贵州麻阳河黑叶猴秋季主要食物营养分析及对食物选择的影响

2009年9～11月,采集贵州麻阳河黑叶猴取食较多的23种主要食物及取食较少的14种非主要食物,用称重法、凯氏定氮法、酸碱洗涤法及范式洗涤法分析各独立样本的水分、粗蛋白、粗纤维和酸性洗涤纤维(ADF)的营养含量,计算相应的粗蛋白/酸性洗涤纤维(PROT/ADF)比值,并将所得到的各样本的营养含量与相应的秋季取食比例进行...     

贵州麻阳河地区野生黑叶猴与同域放养山羊冬季食物重叠的初步分析

于2009年12月～2010年2月采用瞬时扫描取样法对贵州麻阳河自然保护区的5个黑叶猴Trachypithecus francoisi猴群以及同域放养的山羊羊群的取食行为进行观察记录,并对两者的取食数据进行比较分析,以期了解该地区黑叶猴与放养山羊在食物资源最为匮乏的冬季的资源竞争关系,为黑叶猴的保护管理提供科学依据.研究结果表明:黑叶猴冬季取食植物67种,放养山羊同期取食植物44种,两者食物重叠26种;对26种重叠食物的采食分别占黑叶猴与放养山羊冬季取食时间的76.2％与22.0％;黑叶猴冬季采食的19种主要食物(＞1％冬季采食时间)中,有14种为放养山羊所采食,占黑叶猴与山羊冬季采食时间的71.7％与17.8％;黑叶猴与山羊冬季食物生态位宽度分别为0.68与0.39,两者的冬季食物生态位重叠指数C=0.74.表明贵州麻阳河地区黑叶猴与同域放养山羊在食物最为匮乏的冬季存在较为激烈的食物资源竞争关系.     

广西扶绥黑叶猴的主要食源植物及其粗蛋白含量

食物的营养物质是影响动物食物选择的生态因子。研究动物食物的营养组成及其对野生动物取食的影响对野生动物的保护具有重要的参考意义。为了研究喀斯特环境中食物粗蛋白对黑叶猴食物选择的影响,2006年1月-12月在广西扶绥自然保护区, 采用焦点动物取样法和连续记录法研究了片断化栖息地中黑叶猴的觅食行为,同时采集黑叶猴取食部位样本共40种190份,用凯氏定氮法测量其粗蛋白含量。结果表明,黑叶猴取食的食物包括嫩叶、成熟叶、花、果和种子等部位;食源植物的生活型包括了乔木、灌木、藤本和草本。食物的平均粗蛋白含量为12.7%,有明显的季节性变化。4月份样品的月平均粗蛋白含量全年最高,高达19.1%,而最低在6月份,仅为5.4%。食物的粗蛋白含量在前半年和后半年之间没有显著的差异（z= -1.28,p= 0.20）,在雨季和旱季之间亦无差异（z= -1.22,p= 0.22）;不同食源植物部位的平均粗蛋白含量不同,嫩叶的年平均粗蛋白含量最高,为13.7%,其次是成熟叶和花,分别是13.0%和12.1%,果实最低,仅为9.6%;不同生活型的食源植物粗蛋白含量不同,藤本的粗蛋白含量最高,为 14.1%,草本的最低,仅为10.1%,乔木和灌木分别是11.3%。不同食源植物的取食时间与其粗蛋白含量没有显著的相关关系（p>0.05）,粗蛋白含量不是影响黑叶猴取食的主要因素。     

广西扶绥破碎化生境中黑叶猴的食物种类多样性和季节性重叠

动物使用生境中食物种类的方式对其适应性有重要的影响。为了研究黑叶猴在破碎化栖息地中利用食物的方式,2006年1—12月,采用焦点动物取样法和连续记录技术于每月初连续观察8 d,记录破碎化栖息地中黑叶猴取食的种类和时间,分析其食物多样性和月份间种类的重叠度。结果表明,黑叶猴年均食物多样性指数为3.03(范围1.93—2.62),且多样性指数在各月间没有显著的差异(One-sample K-S Test,P=0.99),说明黑叶猴在各月份中取食的食物种数相似,不同季节利用食物种数的变异程度不大。在所有的食物种类中,仅两种食物青檀Pteroceltis tatarinowii和潺槁树Litsea glutinosa在12个月份都被取食,其他种类则表现了月份间明显的季节性替代。各月份间食物种类的相似性在0.42(3—4月)和0.75(9—10月)之间变化。黑叶猴对破碎化生境中食物种类的利用方式是:首先利用常年均有的食物种类以保证食物来源稳定,同时选择性地利用新出现的种类,使食物种类多样化,满足不同的营养需求。     

广西扶绥片段化栖息地中黑叶猴的食物选择

为了研究黑叶猴在片段化生境中的适应能力,2006年1～12月,采用焦点动物取样法和连续记录技术于每月初连续观察8 d,记录片段化栖息地中的一群黑叶猴觅食行为,同时采用样带法监测黑叶猴家域内食物可获得性的季节性变化。结果显示,黑叶猴以61种植物为食,月平均食物种类为21.8种。黑叶猴取食的食物部位中,嫩叶占比例最大,达55.8%,其次为果实的比例达12.4%,其他依次为成熟叶占12.1%,种子10.6%、花4.3%、芽2.7%和树皮2.4%。成熟叶的可获得性最大,可获得性指数在75%(2月)到100%(7～9月)之间;其次为嫩叶,可获得性指数在25%(11月)到94%(7月)之间,芽、花和果实等食物部位的可获得性指数在20%以下。取食各食物部位的时间与相应部位的可获得性指数间没有显著的相关关系(P>0.05)。月食物种类与生境中食物种数的可获得性间没有显著的相关关系(P>0.05)。因此,在片段化的栖息地中黑叶猴选择性地利用生境中的食物资源。     

黑叶猴食物组成的地域性差异比较

研究同一个物种在不同生境觅食对策的差异不仅有助于了解其行为和生态的可塑性,还有助于评价其对自然或人为干扰导致的生境质量的改变的适应能力,从而为物种的有效保护和管理提供科学依据。本文以广西弄岗国家级自然保护区和扶绥保护区的黑叶猴为研究对象,采用瞬时扫描取样法收集相关的食性数据,并结合贵州麻阳河国家级自然保护区黑叶猴的食性研究结果,比较分析黑叶猴食物组成的区域性差异以探讨黑叶猴对不同喀斯特石山生境的行为适应对策。结果表明:黑叶猴3个地理种群共采食77科、182属、259种植物,木本植物(包括乔木和灌木)是其最重要的食物来源。3个地理种群均表现出较高程度的叶食性,树叶分别占其食物组成的52.7%、63.9%和79.7%。然而,3个地理种群的食物组成却存在显著差异,种群间总的食物重叠指数仅为1.33%-7.43%,主要食物的重叠指数仅为0-13.51%。这些差异可能与栖息地中植被组成的差异有关。与弄岗和麻阳河黑叶猴相比,扶绥黑叶猴采食更多的嫩叶和灌木。人为干扰对栖息地植被结构的影响可能是导致上述差异的主要原因。我们认为黑叶猴不同地理种群食物组成的显著差异反映其觅食的灵活性以应对不同喀斯特石山生境。     

野生藏酋猴冬季食物组成及营养成分

觅食是获取营养物质和能量的重要途经。对于栖息在四季分明地区的灵长类动物而言,低温以及食物资源相对匮乏的冬季是其生存和生长发育的瓶颈期。本研究以安徽黄山的野生藏酋猴（Macaca thibetana）天湖山群为对象,于2019年11月至2020年1月采用瞬时扫描取样法（Instantaneous scan sampling）采集猴群觅食行为数据,并分析其冬季食物组成及食物中各化学成分含量对取食的影响。结果显示,野生藏酋猴在冬季共取食23科31属34种植物,主要包括壳斗科（Fagaceae,21.62%）、樟科（Lauraceae,17.57%）、蔷薇科（Rosaceae,8.11%）的植物,取食部位以叶片（66.22%）和果实（种子）（24.32%）为主。不同取食部位的水分、总糖、淀粉、脂肪、单宁等成分存在显著差异。其中,叶片的水分含量高于果实（种子）、茎和芽,茎和果实（种子）含有较高的总糖,果实（种子）的淀粉和脂肪含量最高,芽的单宁含量最高。此外,取食植物中的总糖含量高于非取食植物。结果表明,野生藏酋猴适应寒冷冬季与食物匮乏的觅食策略是对植物种类、植物部位及其主要营养成分的综合结果。     

云南龙马山滇金丝猴(Rhinopithecus bieti)冬季食性分析

2006年11月-2007年12月,对云南云龙县龙马山滇金丝猴(Rhinopithecus bieti)冬季食性进行了研究.采用粪便显微组织学分析技术分析龙马山滇金丝猴冬季采食植物的种类组成和比例,并测定了该猴群主要取食的15种植物(包括两种松萝科植物)(取食食物百分比>1%)和次要取食的10种植物(取食食物百分比<1%)的化学成分.研究结果表明,龙马山滇金丝猴冬季取食的植物共计26科45种,其中云龙箭竹、长松萝、花松萝、实竹、空心箭竹分别占19.78%、10.28%、8.37%、4.93%、4.46%,是滇金丝猴冬季主要取食的植物种类,占取食植物的47.99%.木本植物和草本植物的叶是滇金丝猴的主要食物,在冬季食物中所占百分比最高,达75%.冬季滇金丝猴比较喜欢采食P/F值较高、单宁含量较低的食物,其主要食物比次要食物含有较高的P/F值和较低的单宁(P<0.05).     

拉沙山黑白仰鼻猴食物中单宁含量的变化

叶食性灵长类食物选择受食物营养及单宁等次生代谢产物影响,为了探讨单宁对黑白仰鼻猴食物选择的影响,通过磷钼酸-钨酸钠(F-D)比色法测定了拉沙山黑白仰鼻猴群(Rhinopithecus bieti)2010年4月-2012年3月间的取食植物(192种)和非取食植物(188种)单宁含量。结果表明,黑白仰鼻猴群全年食用植物中单宁含量低于非食用植物;春季食用植物中单宁含量高于其他季节,而其他季节无差异;不同取食部位单宁由高到低依次为芽、花、叶、果和地衣;不同季节,不同取食部位单宁有差异,春季芽的单宁含量最高,夏秋季果实中单宁含量最高,冬季叶单宁含量最高;不同月份,食物单宁也不同,3月份食用植物中单宁最高(8.36%±6.22%),2月份最低(1.28%±1.19%)。因此,黑白仰鼻猴根据环境食物种类和供给时空特征,可能采取了从高蛋白纤维比/高单宁到低蛋白纤维比/低单宁连续谱觅食策略。     

不同水分含量桑叶对二化性家蚕的营养效应

研究了取食不同水分含量桑叶对二化性家蚕(CSR3×CSR6)5龄幼虫的影响。实验设嫩叶(水分含量80%～85%)、半成熟叶(水分含量65%～70%)和成熟叶(水分含量55%～60%)3个不同处理。采用标准重量分析法分析和计算各种生长、营养和营养效率指数。结果表明,在取食较高水分含量桑叶的处理中,营养指数(包括取食量、消化量和近似消化率等)和营养效率指数(包括食物利用率和转化率等)均显著较高,但不同处理中消化食物向茧壳的转化率及产生每克茧壳所需食物消化量差异不明显。结论是取食水分含量高的桑树嫩叶有助于提高家蚕的取食和营养。     

有机食品、绿色食品和无公害食品

介绍了有机食品、绿色食品和无公害食品的内涵及标准体系,并进行了分析比较。     

Microbial food chains and food webs

Mathematical models for simple microbial food chains and food webs in continuous culture are developed and analyzed. A model for competition of two microbial species for a single scarce resource is also presented as a degenerate case of the food web model. Two models for food chains are developed. The first is based on a model of microbial growth (Monod's) that is widely mentioned and used at the present time. The second is based on a generalization of that model that recent experimental results on microbial food chains seem to require. Experimental data for microbial food webs are almost entirely lacking but a tentative model having what are felt to be the right properties is developed and analyzed. The results obtained from these models seem to be consistent in most circumstances with current ecological thinking on community dynamics.     

Environmental impacts of German food consumption and food losses

Purpose

The objective was to assess the environmental burden of food consumption and food losses in Germany with the aim to define measures to reduce environmentally relevant food losses. To support the finding of measurements, the study provides differentiated information on life phases (agriculture, processing, retailer, and consumption), consumption places (in-house and out-of-home), and the average German food basket consisting of eight food categories.

Methods

In order to obtain information on the environmental impacts of German food consumption, the study analyzed the material flows of the food products in the German food basket starting from consumption phase and going backwards until agricultural production. The analysis includes all relevant impact categories such as GWP, freshwater and marine eutrophication, particular matter formation, and agricultural land and water use. The life stages consumers, retail, wholesale, food production, and agriculture have been taken into account. Furthermore, transports to and within Germany have been considered. Consumption and production data have been taken from the German income and consumption sample, German production and trade statistics, and studies recently carried out on food losses. In order to model German food consumption, some simplifications had to be done.

Results and discussion

Results show that German food consumption is responsible for 2.7 t of greenhouse gases per person and year. Fourteen cubic meters of blue water is used for agricultural food production per person, and 2673 m² of agricultural land is occupied each year per German for food consumption. Between 14 and 20 % of the environmental burdens (depending on the impact category) result from food losses along the value chain. Out-of-home consumption is responsible for 8 to 28 % of the total environmental impacts (depending on the impact category). In particular, animal products cause high environmental burdens. Regarding life cycle phases, agriculture and consumption cause the highest impacts: together, they are responsible for more than 87 % of the total environmental burdens.

Conclusions

The study shows that food production and consumption as well as food losses along the value chain are of high relevance regarding Germany’s environmental impacts. In particular, animal products are responsible for high environmental burdens. Thus, with respect to reducing environmentally relevant food losses, measures should focus in particular on the reduction of food waste of animal origin. The most relevant life cycle phases to reduce environmental impacts are agricultural production and consumption in households and out-of-home.

     

Phytoplankton food quality control of planktonic food web processes

We developed a mechanistic model of nutrient, phytoplankton, zooplankton and fish interactions to test the effects of phytoplankton food quality for herbivorous zooplankton on planktonic food web processes. When phytoplankton food quality is high strong trophic cascades suppress phytoplankton biomass, the zooplankton can withstand intense zooplanktivory, and energy is efficiently transferred through the food web sustaining higher trophic level production. Low food quality results in trophic decoupling at the plant-animal interface, with phytoplankton biomass determined primarily by nutrient availability, zooplankton easily eliminated by fish predation, and poor energy transfer through the food web. At a given nutrient availability, food quality and zooplanktivory interact to determine zooplankton biomass which in turn determines algal biomass. High food quality resulted in intense zooplankton grazing which favored fast-growing phytoplankton taxa, whereas fish predation favored slow-growing phytoplankton. These results suggest algal food quality for herbivorous zooplankton can strongly influence the nature of aquatic food web dynamics, and can have profound effects on water quality and fisheries production. Handling editor: D. Hamilton     

转基因食品安全性评价研究进展

自1996年全球转基因作物大规模商业化生产以来,转基因作物种植面积以年均10%左右的速度迅速增长,2013年种植面积已达1.75亿hm2。其在解决全球粮食问题、环境保护、提升粮食营养质量和品质、制药以及推动经济可持续发展方面展现了重要作用。但是,随着转基因商业化生产的深入,转基因技术的潜在风险性引起了社会以及国际上更广泛的关注。事实上,在转基因技术出现之初,科学家们就开始关注其安全性问题。相关国际组织（FAO、WHO、CAC、OECD等）经过数次研究制订了一系列与转基因食品安全性有关的评价原则、指南与措施等。随着转基因技术的发展,这些安全评价策略也在不断完善。我国目前已经基本建立了转基因食品的安全评价和管理体系。转基因食品在进入市场前要经过十分全面以及系统的安全性评价,包括营养学、毒理学、过敏性等方面,从而保障转基因食品的安全性。     

Effects of food processing on the stability of food allergens

The ubiquitous presence of allergens in the human food supply coupled with increased awareness of food allergies warrants undertaking appropriate preventive measures to protect sensitive consumers from unwanted exposure to offending food allergens. Attempts to reduce or eliminate food allergenicity through food processing have met with mixed results. The rationale for using food processing to reduce/eliminate allergenicity and limitations to using this approach are discussed.     

MTII attenuates ghrelin- and food deprivation-induced increases in food hoarding and food intake

Food deprivation triggers a constellation of physiological and behavioral changes including increases in peripherally-produced ghrelin and centrally-produced agouti-related protein (AgRP). Upon refeeding, food intake is increased in most species, however hamsters primarily increase food hoarding. Food deprivation-induced increases in food hoarding by Siberian hamsters are mimicked by peripheral ghrelin and central AgRP injections. Because food deprivation stimulates ghrelin as well as AgRP synthesis/release, food deprivation-induced increases in hoarding may be mediated by melanocortin 3 or 4 receptor (MC3/4-R) antagonism via AgRP, the MC3/4-R inverse agonist. Therefore, we asked: Can a MC3/4-R agonist block food deprivation- or ghrelin-induced increases in foraging, food hoarding and food intake? This was accomplished by injecting melanotan II (MTII), a synthetic MC3/4-R agonist, into the 3rd ventricle in food deprived, fed or peripheral ghrelin injected hamsters and housed in a running wheel-based food delivery foraging system. Three foraging conditions were used: a) no running wheel access, non-contingent food, b) running wheel access, non-contingent food or c) a foraging requirement for food (10 revolutions/pellet). Food deprivation was a more potent stimulator of foraging and hoarding than ghrelin. Concurrent injections of MTII completely blocked food deprivation- and ghrelin-induced increases in food intake and attenuated, but did not always completely block, food deprivation- and ghrelin-induced increases in food hoarding. Collectively, these data suggest that the MC3/4-R are involved in ghrelin- and food deprivation-induced increases in food intake, but other neurochemical systems, such as previously demonstrated with neuropeptide Y, also are involved in increases in food hoarding as well as foraging.     

MTII attenuates ghrelin- and food deprivation-induced increases in food hoarding and food intake

Food deprivation triggers a constellation of physiological and behavioral changes including increases in peripherally-produced ghrelin and centrally-produced agouti-related protein (AgRP). Upon refeeding, food intake is increased in most species, however hamsters primarily increase food hoarding. Food deprivation-induced increases in food hoarding by Siberian hamsters are mimicked by peripheral ghrelin and central AgRP injections. Because food deprivation stimulates ghrelin as well as AgRP synthesis/release, food deprivation-induced increases in hoarding may be mediated by melanocortin 3 or 4 receptor (MC3/4-R) antagonism via AgRP, the MC3/4-R inverse agonist. Therefore, we asked: Can a MC3/4-R agonist block food deprivation- or ghrelin-induced increases in foraging, food hoarding and food intake? This was accomplished by injecting melanotan II (MTII), a synthetic MC3/4-R agonist, into the 3rd ventricle in food deprived, fed or peripheral ghrelin injected hamsters and housed in a running wheel-based food delivery foraging system. Three foraging conditions were used: a) no running wheel access, non-contingent food, b) running wheel access, non-contingent food or c) a foraging requirement for food (10 revolutions/pellet). Food deprivation was a more potent stimulator of foraging and hoarding than ghrelin. Concurrent injections of MTII completely blocked food deprivation- and ghrelin-induced increases in food intake and attenuated, but did not always completely block, food deprivation- and ghrelin-induced increases in food hoarding. Collectively, these data suggest that the MC3/4-R are involved in ghrelin- and food deprivation-induced increases in food intake, but other neurochemical systems, such as previously demonstrated with neuropeptide Y, also are involved in increases in food hoarding as well as foraging.     

Seasonal patterns of food limitation in Daphnia galeata: separating food quantity and food quality effects

Food limitation for the cladoceran Daphnia galeta was measuredgrowing them with natural lake seston for one growing seasonunder standardized conditions in the laboratory. Growth rateswere related to several measures of food quantity. Particulateorganic carbon (POC) <30 µm was the best predictorof total food availability measured. It was better than chlorophyll-a(Chl-a) of the same size fraction, algal volume calculated fromcell counts or total particle volume from Coulter Counter measurements.Daphnids were also grown with Scenedesmus acutus under the sameconditions and their growth rates were compared. Sestonic carbonconcentrations were related to Scenedesmus carbon concentrations,that provided equal growth rates. The ratio of the carbon concentrationsof both food types (seston, Scenedesmus) represented the foodquality of seston. Thus, the nutritional quality of naturallake seston relative to a standard alga was determined overone growing season. Growth rates of seston fed animals revealedthat they were food limited during long periods of the year.This was also ascertained by standard clutch sizes of fieldanimals. However, the causes of food limitation varied withinthe duration of the studied period. Whereas during the clear-waterphase the food quantity was limiting (while the quality washigh: 100% Scenedesmus), shortly after on 10 June and 17 Junefood conditions were close to threshold concentrations due tolow food quality. For the remainder of the summer, a POC of0.3–0.6 mg C I^–1 with a quality of