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精氨酸是一种条件性必需氨基酸,在生理调节方面具有重要的功能。在正常情况下,成年动物对精氨酸的需求可以通过内源性合成满足,但在应激条件下,内源合成的精氨酸不足以满足机体的需求。精氨酸代谢可合成一氧化氮(NO),NO在体内发挥着重要的生理作用。文中综述了高温热应激对母猪的影响、精氨酸在体内的代谢过程及在抗氧化应激方面的作用,以促进高温热应激条件下精氨酸在母猪中的应用及研究。 相似文献
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精氨酸是动物机体代谢的重要氨基酸,是新生哺乳动物的必需氨基酸,正常情况下成年哺乳动物能够合成满足机体自身需要的精氨酸,但在受伤、肠道受损等应激状态或病态下合成精氨酸的量不能满足机体的需要量,所以精氨酸是成年哺乳动物的条件性氨基酸。由于家禽体内缺乏甲酰磷酸酶等关键酶,不能合成精氨酸,只能由日粮提供,所以精氨酸是家禽的必需氨基酸。精氨酸在动物营养代谢中发挥着重要的作用,同时在畜禽生产中也存在着广泛的应用。本文对精氨酸的主要生理作用及其在畜禽生产中的研究与应用进行综述。 相似文献
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精氨酸为条件性必需氨基酸,在应激状态下和特殊生长阶段,它是必需氨基酸,体内合成的精氨酸不能满足生理代谢需要,但长期或者过量补充精氨酸对机体会造成损害。近年来,精氨酸在妊娠母猪日粮中的应用有诸多报道成为养猪生产的一个热点。本文评述了动物机体精氨酸的来源与代谢以及日粮精氨酸对妊娠母猪繁殖性能和仔猪生长性能的影响,以期对养猪生产有所指导。 相似文献
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N-甲酰谷氨酸对仔猪内源性精氨酸的合成调控 总被引：4，自引：0，他引：4
精氨酸(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,促进细胞分裂、伤口复原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拮抗,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。N-乙酰谷氨酸(N-acetylglutamate,NAG)是内源性精氨酸合成途径中的必需辅助因子和限制因素之一。本文就NAG特别是其类似物N-甲酰谷氨酸(N-carbamoylglutamate,NCG)等对机体内源性精氨酸合成调控作一综述。 相似文献
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精氨酸对畜禽来说是一种重要的氨基酸,它参与体内多种营养物质的合成与代谢。同时它又可作为一种免疫调节剂。本文就精氨酸对动物免疫功能的影响作一综述,并阐述了精氨酸影响免疫功能的机理,以期对今后精氨酸的研究提供参考。 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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桑树的遗传变异特点及在品种选育中的应用 总被引：1，自引：0，他引：1
我国具有悠久的桑树栽培历史,拥有3 000余份桑树种质资源,分属15个桑种和4个变种,并逐渐形成适应不同生长环境的8个生态类型。依据已有的研究结果,综述桑树遗传变异的特点包括:广泛分布、自然有性杂交和异花授粉以及缺乏稳定性选择等,促进了桑树的突变发生,形成遗传变异的多样性;无性繁殖方式产生了丰富的无性系变异;性状遗传值中非加性效应占有较大比例;无性系品种间杂种一代存在复杂的多样性分离和经济性状的普遍退化;存在丰富的多倍体系列和普遍的混倍现象等。对桑树品种选育研究提出建议:基于桑树的高度杂合习性,不仅要重视研究不同品种中加性效应在遗传值中所占比率,更要研究非加性效应所占比率及充分利用的方法;基于桑树遗传变异的多样性和丰富的无性系变异,加强无性系和田间选优育种;利用桑树混倍现象,将培育多倍体特别是三倍体品种作为一条有效的多倍体育种途径。 相似文献
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The study deals with the situation regarding housing of dogs and cats in Swiss shelters and kennels. In shelters, dogs were mainly held inside a cubicle with a small outside yard. In kennels, housing of dogs took place mainly in inside rooms. Usually two or three dogs were kept together. Cats were held in rooms, with or without outside yards, mainly in groups; no establishment preferred exclusively the housing in cubicles. Shelters received on average 183 dogs and 262 cats each year. Among them, about a third were lost animals while the remaining ones were relinquished. The study highlights some possibilities for improvements and the great diversity of the establishments regarding their size, infrastructure, housing conditions and aims. 相似文献
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Pinard CL Weiss ML Brightman AH Fenwick BW Davidson HJ 《American journal of veterinary research》2003,64(1):104-108
OBJECTIVE: To evaluate lactoferrin and lysozyme content in various ocular glands of bison and cattle and in tears of bison. SAMPLE POPULATION: Tissues of ocular glands obtained from 15 bison and 15 cattle and tears collected from 38 bison. PROCEDURE: Immunohistochemical analysis was used to detect lysozyme and lactoferrin in formalin-fixed, paraffin-embedded sections of the ocular glands. Protein gel electrophoresis was used to analyze ocular glands and pooled bison tears by use of a tris-glycine gel and SDS-PAGE. Western blotting was used to detect lactoferrin and lysozyme. RESULTS: Immunohistochemical staining for lactoferrin was evident in the lacrimal gland and gland of the third eyelid in cattle and bison and the deep gland of the third eyelid (Harder's gland) in cattle. Equivocal staining for lactoferrin was seen for the Harder's gland in bison. An 80-kd band (lactoferrin) was detected via electrophoresis and western blots in the lacrimal gland and gland of the third eyelid in cattle and bison, Harder's glands of cattle, and bison tears. An inconsistent band was seen in Harder's glands of bison. Lysozyme was not detected in the lacrimal gland of cattle or bison with the use of immunohistochemical analysis or western blots. Western blots of bison tears did not reveal lysozyme. CONCLUSIONS AND CLINICAL RELEVANCE: Distribution of lactoferrin and a lack of lysozyme are similar in the lacrimal gland of cattle and bison. Differences in other tear components may be responsible for variability in the susceptibility to infectious corneal diseases that exists between bison and cattle. 相似文献
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Siamudaala VM Bwalya JM Munang'andu HM Munag'andu HM Sinyangwe PG Banda F Mweene AS Takada A Kida H 《The Japanese journal of veterinary research》2006,54(1):15-23
Anthrax is endemic in Western and North-western Provinces of Zambia. The disease occurs throughout the year and impacts negatively on the economy of the livestock industry and public health in Zambia. During 1989-1995, there were 1626 suspected cases of anthrax in cattle in Western province and of these 51 were confirmed. There were 220 cases of human anthrax cases in 1990 alone and 248 cases during 1991-1998 with 19.1% and 7.7% case fatality rates, respectively. Interplay of the ecology of affected areas and anthropogenic factors seem to trigger anthrax epidemics. Anthrax has drawn considerable attention in recent years due to its potential use as a biological weapon. In this paper, the history, current status and approaches towards the control of the disease in Zambia are discussed. Quarantine measures restrict trade of livestock and exchange of animals for draught power resulting in poor food security at household levels. Challenges of anthrax control are complex and comprise of socio-political, economical, environmental and cultural factors. Inadequate funding, lack of innovative disease control strategies and lack of cooperation from stakeholders are the major constraints to the control of the disease. It is hoped that the information provided here will stimulate continued awareness for the veterinary and medical authorities to maintain their surveillance and capabilities against the disease. This may lead to a culminating positive impact on livestock and human health in the southern African region. 相似文献
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b. bengtsson s-o. jacobsson j. luthman & a. franklin 《Journal of veterinary pharmacology and therapeutics》1997,20(4):258-261
Concentrations of penicillin-G in serum were determined after single intravenous doses of potassium penicillin-G (10 mg/kg body wt) to ewes and cows in late pregnancy and in early lactation. Penicillin-G in serum was analysed by a microbiological method and pharmacokinetic parameters were calculated by model-independent methods. Serum concentrations were lower in early lactation than in late pregnancy in both ewes and cows. The differences were statistically significant at most sampling times in ewes but only during the first hour in cows.
Weight corrected values of clearance and volume of distribution were significantly higher in early lactation than in late pregnancy in both ewes and cows. Mean residence time and elimination-half life were shorter in lactating than in pregnant ewes, however for the latter parameter the difference was not statistically significant. Neither of these parameters changed in cows.
It is concluded that in both ewes and cows pharmacokinetic parameters of penicillin-G are altered from late pregnancy to early lactation but that these changes have little practical impact and do not call for a revised dosage regime of the studied drug. 相似文献
Weight corrected values of clearance and volume of distribution were significantly higher in early lactation than in late pregnancy in both ewes and cows. Mean residence time and elimination-half life were shorter in lactating than in pregnant ewes, however for the latter parameter the difference was not statistically significant. Neither of these parameters changed in cows.
It is concluded that in both ewes and cows pharmacokinetic parameters of penicillin-G are altered from late pregnancy to early lactation but that these changes have little practical impact and do not call for a revised dosage regime of the studied drug. 相似文献
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Ismail Saidi Selemani Lars Olav Eik Øystein Holand Tormod Ådnøy Ephraim Mtengeti Daniel Mushi 《Livestock Science》2013,157(1):173-183
The study was conducted to assess the effects of seasonal variation in the quality and quantity of pasture and management of livestock exclosures (ngitili) on the grazing behavior of cattle and goats. The study was 2×2×2 factorial design with three independent variables: season (Dry or Rainy), ngitili management (Private or Communal) and animal species (Cattle or Goats). Focal and scan observation methods were used to record different behavioral activities. Vegetation attributes from the study areas were measured in two consecutive seasons. Most key forage species had significant higher crude protein (CP) content and in vitro organic matter digestibility (INVOMD) in rainy than in dry season (P<0.05), but Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) did not vary significantly with season (P>0.05). ADF and NDF were significantly higher in species from communal ngitili than those from private ngitili (P<0.05). Above-ground herbaceous biomass and bulk density (BD) were significantly higher in the rainy season and in the private ngitili than in the dry season and in the communal ngitili respectively. Cattle and goats spent considerably more time grazing and browsing respectively in the rainy season than in the dry season (P<0.05). Cattle foraging activities did not vary significantly (P>0.05) with ngitili management, but goats found to spend considerably more time browsing in the communal ngitili and more time grazing in the private ngitili (P<0.05). Despite the merits of stocking cattle and goats together in the heterogeneous pasture, seasonal variation in forage resources requires investigation of other strategies such as use of multipurpose trees and treatment of crop residues to improve livestock production. 相似文献
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兰州地区苜蓿和红豆草根际溶磷菌筛选及菌株部分特性研究 总被引：6，自引：1，他引：5
利用溶磷圈法对苜蓿和红豆草根际不同部位溶磷细菌进行了分离,共获得分离物386个,其中137个具有溶磷能力.苜蓿和红豆草根际不同部位溶磷菌数量分布有差异.其数量为RS>RP>NRS>HP.对筛选获得的12株溶磷圈较大的菌株进行菌落形态特征观察发现,大多数菌落呈灰白色或乳白色、不规则、半透明、边缘不整齐、突起、无光泽、无色素.进一步利用钼蓝比色法对菌株分解磷矿粉能力测定显示,各菌株分解磷矿粉能力差异较大,溶磷量最大为338.4mg/ml,最小为25.9mg/ml,这与其自身溶磷机制有关.溶磷量与菌株培养液pH值之间存在显著相关性.12株菌株大部分具有分泌IAA的能力,其中LM6和LH9分泌IAA能力较强. 相似文献