginine had no effect on daily gain or feed intake, but pigs fed 1.03% lysine and 1.63% arginine had reduced gain/feed (P less than .05). Arginine did not affect gain/feed of pigs fed 1.26% lysine. Plasma lysine levels were reduced (P less than .06) by excess arginine in pigs fed 1.26% lysine, but not in pigs fed 1.03% lysine. The four treatments for the second 26-d growth trial consisted of three diets containing .92% lysine and either .72, 1.10 or 1.61% arginine and a positive lysine control (1.10% lysine, .72% arginine). Lysine was the limiting amino acid in the basal diet, but arginine had no effect on daily gain, daily feed intake, gain/feed or plasma lysine levels. Plasma threonine and methionine levels were reduced by excess arginine in both experiments, while the other plasma essential amino acid levels were not affected by dietary arginine. Conclusions are that large excesses of added arginine may affect lysine utilization, but pig performance was affected only when excess arginine was combined with a lysine deficiency. The arginine levels similar to those found in grain-soybean meal swine diets had no effect on pig performance in these experiments.     

支链氨基酸在动物营养中的研究进展

支链氨基酸作为动物的必需氨基酸,具有重要的营养作用.本文对支链氨基酸的生理代谢特点、生理功能、营养需求量及其在畜禽营养中的应用进行了综述.     

氨基酸过瘤胃保护方法及其在奶牛营养中的应用

保护性氨基酸是调控奶牛小肠氨基酸平衡最直接有效的方法。作者主要就氨基酸的保护方法、保护性氨基酸的应用效果及保护性氨基酸效果的检测方法进行了综述。