胍基乙酸和甜菜碱的生理协同功能及其在反刍动物生产中应用的研究进展

胍基乙酸是一种氨基酸类饲料添加剂,是动物机体内合成肌酸的唯一前体物质。肌酸是合成磷酸肌酸组分之一,补充胍基乙酸可以间接提供能量。甜菜碱是良好的甲基供体,具有调节细胞渗透压、缓解应激反应、提高动物生长性能、改善肉品质以及减少脂质沉积的功能。因此,胍基乙酸和甜菜碱对动物机体生长具有积极的作用。文章阐述了胍基乙酸和甜菜碱的生理功能、协同作用以及二者单独使用、联合使用对反刍动物生产性能的影响,以期为其在动物生产实践中的应用提供参考。     

胍基乙酸及代谢产物肌酸的研究进展

胍基乙酸(guanidinoacetic acid,GAA)为肌酸(creatine)的天然前体,也称胍乙酸(guanidine acetic acid),是一种白色可溶于水的氨基酸衍生物。目前,胍基乙酸作为一种饲料添加剂广泛应用于动物生产中,以提高肌肉产量和胴体品质。本文综述了胍基乙酸的生理功能,包括刺激胰岛素释放、神经调节、改变精氨酸的代谢、调节细胞氧化状态,和胍基乙酸的代谢产物肌酸的功能,包括促进骨骼肌分化和抑制脂肪细胞分化。为后续胍基乙酸相关研究提供参考。     

胍基乙酸生物学功能及在动物生产上的应用

胍基乙酸作为重要的食品添加剂和饲料添加剂,在国内外有着广泛研究。研究成果涵盖猪、鸡、反刍动物及水产等经济动物,其有效性和安全性得到了国内外科学家普遍认可。文章旨在阐述胍基乙酸的性质和作用机理,并综述国内外对胍基乙酸在动物试验中的研究成果,以期为饲料发展和新时代保障动物高生产性能提供胍基乙酸的应用方案和参考意见。     

胍基乙酸对反刍动物消化代谢和生产性能影响的研究进展

胍基乙酸是动物体内肌酸合成的唯一前体物质，属于氨基酸类似物。胍基乙酸能够促进瘤胃微生物生长和微生物蛋白质合成，提高日粮中营养物质的消化率，促进机体内氮沉积；另外胍基乙酸能够提高肌酸供应，促进生长激素分泌，节约精氨酸。因此，胍基乙酸在改善肉品质、体脂分配和增重性能方面效果优良。本文综述了胍基乙酸对反刍动物消化代谢、增重性能和屠宰性能的影响，以期在反刍动物生产实践中提供理论基础。     

胍基乙酸在动物生产上的研究进展

胍基乙酸作为一种新型的饲料添加剂,对促进能量代谢,提高动物的生产性能,改善肉品质方面有显著作用。本文综述胍基乙酸畜禽生产中的研究进展,为后续的相关研究提供参考。     

胍基乙酸在家禽生产中的应用

胍基乙酸作为一种饲料添加剂,可促进肌酸的生物合成,从而促进细胞能量代谢,提高动物生产性能,改善酮体品质。本文就胍基乙酸在提高家禽生产性能,改善酮体品质,提高抗氧化应激反应能力以及改善繁殖能力等方面的作用进行综述。     

胍基乙酸对畜禽生产性能与肉品质的调控作用研究进展

胍基乙酸是动物体内肌酸的前体物,在机体内参与能量代谢调控。胍基乙酸作为一种新型营养性饲料添加剂,具有提高猪、鸡等动物生长性能、屠宰及繁殖性能、改善肉品质等作用。本文综述了近年来胍基乙酸在单胃动物和反刍动物上的的作用效果,主要表现在促生长的作用,提高瘦肉率与嫩度,并能减少脂肪合成,对改善肉鸡精液品质具有促进作用,为胍基乙酸在畜牧业上进一步研究做理论支撑和实践参考。     

胍基乙酸的体内代谢及与甜菜碱联合在动物生产上的应用

胍基乙酸是动物体内肌酸的前体物,经甲基化作用形成肌酸,参与体内能量代谢。本文综述了胍基乙酸在体内的代谢情况以及与甲基供体尤其是与甜菜碱联合应用的营养机理和作用效果,并对胍基乙酸进一步营养研究做了方向性展望。     

胍基乙酸在畜禽饲料中的应用研究进展

主要综述了胍基乙酸在畜禽料中的应用效果和作用机制,并结合文献报道分析了胍基乙酸应用的影响因素。总的来看,胍基乙酸对畜禽生产性能、胴体品质、肉品质和繁殖性能等均表现出了较好的改善效果,在畜禽料中胍基乙酸最适添加量可能为600～1 500 mg/kg,是一类比较有效的营养性添加剂。胍基乙酸的应用效果可能与其添加量、日粮营养水平、机体生理状况和配合应用方案有关。胍基乙酸与肌酸的应用效果存在差异、优化胍基乙酸的应用方案及开展相关代谢组学和分子机制研究仍是当前胍基乙酸应用研究的重点和热点。     

胍基乙酸配伍不同甲基组合物对肉仔鸡生产和屠宰性能的影响

为研究胍基乙酸配伍不同甲基组合物对肉仔鸡生产和屠宰性能的影响,试验选取1日龄AA肉仔鸡320只,随机分为5组,对照组饲喂基础日粮,试验组分别按摩尔比添加胍基乙酸和甲基组合物(蛋氨酸、甜菜碱),连续饲喂42 d,测定各组的的生产和屠宰性能指标。结果表明,胍基乙酸与甲基组合物合理配伍可以改善肉仔鸡生产和屠宰性能,其中按胍基乙酸4 mol配伍蛋氨酸2 mol、甜菜碱2 mol,可以显著降低料肉比(P0.05),按胍基乙酸4 mol配伍甜菜碱4 mol可以显著提高宰后全净膛率(P0.05)。     

胍基乙酸在反刍动物上的研究进展

胍基乙酸是一种氨基酸衍生物,也是一种重要的新型营养性饲料添加剂,其在国内外的应用效果已被普遍认可。本文从胍基乙酸的生理功能、对牛羊的生长性能和对牛羊屠宰性能及肉品质等方面进行了综述,得出了胍基乙酸能够提高反刍动物生产性能和屠宰性能及改善肉品质的结论,但也发现针对不同品种、性别和年龄等方面仍缺乏生产及机理性的研究。     

胍基乙酸对保育猪生长性能、抗氧化能力和糖代谢关键酶的影响

本试验旨在探讨胍基乙酸对保育猪生长性能、抗氧化能力和糖代谢关键酶的影响。选取体重为(19.03±1.30)kg的健康"杜×长×大"三元杂交仔猪64头,随机分为2组,每组4个重复,每个重复8头猪。对照组饲喂基础饲粮,胍基乙酸组饲粮在基础饲粮中添加600 mg/kg胍基乙酸。预试期7 d,正试期14 d。结果表明:1)与对照组相比,胍基乙酸组保育猪的平均日增重显著升高(P0.05),料重比显著降低(P0.05);2组间的末重和平均日采食量无显著差异(P0.05)。2)胍基乙酸组保育猪的血浆超氧化物歧化酶(SOD)抑制率、谷胱甘肽(GSH)含量和总抗氧化能力(T-AOC)显著高于对照组(P0.05),2组间的血浆丙二醛(MDA)含量无显著差异(P0.05)。3)胍基乙酸组保育猪的血浆果糖-6-磷酸激酶(PFK)、丙酮酸激酶(PK)、异柠檬酸脱氢酶(IDH)、苹果酸脱氢酶(MDH)、烟酰胺腺嘌呤二核苷酸-辅酶Q还原酶(NADHCo Q)和肌酸激酶(CK)活性均极显著高于对照组(P0.01),血浆己糖激酶(HK)活性有低于对照组的趋势(0.05≤P0.10),血浆三磷酸腺苷(ATP)合成酶(ATPase)活性有高于对照组的趋势(0.05≤P0.10)。由此可知,饲粮中添加胍基乙酸可改善保育猪的生长性能,提高其抗氧化能力,并可通过提高糖代谢关键酶(PFK、PK、IDH、MDH)及线粒体呼吸链相关酶(NADH-Co Q、ATPase)活性促进体内的分解代谢,提高机体ATP水平,进而可能促进储能组织(肌肉和脂肪)的合成。     

Factors affecting the in vitro production of volatile fatty acids by mixed bacterial populations from the bovine rumen

Factors affecting in vitro ruminal bacterial VFA production were examined. Treatments consisted of high and low initial pH (6.7, 5.7), osmolality (600, 400 mOsm) and concentrations of acetic (40, 0 mM) and propionic acids (20, 0 mM). Response variables measured included the production of acetic, propionic and total VFA, total gas and methane. Initial pH affected (P less than .05) most variables either independently or in combination with one or more of the other factors. Acetic acid production was reduced 40% (P = .03) when initial acetic acid concentrations were 40 mM compared with 0 mM. Also, acetic acid production was less (P less than .01) at low initial pH (5.7) than at high initial pH (6.7). Propionic acid production was greater (P = .05) at high vs low initial acetic acid concentrations. Propionic acid production was greater in response to low vs high initial osmolality, although the magnitude of this difference depended on initial pH (interaction P = .02). Total production of VFA was greater (P less than .01) at high than at low initial pH; however, at low initial pH, no difference (P greater than .05) was observed due to initial osmolality, whereas at high pH, production was greater (interaction P = .04) for low than for high initial osmolality. The diminished production of total VFA at pH 5.7 occurred primarily due to reduced acetic acid production, although increased production of propionic and butyric acids was noted.(ABSTRACT TRUNCATED AT 250 WORDS)     

Disappearance of acetic acid from the bovine reticulorumen at basal and elevated concentrations of acetic acid.

Disappearance of acetic acid was quantified to determine whether removal of this acid from the reticulorumen is altered when ruminal acetic acid concentrations are elevated. Ruminally fistulated beef steers (n = 3 per experiment; BW = 320 +/- 9 kg) were fed eight times daily a 46% corn-based concentrate:54% mixed hay diet to meet maintenance energy requirements (3.5 kg of DM/d). In situ production of acetic acid, determined by pulsed-continuous infusion of [1-14C]acetic acid, was 530 mmol/h (CV = 12%). Disappearance from the reticulorumen (i.e., presumed absorption) was 460 mmol/h (CV = 2%) or 87% (CV = 2%) of ruminal production. Variation is described within an operational steady state. Acetic acid concentrations were increased by continuous infusion of unlabeled acetic acid into the reticulorumen. Ruminal disappearance (mmol/h) increased when this simulated production was elevated up to and exceeding in situ rates reported previously (530 to 2,700 mmol/h). These data suggest that two-thirds to three-fourths of ruminal acetate production disappeared across the reticuloruminal wall when concentration was elevated; the complement exited from the rumen with the liquid phase. The reticulorumen has an additional capacity to remove acetic acid; however, it does so with an apparent reduced efficiency at higher production rates. Liquid out-flow may affect the efficiency of reticuloruminal disappearance. Sites distal to the rumen become quantitatively important when ruminal acetic acid concentrations are increased.     

瘤胃发酵产物乙酸和丙酸比对奶牛生产性能及乳成分影响的荟萃分析

本研究旨在探讨瘤胃发酵产物乙酸、丙酸以及乙酸和丙酸比对奶牛干物质摄入量（DMI）、产奶量（MY）和乳成分的影响。通过回顾已发表文献，使用荟萃分析的方法构建模型并进行相应的回归分析和相关性分析。试验整理了关于奶牛生产性能的中文及英文相关文献51篇，共计181个处理，研究不同的饲料原料、营养成分、饲料添加剂对不同生理阶段泌乳奶牛瘤胃发酵指标及生产性能的影响。基于此51项试验的荟萃分析结果表明，与瘤胃内乙酸和丙酸产量相比，奶牛的产奶量（R²=-0.426，P<0.01）、乳脂率（R²=0.359，P<0.01）、乳脂产量（R²=-0.257，P<0.01）、挥发性脂肪酸（VFA）（R²=-0.226，P<0.05）和干物质采食量（DMI）（R²=-0.485，P<0.01）与瘤胃发酵产物乙酸和丙酸比有更强的相关性；瘤胃乙酸和丙酸比与奶牛的产奶量、乳脂率、乳脂产量和DMI存在极显著的一元线性回归关系（P<0.01），其比值的增加会导致DMI、产奶量、乳脂产量极显著降低（P<0.01），乳脂率极显著升高（P<0.01），瘤胃乙酸和丙酸的比值每增加1，乳脂率增加0.26%，奶牛的干物质摄入量、产奶量分别减少2.34和4.99 kg。通过荟萃分析发现，乙酸与丙酸的比值可以更科学地预测乳脂在乳中的占比且准确反应牛奶乳脂率的变化，为饲粮的选取及调控乳品质提供了参考价值。     

过二硫酸盐提升奶牛养殖废水厌氧消化产甲烷性能研究

厌氧消化是实现奶牛场养殖废水资源化、无害化的常见处理方法,而传统厌氧消化的水解效率低,是影响厌氧消化推广应用的主要限制因素。结果表明,通过投加适量过二硫酸盐（Perdisulfate, PDS）能够有效提升奶牛养殖废水产甲烷效果与沼液的植物可利用性。在PDS投加量3.4 g/L时,产甲烷量提升最为明显,相较于未投加PDS的对照处理组,甲烷产量提升了130.00%。进一步对PDS提升厌氧消化产甲烷机理进行研究,结果表明,PDS投加能有效提高挥发性脂肪酸（Volatile Fatty Acids,VFAs）产量,其中乙酸产量的提高有利于乙酸型产甲烷过程。对试验样品的高通量测序证实了PDS处理提高了乙酸型产甲烷菌的相对丰度,PDS促进乙酸型产甲烷过程是提高甲烷产量的重要原因。     

Dependence of rumen fatty acid production on the composition of rations

In three experiments with two Black-and-White dairy cows the influence of soybean oil and coconut fat as well as that of rations rich in roughage and concentrated feed on the production of fatty acids were determined with the isotope dilution method. A change in the method of sampling from the rumen in the course of the investigations resulted in distinctly different absolute production quotas, which can presumably be traced back to the disproportionate mixing in of the isotope and/or different production quotas in various regions of the rumen. The relative differences between the production quotas dependent on the rations, however were approximately the same with both sampling methods, so that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation o that they make the comparison of the rations concerning rumen fermentation possible. The production of acetic acid and the total production of fatty acids (C2--C4) correlated closely both with the intake of digestible energy and the intake of digestible organic matter. There was also a highly significant correlation between the relation of acetic and propionic acid in the rumen fluid and the quotient from acetic and propionic acid produced. In contrast to this, a significant relation between the concentration of fatty acids and the production of fatty acids could not be ascertained. Soybean oil and coconut fat brought about a slightly better utilisation of the fat-free organic matter for the production of fatty acids in the rumen. This could mainly be traced back to the increased production of propionic acid. The production of acetic acid per kg fat-free organic matter was insignificantly reduced. A reduced quota of roughage in the ration as well as the use of feed fats resulted in a decrease in the production of acetic acid and an increase in the production of propionic acid. The influence of the quota of roughage, however, was bigger than that of the use of fats. When rations rich in roughage were given, the share the energy contained in the total fatty acids has in the total of the digested energy was, on an average of both animals, slightly lower in comparison to rations rich in concentrated feed. However, the reason for this is not to be found in a lower share the energy digested in the stomachs has in the total of digested energy but in a higher amount of fermentation losses with a nutrition rich in roughage.     

丁酸梭菌的功能性研究进展及其在畜禽生产中的应用

丁酸梭菌（Clostridium butyricum）又名丁酸梭状芽孢杆菌、酪酸梭菌,是一种产丁酸、乳酸和乙酸的厌氧异养的革兰氏阳性芽孢杆菌,具有耐高温、耐酸和耐多种抗生素等生物学特性。丁酸梭菌定植于畜禽肠道,可抑制肠道有害菌的生长,同时促进有益菌的增殖,有效提高畜禽对营养物质的消化吸收及其抵抗力,进而提高畜禽养殖经济效益。丁酸梭菌存在于土壤或健康动物的粪便中,具有绿色、无残留、安全性好,以及稳定性及耐药性强等特点,是一种具有广泛开发潜力的绿色添加剂。作者主要介绍了丁酸梭菌的特性,简述了其对畜禽肠道形态、肠道屏障、肠道菌群、免疫等方面的影响,回顾了近十年来丁酸梭菌在畜禽生产中的应用进展,并探讨了其在生产应用中的问题,以期为丁酸梭菌的进一步应用提供理论依据。     

不同饲料原料的体外发酵性能及产甲烷潜力

优化日粮配方是减少反刍动物甲烷产生的最有效途径。本研究利用体外瘤胃液发酵技术,对14种饲料原料(糠麸、植物蛋白和谷物)体外发酵性能相关性及产甲烷潜力进行评估。根据各成分的产甲烷量将饲料配方分为高产、中产和低产类型,然后进行体外发酵,以确定实际产甲烷量及其对消化率的影响。结果:3类原料中总可消化养分水平最高的分别是棕榈粕、玉米DDGS和小麦。糠麸原料pH与除乙酸与丙酸比值外的所有参数均呈负相关,而乙酸与丙酸比值与除pH、CO2外的所有参数均呈负相关,植物蛋白原料pH和乙酸与丙酸比值呈正相关,而这两个参数与其他参数呈负相关,而谷物原料为基质进行体外发酵时,pH与乙酸与丙酸比值为正相关,而与其他参数表现为负相关。当以玉米皮、棉粕和大麦作为基质孵育72 h后,甲烷产量最低,而以本地麸皮、豆粕和玉米为基质时,甲烷产量最高。结论:低产甲烷饲料配方可以降低甲烷产量,但提高了非纤维碳水化物、总可消化养分和挥发性脂肪酸产量。