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本文旨在应用Meta分析方法研究10~25 kg仔猪赖氨酸(Lys)需要量及其影响因素。本研究检索了1990年至2016年期间发表的有关仔猪Lys需要量的研究,根据文献筛选标准共17篇文献被纳入研究。用二次曲线(QC)模型、线性平台(LP)模型和曲线平台(CLP)模型估计了标准回肠可消化赖氨酸(SID Lys)需要量。结果表明:LP模型估计得到的SID Lys需要量较低,而QC和CLP模型的估计值较高且基本一致。其中,饲粮SID Lys含量变化不影响仔猪的平均日采食量(ADFI)(PQC=0.828 0,Plinear=0.584 4);以平均日增重(ADG)和料重比(F/G)为因变量,SID Lys含量为自变量,用QC模型估计得出10~25 kg仔猪饲粮SID Lys需要量分别为1.280%(P0.000 1)和1.260%(P0.000 1)。饲粮类型以及遗传背景等因素影响SID Lys需要量。其中,玉米-豆粕饲粮和非玉米-豆粕饲粮的SID Lys需要量分别为1.307%(P=0.005 0)和1.138%(P=0.000 1);中国地方猪种和瘦肉型猪种的SID Lys需要量分别为1.060%(P=0.001 2)和1.334%(P=0.004 3)。综上,为满足10~25 kg仔猪达到最佳生长性能,饲粮SID Lys需要量为1.230%~1.280%,同时应考虑饲粮类型以及猪的遗传背景等因素 相似文献
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过度地添加氨基酸会降低生产性能 总被引:1,自引:0,他引:1
结晶氨基酸常被添加入饲料中,这是因为在玉米——大豆粉组成的基础日粮中蛋氨酸(Met)和赖氨酸(Lys)是高度限制性氨基酸。饲料中添加结晶蛋氨酸和赖氨酸可以促进动物生长,提高动物对饲料的利用率。 然而,过量地添加氨基酸会造成因添加量高或者是由于氨基酸剂量控制设备失灵而 相似文献
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鱼粉作为优质动物蛋白质广泛用于饲料工业,用以平衡饲料原料如玉米、棉籽粕的赖氨酸(Lys)缺乏,豆粕、花生饼蛋氨酸(Met)缺乏,麦类Lys、苏氨酸(Thr)、Met缺乏以及大米Lys、Thr的缺乏。因此鱼粉中必需氨基酸(EAA)Lys、Met和Thr等成为衡量鱼粉优劣极其重要的指标。这三种EAA受鱼种、加工工艺、贮存方法和时间等因素的影响,查明其准确含量十分必要。笔者结合十多年来工作中的测试数据,试图探讨鱼粉中蛋白质与这三种EAA相关关系,以便实际生产中确定含量。1 材料与方法1.1 材料 鱼粉主要来自我国浙江、福建、山东、广东等沿海省份… 相似文献
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詹海琴 《畜牧兽医科技信息》2015,(4):7-8
小肽(Small Peptide)是动物在进行蛋白质消化时产生的中间物质,通常情况下是指由2~3个氨基酸缩合而成的寡肽。小肽具有吸收快、能被动物直接利用等特点。传统蛋白质理论认为蛋白质只有分解为游离氨基酸(FAA)才能被动物吸收利用,但是近年来的研究表明,小肽能以完整的形式被动物机体直接吸收利用,并且具有促进蛋白质的合成、促进矿物元素吸收等营养作用。目前,各种小肽制品也逐步应用于动物生产之中。 相似文献
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赖氨酸对奶牛乳腺上皮细胞内乳糖合成相关基因表达的影响 总被引:1,自引:0,他引:1
本试验旨在研究赖氨酸(Lys)对奶牛乳腺上皮细胞(BMECs)内乳糖合成相关基因表达的影响,深入探讨Lys对乳糖合成的影响机理。将第3代BMECs随机分为6个组,每组6个重复,各组细胞培养液中Lys的终浓度分别为0.5(对照)、1.0、2.0、4.0、8.0和16.0 mmol/L,细胞在37℃、5%CO2条件下培养48 h。结果表明:适宜浓度Lys对乳糖含量和葡萄糖转运载体蛋白1(GLUT1)、已糖激酶Ⅰ(HKⅠ)和已糖激酶Ⅱ(HKⅡ)基因表达量的影响呈显著的剂量依赖关系(P0.05);方差分析结果显示,添加Lys显著或趋于显著影响乳糖含量及乳糖合成相关基因表达。与对照组相比,2.0~16.0 mmol/L组乳糖含量较高(0.05P0.10),4.0~16.0 mmol/L组G LUT1基因表达量显著升高(P0.05),2.0~8.0 mmol/L组α-乳清白蛋白(LALBA)和β-1,4-半乳糖基转移酶-1(β-4GALT1)基因表达量显著升高(P0.05),8.0~16.0 mmol/L组HKⅡ基因表达量显著升高(P0.05);但1.0~2.0 mmol/L组HKⅡ基因表达量显著下降(P0.05),4.0~16.0 mmol/L组HKⅠ基因表达量下降,尤以16.0 mmol/L组显著低于对照组(P0.05)。综上所述,Lys对乳糖含量和GLUT1、HKⅠ和HKⅡ基因表达量的影响存在显著的剂量依赖,Lys浓度为2.0~8.0 mmol/L时,对BMECs内乳糖合成促进效果较好。 相似文献
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骨骼肌是机体的重要组成成分,与生命体的生长、运动和代谢等密切相关。研究表明,骨骼肌质量的增加主要依赖于蛋白质合成与降解的相对速率,而蛋白质合成的效率与饲粮氨基酸的组成和含量直接相关。赖氨酸(Lys)等碱性氨基酸作为动物体限制性或必需氨基酸,其吸收利用效率对动物的生长发育至关重要。前期研究发现,碱性氨基酸转运载体(CATs)是细胞吸收碱性氨基酸的主要转运载体,在Lys、精氨酸等碱性氨基酸的吸收过程中发挥重要作用。本文就CATs的分类、功能、表达规律及其调控机制等方面进行综述,为机体氨基酸的高效利用和肌肉生长发育调控提供理论参考。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献