Antibodies reactive with Bartonella henselae and Ehrlichia canis in dogs from the communal lands of Zimbabwe

The prevalences of antibodies against Bartonella henselae and Ehrlichia canis were determined in sera from 228 dogs in 5 communal lands of Zimbabwe, areas where traditional subsistence agro-pastoralism is practised. The sera were collected from apparently healthy dogs during routine rabies vaccination programmes and tested with indirect fluorescent antibody assays using B. henselae (Houston-I) and E. canis (Oklahoma) as antigens. We found reactive antibodies (> or =1:80) against B. henselae in 14% of the dogs tested. Seropositive animals were found in Bikita (41%; 17/42), Omay (13%; 6/48), Chinamora (5%; 2/38) and Matusadona (15%; 7/48). No seropositive dogs were found in Chiredzi (0%; 0/52). Antibodies reactive with E. canis (> or =1:80) were found in 34% of the dogs tested, from Bikita (88%; 37/42), Chiredzi (31%; 16/52), Omay (17%; 8/48), Chinamora (26%; 10/38) and Matusadona (15%; 7/48). Our survey shows dogs in the communal lands of Zimbabwe are frequently exposed to E. canis and B. henselae or closely related species. Further studies are indicated to determine the pathogenicity of the organisms infecting these dogs and their clinical significance.     

The grazing index method of range condition assessment

Abstract

Owing to the difficulty of examining succession theory in the Karoo, it is suggested the ecological index method (EIM), be replaced by the grazing index method (GIM), through the introduction of grazing index values (GIV) for Karoo plant species. The GIM may provide more acceptable range condition scores and more realistic estimates of the current grazing capacity. Using GIVs, arrived at by scoring the agronomic attributes of the plant species (productivity, forage value, perenniality), the estimated current grazing capacities are found to be closely similar to the grazing capacity norms established for the different agro‐ecological areas in the Karoo. The manner in which the range condition survey is conducted and the application of the grazing index method, ensures the computation of a figure representative of the agronomic potential of the area to support livestock. The cover figure and the range condition score determined for a sample site, can be employed in monitoring the trend in changes in the vegetation, brought about by climatic and biotic variables. Grazing capacity norms are closely related to median annual precipitation (r² = 0.98). The GIM is more closely related to grazing capacities than the EIM (r² = 0.96 and 0.68 respectively).     

A spatial risk assessment of bighorn sheep extirpation by grazing domestic sheep on public lands

Bighorn sheep currently occupy just 30% of their historic distribution, and persist in populations less than 5% as abundant overall as their early 19th century counterparts. Present-day recovery of bighorn sheep populations is in large part limited by periodic outbreaks of respiratory disease, which can be transmitted to bighorn sheep via contact with domestic sheep grazing in their vicinity. In order to assess the viability of bighorn sheep populations on the Payette National Forest (PNF) under several alternative proposals for domestic sheep grazing, we developed a series of interlinked models. Using telemetry and habitat data, we characterized herd home ranges and foray movements of bighorn sheep from their home ranges. Combining foray model movement estimates with known domestic sheep grazing areas (allotments), a Risk of Contact Model estimated bighorn sheep contact rates with domestic sheep allotments. Finally, we used demographic and epidemiologic data to construct population and disease transmission models (Disease Model), which we used to estimate bighorn sheep persistence under each alternative grazing scenario. Depending on the probability of disease transmission following interspecies contact, extirpation probabilities for the seven bighorn sheep herds examined here ranged from 20% to 100%. The Disease Model allowed us to assess the probabilities that varied domestic sheep management scenarios would support persistent populations of free-ranging bighorn sheep.     

Estimation of feed intake and apparent digestibility of equines and cattle grazing on heathland vegetation communities using the n-alkane markers

The application of n-alkanes as faecal markers to estimate feed intake and apparent digestibility (DMD_ap) of equines and cattle was studied. Additionally, the effect of using different data on diet composition, known proportions of the diet components (DC1) and those estimated using the alkane markers (DC2), on the accuracy of intake and DMD_ap estimates was evaluated. Six mature horses, divided in two groups of three animals (H1 and H2), and three adult non-lactating cows of Asturiana de los Valles breed (C) were housed in individual stalls. H1 and C groups were fed on a diet composed of Lolium perenne L. (70%) and heather (30%) and H2 received L. perenne (40%), heather (30%) and Ulex gallii Planchon (30%). The dietary component heather represented the field proportions of different plant species of heathland, namely Erica umbellata L., Erica cinerea L. and Calluna vulgaris L., at this experimental period. All animals received a daily dose of paper pellets containing C₂₄, C₃₂ and C₃₆ n-alkanes as external markers with the purpose of using different n-alkane pairs of adjacent chain length for feed intake estimations. The results indicated that a period of 3 and 5 days was sufficient for these external markers to reach a steady concentration in faeces of cattle and equines, respectively. In contrast to the results obtained in cattle, the alkane faecal recovery in equines was unrelated to the carbon chain length. Diet composition only affected the faecal recovery of the alkanes C₂₄ (P < 0.05), C₃₁ (P < 0.05), C₃₂ (P < 0.05) and C₃₆ (P < 0.01) in the faeces of the equines, suggesting a different dispersion of the synthetic n-alkanes in the digesta. In equines, DMD_ap estimates were not affected by the n-alkane (C₂₇, C₂₉, C₃₁ and C₃₃) used in the calculations, contrasting with the significant (P < 0.001) effect observed in cattle. In both animal species, the data on diet composition (DC1 or DC2) used in the calculations did not affect DMD_ap estimates. Feed intake estimates were affected by the alkane pair used in the calculations in H1 (P < 0.05), H2 (P < 0.001) and C (P < 0.001). The data on diet composition used in the intake calculations affected the resultant estimates in H1 (P < 0.05) but not in H2 and C. The differences from the known intake values were lower when using C₃₁:C₃₂ alkane pair, overestimating intake in only an average of 4.5, 13.0 and 1.3% in H1, H2 and C, respectively, using DC1 or DC2. The results obtained in this study confirm the accuracy of the n-alkane markers to estimate simultaneously feed intake, apparent digestibility and diet composition of equines and cattle grazing these type vegetation communities.     

Epidemiological studies of amphistome infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe

During the period between January 1999 and December 2000, the distribution and seasonal patterns of amphistome infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Cattle faecal samples were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas, respectively. Patterns of distribution and seasonal fluctuations of intermediate host-snail populations and the climatic factors influencing the distribution were also determined by sampling at monthly intervals for a period of 24 months (November 1998 to October 2000) in six dams and six streams in the highveld and in nine dams in the lowveld communal grazing areas. Each site was sampled for relative snail density and the vegetation cover and type, physical and chemical properties of water, and mean monthly rainfall and temperature were recorded. Aquatic vegetation and grass samples 0-1 m from the edges of the snail habitats were collected monthly to determine the presence or absence of amphistome metacercariae. Snails collected at the same time were individually checked for the emergence of larval stages of amphistomes. A total of 16,264 (calves 5418, weaners 5461 and adults 5385) faecal samples were collected during the entire period of the study and 4790 (29.5%) of the samples were positive for amphistome eggs. For both regions the number of animals positive for amphistome eggs differed significantly between the 2 years, with the second year having a significantly higher prevalence (P < 0.01) than the first year. Significantly higher prevalences were found in the highveld compared to the lowveld (P < 0.001), for adult cattle than calves (P < 0.01), and in the wet over the dry season (P < 0.01). Faecal egg output peaked from October to March in both years of the study. Bulinus tropicus, Bulinus forskalii and Biomphalaria pfeifferi were recorded from the study sites. The main intermediate host for amphistomes was B. tropicus with a prevalence of infection of 8.5%. However, amphistome cercariae were also recorded in Biom. pfeifferi and B. forskalii. Amphistome cercariae were recorded from both the highveld and lowveld areas with peak prevalence during the post-rainy season (March to May). Metacercariae were found on herbage from the fringes of the snail habitats between February and August, with most of the metacercariae concentrated on herbage 0-1 m from the edges of the habitats. Based on the epidemiological findings a control programme was devised. From this study, large burdens of immature flukes could be expected in cattle during the dry months. Since adult cattle would be resistant to the pathogenic effects of the migrating immature amphistomes the target for control would be young animals being exposed to the infection for the first time. Therefore, the first anthelmintic treatment can be administered in calves in mid June when maximum migration of immature amphistomes starting 3-4 weeks after infection in the early dry season would be expected. A second treatment could be given in late July or early August to remove potentially dangerous burdens of immature flukes acquired later in the dry season. Where resources permit, another strategy would be to treat against the mature flukes in March or April in order to reduce the number of eggs deposited on pastures and the opportunity for infection of the intermediate host snails. To reduce cercarial shedding by the intermediate host snails molluscicides can also be applied during the peak transmission periods (April/May and August/September).     

榆林沙区主要人工固沙灌丛营养成分及对放牧羊只生育影响的研究

人工固沙灌丛粗蛋白、粗脂肪平均含量比天然草地牧草分别高出１６．２２％、４３．５０％,钙的含量除紫穗槐外,平均高出２７．３７．％。磷的含量低于天然牧草,氨基酸总量平均值为１０．８５％,略低于草地牧草,７种必须氨基酸含量与天然牧草接近,沙柳、紫穗槐的镁、锌含量高,踏郎铁含量。铜的含量各灌丛均高。灌丛地放牧,杂交绵羊体重平均加３．４￣３２．０％,羊毛增加２０．０￣７９．３％,产羔率也有较大提高。     

榆林沙区主要人工固沙灌丛营养成分及对放牧羊只生育影响的研究

人工固沙灌丛粗蛋白、粗脂肪平均含量比天然草地牧草分别高出16.22%、43.50%,钙的含量除紫穗槐外,平均高出27.37%.磷的含量低于天然牧草,氨基酸总量平均值为10.85%,略低于草地牧草,7种必须氨基酸含量与天然牧草接近,沙柳、紫穗槐的镁、锌含量高,踏郎铁含量高,铜的含量各灌丛均高.灌丛地放牧,杂交绵羊体重平均增加3.4%一32.0%,羊毛增加20.0%～79.3%,产羔率也有较大提高.     

宁夏干草原不同放牧方式对植被特征影响的研究

采用不同放牧方式,在宁夏干草原系统地开展了草地植物特性与生态学特性方面的研究,结果表明实行六区的划区轮牧方式是科学利用该类草地的最佳方式.轮牧比对照草地生产力提高73.84%.     

宁夏干草原不同放牧方式对植被特征影响的研究

采用不同放牧方式,在宁夏干草原系统地开展了草地植物特性与生态学特性方面的研究,结果表明:实行六区的划区轮牧方式是科学利用该类草地的最佳方式。轮牧比对照草地生产力提高73.84%。     

Epidemiological studies of Schistosoma mattheei infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe

During the period between January 1999 and December 2000, the distribution and seasonal patterns of Schistosoma mattheei infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Faecal samples of cattle were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas, respectively. Patterns of distribution and seasonal fluctuations of the intermediate host-snail populations and the climatic factors influencing the distribution were also determined at monthly intervals from November 1998 to October 2000, a period of 24 months, in six dams and six streams in the highveld and nine dams in the lowveld communal grazing areas. Monthly, each site was sampled for relative snail density, the vegetation cover and type, and physical and chemical properties of the water. Mean monthly rainfall and temperature were recorded. Snails collected at the same time were individually examined for shedding of cercariae of S. mattheei and Schistosoma haematobium. A total of 16264 (5418 calves, 5461 weaners and 5385 adults) faecal samples were collected during the entire period of study and 734 (4.5%) were positive for S. mattheei eggs. Significantly higher prevalences were found in the highveld compared to the lowveld (P < 0.001), calves compared to adult cattle (P < 0.01) and the wet season compared to the dry season (P < 0.01). Faecal egg output peaked from October/ November to March/April for both years of the study. Bulinus globosus, the snail intermediate host of S. mattheei was recorded from the study sites with the highveld having a significantly higher abundance of the snails than the lowveld (P < 0.01). Monthly densities of B. globosus did not show a clear-cut pattern although there were peaks between March/May and September/November. The mean number of snails collected was positively correlated with the water plants Nymphaea caerulea and Typha species. Overall, 2.5% of B. globosus were shedding Schistosoma cercariae. In the highveld, 2.8% of B. globosus were infected with schistosome cercariae and 1.5% in the lowveld, with the figures at individual sites ranging from 0-18.8% in the highveld and from 0-4.5% in the lowveld. The cercariae recorded here were a mixture of S. mattheei and S. haematobium since they share the same intermediate host. The transmission of Schistosoma cercariae exhibited a marked seasonal pattern, being more intensive during the hot, dry season (September/November).     

Epidemiological studies of Fasciola gigantica infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe

During the period between January 1999 and December 2000, the distribution and seasonal patterns of Fasciola gigantica infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Cattle faecal samples were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas respectively. Patterns of distribution and seasonal fluctuations of the intermediate host-snail populations and the climatic factors influencing the distribution were also determined by sampling at monthly intervals for a period of 24 months (November 1998 to October 2000) in six dams and six streams in the highveld and in nine dams in the lowveld communal grazing areas. Each site was sampled for relative snail density and the vegetation cover and type, physical and chemical properties of water, and mean monthly rainfall and temperature were recorded. Aquatic vegetation and grass samples 0-1 m from the edges of the snail habitats were collected monthly to determine the presence or absence of F. gigantica metacercariae. Snails collected at the same time were individually checked for the emergence of larval stages of F. gigantica. A total of 16264 (calves 5418; weaners 5461 and adults 5385) faecal samples were collected during the entire period of the study and 2500 (15.4%) of the samples were positive for F. gigantica eggs. Significantly higher prevalences were found in the highveld compared to the lowveld (P < 0.001), for adult cattle than calves (P < 0.01) and in the wet season over the dry season (P < 0.01). Faecal egg output peaked from August/September to March/April for both years of the study. Lymnaea natalensis, the snail intermediate host of F. gigantica was recorded from the study sites with the highveld having a significantly higher abundance of the snail species than the lowveld (P < 0.01). The snail population was low between December and March and started to increase in April reaching a peak in September/October. The number of juvenile snails peaked between April and August. The mean number of snails collected was negatively correlated with rainfall and positively correlated with temperature. Mean number of snails collected was also positively correlated with Potamogeton plant species and negatively correlated with Cyperus plant species. However, none of the L. natalensis collected from the habitats were found shedding Fasciola cercariae. Metacercariae were found on herbage from the fringes of the snail habitats between February and August for both years, with most of the metacercariae concentrated on herbage 0-1 m from the banks of the habitats. Based on the findings of this study, anthelmintic treatment should be administered in December/January to control chronic and mature fasciolosis. A second treatment should be given in April/May to reduce pasture contamination and subsequently snail infection, as this is the time the snail population starts to build up. To control acute fasciolosis due to the immature liver flukes a third treatment should be given in August. The first application of molluscicides to control the snail intermediate hosts can be done in June the time when the snail is harbouring the parasite and a second application in September in order to kill new generations of infected snails     

Evaluation of veld potential in east griqualand using beef cattle under two grazing management systems

Abstract

Beef production from veld, in the short term, was found to be greater under a continuous grazing system than under a rotational grazing system. Average daily gains decreased from a maximum in late‐spring and the highest three‐year mean value was 0,5 kg/animal/day. Livemass gains/ha were highest at a stocking rate of 2,2 animals/ha and were 131,4 kg/ha under continuous grazing and 88,6 kg/ha under rotational grazing. Estimated mean maximum gains/ha were 0,78 kg/ha/day at a stocking rate of 2,5 animals/ha under continuous grazing and 0,55 kg/ha/day at a stocking rate of 1,7 animals/ha under rotational grazing. However, optimum economic stocking rates were estimated to occur below those where beef production/ha was maximum.     

Macro and trace elements of 26 browse species growing in semi-arid grazing lands of Eastern Cape,South Africa

ABSTRACT

Leaves and twigs from woody plants provide essential nutrients to range animals. We examined variation in the mineral status of 26 woody species, and the influence of harvesting height as well as the interactions of the main effects on minerals levels. Leaves were harvested from five individual plants per species at two height levels: low (<1 m) and upper (>1.5 m). For trees, all mineral levels showed variation (p < 0.05) between species. For shrubs and intermediate growth forms (between shrubs and trees), mineral levels except potassium (K) and zinc (Zn) were influenced (p < 0.05) by height × species interactions. Most browse species had calcium (Ca) contents (8.5–50 g kg^-1) above the required levels, with the majority of the species having Ca beyond the maximum tolerable limit. Most browse plants had sufficient K, phosphorus, magnesium, manganese, iron and Zn concentrations to meet the requirements for ruminants. Copper was deficient in many browse leaves, thus supplementation should be considered in winter. We conclude that such knowledge is essential for sustainable use of browses as mineral supplements, especially during critical periods when climatic conditions limit the feed value of grasses.     

休牧对三江平原小叶章草甸植被特征及生产力的影响

为了研究休牧对三江平原小叶章草甸的影响,在2010年对不同放牧强度的草地植被盖度、高度、密度、生物量等进行了测定。结果表明:除个别数值外,夏季、秋季休牧对草地植物群落和主要植物种盖度、密度、高度、重要值基本无显著影响(P>0.05)。夏季休牧可以显著提高中度、重度放牧区草地植物群落生物量,同时也可以显著降低植物种丰富度(P<0.05);秋季休牧仅在轻度放牧区可以显著降低草地植物种丰富度(P<0.05);而对草地植物群落生物量的影响不显著(P>0.05)。     

Evaluation of a feed intake model for the grazing beef steer

Responses of a feed intake model for grazing beef cattle to changes in model parameters, forage composition, and supplementation programs with energy and protein were evaluated. Without supplements, the model systematically underpredicted intake of low-quality (low digestibility) forages and subsequent overprediction was observed for high-quality diets. In general, for a reference diet of Italian ryegrass, the model was relatively insensitive to microbial growth parameters, highly sensitive to the microbial carbohydrate composition constant, and moderately sensitive to the microbial N composition constant. Intake prediction was sensitive to changes in the microbial use rate constant for fiber but insensitive to those for protein and starch. Model predictions were highly sensitive to the amount of nondegradable fiber in each of the forages tested. Supplementation effects on forage intake were quantified by supplementing all forage diets with chemical components equivalent to that provided by 1 kg of corn grain or 1 kg of cottonseed meal. Supplementation of the forage diet with the concentrate source resulted in substitution ratios of forage to supplement intake consistent with in vivo results. As forage quality increased, substitution of concentrate for the forage increased. However, the model failed to predict the increased forage intake typically observed with protein supplementation, suggesting that it is insufficient for intake prediction in protein-limiting situations. Nevertheless, the model correctly predicted effects of energy supplementation and forage composition on forage intake, suggesting that different controls must regulate intake responses to supplemental protein.     

Evaluation of the effects of nematode parasitism on grazing behaviour, herbage intake and growth in young grazing cattle

Parasitic nematodes, even in the absence of any clinical disease, can cause a reduction in voluntary feed intake in housed ruminants. This trial examined these effects on young cattle grazing pastures. Twenty dairy heifer calves, born in the previous autumn, were blocked according to liveweight and allocated to one of two groups: either untreated or dosed with an IVOMEC((R)) (ivermectin) SR Bolus 10 days prior to turnout on 1 May 1998. The groups grazed separately on two paddocks on predominately ryegrass swards. Liveweights were recorded every 28 days and faecal samples taken for worm egg counts at the same time.In mid-May and mid-July, for two 14-day periods, animals were paired within treatment groups and transferred to one of 10 replicate paddocks of similar sward height and herbage mass. Grazing behaviour and herbage intake were measured during these periods.In mid-May, 2 weeks after turnout, treated and untreated animals showed no difference in grazing behaviour or daily intake of grass. By mid-July, 10 weeks after turnout, the untreated heifers spent on average 105min less per day in grazing time and their daily herbage intake was 0.78kg dry matter (DM) per day lower than that of the treated animals. Residual sward height, mass and composition in the trial paddocks reflected these differences. There were no clinical signs of gastrointestinal parasitism in the untreated group up to this time; in July, the mean worm egg count in this group was 120 eggs per gram (e.p.g.) of faeces. Faecal samples from several untreated animals were positive for lungworm larvae by July, mild clinical signs of bronchitis were observed in two of these animals in mid-July. Over the period from turnout until mid-July, the untreated heifers showed a reduction in mean daily liveweight gain of 150g, compared to the treated animals.     

The impact of grazing on forage quality of the herbaceous vegetation in the Mamora cork oak forest,Morocco

Abstract

This research was conducted in the Mamora cork oak forest of Morocco to describe the impacts of sheep grazing (no use, 35% use, 70% use) in March, April, May and June of 1987 and 1988 on seasonal changes in forage quality of the herbaceous vegetation. The study showed that trends in herbage quality were related mainly to plant maturity. As more species mature, forage quality declines and falls below animal nutritional requirements, especially for young animals. With declining forage quality, the manager has the option of moving stock to areas of less‐mature forage, supplementing the forage or modifying the demand placed upon it.     

复合植被指数在稀疏高寒草原植被盖度遥感反演中的应用

基于Landsat 8遥感影像数据,以西藏日喀则经南木林到申扎县的一条样带高寒草原作为研究对象,选择较为常用的归一化植被指数(normalized difference vegetation index,NDVI)、土壤调整植被指数(soil adjusted vegetation index,SAVI)、修改型土壤调整植被指数(modified soil adjusted vegetation index,MSAVI)以及对半干旱区低覆盖植被信息较为敏感的转换型土壤调整植被指数(transformational soil adjusted vegetation index,TSAVI),结合地表反射率改进运算的FCD模型(forest canopy density mapping model)裸土(bare soil index,BI)和阴影指数(shadow index,SI)构建适合低植被覆盖区域的复合植被指数(vegetation bare shadow index,VBSI);基于各植被指数构建像元二分模型,定量反演高寒草原植被盖度;并利用网格法实测的植被盖度分析反演精度。研究结果表明,8种植被指数所构建的像元二分模型对高寒草原植被盖度的反演精度以VBSI(TSAVI)最高,反演精度为85.66%;并证明了基于野外采集的土壤光谱曲线获取的TSAVI所构建的像元二分模型对高寒草原植被盖度信息的提取具有一定的实用性;改进运算的FCD模型裸土和阴影指数能较好地削弱土壤和阴影对植被信息的影响,所构建的复合植被指数对提取稀疏高寒草原植被盖度信息具有重要的实际意义。     

不同放牧强度对荒漠草原植被和滩羊生产性能影响研究

通过放牧强度对荒漠草原植被和滩羊生产性能影响的研究得出:(1)随着放牧强度的增大,草地牧草生活力减弱;(2)放牧强度与植被总盖度之间存在负相关关系,随着放牧强度的增大草地植被总盖度减小;(3)放牧强度与草地牧草现存量之间存在负相关关系,随着放牧强度的增大,草地牧草现存量减少;(4)放牧强度越大,禾本科、豆科和杂类草牧草所占总产草量的比例越小;(5)滩羊个体增重与放牧强度之间存在着强的负相关,回归方程为:Ga=18.48-7.01G(r=-0.97**);单位革地面积(1 hm2)增重与放牧强度之间呈强的相关,回归方程为:Gh=0.31 17.60G-6.60G2(r=0.87*);(6)综合考虑各研究指标,本类草地放牧强度应以不超过0.75只/hm2为宜.     

我国退牧还草工程重点县草原植被长势遥感监测

利用遥感和地理信息系统等先进技术手段,基于MODIS数据,对我国4大主要草地类型区的退牧还草工程县的草原植被长势进行了监测,主要结论如下:1)内蒙古东部退化草原区2005年草原植被长势虽然差于2004年的面积有上升趋势,但是总体长势良好,明显好于2004年;2)蒙甘宁西部荒漠草原区2005年草原植被长势较差,虽然生长季节草原植被长势差于2004年的面积呈上升趋势,但总体相对比较稳定;3)新疆北部退化草原区2005与2004年相比长势持平的草地面积所占比重大,比较稳定,呈现出长势好差交替的时序变化格局;4)青藏高原东部江河源草原区2005年草原长势好于2004年的草地面积占本区总草地面积的48.07%,长势差于2004年的草地面积占本区草地总面积的32.56%,与2004年持平的占19.37%,由此表明青藏高原东部区草原长势明显好于2004年同期,长势差和长势好于2004年的草原面积波动较为明显。