不同光照强度下乌鳢幼鱼的摄食强度及动力学

在103－10－3lx光照强度范围内,乌鳢幼鱼对浮游动物的摄食强度随光照强度的减弱而增强,在10-3lx时达最大值;摄食丰在10-3lx时最高,并随时间的延长而显著降低。     

Feeding rank and dominance in Tilapia rendalli under defensible and indefensible patterns of food distribution

In four scatter-fed groups of Tilapia rendalli , the distribution of food between individuals was not significantly different from that expected if the food was shared uniformly between all the fish in the group for nine of the 12 radiographic assessments of feeding behaviour. Individual fish maintained the same feeding rank over time, indicating a stable feeding hierarchy, in only one of the four scatter feeding groups. In contrast, in four point source feeding groups, the distribution of food between individuals differed significantly from uniformity in 10 of the 12 radiographic assessments of feeding behaviour and stable feeding hierarchies were maintained over time in three of the four groups. Thus, scatter feeding promoted a more uniform distribution of food between individuals within the group and prevented the formation of feeding hierarchies. There was no significant correlation between individual feeding rank and dominance index in all four scatter feeding groups. In contrast, significant positive correlations were found between individual feeding rank and dominance index in all four point source feeding groups. The results of this study confirm that feeding rank can be used as a correlate of relative social status under defensible feeding conditions.     

食蚊鱼昼夜摄食节律观察

以分时段采样法研究入侵物种食蚊鱼的夏季昼夜摄食节律。食蚊鱼夏季种群内有雌鱼、雄鱼和幼鱼三个不同的摄食类群,这三个类群的摄食节律差异明显。雌鱼摄食节律成双峰型,第一高峰在10:00,而最高峰在22:00,此时肠道食物团平均重量11.70±11.60mg,饱满指数为190.22±155.61。幼鱼也成双峰型,分别在6:00和18:00有两个摄食高峰,以清晨6:00为最高,肠道食物团平均重1.08±1.09mg,饱满指数为128.44±105.49。雄鱼则成单峰型,摄食高峰出现午后14:00左右,肠道食物团平均重0.71±0.96mg,饱满指数为71.80±107.65。食蚊鱼不同摄食类群间的摄食高峰交错出现,是其协调种内关系,降低种内竞争的一种有效行为机制。     

高黎贡山赧亢白眉长臂猿食性及日取食量

通过确定白眉长臂猿的取食特征及日取食量,探讨不同个体间和春、秋季间日取食量是否存在差异,分析影响日取食量和取食特征的因素,为白眉长臂猿日能量需求及其营养容纳量研究奠定基础。2007—2008年春、秋季,在高黎贡山赧亢采用焦点动物取样法观察和记录数据。结果发现,白眉长臂猿取食36种食物的40个部位,其果实的食物单元、取食速度、单个鲜重值等取食特征不同于嫩叶。春、秋季白眉长臂猿每日取食果实量所占百分比最高、嫩叶所占百分比次之、茎和花所占百分比最低。春、秋季家群中雌猿的日取食量均高于雄猿。与家群的雌猿相比,独猿(♀)春季的日取食量稍高。在春季,独猿取食果实持续时间约为家群的2倍,而取食嫩叶的则与家群几乎相等。相同个体秋季的日取食量高于春季的,且春、秋季日取食各部位的量所占百分比也不同。分析结果表明,食性及日取食部位的量反映了白眉长臂猿选择食物的最基本策略。雌雄个体大小差异、能量消耗、食物特征、动物生理需求等因素影响白眉长臂猿的日取食量。白眉长臂猿取食持续时间与觅食树的食物资源量相关。     

Feeder design and available feeding space influence the feeding behaviour of hens

This paper describes a study of the influences of feeder design and available feeding space on the feeding behaviour of laying hens.When feeders were partitioned, feeding rates and the number of feeding bouts were higher than when the feeders were unpartitioned, but feed consumption was lower and the duration of feeding was shorter. Increased feeding space led to longer feeding times with fewer but longer feeding bouts. These results are discussed in relation to animal welfare, with particular reference to feather-pecking.     

Rank and age related feeding strategy observed through field experiments in the Koshima group of Japanese macaques

The feeding process of Japanese monkeys on soy beans which were scattered over a sandy beach on Koshima islet was studied. Younger monkeys were able to pick up more beans when 8 kg of beans were divided and given two times (“two times feeding”) than when the whole amount (8 kg) of beans was given at one time (“one time feeding”). The effect of saturation of the food intake capacity in younger monkeys at the first feeding in “two times feeding” did not appear at the second feeding one hour later. The minutely intake of soy beans (feeding speed) for each age class was analyzed. The decline of feeding speed in adult females after the peak in “one time feeding” was not related to the decline in density of beans on the ground, and this decline was caused by saturation of their food intake capacity. Adult females were divided into four classes according to their dominance rank order: high, lower-high, higher-low, and low classes. The total amount of intake in “one time feeding” was far larger in the high class than in any of the other classes. The total amount of feeding in the first feeding of “two times feeding” increased in accordance with rise in the dominance rank class, and there was no relation to rank and total feeding amount in the second feeding of “two times feeding.” Differences existed in the process of feeding between the rank classes. The feeding speed of the low class was as high as that of the high class on the curve of minutely intake, while the low class stopped feeding much earlier than the high class. The lower-high class displayed a low feeding speed, and stopped feeding the latest. The order of the duration to stay and to feed in the feeding area was lower-high > high > higher-low > low, and this order did not change under the three different feeding conditions, “one time feeding,” and the first and second feedings of “two times feeding.” Adolescent females tended to stay the longest duration in the feeding area among all age classes. Both the lower-high class females and adolescent females had an unstable social status in the Koshima group, and their social status affected their feeding behaviors. The feeding behaviors were similar in attitude depending on social status, and are considered to be maintained for a fairly long time. The feeding strategy of the lower-high class, in staying a longer duration in the artificial feeding area, and departing later, may be effective under the artificial feeding conditions, but it may be a bad strategy in a natural habitat where the food is not so clumped as in artificial feeding, and where choice of other food patches is possible. The above results agree well with previous reports for the Koshima group, indicating that the rank of the lower-high class females was unstable (Mori et al., 1989), and that their reproductive success was low (Watanabe et al., 1992).     

Representing infant feeding: content analysis of British media portrayals of bottle feeding and breast feeding

ObjectiveTo examine how breast feeding and bottle feeding are represented by the British media.DesignContent analysis.Subjects Television programmes and newspaper articles that made reference to infant feeding during March 1999.SettingUK mass media.ResultsOverall, 235 references to infant feeding were identified in the television sample and 38 in the newspaper sample. Bottle feeding was shown more often than breast feeding and was presented as less problematic. Bottle feeding was associated with “ordinary” families whereas breast feeding was associated with middle class or celebrity women. The health risks of formula milk and the health benefits of breast feeding were rarely mentioned.ConclusionsThe media rarely present positive information on breast feeding, even though this feeding practice is associated with the most health benefits. Health professionals and policy makers should be aware of patterns in media coverage and the cultural background within which women make decisions about infant feeding.     

Legal regulation of supplementary cervid feeding facing chronic wasting disease

The supplementary feeding of cervids is a widespread practice across the northern hemisphere. There are few studies, however, regarding the extent of feeding in space and time. There are adverse effects of supplementary feeding, of which the most severe are increased parasite and disease transmission. With the recent emergence of chronic wasting disease (CWD) among cervids in Norway, a legal regulation was issued that banned all supplementary cervid feeding. We quantified the spatial extent and intentions of feeding cervids across all of Norway using a questionnaire at the municipality scale. We also compared spatial extent of feeding before and after the feeding ban to shed light on the ability of regulations to control supplementary feeding. Supplementary feeding to increase winter survival and targeting roe deer (Capreolus capreolus) was more common (48.4% of the municipalities) than the feeding of red deer (Cervus elaphus; 20.5%) and moose (Alces alces; 7.4%). The main feeding period was January–March, but extensive feeding also occurred from November to December and in April. Reducing traffic accidents was also a motivation, particularly for the feeding of moose (14.5%), and this was the main motivation (86%) for public feeding. Among the 65.7% that responded, 53.3% reported they knew about supplemental feeding of cervids in their municipality. In the region with the first feeding ban, 80.2% of municipalities were feeding in 2015–2016 before the ban, which was reduced to 68.4% in 2016–2017 and remained at 68.4% in 2017–2018. In the remainder of Norway, 81.4% were feeding in 2015–2016, and 72.6% were feeding in 2016–2017, but after the ban, this increased to 78.6% in the harsh winter of 2017–2018. Our study highlights that regulations across broad scales may not be followed and that more spatially targeted regulations and increased enforcement are required for disease transmission to be more effectively combated. © 2019 The Authors. Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

On the feeding and social behaviour of the laying hen

This paper describes a study of the influences of early husbandry conditions, social attraction and social rank on various aspects of the feeding behaviour of laying hens.Birds were raised in flocks of 10, 60 or 500. Groups of 3 birds, selected from flocks of the same size, were then housed in pens. Some groups consisted of hens raised in the same flock, and some of birds raised in different flocks. The feeding and agonistic behaviour of each group at each of 5 types of feeder was observed and compared with the behaviour shown when the birds had free access to a 1-m long food trough. Each of the 5 feeders offered the same area of feeding space, but differed in its partitioning and spatial distribution. One feeder had a single unpartitioned feeding space. The other 4 feeders had 3 partioned feeding spaces which were adjacent, or separated by distances of 10, 20 or 40 cm, respectively.For the 5 feeders, total feeding times and lengths of feeding bouts were greatest, and the number of feeding bouts least, when the feeding space was unpartitioned. Synchrony of feeding behaviour was low when the feeding space was unpartitioned or the partitioned spaces adjacent, but was comparable to that at the 1-m long food trough when the distance between partitioned feeding spaces was 10 cm or greater. When feeding space was partitioned, the likelihood that 2 birds would eat together at the same site increased with the distance between feeding space. Dominant birds always exhibited the longest feeding bouts and greatest total feeding times, but were less likely to feed in the same space as another bird, and exhibited less synchrony of feeding behaviour than subordinates. The size of the flock in which the birds were raised, and whether or not the birds in a group had been raised together or apart, had no clear effect on behaviour.These results indicate that, within the limits of this experiment, early husbandry conditions do not influence behaviour shown during feeding in later life, and that social attraction has a greater influence on the feeding behaviour of hens than is generally assumed. In view of this latter finding, it is postulated that in attempting to determine the requirements of laying hens for feeding space, attention must be paid to social attraction as well as to competition at the feeder.     

Patterns of feeding and food pellet retrieval by Norway rats during food deprivation

This study examined whether, for Norway rats suffering a body weight deficit of sufficient magnitude, food hoarding is prepotent over feeding. Rats food-deprived to 85% ad lib weight were videotaped during hoarding sessions that lasted until they ceased to hoard or eat to obtain complete records of retrieval and feeding. During the early minutes of a trial, feeding was the predominant activity, and food pellet retrieval occurred singly or in short bouts. This gave way over time to diminished eating and extended bouts of retrieval (hoarding). Closer analysis suggested that retrieval and feeding were aroused together and at the beginning of such arousal retrieval was momentarily prepotent over feeding. But once retrieval had occurred, there was a shift in favor of feeding. After the rat had consumed a sufficient amount of food, feeding was no longer aroused to the same degree, so bouts of retrieval occurred without feeding. Electronic Publication     

Effect of feeding frequency on growth, feed utilization, and size variation of juvenile gibel carp (Carassius auratus gibelio)

Juvenile (3.0 ± 0.2 g) gibel carp (Carassius auratus gibelio) were fed to satiation for 8 weeks to investigate the effect of feeding frequency on growth, feed utilization and size variation. Five feeding frequencies were tested: two meals per day (M2), three meals per day (M3), four meals per day (M4), 12 meals per day (M12) and 24 meals per day (M24). The results showed that daily food intake increased significantly with the increase in feeding frequency and there was no significant difference between daily food intakes in M12 and M24 treatments. Growth rate, feed efficiency increased significantly with increasing feeding frequencies. Size variation was not affected by feeding frequency. Apparent digestibility of dry matter was not influenced by feeding frequency, while apparent digestibility of protein and energy increased significantly at high feeding frequencies. The feeding frequency had no significant effect on the moisture, lipid, protein, or energy contents of gibel carp, while the ash content decreased with increased feeding frequency. It was recommended that 24 meals per day was the optimal feeding frequency for juvenile gibel carp.     

Feeding Kinematics,Suction, and Hydraulic Jetting Performance of Harbor Seals (Phoca vitulina)

The feeding kinematics, suction and hydraulic jetting capabilities of captive harbor seals (Phoca vitulina) were characterized during controlled feeding trials. Feeding trials were conducted using a feeding apparatus that allowed a choice between biting and suction, but also presented food that could be ingested only by suction. Subambient pressure exerted during suction feeding behaviors was directly measured using pressure transducers. The mean feeding cycle duration for suction-feeding events was significantly shorter (0.15±0.09 s; P<0.01) than biting feeding events (0.18±0.08 s). Subjects feeding in-water used both a suction and a biting feeding mode. Suction was the favored feeding mode (84% of all feeding events) compared to biting, but biting comprised 16% of feeding events. In addition, seals occasionally alternated suction with hydraulic jetting, or used hydraulic jetting independently, to remove fish from the apparatus. Suction and biting feeding modes were kinematically distinct regardless of feeding location (in-water vs. on-land). Suction was characterized by a significantly smaller gape (1.3±0.23 cm; P<0.001) and gape angle (12.9±2.02°), pursing of the rostral lips to form a circular aperture, and pursing of the lateral lips to occlude lateral gape. Biting was characterized by a large gape (3.63±0.21 cm) and gape angle (28.8±1.80°; P<0.001) and lip curling to expose teeth. The maximum subambient pressure recorded was 48.8 kPa. In addition, harbor seals were able to jet water at food items using suprambient pressure, also known as hydraulic jetting. The maximum hydraulic jetting force recorded was 53.9 kPa. Suction and hydraulic jetting where employed 90.5% and 9.5%, respectively, during underwater feeding events. Harbor seals displayed a wide repertoire of behaviorally flexible feeding strategies to ingest fish from the feeding apparatus. Such flexibility of feeding strategies and biomechanics likely forms the basis of their opportunistic, generalized feeding ecology and concomitant breadth of diet.     

南美斑潜蝇取食和产卵行为研究

在室内用菜豆和蚕豆作为寄主植物饲养南美斑潜蝇Liriomyzahuidobrensis (Blanchard) ,观察其取食和产卵习性 ,测量出南美斑潜蝇在这两种作物上的取食孔、取食斑、产卵孔及卵的大小。研究表明 :南美斑潜蝇主要在叶片正面取食 ,在叶片背面产卵 ;南美斑潜蝇在蚕豆和菜豆上取食斑的数量与卵粒数无相关性。     

Alternative Feeding Strategies and Potential Disease Transmission in Wisconsin White-Tailed Deer

ABSTRACT We conducted experimental feeding using 3 feeding methods (pile, spread, trough) and 2 quantities (rationed, ad libitum) of shelled corn to compare deer activity and behavior with control sites and evaluate potential direct and indirect transmission of infectious disease in white-tailed deer (Odocoileus virginianus) in central Wisconsin, USA. Deer use was higher at 2 of the feeding sites than at natural feeding areas (P ≤ 0.02). Deer spent a higher proportion of time (P < 0.01) feeding at pile (49%) and spread (61%) treatments than at natural feeding areas (36%). We found higher deer use for rationed than ad libitum feeding quantities and feeding intensity was greatest at rationed piles and lowest at ad libitum spreads. We also observed closer pairwise distances (≤0.3 m) among deer when corn was provided in a trough relative to spread (P=0.03). Supplemental feeding poses risks for both direct and indirect disease transmission due to higher deer concentration and more intensive use relative to control areas. Concentrated feeding and contact among deer at feeding sites can also increase risk for disease transmission. Our results indicated that restrictions on feeding quantity would not mitigate the potential for disease transmission. None of the feeding strategies we evaluated substantially reduced the potential risk for disease transmission and banning supplemental feeding to reduce transmission is warranted.     

Effect of post-induction nutrient feeding strategies on the production of bioadhesive protein in Escherichia coli

The effect of post-induction nutrient feeding strategies on the production of bioadhesive protein using an IPTG inducible expression system in Escherichia coli was investigated. Cells were cultured in an exponential fed-batch mode to the OD600 of ca. 100 (48 gDCW/L) prior to induction. Six different post-induction nutrient feeding strategies (pH-stat, exponential, constant and linear change in feeding rate with three different slopes) were then applied, and bioadhesive protein production was examined. It was found that post-induction cell growth was independent of nutrient feeding rate. However, bioadhesive protein production was significantly affected by post-induction feeding strategies. Linearly changing post-induction feeding rate with a suitable slope allowed production of bioadhesive protein up to 5.3 g/L, which was higher than that obtained by the other post-induction feeding strategies.     

Laboratory and Field Observations of the Behavior of <Emphasis Type="Italic">Eustenopus villosus</Emphasis> while Feeding and Ovipositing on Yellow Starthistle

The feeding and oviposition behavior of postdiapausal Eustenopus villosus (Boheman) on young and late stage buds, respectively of yellow starthistle, Centaurea solstitialis L., was documented in the laboratory and field. Postdiapausal adult feeding on young buds took over an hour to complete in most cases and was conducted by both sexes. Feeding bouts generally occurred in the sequence of explore, feeding, and budwalk. Oviposition included a feeding phase to prepare an oviposition cavity within the bud; thus, oviposition bouts included some of the same behavioral elements as postdiapausal feeding. The standard sequence of behavioral elements involved with oviposition included exploring, feeding, turning, ovipositing, and budwalking. The feeding element during the oviposition bout often lasted 2 h and was similar in the field and in the lab. Postdiapausal adult feeding on young capitula and stems, and larval feeding on developing ovaries and achenes, makes this weevil especially destructive on a per insect basis.     

不同喂养方式对婴儿骨密度及维生素A的影响

目的:探讨不同喂养方式对婴儿骨密度、维生素A的影响。方法:选择2015~2016年来我院体检的婴儿120例,根据不同喂养方式的不同分为母乳喂养组、混合喂养组及人工喂养组,比较三组婴儿1、3、6月的身长、头围、体质量、骨密度,6月时的维生素A及6月内的患病率。结果:三组婴儿1、3、6月内身长、体质量及头围对比差异无统计学意义(P0.05);1月、3月时,母乳喂养组与混合喂养组骨密度与明显高于人工喂养组(P0.05);母乳喂养组与人工喂养组对比差异无统计学意义(P0.05);6月时,混合喂养组婴儿的骨密度显著高于人工喂养组和母乳喂养组(P0.05),人工喂养组显著低于母乳喂养组(P0.05)。6月时,母乳喂养组的维生素A明显低于人工喂养组及混合喂养组(P0.05)。母乳喂养组6月内的患病率明显低于混合喂养组及人工喂养组(P0.05)。结论:6个月前不同喂养方式对婴儿的体格发育无明显影响,而6个月左右母乳喂养的婴儿骨密度及维生素A含量均低于混合喂养,母乳喂养可降低婴儿的患病率,6个月内应提倡母乳喂养。     

南黄海、东海鲐鲹鱼索饵场浮游动物生态特征

本文采用比较的方法,研究了黄海南部东海北部和东海中南部两个鲐鲹鱼索饵场浮游动物生态特征。结果表明,南部渔场生物量的极差、变异系数小于北部渔场。若扣除个别站位的影响,则南部渔场的平均值高于北部渔场。北部渔场群落多样度、均匀度、丰富度、单纯度较高,南部渔场则相反。北部渔场浮游动物优势种较少,且大多数种具有较高的聚集强度;而南部渔场优势种较多,优势度低,聚集性差。     

What influences aggression and foraging activity in social birds? Measuring individual,group and environmental characteristics

For specialised feeders, accessing food resources may impact on the performance of appetitive foraging and social behaviours at individual and population levels. Flamingos are excellent examples of social species with complex, species-specific feeding strategies. As attainment of coloured plumage depends upon intake of dietary carotenoids, and as study of free-ranging flamingos shows that foraging is disrupted by aggression from other birds, we investigated the effect of four feeding styles on foraging and aggression in captive lesser flamingos. We evaluated individual and group differences in foraging and aggression when birds consumed bespoke “flamingo pellet” from a bowl, an indoor feeding pool and an outdoor feeding section of their pool. Natural foraging (when birds were feeding irrespective of the presence of pellet) was recorded for comparison with artificial feeding styles. One-minute long video footage of the birds' activities in these different locations, recorded between 2013 and 2016, was used to evaluate behaviour. Total number of seconds engaged in feeding and in aggression was recorded by continuous sampling. The colour of individual birds was scored from 1 (mainly white) to 4 (mainly pink). For natural filter feeding in the outdoor pool, maximum foraging was twice as much as bowl feeding, whilst aggression was less than half as much as other feeding methods. Overall, a more restricted feeding style significantly predicted aggression, along with increasing group size. Plumage colour significantly influenced aggression (brightest flamingos were more aggressive) and showed a non-significant trend with foraging (brighter birds fed less than paler birds). No sex effect on feeding or aggression was found. This study enhances our understanding of husbandry and species' biology impacts on captive behaviour and provides data-based evidence to improve food presentation. For flamingos, implementation of spacious outdoor feeding areas can encourage natural foraging patterns by reducing excess aggression and enhances welfare by improving flock social stability.     

铜和镉胁迫对海洋青鳉摄食行为的影响

以海洋青鳉(Oryzias melastigma)为试验动物, 分析了铜和镉两种重金属离子胁迫对海洋青鳉摄食行为特征的影响, 包括摄食响应时间、摄食量、摄食成功率和摄食效率等参数。结果显示, 随着Cu2+浓度的升高, 开始时, 海洋青鳉的摄食量有所升高, 当Cu2+浓度达到0.087 mg/L时有最大的摄食量和最短的摄食响应时间。随后, 摄食量出现下降, 在0.174 mg/L时达到最低。低浓度的Cu2+还能提高海洋青鳉的摄食成功率和摄食效率, 而Cu2+的高浓度和长时间暴露则降低海洋青鳉的摄食成功率和摄食效率。Cd2+对海洋青鳉的摄食行为具有明显的抑制效应, Cd2+抑制海洋青鳉摄食的最低可见效应浓度为 0.65 mg/L, 摄食量、摄食成功率和摄食效率均随着Cd2+浓度的升高而降低。此外, 在Cu2+和Cd2+胁迫下, 对食物的响应时间有性别差异, 雌性显著短于雄性, 还存在群体显著短于个体等现象。