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1.
综述了影响生长猪氨基酸利用的主要因素，探讨了养猪生产中有关氨基酸营养问题。结果表明，通过测定体沉积蛋白质（PD）中氨摹酸的沉积、生理氨摹酸损失（主要是皮肤和毛发、肠道内源氨基酸损失）与不可避免的氨基酸的分解代谢来估测氨基酸的需要量，估测氨基酸需要量的数据必须建立在蛋白质沉积、活体重、饲喂水平、饲料原料组成和饲料原料的可利用氨基酸含量上。既然PD是氧基酸需要量的决定因素，在建立日粮最佳氨基酸水平时，必须认真考虑活体重或动物问的差异对PD的影响。因此，饲料组成与机体蛋白质中氨基酸组成的变化对用于蛋白质沉积需要的可利用氨基酸利用的影响必须进行更精确的定量。 相似文献
2.
本研究旨在通过建立数学模型估测肉鹅的氨基酸需要量.利用析因法将肉鹅的氨基酸需要量剖分为生长和维持2部分.试验1:设计无氮和低氮2种饲粮,研究维持状态下肉鹅蛋白质需要量.试验2:利用屠宰试验,分析肉鹅沉积于羽毛、胴体和内脏中的蛋白质量,研究肉鹅生长的蛋白质需要量.结果表明:肉鹅由皮肤脱落损失的蛋白质量为6.52 g/d,肌酐代谢排出的蛋白质量为1.26 g/d,内源损失的蛋白质量为3.48 g/d,由此得出肉鹅维持每千克代谢体重的蛋白质需要量为5.37 g/d;单位体增重中沉积于羽毛和体组织(胴体和内脏)中的蛋白质量分别为0.045 1和0.141 8 g/d.由上述结果估测肉鹅氨基酸需要量的数学模型为:AA＝5.37W2/3×MAA+0.045 1ΔW×FAA+0.141 8ΔW×CAA.式中:AA为氨基酸需要量(g/d);W2/3为代谢体重(kg);ΔW为日增重(g);MAA、FAA、CAA分别为维持、羽毛、胴体生长的氨基酸模式.利用此模型对肉鹅0～9周龄的氨基酸需要量进行动态估测,多数氨基酸的需要量高于前苏联畜牧科学研究所(1985)的建议量. 相似文献
3.
近年来 ,许多国家建立了猪的生长模型以估测不同品种生长育肥猪在不同环境条件下的氨基酸需要量 ,这对于充分利用饲料资源 ,提高养猪生产效率、减少环境污染起到了十分重要的作用。NRC(1 998)生长育肥猪氨基酸需要模型是专门用于估测生长育肥猪氨基酸需要量的方法 ,它采用析因法估测 ,把氨基酸需要量分为维持需要和蛋白质沉积需要两部分 ,先确定蛋白质沉积速度 ,再根据蛋白质日沉积量和每沉积 1g蛋白质所需真回肠可消化赖氨酸量确定赖氨酸需要量 ,其他必需氨基酸的需要量按理想蛋白质模式确定 ,蛋白质的沉积速度由胴体无脂瘦肉沉积模型确… 相似文献
4.
4家禽的可消化氨基酸需要量由于饲料原料的消化率能显著影响家禽对某种氨基酸需要量的估计值，所以在相同的基础上表述推荐量就显得很重要。估测氨基酸需要量有两种方法：稀释法：利用限制性氨基酸已知的蛋白源，用低蛋白日粮逐步稀释。这种方法的优点是提供许多必需氨基酸的需要量信息，然而饲料组成变化很大，或许会改变能量含量。对于非常规饲料原料，在使用水平高的情况下，一些氨基酸可能不能被利用。低蛋白日粮法：利用只有一种氨基酸不足的基础日粮。逐量添加这种合成的氨基酸，就可能研究出能改进动物生产性能的某一添加水平。这一… 相似文献
5.
饲料是家禽所需能量和蛋白质的物质基础,饲粮中碳水化合物、蛋白质和脂肪在体内经生物氧化供能,而家禽所需的蛋白质实际上是饲料中的各种氨基酸。准确测定家禽饲料原料有效能和可利用氨基酸是确定家禽营养需要量及优化饲粮配方的关键。在家禽营养研究中,科学合理的评定体系及方法对准确测定饲料原料有效能和可利用氨基酸至关重要。然而,家禽饲料原料营养价值评定受诸多因素影响,如动物因素、评定体系及方法、饲料及原料因素、饲料加工工艺和饲料添加剂等。为此,本文就家禽饲料原料有效能和氨基酸消化率评定体系及影响因素进行综述,且就近3年来本课题组开展的有关肉仔鸡饲料原料营养价值评价工作进行了介绍。 相似文献
6.
所谓的理想蛋白质 ,是指日粮中各必需氨基酸的组成和比例与动物的需要相吻合 ;理想的氨基酸模式 ,意指理想蛋白质各必需氨基酸的组成相对于Ｌｙｓ的比例。在 1 998年 ,ＮＲＣ根据以往的研究 ,总结并出版了各种状况下的肥育猪理想的氨基酸比例 (表 1 )。ＮＲＣ(1 998)虽然首次系统给出了不同体重和生产水平的可消化氨基酸的需要量 ,但不是实测值 ,而是根据动物的生长模型 ,按照理想蛋白质的原理 ,运用维持加体蛋白沉积的析因法推算而得。在猪的实用日粮中 ,Ｌｙｓ是必需氨基酸中的第一限制性氨基酸 ,模型首先对其需要量进行了估测。每日Ｌｙ… 相似文献
7.
猪的支链氨基酸营养研究进展 总被引：3，自引：0，他引：3
支链氨基酸 (亮氨酸、异亮氨酸与缬氨酸 )作为畜禽的必需氨基酸 ,不仅是合成机体蛋白质的原料 ,而且具有许多重要的生物学功能。本文着重阐述了支链氨基酸的特殊营养生理作用及其对猪免疫反应的影响 ,不同阶段猪对支链氨基酸的需要量及其模式 ,常用饲料原料中支链氨基酸含量与模式的特点 相似文献
8.
《中国畜牧兽医》2020,(8)
饲料原料中蛋白质的质量直接影响着动物的营养吸收与饲料的利用效率,目前对饲料原料蛋白质的评价多采用生物价法,利用蛋白质评分法的研究则很少。因此,作者对现今国际上通用的6种蛋白质营养评价方法进行概述,并以50～75 kg生长猪营养需要量(NRC,2012)为参考蛋白,运用氨基酸评分(AAS)、化学评分(CS)、必需氨基酸指数(EAAI)、必需氨基酸相对比值(EAARR)、氨基酸比值系数分(SRCAA)和模糊评分法(FCM)作为评价标准,对9种常用饲料原料(玉米、小麦、大麦、大豆粕、棉籽粕、菜籽粕、玉米蛋白粉、鱼粉、乳清粉)蛋白质营养价值进行评价,进而得到6种蛋白质营养评价方法在饲料营养价值评定分析中的应用结果。经综合分析探讨,EAARR与FCM对饲料原料蛋白质的评价较其他方法更为科学合理,可为生长猪饲料配方设计提供参考。 相似文献
9.
按可消化氨基酸配合猪日粮 总被引：2，自引：0，他引：2
<正> 在我国现行猪饲养标准及享有盛誉的NRC猪饲养标准(1988年版)中,由于有关蛋白质和氨基酸的营养指标只列出了粗蛋白质和必需氨基酸总量的需要量,因此饲料配方设计人员总是根据饲料原料氨基酸的组成来配合日粮以满足猪的蛋白质需要。他们通常是依靠化学分析法来估测氨基酸,得出总氨基酸量(或称摄入氨基酸量)。然而,动物并不是纯粹的化学反应器,同一种配料的不同样品,其氨基酸组成也不尽相同。特别在使用农作物副产品时更是如此。为了保险起见,人们常在设计配方时给日粮提供一个安全系数而过量添加氨基酸或蛋白质。显然,这是很不准确也不经济的。解决这个问题的办法,就是按可消化氨基酸配合日粮。 相似文献
10.
一、可消化氨基酸配方的理论基础蛋白质原料是饲料原料中最贵重的物质之一,蛋白质的开销是饲料成本中最重要的部分。如何节约蛋白资源,利用可消化氨基酸平衡理论进行饲料日粮配方的设计是行之有效的方法。配合饲料中可消化氨基酸的含量及其平衡程度是影响饲料品质和效益的一个重要因素。准确地测定饲料中可消化氨基酸含量及动物可消化氨基酸的需要量是配制可消化氨基酸平衡日粮的技术关键。动物可消化氨基酸的需要量是源于理想蛋白质的概念。所谓理想蛋白质就是能够被特定动物完全 相似文献
11.
Influence of dietary lysine and energy intakes on body protein deposition and lysine utilization in the growing pig 总被引：2，自引：0，他引：2
A serial slaughter study was conducted to determine the effects of true ileally digestible lysine (IDLys) intake and metabolizable energy intake (MEI) on whole-body protein deposition (PD) and dietary lysine utilization in pigs between 45 and 75 kg live weight (LW). Conventional N balances were determined at the start and end of the serial slaughter study. Semisynthetic diets based on casein and cornstarch provided protein-bound lysine to support protein depositions of approximately 70% (Lys70%, IDLys 11.1 g/d) or 90% (Lys90%, IDLys 13.2 g/d) of a determined maximum PD. During the serial slaughter study and at Lys70%, pigs were fed one of six levels of MEI ranging from 14.1 to 23.5 MJ/d; at Lys90%, pigs were fed one of seven levels of MEI ranging from 15.6 to 26.4 MJ/d. The serial slaughter study and N balances indicated that MEI and IDLys had independent effects on PD and lysine utilization. Lysine utilization (calculated as the fraction of absorbed available lysine, over and above maintenance lysine requirements, that was retained in body protein) and PD increased with increasing MEI until plateau values were reached. At the plateaus, PD was determined by lysine intake. When lysine intake determined PD, lysine utilization did not decline (P > 0.10) with increasing lysine intake. Based on the N balance study, there was no effect (P > 0.1) of LW on lysine utilization. The marginal efficiency of using absorbed available lysine for PD was 0.75 and was not affected by LW, MEI, or IDLys. 相似文献
12.
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. 相似文献
13.
Physiologically based statements on the effectivity of lysine, methionine/cystine and threonine of protein sources as well as on the requirement of these amino acids depending on performance were derived on the basis of a total of 568 N balance measurings at growing female fattening pigs in the live weight range between 30 and 50 kg (Liebert, 1986) with the application of the N utilization model by Gebhardt (1963) as well as of particular further developments by the linking of N utilization and the utilization of the respective limiting amino acid. By means of combining protein sources with known amino acid effectivity, the additivity principle for content values of effective amino acid in the feed protein (c.k) suggested as criteria was verified. On the whole, it could thus be proved that the suggested method can decisively contribute to the elaboration of a closed system of quality assessment and requirement assessment depending on performance as well as of supply covering requirements of growing pigs. The advantages in particular over the 'slope ratio' method are emphasized. 相似文献
14.
Exogenous porcine somatotropin (PST) administration stimulates protein deposition and inhibits lipogenesis, resulting in dose-related improvements in growth performance and reduction of carcass fat content. However, the associated impacts of this technology on dietary nutrient requirements and energy partitioning between maintenance, protein, and fat remain unclear. Studies with pigs between 25 and 60 kg body weight indicate that, because of unknown improvements in amino acid utilization and(or) in the energy available for protein synthesis, only marginal increases in dietary protein percentage are required to support 20 to 25% improvements in protein deposition induced by PST administration. In contrast, an increased dietary protein concentration is required to support maximal protein deposition in pigs 60 to 100 kg. Exogenous PST administration increased the maintenance energy requirement and altered the relationship between energy intake and protein deposition, although the magnitude of these changes and the consequent effects on expression of dietary protein (amino acid) requirements was influenced by gender. Albeit limited, information suggests that PST alters nutrient demand at the tissue level. Information of this type will form the basis for rational decisions concerning the method for expression of dietary nutrient requirements (% vs g/d) for PST-treated pigs. Further quantitative information is required on the effects of PST dosage on the relationship of protein deposition to energy intake and on any underlying changes in amino acid utilization and metabolism. 相似文献
15.
Much of our understanding of energy metabolism in the pig has been derived from studies in which the energy supply was controlled through regulated feed intake. In commercial situations, where ad libitum feeding is practiced, dietary energy concentration, but not daily feed intake, is under producer control. This study evaluated the interactive effects of dietary energy concentration and feeding level (FL) on growth, body composition, and nutrient deposition rates. Individually penned PIC barrows, with an initial BW of 9.5 +/- 1.0 kg, were allotted to 1 of 9 treatments in a 3 x 3 factorial arrangement plus an initial slaughter group (n = 6) that was slaughtered at the beginning of the trial. Three NE concentrations (low, 2.15; medium, 2.26; and high, 2.37 Mcal of NE/kg) and 3 feeding levels (FL: 100, 80, or 70% of ad libitum access to feed) were investigated. Daily feed allowance for the restricted-fed pigs was adjusted twice per week on a BW basis until completion of the experiment at 25 +/- 1 kg of BW. Average daily gain, ADFI, and G:F were unaffected by NE (mean = 572 g, 781 g, and 0.732 g/g, respectively). Average daily gain and ADFI, but not G:F, increased (P < 0.05) with FL. Empty body lipid concentration increased with dietary NE concentration and with FL; a significant (P < 0.01) interaction revealed that empty body lipid concentration increased most rapidly as ADFI increased on the highest energy diet. Empty body lipid concentration was greatest in pigs with ad libitum access to the high-NE diet. Empty body protein concentration decreased with increasing NE (P < 0.05) but was not affected by FL. Empty body protein deposition (PD) increased with increasing FL (P < 0.001), but not with NE. Empty body lipid deposition (LD) and the LD:PD ratio increased (P < 0.01) in pigs with ad libitum access to the high-NE diet. In conclusion, NE did not interact with FL on growth, body protein concentration, or PD, suggesting that the conclusions regarding energy utilization obtained from experiments using restricted feed intake may not easily be applied to pigs fed under ad libitum conditions. The interactive effects of NE and FL on body lipid concentration, LD, and the LD:PD ratio indicate that changes in dietary energy concentration alter the composition of gain without necessarily changing overall BW gain. Consequently, the composition of gain is an important outcome in studies on energy utilization. 相似文献
16.
The effects of dietary level of lysine and of level and source of CP on voluntary feed intake, growth performance, plasma free amino acids, and carcass characteristics were investigated in a study involving 60 female and 60 castrated male Large White finishing pigs (from 42 to 101 kg live weight) with ad libitum access to feed. Six treatments were compared according to a 2 x 3 factorial plan, with two levels of lysine (.55 and .65% selected below the recommended levels for both sexes) and three types of CP (N x 6.25) supply: a 13% CP diet based on wheat, peanut meal and soybean meal; a 15.6% CP diet providing the same amino acid pattern as that of the basal diet; and a 15.2% CP diet containing the same levels of essential amino acids as the 13% CP diet, with the addition of glutamic acid as a source of nonessential amino acids. By maintaining a constant amino acid pattern separate changes in dietary lysine and CP levels resulted in a relative independency of their effects on feed intake, growth performance, and body composition. Muscle gain increased with supplementary lysine, with a lower response at the lower CP level (13%). At the same level of lysine (.55 or .65%), increasing protein content from 13 to 15.6% did not affect feed intake, but growth rate was lower and feed/gain was increased, partly because of an additional energy cost resulting from catabolism of excess protein.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
17.
Scientific feeding experiments were carried out with 7 male castrated pigs of the genetic origin land race pig X large white with the test animals fed individually and the rations containing approximately the same amounts of protein, amino acids, minerals and vitamins but varied amounts of energy. Energy intake was adjusted to three levels: 100%, 85% and 70% of semi-ad-libitum intake (group 1 = 100%). With regard to protein supply there was a subdivision into 30-60 and 60-100 kg live weight. In addition to this, the digestibility of the feed mixture used and the N-balance were determined in both fattening periods. Having reached 100 kg live weight, the animals were slaughtered and a number of slaughtering parameters was determined. The average daily live weight gain in the three test groups was 749, 664 and 540 g over the whole fattening period. The feed expenditure was 3.7, 3.9 and 4.3 kg mixed feed per kg live weight gain so that, with regard to live weight performance and feed expenditure the group with the highest energy supply showed the best results. The level of energy supply had a remarkable influence on the composition of weight gain; thus the amount of fat in the carcass of the animals of groups 3 was by 1.8 kg and 2.5 kg resp. lower than of the animals in groups 2 and 1. 相似文献
18.
Growing pigs provided with ileocaecal re-entrant cannulae were fed three rations containing plant protein sources and two N-free rations. The crude protein and amino acid flow in the digestive tract as well as the apparent and true digestibility of the crude protein and the amino acids for the individual sections of the intestines are explained. It shows that relating the calculation of metabolic faecal amino acids to live weight results in more realistic values than relating it to feed intake. 相似文献
19.
The following values were derived from experimental studies of the crude protein (CP) and amino acid (AA) metabolism of growing fattening bulls, the detailed results of which were described in installments 1-6, for the ascertainment of the content of apparently digestible total protein at the duodenum (ADTPD): a) partial method: Degradation quotaCP = NPN + 0.69 X g pure protein/CP; g AD feed PD = g CP (1 -decomposition quotaCP) X 0.72 or g AD feed PD = 0.31 X g pure protein X 0.72; g ADBPDE = 0.149 X g AD org. matter X 0.80 X 0.72 (ADBPDE = apparently digestible pure bacteria protein at the duodenum, dependent on energy release in the reticulo-rumen; g ADBPDN = g CP X (degradation quotaCP) X 0.80 X 0.72 (ADBPDN = apparently digestible pure bacteria protein at the duodenum, dependent on CP supply of rumen microbes); g AD total PD = g AD feed PD + ADBPDE g AD total PD = g AD feed PD + ADBPDN; b) summarizing method: AD total PD = 0.429 + 10.9 X 0.80/CP in % AD org. matter X (CP intake) X 0.72; AD total PD = 0.196 + 16.6 X 0.80/pure protein % AD org. m. X pure pr. intake X 0.72. The requirement of AD total PD was calculated under consideration of the endogenous urine N, skin N and hair N losses as well as protein retention per kg live weight assuming a utilization of 0.70 for this partial performance. The practical application of this balance method is demonstrated in comparison to the digestible CP-system. 相似文献
20.
S.H.M. Metz P.L. Bergström N.P. Lenis M. De Wijs R.A. Dekker 《Livestock Production Science》1980,7(1):79-87
An experiment with 29 crossbred female growing pigs (Dutch Landrace × Dutch Yorkshire) was carried out to measure the effect of daily energy intake on growth rate, N retention (according to the balance method) and composition of the weight gain. The weight gain composition was analysed by slaughtering pigs at regular intervals between 25 and 110 kg live weight. Two levels of daily energy intake, at an adequate protein intake, were used, and pigs on both treatments were slaughtered at the same age.Differences in daily energy intake affected growth rate and composition of the weight gain. Restriction of the daily energy intake by 20% caused a 15% lower live weight gain and a 12% lower N retention. Carcass muscle growth was 8% lower and fatty tissue growth was lower by 28%. Growth of bone was unaffected. Chemical analysis of different parts of the body revealed that reducing the daily energy intake by 20% caused an 8% lower protein deposition and a 28% lower fat deposition in the total body. However, there were differences between different anatomical parts of the body.Efficiency of pig meat production is discussed in relation to the effects of energy supply on weight gain composition. 相似文献