Mapping quantitative trait loci controlling variation in forage quality traits in barley

Barley forage quality has a direct relationship to animal performance, but forage quality traits are often neglected or not accessible to the plant breeders. Doubled haploid lines (145) from the cross Steptoe × Morex were grown in 2 years of trails under irrigated conditions to evaluate the variation in forage quality characteristics, identify quantitative trait loci (QTL) for these traits and determine if variation in forage quality characteristics among barley lines is heritable. Forage quality traits were determined at plant anthesis and at peak forage yield stages. A total of 32 QTL were identified that conditioned forage traits at anthesis stage, and 10 QTLs were identified at peak forage yield. At anthesis, forage traits were highly to moderate heritablely, while at peak forage yield, all traits were weakly heritable, indicating that selection progress for these traits will be effective at early stages of maturity. This research has identified and mapped QTL for barley forage quality and will allow deployment of genes for improved forage quality via marker-assisted selection.     

Introduction to automatic forage stations and measurement of forage intake rate in an active open barn for horses

Interest in the use of open barns on Swedish horse farms is increasing as an alternative to keeping horses in box stalls and as a 2007 law requires phasing out of tie stalls. To provide adequate forage to satisfy welfare requirements for nutrition, gut health and behavioural needs, the use of automated feeding is also increasing. Studies on forage intake rate report wide variation but provide little information on how to introduce horses to an automatic forage station and on how forage intake rate varies in individual horses fed using an automatic forage station. This study documented the process of training 22 horses to use a transponder-controlled automatic forage feeding station and measured forage intake rates. Observations on the learning period of horses for transponder-controlled automatic forage stations showed that after 4 days, 48% of the horses had reached the goal of 90% intake. After 8 days, learning was completed in 71% of horses and at 16 days in 95% of horses. Measurements of forage intake rate revealed significant differences between individual horses. Overall mean intake rate ± SD, based on 314 observations, was 22.4 ± 6.7 min/kg forage DM. Evaluation of the number of intake measurements required to set a representative average ration in the automatic station for an individual horse showed that the variation levelled off at four samples. In conclusion, horses quickly learned how to use an automatic forage station, with two-thirds of horses achieving this within 7 days. To ensure the correct ration in a timed transponder-controlled automatic forage station, each horse’s forage intake rate must be measured at least four times to obtain a representative average.     

Effects of sward structure on herbivore foraging behaviour in a South African savanna: An investigation of the forage maturation hypothesis

Abstract: The grass layer of savannas is characterized by strong temporal and spatial heterogeneity in the quantity and quality of forage. Besides this, there is strong variation in other aspects of sward structure, here defined as sward chemistry, morphology, architecture and species composition. The forage maturation hypothesis (FMH) is based on the temporal dynamics of forage quantity and quality of grasslands. Recently this hypothesis has been used to explain the foraging behaviour of large herbivores as an optimal solution for balancing forage ingestion and forage digestion, leading to a maximization of daily rates of forage intake in patches of intermediate forage quantity. However, so far studies using this hypothesis have been constrained to mono‐specific forage resources or have ignored inter‐patch variation in sward structure. We studied the foraging behaviour of cattle in a South African savanna. We explicitly addressed forage quantity and quality, and the structure of seven sward types in order to investigate (i) their effects on foraging behaviour; and (ii) the assumptions and predictions of the FMH for foraging behaviour in grasslands with pronounced variation in sward structure. The results indicated that the assumptions of the FMH were met and that forage quantity affected forage intake the most, with sward structure having little or no effect. The predicted maximum rate of daily forage intake agreed with the results of previous studies. However, the forage quantity at which this maximum intake rate was found, was larger than expected based on the results of some studies. It is likely that this discrepancy resulted from the use of artificial leaf‐only grass swards in these studies. The results suggest that the FMH can be used to explain the foraging behaviour of herbivores over a wide range of sward structures.     

中国典型草原放牧草场蝗虫为害损失及经济阈值的估算(英语)

传统上估算蝗虫在放牧草场为害损失的方法几乎都是用来测定对牧草秋季产量的影响,而实际上,在估算放牧草场蝗虫为害损失及经济阈值时,牧草的现存量而非秋季产量是更应考虑的因素.本文提出了一种适合测定蝗虫对牧草现存生物量影响的新方法,即野外挂笼饲养与蝗虫种群动态相结合的估算方法,并在此基础上组建了放牧草场蝗虫种群经济阈值模型;α_0 α_1M_1_α_2M_2_ α_3S_1 α_4S_2=C其中,M_1:狭翅雏蝗生物量;M_2:宽须蚁蝗生物量;S_1:狭翅雏蝗平均个体重量,S_2:宽须蚁蝗平均个体重量;α_0-α_4:常数.同时引入蝗虫种群数量和生物量两项参数来表达蝗虫种群的发生程度.     

Consequences of migratory strategy on habitat selection by mule deer

Ungulate behavior is often characterized as balancing selection for forage and avoidance of predation risk. Within partially migratory ungulate populations, this balancing occurs across multiple spatial scales, potentially resulting in different exposure to costs and benefits between migrants and residents. We assessed how availability and selection of forage and risk from predators varied between summer ranges of migrant and resident mule deer (Odocoileus hemionus; a species in which individual migratory strategies are generally fixed for life) in 3 study areas in western Montana, USA, during summers 2017–2019. We hypothesized that mule deer would face a tradeoff between selecting forage and avoiding predation risk, and that migration and residency would pose contrasting availability of forage and risk at a broad (summer range) spatial scale. We hypothesized deer exposed to lower forage at a given spatial scale would compensate for reduced availability by increasing selection of forage at the cost of reduced avoidance of predators, a mechanism whereby migrants and residents could potentially achieve similar exposure to forage despite disparate availability. We compared the availability of forage (kcal/m²) and predation risk from wolves (Canis lupus) and mountain lions (Puma concolor) between summer ranges of each migratory strategy, then assessed how selection for those factors at the home range (second order) and within-home range (third order) scales varied using resource selection functions (RSFs). As forage availability increased among mule deer summer ranges and individual home ranges, selection for forage decreased at the second-order (P = 0.052) and third-order (P = 0.081) scales, respectively, but avoidance of predators varied weakly. In 1 study area, summer range of residents contained lower forage and higher risk than summer range of migrants, but residents compensated for this disadvantage through stronger selection of forage and avoidance of risk at finer spatial scales. In the other 2 study areas, summer range of migrants contained lower forage and higher risk than residents, but migrants did not compensate through stronger selection for beneficial resources. The majority of mule deer in our study system were migratory, though the benefits of migration were unclear, suggesting partial migration may persist in populations even when exposure to forage and predation risk appears unequal between strategies.     

扎龙湿地白枕鹤孵化期觅食生境选择

2002—2008年4—5月,采用定点观察、GPS定位、样方调查和因子分析等方法,研究了扎龙湿地白枕鹤孵化期对觅食生境的选择.结果表明：在孵化期,研究区白枕鹤的觅食生境类型主要为芦苇沼泽(74.36%),觅食生境的选择以标识因素和能量因素为主,其次是可觅性因素、安全距离因素和隐蔽因素;扎龙湿地白枕鹤孵化期的觅食生境类型多样化,以湿地(芦苇沼泽)为主,兼含陆地(农田);白枕鹤孵化期的觅食生境包括生境标识、食物、水和隐蔽物四大要素,其对觅食生境的选择分2个层次（大生境层次和小生境层次）3个过程（觅食生境类型选择、觅食区选择、觅食微生境选择）.     

Evaluation of sewage sludge, septic waste and sludge compost applications to corn and forage: Ca, Mg, S, Fe, Mn, Cu, Zn and B content of crops and soils

This is the second of two papers presenting the data from an experiment on the application of aerobically-digested sewage sludge (AES), anaerobic lagoon septic wastes (ANS), sewage sludge compost and fertilizer to soils for grass forage and feed corn production at two different sites in Nova Scotia. Crop yields, plant tissue and Mehlich-1 extractable soil nutrients were evaluated; 15 elements were analyzed in the plant tissue and 9 elements in the soil extracts. This paper describes the Ca, Mg, S, Fe, Mn, Cu, Zn and B content of the crops and the Mehlich-1 extractable content of the soils. The response to the amendments was not consistent at the two sites with the two different crops. We found that the septic sludge (ANS) produced the highest forage Fe, Cu and Zn levels and was equal to compost in elevating corn stover and forage S and the forage B content. The compost produced the highest forage Ca and corn Zn, the AES produced the highest corn Mn, and fertilizer produced the highest forage Mn. None of the amendments produced excessive levels of the above nutrients; rather, the amendments improved the feed quality of the forage and corn stover. Lastly, it was noted that the Mehlich-1 extract only had a significantly positive correlation with forage Cu content.     

Sows’ preferences for different forage mixtures offered as fresh or dry forage in relation to botanical and chemical composition

Providing forage to feed-restricted pregnant sows may improve their welfare by reducing their high feeding motivation. The aim of this study was to determine sows’ preferences for four forage mixtures cultivated in Canada. Forage mixtures were compared when offered either fresh or dry. The four forage mixtures were composed of different proportions and species of legumes (alfalfa (Alf) or red clover (Clo)) and grasses (tall fescue (F) and/or timothy (T)): (1) Alf-F, (2) Alf-F-T, (3) Clo-T and (4) Clo-F-T. Voluntary intake was measured, and preference tests were carried out for two experiments: one in spring for fresh forages ( n = 8) and the other in autumn for hays ( n = 8) with different sows housed in individual pens and fed a concentrated diet meeting their nutritional requirements for maintenance and foetal growth. Voluntary intake was measured by offering each forage mixture separately (one forage mixture/day) during 90 min according to a 4 × 4 Latin square design replicated four times. During preference tests, all six combinations of two forage mixtures were offered once (one combination/day) for 45 min to each sow. Individual forage intake was measured, and feeding behaviour was observed. Forages were analysed for botanical and chemical composition. Difference in voluntary intake among the four forage mixtures was determined using a variance analysis followed by Tukey tests for post hoc comparisons. In preference tests, differences between the two forage mixtures offered were determined using a paired Student’s t test, and the most ingested forage mixture was considered the preferred one. Results from both experiments revealed clear preferences for some forage mixtures when offered either fresh or dry. Forage mixtures with a greater proportion of legumes (AlfT and CloT) were preferred over forage mixtures with a higher proportion of grasses (AlfFT and CloFT). The AlfFT and CloFT forage mixtures contained at least 30% of fescue; therefore, the greater preference for the AlfT and CloT forage mixtures could also be due to the absence of fescue. Sows preferred forages with low DM and NDF concentrations and high CP and non-structural carbohydrates concentrations. Based on results from previous studies, the preferences seen in the present study are most likely due to the greater proportion of legumes, although an effect of tall fescue in preference cannot be excluded. Therefore, offering forages with a high proportion of legumes would be a good strategy to maximise both fresh and dry forage intake in pregnant sows.     

我国白裤瑶饲料植物的民族植物学研究

白裤瑶非常喜欢饲养和食用当地黑猪，对饲料植物的采集和管理具有独特而丰富的经验和知识。该研究旨在对白裤瑶地区饲料植物及其有关的本土知识进行民族植物学编目，在2019—2021年期间，该文作者多次前往当地进行饲料植物的民族植物学调查，利用了关键人物访谈、半结构式访谈和小组讨论，同时该研究还通过打分排序和统计植物利用频度来筛选出综合利用价值高的饲料植物。结果表明：(1)白裤瑶传统饲料植物共104种，隶属于42科85属；被引用植物种数最多的科是菊科(16种，占总种数的15.38%),其次为荨麻科(13种，占总种数的12.5%)。(2)枝叶(56.73%)、全草(26.92%)和叶(8.65%)为当地饲料植物的主要利用部位，大多数饲料植物是草本植物(88.46%),多数饲料植物(占总数的64.42%)一年四季都可以采集，保障了家猪食物来源充足。(3)饲料植物的主要加工方法是将其切碎或打碎后煮熟饲喂。(4)当地被受访者引用最多的物种是玉蜀黍、构树、番薯、桑、金荞麦、稻。(5)根据综合打分排序，在当地具有较高综合评价的饲料植物分别为构树、番薯、桑、金荞麦、南瓜。白裤瑶对饲料植物用于养猪的传统知识非常...     

Assessment of Molybdenum Status in Soil and Forage for Ruminant Production Under Semiarid Environmental Conditions in Sargodha, Pakistan

The present investigation was carried out to determine the molybdenum (Mo) status of soil and forage at the Livestock Experimental Station, Khizer abad, Sargodha, Pakistan. This site falls under semiarid climatic conditions. Soil and forage samples were collected on a monthly basis during the winter season (from October through January) and analyzed after wet digestion to determine the effect of sampling intervals on Mo content as well as its transfer from soil to forage during the whole study period. The effect of sampling intervals on soil Mo content was found to be highly significant, but in contrast, this effect on forage Mo was nonsignificant. The Mo content of soil was found to be highly sufficient to meet the requirement of forage crops, whereas those of forage at the borderline of the ruminant requirement is insufficient. It is expected that with time, further depletion of Mo in the pasture soil due to interaction with Cu and other antagonistic elements may take place, which could finally lower Mo levels in the forage being used for rearing livestock. Thus, at some stage in the future, addition of standard fertilizers enriched with Mo to the soils may be required at the livestock farm.     

Vulnerability of marine forage fishes to piscivory: effects of prey behavior on susceptibility to attack and capture

We conducted a series of size-structured laboratory experiments to quantify and compare the susceptibility of several estuarine and marine forage fishes to attack and capture by piscivorous predators. Size-dependent estimates of capture success, handling time, and prey profitability were generated from single-species experiments offering bay anchovy, Atlantic menhaden, Atlantic silverside, and age-0 striped bass to piscivores. Bay anchovy and Atlantic menhaden were most susceptible to capture and yielded high profitability compared to Atlantic silverside and age-0 striped bass prey. Variation in capture success among forage species was particularly influential in generating disparate profitability functions. Although morphological differences among forage species contributed to variation in susceptibility to predation, behavioral analyses indicated that variable reaction distances to approaching predators and activity levels of prey may explain a large fraction of the observed differences in susceptibility. When several forage species were offered to predators simultaneously in larger enclosures, mortality was highest and occurred earlier for bay anchovy and Atlantic menhaden compared to other prey, which points to the strong influence of predator capture success on overall forage fish vulnerability. Our results demonstrate species-specific differences among forage fishes in the ability to avoid attack and capture by piscivores, and we conclude that the expression of antipredator behaviors contributes significantly to variation in forage species vulnerability.     

牧草种质资源中心库存资源的多样性及其利用

对我国牧草种质资源中心库入库资源的多样性进行了综述。入库资源种类及种质类型多样,特有牧草种质资源突出,栽培牧草的野生祖型及野生近缘种、优良牧草种类多;对牧草种质资源中心库入库资源的开发利用情况进行了介绍;建议今后扩大种质搜集、加强研究、规范入库资源的质量控制,为牧草种质资源的高效利用奠定基础。     

Multiple stressors: using the honeybee model BEEHAVE to explore how spatial and temporal forage stress affects colony resilience

The causes underlying the increased mortality of honeybee Apis mellifera colonies observed over the past decade remain unclear. Since so far the evidence for monocausal explanations is equivocal, involvement of multiple stressors is generally assumed. We here focus on various aspects of forage availability, which have received less attention than other stressors because it is virtually impossible to explore them empirically. We applied the colony model BEEHAVE, which links within‐hive dynamics and foraging, to stylized landscape settings to explore how foraging distance, forage supply, and “forage gaps”, i.e. periods in which honeybees cannot find any nectar and pollen, affect colony resilience and the mechanisms behind. We found that colony extinction was mainly driven by foraging distance, but the timing of forage gaps had strongest effects on time to extinction. Sensitivity to forage gaps of 15 days was highest in June or July even if otherwise forage availability was sufficient to survive. Forage availability affected colonies via cascading effects on queen's egg‐laying rate, reduction of new‐emerging brood stages developing into adult workers, pollen debt, lack of workforce for nursing, and reduced foraging activity. Forage gaps in July led to reduction in egg‐laying and increased mortality of brood stages at a time when the queen's seasonal egg‐laying rate is at its maximum, leading to colony failure over time. Our results demonstrate that badly timed forage gaps interacting with poor overall forage supply reduce honeybee colony resilience. Existing regulation mechanisms which in principle enable colonies to cope with varying forage supply in a given landscape and year, such as a reduction in egg‐laying, have only a certain capacity. Our results are hypothetical, as they are obtained from simplified landscape settings, but they are consistent with existing empirical knowledge. They offer ample opportunities for testing the predicted effects of forage stress in controlled experiments.     

典型草原啮齿动物密度与牧草损失量的关系

研究啮齿动物密度对牧草损失量的关系,对于计算草地经济损害水平至关重要,可以为草地畜牧业管理决策提供指导。本研究于2012 - 2016 年,在锡林郭勒典型草原(东乌珠穆沁旗),应用标志重捕法和样方法对啮齿动物密度以及9 月份植物地上生物量进行调查,用啮齿动物密度及其日食量来估算鼠类对牧草的损害程度,确定牧草损失量。研究结果表明:(1)啮齿动物密度与牧草损失量的最佳拟合曲线是三参数S 型曲线,为:Loss = k/(1+e ^{a - rdensity});(2)当啮齿动物密度>906 个标准鼠单位/hm² 时,牧草产量发生最大损失(牧草产量损失比=23.30% );(3)根据所拟合的曲线,得出该类型草地啮齿动物对牧草损害的危害阈值为174 个标准鼠单位/hm² 。     

热带牧草种质圃资源收集、保存及分发利用研究

简述了农业部儋州热带牧草种质圃概况,介绍了热带牧草种质资源收集、保存及分发利用状况。截止到2013年底,共收集国内外热带牧草种质7760份,先后从中选育出22个牧草及饲料作物新品种通过全国牧草品审会审定。圃内无性繁殖材料活体保存草种质1552份,隶属3科68属202种,其中禾本科牧草种质有60属186种,豆科牧草资源有6属42种,莎草科有4属5种,引进种质有378份。每年向国内外相关科研院所、大专院校及企业和个人提供实物草种质材料300余份,提供种质数据信息400余条,指出了今后热带牧草种质圃在热带牧草资源收集、保存、分发利用方面的研究重点和研究方向。     

Quantitative characteristics of nutrition in free-ranging reindeer (<Emphasis Type="Italic">Rangifer tarandus</Emphasis>) and musk oxen (<Emphasis Type="Italic">Ovibos moschatus</Emphasis>) on Wrangel Island

In 2004 to 2006, studies on free-ranging reindeer and musk oxen on Wrangel island were performed to estimate the nutrient value, daily intake, and digestibility of forage in different seasons of the year. Forage digestibility was determined from the ratio between the contents of indigestible components (lignin) in forage and animal feces. Daily forage intake was calculated from data on daily feces excretion and forage digestibility. The amount of feces and parameters of life activity of individual animals were estimated by following their 24-hour tracks. The results show that the daily intake of forage (dry weight) in musk oxen amounts to 7.8 kg in the summer period and decreases to 6.1 kg in the snow period (March–April). Grazing reindeer in the snow period consume 3.9 kg of forage per day. Forage digestibility in reindeer reaches 56% in March to April and decreases to 52% in June. In musk oxen, forage digestibility in different seasons (March, June, September) varies within a similar range (53–57%). Nutrition parameters (diet composition, forage intake rate and digestibility) of reindeer and musk oxen on grazing grounds of Wrangel Island are similar. Metabolizable energy consumption in both animals during the winter period is at the maintenance level (917–930 kJ/kg0.75 body weight). In the summer period, this parameter in musk oxen increases to 1163 kJ/kg0.75 body weight to meet the energy demand of the animals.     

Landscape context not patch size determines bumble-bee density on flower mixtures sown for agri-environment schemes

Bumble-bee declines across Europe have been linked to loss of habitat and forage availability due to agricultural intensification. These declines may have severe ecological and commercial consequences since bumble-bees pollinate a range of wildflowers and crops. In England, attempts are being made to reintroduce forage resources through agri-environment schemes, yet there are few data on how the area of forage, or the landscape context in which it is provided, affects their success. We investigated the effects of sown forage patches on bumble-bees across sites varying in landscape characteristics. Bumble-bee densities were higher on sown patches compared with control habitats but did not vary with patch size, i.e. total forager numbers were proportional to patch area. Importantly, the relative response to sown forage patches varied widely across a landscape gradient such that their impact in terms of attracting foraging bumble-bees was greatest where the proportion of arable land was highest.     

Forage nutritional characteristics and yield dynamics in a grazed semiarid steppe ecosystem of Inner Mongolia,China

In the steppe of Inner Mongolia, forage is the only source of feed for sheep. The forage intake of sheep can be characterized in both quantity and quality terms, which are determined by environmental and anthropogenic factors and grazing has a strong effect on steppe productivity and the grassland ecosystem. Evaluation of forage quality and quantity is therefore of critical importance. The effects of grazing intensity, interannual variability effects, and species composition on aboveground net primary productivity (ANPP) and forage nutritional characteristics were investigated in a controlled grazing experiment along a gradient of 7 grazing intensities (from non-grazed to very heavily grazed) over six years (2005–2010) on typical steppe in Inner Mongolia. Forage nutritional characteristics were defined by the nutritional value (concentrations of crude protein (CP), cellulase digestible organic matter (CDOM), metabolizable energy (ME) and neutral detergent fibre (NDF)) and the nutritional yield. The forage nutritional yield is a function of ANPP and the forage nutritional value. Forage nutritional value increased but ANPP and nutritional yields decreased with increasing grazing intensity. The inter-annual variation of ANPP, forage nutritional value and yield were weakly linked to the inter-annual variability of precipitation. However, ANPP and nutritional value also varied during the growing season, depending on the seasonal distribution of precipitation and temperature, which influence forage digestibility (CDOM) and metabolizable energy (ME), with higher CDOM and ME under high seasonal precipitation and low seasonal mean temperature. Forage nutritional value and yield, as well as ANPP, were predominantly determined by the dominant species rather than by species diversity. The results suggest that forage nutritional yield in the Inner Mongolian steppe is predominantly determined by the ANPP and only to a minor extent by forage nutritional value, and is predominantly determined by the dominant species and only to a minor extent by species diversity. Therefore, herbage productivity seems to be the most limiting factor in managing this steppe ecosystem as a feeding resource for livestock and to be the best ecological and environmental indicator for grassland management practices.     

Lambs Fed Fresh Winter Forage Rape (Brassica napus L.) Emit Less Methane than Those Fed Perennial Ryegrass (Lolium perenne L.), and Possible Mechanisms behind the Difference

The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems.     

氮素补给对呼伦贝尔草甸草原退化草地牧草产量和品质的影响

长期过度利用导致我国草原的生产功能严重衰退,适量补充关键性养分元素是提升牧草产量的关键.以往研究表明,氮素输入可提升牧草产量,但对牧草品质的影响鲜有涉及.本研究以内蒙古草甸草原退化草地为对象开展控制试验,旨在明确氮素补给如何通过改变不同植物类群的牧草品质和植物群落结构影响群落水平上的牧草品质.结果表明: 氮素输入显著提升了牧草产量达23%,主要得益于根茎禾草类群的贡献; 氮素输入对其他植物类群的生产力无显著影响.不同植物类群的粗蛋白、粗脂肪、粗纤维含量均存在显著差异.氮素输入显著提高了根茎禾草、丛生禾草、豆科植物、苔草类植物的粗蛋白含量,提高了根茎禾草的粗脂肪含量,而对所有类群的粗纤维含量均无显著影响.在群落水平上,氮素输入显著提高了粗蛋白和粗脂肪含量.这对于理解氮素补给对草甸草原牧草生产的影响具有重要意义.