猪苏氨酸的营养

本综述了近20多年来苏氨酸在猪体内的代谢，苏氨酸的生物学作用，猪的苏氨酸的需要量，耐受量，缺乏症，低蛋白日粮中苏氨酸的添加量，以及苏氨酸与猪的免疫作用等方面的营养研究进展，对有待继续研究的问题进行了探讨，并展示了苏氨酸的应用前景。     

生长猪苏氨酸需要量研究进展

1 前言 在现代养殖业生产中,动物营养需要参数及饲料营养价值评定方法不断改进。蛋白质是生长猪最重要的营养物质之一,饲料中蛋白质质量和氨基酸平衡对生长猪生产性能、饲料报酬和饲料成本等有影响,实现配合饲料中氨基酸的平衡,已是大势所趋(王振勇,1997;钟运炎等,1989)。在常用的猪饲料原料中,苏氨酸被认为是第二或第     

猪苏氨酸营养的研究进展

苏氨酸（Thr)是猪的第二或第三限制性氨基酸，它在动物体内具有极其重要的生理作用，如促进生长、提高免疫机能等；并且添加Thr可以更好地平衡日粮氨基酸，使氨基酸比例更接近于理想蛋白质从而降低猪对饲料中蛋白含量的要求。Thr这些作用使其在饲粮中的添加愈来愈重要。本文就Thr的代谢途径、生理作用、猪Thr需要量等作一介绍。     

畜禽苏氨酸的营养研究进展

苏氨酸（Thr)是由W．C．Rose在1935年从纤维蛋白水解产物中分离、鉴定出来的,因其结构类似苏糖,故将其命名为苏氨酸。现已证明苏氨酸是最后被发现的一种必需氨基酸,它是畜禽的第二或第三限制性氨基酸,它在体内发挥着极其重要的生理作用。近年来,随着赖氨酸、蛋氨酸在配合饲料中的广泛应用．苏氨酸逐渐成为影响动物生产性能的限制性因素．因此对苏氨酸营养代谢的进一步探讨也显得尤为必要。本文特对苏氨酸的应用作一简要综述,以期更有效地指导饲料生产。     

生长猪苏氨酸需要量研究

选择１００ 头体重（２１－１５ ±１－９２） ｋｇ 的三元杂交（ 杜洛克×长白×大约克） 生长猪, 探讨其对苏氨酸需要量。以可消化氨基酸为基础配制饲粮。饲粮苏氨酸水平分为０－５０％ 、０－５５ ％ 、０－６０ ％ 、０－６５ ％ 和０－７０ ％ ５ 个处理, 各处理饲粮其它组分相同。经回归分析得到２ 个方程, 分别求导得出： 当苏氨酸（ＴｈｒＩ） 日采食量为１０－０５ ｇ 时, 平均日增重（ＡＤＧ） 最高; ＴｈｒＩ为７－９３ ｇ 时, 饲料转化率（ＦＣＲ） 最高。对ＡＤＧ 及ＦＣＲ 进行综合考虑, ＴｈｒＩ以９－０ ｇ 为宜。以平均日采食量１－４２ ｋｇ 计, 饲粮苏氨酸水平应为０－６３ ％ , 赖氨酸∶苏氨酸为１００∶７４。血清游离氨基酸及血清尿素氮检测结果与上述结论较为吻合。     

生长肥育猪的苏氨酸营养需要及其应用进展

从苏氨酸的特性、在猪常用饲料中的地位、代谢途径、生物学功能、生长肥育猪的需要量以及在低蛋白饲粮中的应用等方面,综述了苏氨酸的营养研究进展.     

苏氨酸在畜禽营养中的研究进展

苏氨酸是百合的必需氨基酸，是畜禽日粮中的第二或第三限制性氨基酸，它在动物体内具有极其重要的生理作用，如提高饲料报酬、促进生长、增强免疫机能等；添加苏氨酸可以平衡百合日粮中的氨基酸水平，使氨基酸比例更接近于理想蛋白质模式，从而降低畜禽对饲料中蛋白含量的要求。本文就苏氨酸的理化特性、代谢途径、生理作用及其在畜禽饲料中的应用情况等研究进展进行了分析，以利于苏氨酸在畜禽生产中得到更好的应用。     

苏氨酸在家禽营养中的研究与应用进展

苏氨酸是家禽维持和生长所必需的氨基酸,大量试验结果证明,苏氨酸对不同生长阶段和生产目的的家禽都有营养功能.作者综述了苏氨酸的生化特性,在家禽体内的代谢途径、生物学作用、营养需要量、缺乏症及与赖氨酸的相互作用.     

中华绒螯蟹的营养研究进展

１蛋白质和氨基酸需要关于河蟹蛋白质需要量的研究，国内多数学者是根据河蟹蟹体组织蛋白质的组分，作为设计配合饲料蛋白质组分的主要依据，同时结合河蟹对天然饵料的选择摄食习性，进行试验设计。徐新章等（１９８８）用２０μm～４０μm胶囊饲料饲养蚤状幼体，以蚤状幼体变态为大眼幼体的成活率为分析指标，结果表明，饲料蛋白质的适宜含量为４５％。韩小莲等（１９９１）根据幼蟹体蛋白的氨基酸组成，以贻贝、糠虾、乌贼、玉米蛋白粉、黄豆粉为主要蛋白源，研究指出河蟹从大眼幼体至II期幼蟹饲料蛋白质含量为４５％，幼体蜕皮时间短、…     

母猪营养研究进展

受试验动物、研究方法等诸多客观条件的限制，母猪营养研究资料明显少于商品猪，其中，以国外资料为主，国内资料较少且多为综述性文章或译文，科学试验报告很少。由此，母猪营养仍是研究热点。本文拟对母猪营养研究予以综述，其中以能量、蛋白质（氨基酸）营养为主，并侧重于营养需要量研究。１能量１．１能量概念描述猪的能量需要和饲料的能量浓度主要有消化能（DE）及代谢能（ME）两体系。DE是动物采食饲料的总能减去未被消化以粪形式排出的饲料能量的差值；ME是DE减去尿能及消化道气体能的差值（杨凤，１９９３）。通常能量利用研究…     

苏氨酸在猪营养中的研究进展

苏氨酸（Ｔｈｒ）是猪所需的必需氨基酸，通常是猪日粮中的第二或第三限制性氨基酸。近年来，随着合成赖氨酸（Ｌｙｓ）、蛋氨酸（Ｍｅｔ）在配合饲料中的广泛应用，Ｔｈｒ逐渐成为影响猪生产性能的主要限制性氨基酸之一。Ｈａｎｓｅｎ（１９９３ａ）研究表明，在低蛋白质高粱—豆粕基础日粮中添加合成Ｌｙｓ后，Ｔｈｒ成为生长猪的第一限制性氨基酸。因此对Ｔｈｒ营养代谢的进一步探讨与研究，有助于有效地指导养猪生产。　１　苏氨酸的代谢及生物学作用　在动物体内的代谢途径中，Ｔｈｒ是唯一不经过脱氨基作用和转氨基作用，而是通过Ｔｈ…     

虾类营养研究进展

虾类肉嫩味美 ,营养丰富 ,易于消化吸收 ,是人们喜爱的营养食品。我国养虾业虽然起步较晚但发展很快 ,已成为养虾大国 ,在虾类的营养研究方面也取得了较大的进展。1　蛋白质和氨基酸综合国内外研究资料表明 ,虾类对可消化蛋白质需求量多少依次为 :对虾 >罗氏沼虾 >青虾。而同一品种在不同发育阶段又为 :虾苗 >仔虾 >亲虾 >成虾。对虾饲料中蛋白质适宜含量问题 ,由于研究工作者所用饲料源、试验方法和试验条件不同 ,其结果相差很大。Ｍ .Ｂ .Ｎｅｗ报道 ,对虾饲料的适宜蛋白质含量为 2 7%～ 3 5 %,但有报道认为 40 %～ 6 0 %较适合。这个问题…     

Influence of threonine intake on whole-body protein deposition and threonine utilization in growing pigs fed purified diets.

The relationship between available threonine (Thr) intake and whole-body protein deposition (PD) was established using the serial slaughter method in 36 individually housed growing gilts between 39 and 77 kg live BW. Pigs were prescreened for their maximum PD (PDmax), based on a N balance starting at 25 kg BW while they consumed semi-ad libitum a nonlimiting diet. Pigs were fed combinations of a casein and cornstarch-based diet that was confirmed to be first-limiting in Thr and a protein-free diet starting at approximately 30 kg BW. Casein-bound Thr was provided at 60, 70, 80, 90, 100, or 120% of estimated Thr requirements for PDmax. Energy intake was kept constant across treatments and exceeded requirements for PDmax. Pigs were fed three equal meals per day; feeding levels were adjusted weekly based on BW. Pigs were killed at either 39 kg BW (n = 2 per treatment) or 77 kg BW (n = 4 per treatment) for determining chemical body composition. Composition of 39-kg BW pigs was not different across treatments (P > 0.10); therefore, an overall mean initial body composition was used to estimate body protein content at the initial BW. Across treatments, mean daily ME intake was 25.3 (SE 0.08) MJ/d and did not differ (P > 0.10) among treatments. Average daily true ileal digestible Thr intake varied between 5.33 and 9.66 g/d, representing means for pigs on the lowest and the highest Thr intakes, respectively. Mean PD was 93, 102, 118, 124, 139, and 133 (SE 4.2) g/d for pigs on the six respective treatments. Dietary Thr intake did not influence (P > 0.10) Thr content of body protein at the final BW or the partitioning of body protein between carcass, viscera, and blood. The efficiency of Thr utilization for PD was lowest (P < 0.05) at the highest Thr intake level and highest (P < 0.05) at the lowest Thr intake level. It was similar (P > 0.10) at the four intermediate Thr intake levels, in which the relationship between true ileal digestible Thr intake and PD was linear. Based on these four treatments, calculated Thr disappearance, which is closely associated with inevitable Thr catabolism, was 23.5 (SE 0.55)% of available Thr intake. This value is consistent with an efficiency of using available Thr intake above maintenance Thr requirements (54 mg/kg BW0.75) for Thr retention with PD of 73.4 (SE 1.11)%. Based on N balances conducted at approximately 40 and 75 kg BW, the marginal efficiency of Thr utilization was not influenced by BW.     

Requirement of true ileal digestible threonine of growing and finishing pigs

Ninety-six crossbred barrows and gilts were used to investigate the optimum supply of true ileal digestible threonine for growing (approximately 35-65 kg body weight) and finishing (approximately 65-110 kg body weight) pigs. For this purpose, according to a bifactorial arrangement in the grower as well as in the finisher phase four dietary threonine levels were combined with two dietary levels of lysine. Measurement criteria were body weight gain, feed intake, feed conversion rate and carcass characteristics. In the grower stage at the lower lysine level daily gain increased numerically (p < 0.1) and the feed to gain ratio decreased significantly with an increasing dietary true ileal digestible threonine concentration. Increasing the true ileal digestible lysine concentration of the diet from 7.8 to 9.2 g/kg increased average daily gain in the grower stage significantly from 815 to 855 g and decreased the feed to gain ratio significantly. In finishing pigs, daily gain and feed to gain ratio were significantly improved by an increasing dietary true ileal digestible threonine concentration from 821 to 902 g and from 3.14 to 2.94 kg/kg, respectively, but not by the differing lysine supply. As in the grower stage, barrows consumed more feed than gilts at similar growth rates and this resulted in a significantly reduced feed to gain ratio in gilts compared with barrows. The requirements of true ileal digestible threonine for optimize both, daily gain and feed to gain ratio, as derived by the broken-line model were 10.3 g/animal and day for growing and 10.7 g/animal and day for finishing pigs respectively.     

苏氨酸的营养免疫作用及畜禽对其需要量的研究

苏氨酸作为畜禽的第二或第三限制性氨基酸,对机体有重要的营养免疫作用,在日粮氨基酸的平衡中也起重要作用。不同生长阶段的畜禽对苏氨酸的需要量不同。此外,其它一些氨基酸如赖氨酸、蛋氨酸、色氨酸、甘氨酸等均对苏氨酸的需要量有影响。