高寒区多源降水产品精度与水文模拟效果评估——以雅鲁藏布江流域和拉萨河流域为例     

班春广  左德鹏  徐宗学  董义阳  王静  达瓦次仁 《水土保持学报》2023,37(2):159-168,226

卫星降水产品在缺资料地区开展水文气象研究及径流模拟中发挥着至关重要的作用,然而卫星降水产品的精度可能会影响径流模拟效果。采用多种统计指标和VIC水文模型综合评估5种卫星降水产品(CMORPH-BLD、GSMaP＿Gauge、CMFD、MSWEP和PERSIANN-CDR)在雅鲁藏布江流域的精度和拉萨河流域的水文模拟效果。结果表明：(1)CMORPH＿BLD和GSMaP＿Gauge在少雨季存在低估,CMFD在少雨季与观测值具有很好的一致性。MSWEP和PERSIANN-CDR在多雨季和少雨季存在高估。降水量方面,CMORPH-BLD和CMFD均较为接近观测值,其他降水产品存在不同程度的高估。(2)日尺度上,除CMFD外其他卫星降水数据与观测值具有较小的相关性(0.26～0.45),CMORPH-BLD和CMFD和观测值具有较好的一致性,CMFD和MSWEP探测小降水事件(0.1,0.5,1 mm/d)的能力优于GSMaP＿Gauge。各卫星降水产品在探测强降水(2,5,10 mm/d)方面能力不足。日降水2 mm/d的降水阈值为各分类指数的变化点。(3)月尺度上,各降水产品与观测值具有很...  相似文献   

武冈铜鹅与其他3种鹅肉品质特性的比较     

曲湘勇  何俊  贺长青  金宏  杨丹丹  朱立涛  范志勇  达代又  林立东 《动物营养学报》2013,(10):2277-2285

本试验旨在测定武冈铜鹅、四川白鹅、武川鹅以及天府肉鹅的常规肉品质和矿物质元素、氨基酸、风味脂肪酸、肌苷酸含量及肌纤维直径与密度,并进行比较。选取1日龄体格健壮的武冈铜鹅、四川白鹅、武川鹅和天府肉鹅各30只,分为4组,每组5个重复,每个重复6只鹅,公母各占1/2,饲喂相同饲粮。试验期为70 d。结果表明:1)武冈铜鹅胸肌粗蛋白质含量显著高于其他3种鹅(P<0.05),胸肌粗脂肪含量显著高于四川白鹅(P<0.05);而腿肌粗脂肪含量与其他3种鹅差异不显著(P>0.05),腿肌贮存损失率显著低于其他3种鹅(P<0.05)。2)武冈铜鹅肌肉铁、镁、钾含量均显著高于四川白鹅和天府肉鹅(P<0.05)。3)武冈铜鹅肌肉中天门冬氨酸、谷氨酸、丙氨酸、缬氨酸、赖氨酸的含量极显著高于武川鹅和四川白鹅(P<0.01),甘氨酸和脯氨酸含量极显著高于其他3种鹅(P<0.01),而胱氨酸和苯丙氨酸与其他3种鹅差异不显著(P>0.05)。4)武冈铜鹅肌肉中肉豆蔻酸含量极显著高于其他3种鹅(P<0.01);十六烯酸含量极显著高于武川鹅(P<0.01);亚麻酸含量显著高于武川鹅(P<0.05);二十烯酸含量极显著高于天府肉鹅(P<0.01)。5)武冈铜鹅胸肌肌纤维密度显著高于四川白鹅和武川鹅(P<0.05),而各组肌纤维直径没有显著差异(P>0.05)。由此可见,武冈铜鹅肌肉品质以及风味优于武川鹅、四川白鹅以及天府肉鹅。  相似文献   

Feeding value of pastures for ruminants     

GC Waghorn  DA Clark 《New Zealand veterinary journal》2013,61(6):320-331

Perennial ryegrass is the primary forage component of ruminant diets in New Zealand. It is persistent and palatable, and immature ryegrass has a high nutritive value (NV). However, seed-head development substantially lowers its feeding value (FV) as fibre concentration increases, the rate and extent of digestibility decreases, and voluntary intake declines. Ryegrass pastures are susceptible to accumulation of endophytic and saprophytic fungi in dead material at the base of the sward, especially when mature and laxly grazed. Feeding forage legumes to ruminants grazing grass-dominant pastures will improve animal performance and lessen the reliance on a single species to meet all nutritional requirements.

The FV of forage is a function of intake and NV, measured by chemical analyses and animal feeding trials. Performance of individual animals grazing forages is usually limited by energy intake because structural fibre can slow digestion and clearance from the rumen and because of competition between individuals for available feed. The use of metabolisable energy (ME) content of forage to signify FV can give a reasonable indication of animal performance, but it should be used in conjunction with chemical analyses to improve the accuracy of predictions.

The relationship between FV, pasture production, animal performance and profitability is complex. The importance of skilled management to maintain pasture quality and optimise animal performance under inconsistent climatic conditions should not be underestimated. Acceptable animal performance with minimal veterinary intervention requires good nutrition, but the genetic potential of livestock in New Zealand cannot be met solely by grazing pasture, especially when a high utilisation of pasture is required to maintain quality and profitability.

Producers are responding to industry demands to reduce the seasonality in supply of milk and meat by changing lambing and calving dates, and extending lactation length in dairy cows. Social changes include adoption of once-daily milking in the dairy industry. Some changes have necessitated increased use of supplements and others can be met by feeding forages with a higher FV than ryegrass, all of which require an improved knowledge of feed quality. This information is available through rapid and inexpensive near infrared spectroscopy (NIRS) analysis, enabling animal nutritional needs to be balanced by appropriate nutrient supply. It is essential that producers continue to improve animal welfare, limit excessive use of fertilisers and meet the demands of overseas consumers. Good nutrition, with an increased use of legumes and other forages to complement ryegrass pastures, will enable these objectives to be achieved.  相似文献   

Aural plaques in two imported horses in New Zealand     

RA Fairley  CM Morley  SD Williams  DA Senior  MA Neill 《New Zealand veterinary journal》2013,61(4):232-233

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西藏原始林芝云杉林空间结构参数分布特征     

韩艳英    盛基峰  李垚  大布穷  叶彦辉   《西北林学院学报》2023,38(1):146-152

以藏东南波密岗乡自然保护区原始林芝云杉林为研究对象,应用空间结构参数角尺度、混交度和大小比数,建立空间结构参数的三元分布,揭示林分的空间结构特征。结果表明,从一元分布看,林木整体属于随机分布,林分强度混交,树种的优劣程度参差不齐,整体处于中庸状态;在混交度和角尺度分布中,以随机分布和强度混交林木株数最多,大小比-角尺度组合中,均以随机分布轴线和中庸轴线两侧基本对称;三元结构参数组合为强度混交、随机分布、亚优势状态林木分布较多。主要树种的混交程度较高,呈现强度和极强度混交状态;其中林芝云杉和华山松为该群落的优势树种随机分布,其他主要树种都为轻度聚集分布;树种间大小比数差异明显,其中林芝云杉最低,<0.252,处于亚优势状态。全面分析原始林芝云杉林的空间结构,为林芝云杉林结构优化调整提供重要参考,为藏东南天然林可持续发展提供科学依据。  相似文献   

浅析阿拉善左旗林业有害生物防治现状及应对措施   总被引：1，自引：0，他引：1  

姚艳芳  杨芹  巴依尔  王晓勤  常桂霞  郝淑香  达来夫 《内蒙古林业调查设计》2019,(4):54-56

文章对阿拉善左旗林业有害生物防治现状进行了调查,分析了林业有害生物监测防治工作存在的问题,提出做好林业有害生物防治社会化服务工作应对的措施,对于建立起适应当前林业改革和发展形势需要的林业有害生物防治公共服务保障体系提供了理论依据。  相似文献   

Inter-observer agreement between two observers for bovine digital dermatitis identification in New Zealand using digital photographs     

DA Yang  RA Laven 《New Zealand veterinary journal》2019,67(3):143-147

Aims: To assess the inter-observer agreement for detecting bovine digital dermatitis (BDD) lesions in digital colour photographs of the hind feet of cows, which had been taken while the animals were standing to be milked, between two trained observers.

Methods: Thirty-six photographs were selected from a total of 184 photographs held by the first author (R1), who had classified them as negative (n=11) or positive (n=25) for BDD. They were delivered to a technician (R2) who had previously visually inspected cattle for BDD lesions, and who then recorded the photographs as being either BDD-positive or BDD-negative. The percentage agreement between R1 and R2, and two other inter-observer agreement statistics, Cohen’s κ and Gwet’s first-order chance correction agreement coefficient (AC1), were calculated. The cumulative membership probabilities of Cohen’s κ and Gwet’s AC1 were then calculated for different benchmark ranges of κ.

Results: The percentage agreement between R1 and R2 was 33/36 (92%), Cohen’s κ was 0.80 (95% CI=0.57–1.0) and Gwet’s AC1 was 0.86 (95% CI=0.69–1.0). Based on the cumulative membership probabilities for Gwet’s AC1, there was 75% probability that the two observers had almost perfect agreement (κ≥0.81). For both Cohen’s κ and Gwet’s AC1, there was >95% probability that the two observers had at least substantial agreement (κ≥0.61).

Conclusions: The two trained observers had at least substantial agreement in identifying from a digital photograph as to whether BDD lesions were present or absent. Therefore results from the two could be used interchangeably.

Clinical Relevance: Visual assessment for BDD lesions in the milking parlour can be subjective. However a high agreement between these two trained BDD inspectors means BDD prevalence reported from different regions in New Zealand by these two can be directly compared.  相似文献   

Impact of a catastrophic hurricane on island populations     

DA Spiller  JB Losos  TW Schoener 《Science (New York, N.Y.)》1998,281(5377):695-697

Lizard and spider populations were censused immediately before and after Hurricane Lili on islands differentially affected by the storm surge. The results support three general propositions. First, the larger organisms, lizards, are more resistant to the immediate impact of moderate disturbance, whereas the more prolific spiders recover faster. Second, extinction risk is related to population size when disturbance is moderate but not when it is catastrophic. Third, after catastrophic disturbance, the recovery rate among different types of organisms is related to dispersal ability. The absence of the poorer dispersers, lizards, from many suitable islands is probably the result of long-lasting effects of catastrophes.  相似文献   

Amplification of Bovine Viral Diarrhoea Virus Introduced into an In Vitro Embryo Production System Via Oocytes from Persistently Infected Cattle     

MSD Marley  MD Givens  PK Galik  KP Riddell  DA Stringfellow 《Reproduction in domestic animals》2009,44(3):532-535

The purpose of this study was to determine whether or not embryos derived from in vitro fertilization of oocytes from persistently infected (PI) cattle would contain infectious virus. Three in vitro embryo production treatment groups were assessed: 1) oocytes and uterine tubal cells (UTC) free of bovine viral diarrhoea virus (BVDV) (negative control), 2) oocytes free of BVDV fertilized and cultured in media containing UTC obtained from PI heifers, and 3) oocytes from PI heifers fertilized and cultured in media containing UTC free of BVDV. The developmental media, UTC and embryos (individual or groups of five) were assayed for virus. Virus was not isolated from any samples in treatment group 1. As shown in previous studies, a proportion of embryo samples were positive for BVDV in treatment group 2. In treatment group 3, the virus associated with the oocytes contaminated the developmental media and infected susceptible co-culture cells used during fertilization and culture. In addition, 65% (11/17) of the degenerated ova from treatment group 3 had infectious virus associated with them. While none of the ova developed into transferable embryos, the study did confirm that use of oocytes from PI cows could lead to amplification of BVDV and cross contamination during in vitro embryo production.  相似文献   

Treatment of a Periarticular Tibial Fracture in a Foal with a Hybrid External Fixator   总被引：1，自引：0，他引：1  

ROBERTA FERRO DE GODOY  DScVM    RICHARD R. FILGUEIRAS  MS    LÍLIAN A. GONTIJO  DVM    FÁBIO HENRIQUE BEZERRA XIMENES  DVM    LIANA VILLELA DE GOUVÊA  DVM    CRISTIANE DA SILVA PEREIRA  DVM    RICARDO M. ALMEIDA  MS    CECI RIBEIRO LEITE  DVM    ANTÔNIO RAPHAEL T. NETO  DScVM    JOSÉ RENATO JUNQUEIRA BORGES  DScVM 《Veterinary surgery : VS》2009,38(5):650-653

Objective— To report repair of a right proximal tibial Salter-Harris type II fracture in a foal with a hybrid external fixator (HEF).
Study Design— Case report.
Animals— A 5-month-old male foal.
Methods— After open surgical reduction, an HEF built with wires, 2 half-rings, 3 half-threaded connecting rods, and Schanz pins was used to stabilize the fracture.
Results— Immediately after surgery, the foal had relatively good weight bearing. The HEF was removed at 60 days after radiographic confirmation of healing.
Conclusions— HEF can be used to stabilize a proximal tibial Salter-Harris type II fracture in a 5-month-old foal.
Clinical Relevance— HEF should be considered as another option for repair of proximal tibial Salter-Harris type II fractures in foals.  相似文献