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动物肠道具有感应肠腔葡萄糖的功能,机体通过葡萄糖激酶(GCK)、味觉受体、葡萄糖转运蛋白GLUT2、mTORC1信号通路及AMPK等机制感应葡萄糖,影响肠道内分泌细胞(enteroendocrine cells,EECs)分泌激素,形成复杂的内分泌调控网络,调节机体营养物质代谢和采食行为等重要生理活动。文章综述了动物葡萄糖的感应机制及其对肠道内分泌调控的影响。 相似文献
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关于5-羟色氨(5-HT)对采食量的影响已有几十年的研究历史。机体内的5-HT主要是以必需氨基酸色氨酸(Trp)作为前体物,在大脑和肠道中合成,并在机体中发挥重要的作用。5-HT无法直接透过血-脑屏障,因此中枢神经系统和外周5-HT作为两个相对独立的系统各自发挥作用。目前,已有大量的研究表明中枢5-HT的多种受体以不同的方式调控动物采食,主要有5-HT1A、5-HT1B、5-HT2A、5-HT2C、5-HT3A、5-HT4、5-HT5A、5-HT6和5-HT7。例如,现在临床上被批准使用的抗肥胖药物氯卡色林就是一种5-HT2C受体激动剂。此外,中枢5-HT还可以协同胰高血糖素样肽-1、饥饿素和胆囊收缩素等外周激素共同调控动物采食行为。外周5-HT也能够通过介导胰高血糖素样肽-1和胆囊收缩素来诱导饱腹感。畜禽生产中主要通过在饲料中添加Trp来增加动物体内5-HT的合成。但目前对于Trp对畜禽采食量的调控机制的研究尚不完善,且有研究表明,不同浓度的Trp对动物采食量的影响不同,不同畜禽饲料中最适Trp的浓度也不同。而Trp主要是通过其代谢产物5-HT来调控动物采食。作者查阅了大量国内外最新的研究成果,从中枢和外周两个途径对5-HT调控动物采食行为的研究进展作一综述,期望通过对Trp的代谢产物5-HT对动物采食调控机制的探讨,为Trp在畜禽生产中的应用提供一定的理论依据。 相似文献
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功能性氯基酸——精氦酸（Arg）具有重要的生理、代谢和营养作用,几乎机体中所有组织均利用Arg合成胞浆蛋白和核蛋白,精氨酸在促进肌肉蛋白质合成、增强机体的免疫力、细胞分裂、伤口复尿和激素分泌等各种生理过程中,也都有着重要的角色。Arg为条件性必需氨基酸,在应激状态下和特殊生长阶段,为必需氨基酸,仔猪体内合成的精氨酸不能满足生理代谢需要。但是精氨酸的吸收与赖氨酸等桔抗,因此,对精氨酸及其内源性合成调控研究具有极大的应用价值和实践意义。精氨酸生素（Arginineactivatoradditive,AAA）是N-乙酰谷氨酸（N-acetylglutamate,NAG）的类似物,作为一种新型的功能性氨基酸,可以有效调控内源性精氨酸合成,进而促进动物生长性能。本文就精氨酸和精氨酸生素特别是其对机体内源性精氨酸合成调控及其在仔猪和母猪中的研究进展与应用作一综述。 相似文献
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动物的生命活动是受到由机体神经和内分泌两大系统构成的调节网络精确调控的过程，一些与动物生产性能密切相关的生理活动，包括采食、消化、吸收、代谢、生长、发育、繁殖和泌乳等，都受到这一调节网络的精确调控。生理调节剂就是根据这些生理活动的调节机制有针对性地开发出的相关产品，对这些生理过程进行有目的的调控， 相似文献
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采食是动物维持生命活动的基本生理过程,是动物生长发育的基础。畜禽采食量的高低直接影响到营养物质的摄入量及生产性能的发挥。在畜牧业生产中,影响采食的因素很多,而应激是其中一个非常重要的影响因素。动物机体的应激反应主要由下丘脑-垂体-肾上腺(HPA)轴来调控。下丘脑、垂体和肾上腺皮质通过释放促肾上腺皮质激素释放激素(CRH)、促肾上腺皮质激素(ACTH)和糖皮质激素(GC)这3种应激激素来协同调控动物的应激反应。应激激素对采食行为的调节是一个非常复杂的过程,主要通过稳态和非稳态途径来调节采食,可以双向调控食物的摄入量。稳态途径指的是通过调控机体能量稳态而调控采食。CRH和ACTH通过抑制下丘脑促食欲肽的表达而抑制采食;而GC在中枢和外周发挥着完全相反的作用。非稳态途径指的是通过影响中脑奖赏系统调控采食的愉悦感,是近年来食欲调控研究的热点,越来越多的研究证明了应激激素与奖赏系统的联系。作者针对应激激素调控采食的最新研究报道进行综述,以期为生产实践中新型的采食调控技术研发提供一定的参考。 相似文献
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采食是动物维持生命活动的基本生理过程，是动物生长发育的基础。畜禽采食量的高低直接影响到营养物质的摄入量及生产性能的发挥。在畜牧业生产中，影响采食的因素很多，而应激是其中一个非常重要的影响因素。动物机体的应激反应主要由下丘脑-垂体-肾上腺（HPA）轴来调控。下丘脑、垂体和肾上腺皮质通过释放促肾上腺皮质激素释放激素（CRH）、促肾上腺皮质激素（ACTH）和糖皮质激素（GC）这3种应激激素来协同调控动物的应激反应。应激激素对采食行为的调节是一个非常复杂的过程，主要通过稳态和非稳态途径来调节采食，可以双向调控食物的摄入量。稳态途径指的是通过调控机体能量稳态而调控采食。CRH和ACTH通过抑制下丘脑促食欲肽的表达而抑制采食；而GC在中枢和外周发挥着完全相反的作用。非稳态途径指的是通过影响中脑奖赏系统调控采食的愉悦感，是近年来食欲调控研究的热点，越来越多的研究证明了应激激素与奖赏系统的联系。作者针对应激激素调控采食的最新研究报道进行综述，以期为生产实践中新型的采食调控技术研发提供一定的参考。 相似文献
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Ghrelin是第一个被发现的生长激素促分泌素受体(GHS-R)的内源性配体。这个脑肠肽在调节生长激素释放、增进食欲、调节能量代谢等方面发挥重要作用,他还具有其他重要的生物学功能。加强Ghrelin在营养生理学上的研究具有重要的理论意义和广阔的应用前景。 相似文献
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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. 相似文献
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Recent advances in swine protein nutrition are characterized by the development of functional amino acids (AA) in regulating fetal and postnatal survival, growth and development. These AA include arginine, glutamine, glutamate, proline, leucine, cysteine and tryptophan. Due to limited knowledge on AA nutrition, pork producers have traditionally paid little attention to supplementing the arginine family of AA to swine diets. Results of recent studies indicate that functional AA serve important regulatory functions in nutrient metabolism, protein turnover, and immune function, therefore enhancing efficiency of feed utilization by pigs. The underlying mechanisms include activation of nitric oxide, mammalian target of rapamycin, gaseous signaling, and AMP-activated protein kinase pathways, as well as anti-oxidative function. Dietary supplementation with arginine, glutamine, proline or leucine to weanling piglets enhances their growth performance. Arginine or glutamine is also effective in increasing milk production by lactating sows. Furthermore, supplementing arginine to the diet of pregnant gilts between days 30 and 114 of gestation increases the number of live-born piglets and litter birth-weight. Availability of feed-grade functional AA holds great promise for improving animal health and nutrient utilization in pig production worldwide. Additionally, feedstuffs of animal origin [e.g., blood meal (ring dried), feather meal (hydrolyzed), meat and bone meal, porcine protein meal, and poultry by-product meal (both feed- and petfood-grades)] are excellent and cost-effective sources of both essential and functional AA for formulating balanced swine diets. New knowledge on AA nutrition provides a much needed scientific basis for revising the next edition of swine nutrient requirements. 相似文献
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Guoyao Wu 《畜牧与生物技术杂志(英文版)》2010,1(2)
Recent advances in swine protein nutrition are characterized by the development of functional amino acids(AA)in regulating fetal and postnatal survival,growth and development. These AA include arginine,glutamine,glutamate,proline,leucine, cysteine and tryptophan. Due to limited knowledge on AA nutrition,pork producers have traditionally paid little attention to supplementing the arginine family of AA to swine diets. Results of recent studies indicate that functional AA serve important regulatory functions in nutrient metabolism,protein turnover, and immune function,therefore enhancing efficiency of feed utilization by pigs. The underlying mechanisms include activation of nitric oxide,mammalian target of rapamycin,gaseous signaling,and AMP-activated protein kinase pathways, as well as anti-oxidative function. Dietary supplementation with arginine,glutamine, proline or leucine to weanling piglets enhances their growth performance. Arginine or glutamine is also effective in increasing milk production by lactating sows. Furthermore,supplementing arginine to the diet of pregnant gilts between days 30 and 114 of gestation increases the number of live-born piglets and litter birth-weight. Availability of feed-grade functional AA holds great promise for improving animal health and nutrient utilization in pig production worldwide. Additionally, feedstuffs of animal origin[e. g. , blood meal (ring dried),feather meal(hydrolyzed),meat and bone meal, porcine protein meal,and poultry by-product meal(both feed- and petfood-grades )]are excellent and cost-effective sources of both essential and functional AA for formulating balanced swine diets.New knowledge on AA nutrition provides a much needed scientific basis for revising the next edition of swine nutrient requirements. 相似文献
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Effect of a prolonged low-dose lipopolysaccharide infusion on feed intake and metabolism in heifers.
M Steiger M Senn G Altreuther D Werling F Sutter M Kreuzer W Langhans 《Journal of animal science》1999,77(9):2523-2532
Prolonged infusions of bacterial lipopolysaccharides (LPS) are known to model gram-negative bacterial infections, but the basic mechanisms of the LPS effects on feed intake and metabolism and their potential interdependence are largely unknown. The aim of the present study was to distinguish and to better characterize the feeding suppressive and metabolic effects of LPS. Six heifers were infused intravenously for 100 min with either 1) LPS (2 microg/kg BW) with free access to feed, 2) saline with free access to feed, or 3) saline with feeding restricted to the amount of feed consumed after LPS infusion. Feed intake, body temperature, plasma concentrations of various metabolites and hormones, and the respiratory quotient and heat production were measured. The LPS reduced feed intake and induced pronounced changes in metabolic energy turnover and fat and carbohydrate metabolism that were largely independent of the concomitant feed intake reduction. Some of the metabolic changes were biphasic; the first phase resembled a stress response with increases in plasma glucose and cortisol, and the second phase reflected a beginning energy deficit with low plasma glucose and enhanced lipolysis. The coincidence of a short-term surge of plasma insulin with marked transient decreases in plasma FFA, glycerol, and beta-hydroxybutyrate as well as with the transition from hyper- to hypoglycemia indicates that insulin plays a role in some of the metabolic responses to LPS. The failure of LPS to clearly increase energy expenditure despite the increase in body temperature suggests that anaerobic mechanisms of heat production and, perhaps, a reduced peripheral blood flow contributed to the fever. Many of the initial metabolic responses occurred before and, therefore, independent of, an increase in circulating tumor necrosis factor-alpha. 相似文献
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本试验旨在研究饲粮精氨酸添加水平对冬毛期雌性蓝狐生产性能、营养物质消化率及氮代谢的影响。选取120日龄、体重相近的60只健康雌性蓝狐,随机分为6组,每组10个重复,每个重复1只。各组饲粮精氨酸添加水平分别为0(对照组)、0.2%、0.4%、0.6%、0.8%和1.0%,预试期7 d,正试期80 d。结果表明:1)0.6%添加组蓝狐的平均日增重极显著高于其他各组(P0.01),体长和皮长较对照组分别提高了1.42%和1.26%(P0.05),料重比极显著低于对照组(P0.01);0.4%添加组蓝狐平均日采食量显著低于对照组(P0.05)。2)饲粮精氨酸添加水平极显著影响蓝狐脂肪消化率(P0.01),各组蓝狐脂肪消化率随着饲粮精氨酸添加水平的升高而提高;0.6%添加组干物质消化率极显著高于对照组和0.2%、0.4%添加组(P0.01),饲粮精氨酸添加水平对蓝狐蛋白质消化率和碳水化合物消化率无显著影响(P0.05)。3)0.4%添加组蓝狐食入氮显著低于除0.6%添加组外其他各组(P0.05);0.6%添加组粪氮和尿氮含量均最低,而氮沉积、净蛋白质利用率、蛋白质生物学价值和蛋白质效率比均最高。综合各项指标,冬毛期雌性蓝狐饲粮中添加0.6%精氨酸(饲粮总精氨酸水平为2.04%)可提高平均日增重,降低料重比。 相似文献
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Restricted feed intake influences thyroid hormone production and peripheral deiodination in chickens
Thyroid hormones are of major importance in determining metabolic state both in mammals and in birds. Whether or not feed intake itself has an autoregulatory role in adjusting the setpoint of thyroid hormone activity is yet not well understood. The present work investigates the effects of restricted feed intake on the serum levels and on the peripheral metabolism of thyroid hormones. Also, the sensitivity of the pituitary-thyroid axis was looked at by means of thyrotropin releasing hormone provocation test. Several groups of Hunniahybrid chickens aged 2-6 weeks were used. Restriction was made by providing the experimental animals 70 and 85 percent of the amount of food consumed in the ad libitum fed control group. It was found that feed restriction lowers circulating concentration of triiodothyronine probably by inhibiting the activity of liver deiodinase and also decreases the sensitivity of the pituitary-thyroid axis meaning that both central and peripheral regulatory mechanisms of thyroid economy are affected by feed restriction. 相似文献
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S Wang P Khondowe S Chen J Yu G Shu X Zhu L Wang P Gao Q Xi Y Zhang Q Jiang 《畜牧与生物技术杂志(英文版)》2012,3(1):27-8
ABSTRACT: Feed intake control is vital to ensuring optimal nutrition and achieving full potential for growth and development in poultry. The aim of the present study was to investigate the effects of L-leucine, L-glutamate, L-tryptophan and L-arginine on feed intake and the mRNA expression levels of hypothalamic Neuropeptide involved in feed intake regulation in broiler chicks. Leucine, glutamate, tryptophan or arginine was intra-cerebroventricularly (ICV) administrated to 4d-old broiler chicks respectively and the feed intake were recorded at various time points. Quantitative PCR was performed to determine the hypothalamic mRNA expression levels of Neuropeptide Y (NPY), agouti related protein (AgRP), pro-opiomelanocortin (POMC), melanocortin receptor 4 (MC4R) and corticotrophin releasing factor (CRF). Our results showed that ICV administration of L-leucine (0.15 or 1.5 mumol) significantly (P < 0.05) increased feed intake up to 2 h post-administration period and elevated both hypothalamic NPY and AgRP mRNA expression levels. In contrast, ICV administration of L-glutamate (1.6 mumol) significantly (P < 0.05) decreased feed intake 0.25, 0.5 and 2 h post-injection, and increased hypothalamic CRF and MC4R mRNA expression levels. Meanwhile, both L-tryptophan (10 or 100 mug) and L-arginine (20 or 200 mug) had no significant effect on feed intake. These findings suggested that L-leucine and L-glutamate could act within the hypothalamus to influence food intake, and that both orexigenic and anorexigenic Neuropeptide genes might contribute directly to these effects. 相似文献
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Ludmilla C. Brunes Fernando Baldi Fernando B. Lopes Raysildo B. Lbo Rafael Espigolan Marcos F. O. Costa Nedenia B. Stafuzza Cludio U. Magnabosco 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2021,138(1):23-44
The aim was to conduct a weighted single‐step genome‐wide association study to detect genomic regions and putative candidate genes related to residual feed intake, dry matter intake, feed efficiency (FE), feed conversion ratio, residual body weight gain, residual intake and weight gain in Nellore cattle. Several protein‐coding genes were identified within the genomic regions that explain more than 0.5% of the additive genetic variance for these traits. These genes were associated with insulin, leptin, glucose, protein and lipid metabolisms; energy balance; heat and oxidative stress; bile secretion; satiety; feed behaviour; salivation; digestion; and nutrient absorption. Enrichment analysis revealed functional pathways (p‐value < .05) such as neuropeptide signalling (GO:0007218), negative regulation of canonical Wingless/Int‐1 (Wnt) signalling (GO:0090090), bitter taste receptor activity (GO:0033038), neuropeptide hormone activity (GO:0005184), bile secretion (bta04976), taste transduction (bta0742) and glucagon signalling pathway (bta04922). The identification of these genes, pathways and their respective functions should contribute to a better understanding of the genetic and physiological mechanisms regulating Nellore FE‐related traits. 相似文献