北美落基山自然风光与动植物纪事

北美洲落基山脉纵贯加拿大西南和美国西北部,跨越北极带、寒带和温带高原气候带,是全球著名山脉之一。有奇特的高原地貌、世界最大的冰原、众多冰河、瀑布、高原湖泊、温泉及间歇喷泉等自然景观,以及多种植被、特有动物,每年吸引来自世界各地的众多游客。美国、加拿大政府和联合国教科文组织重视环保,在落基山脉建立众多国家公园,其中有7处划定为《世界遗产目录》《世界遗产公园》。国家公园重视环保,订立各种保育措施,值得借鉴。     

Field evaluation of live chilling with CO2 on stunning Atlantic salmon (Salmo salar) and the subsequent effect on quality

Atlantic salmon were slaughtered in three ways on a commercial slaughter line: (1) killed by a percussive stun after crowding; (2) killed by percussive stun after crowding, pumping and live chilling; (3) killed by exsanguination after crowding, pumping and live chilling. The live‐chilled fish were exposed to seawater (2°C) saturated with carbon dioxide (pH 5.5–5.7) for 40 min. The fish were calm after live chilling, but not unconscious, as eye rolling was observed in all individuals. Subsequent exsanguination of the unstunned fish resulted in death. Both rapid live chilling and the subsequent exsanguination appeared stressful to the fish, as a large and rapid pH drop coupled with earlier onset of rigor mortis, indicative of high muscle activity during the process were observed. The muscle core temperature during ice storage showed that live chilling only has an effect on carcass temperature during the first 6 h post mortem. After 6 h, no significant differences in temperature were detected between live‐chilled and traditionally ice‐chilled fish. We conclude that commercial use of live chilling in combination with high levels of CO₂ does not stun Atlantic salmon. Live chilling followed by exsanguination of the unstunned fish appears to be highly stressful and should be avoided.     

Preslaughter electrical stunning of eels

The current procedures for slaughtering European eels (Anguilla anguilla) for food are very slow and cause suffering. Although there is little legislation for protecting the welfare of fish at slaughter, the legislation covering farmed mammals and birds at slaughter is well defined, requiring that these animals be rendered insensible immediately or without fear or pain prior to being killed. For many mammals and birds this can be achieved using an electrical stun, which is then followed by a procedure that actually kills them, such as exsanguination. This paper reports the investigation of the possibility of using electricity to stun eels, rendering them insensible to pain. Using 1 s duration alternating currents at 50 Hz applied directly across the head of the fish, it was shown that it was possible to stun the fish with currents of 0.1 A and above. Increasing the applied current increased the length of the period of the stun. When the duration of the application of the current was increased to 30 s it was found that the fish could be killed using currents between 0.50 A and 0.95 A. These results show that it is possible to use electricity to instantly stun eels and also to kill them by using longer duration currents. The use of preslaughter electrical stunning at slaughter could allow the welfare of these fish at slaughter to be improved greatly.     

Measuring cultured fish swimming behaviour: first results on rainbow trout using acoustic telemetry in tanks

An experiment was conducted to measure swimming activity of rainbow trout (254.0±33.7 g) held in outdoor tanks under three culture conditions with stocking density used to generate differences: 27 (Culture Density 1, CD1), 80 (CD2) and 136 kg m⁻³ (CD3). Fish were fed dry pellets at 1% of tank biomass from 9h00 to 13h00 with automatic feeders. Using acoustic telemetry, fish positions were monitored every 5 s during 48 h for nine fish (three in each treatment). Swimming behaviour was analysed in terms of trajectories: they varied between (i) holding position (high turning angles), (ii) chaotic trajectories (equal use of all turning angles) and (iii) circular swimming (average turning angle of 60°). Space utilisation differed for each culture condition: CD3 conditions induced a prolonged residence time in the central zone of the tank. Rainbow trout swimming activity patterns and levels differed depending on both day–night alternation and culture conditions. All fish reared at CD1 and one reared at CD2 were day-active. All the other fish showed high activity pattern variability and a higher swimming level was observed under CD3. These results illustrate that monitoring fish swimming activity is feasible even under high densities and provide relevant insights on fish activity which can lead to behavioural welfare indices in relation to constraints imposed by culture conditions.     

不同降温措施和不同日龄放养模式对黄羽肉鸡行为的影响

采用行为学方法研究大棚饲养条件下风扇降温和水帘降温以及舍饲、35日龄开放运动场、70日龄开放运动场对黄羽肉鸡采食、饮水、修饰、站立、运动、觅食、攻击、休息、沙浴,栖架10种行为的影响。结果表明：（1）水帘降温组鸡群采食和修饰行为的百分比极显著高于风扇降温组（P〈0.01）;而饮水、站立和觅食行为的百分比则极显著低于风扇降温组（P〈0.01）;沙浴行为百分比也显著低于风扇降温组（P〈0.05）,其他的行为变化差异不显著（P＞0.05）。（2）放养措施可以极显著增加鸡群的采食、饮水、修饰、运动、觅食、休息以及沙浴等7种行为的百分比（P〈0.01）,极显著降低鸡群的栖架行为及站立行为的百分比（P〈0.01）;其他的行为变化差异不显著（P＞0.05）。表明不同降温措施和不同时间放养措施显著影响肉鸡采食、饮水、站立、修饰、觅食和沙浴行为百分比,上述6种行为指标可作为评价黄羽肉鸡福利养殖水平的参考指标。     

民办高职院校饲料与动物营养专业模块化实训教学体系的构建

近年来,我国民办高职院校迅猛发展,已经成为高职教育中一支不可忽视的生力军。民办高职院校教学的实训、实习以及校企合作正在摸索阶段。文章以饲料与动物营养专业为例,探讨民办高职院校模块化实训教学体系的构建。     

中草药防治动物疾病的研究进展

现阶段的化学药剂、抗生素、生物制剂等对动物疾病的防治容易引起药物残留和耐药性等问题,因此中草药制剂的研究日益受到人们的关注.文章就中草药防治动物疾病的作用特点、效果、应用等三方面进行了综述.     

政府购买服务承接能力建设问题研究——以部属公益二类事业单位为例

政府购买服务是我国公共服务供给的一种模式创新,对经济社会高质量发展具有重要意义。党的十八大以来,部属公益二类事业单位作为政府购买服务新的重要的承接主体,在实践中服务能力与服务质量不断得到提升,但由于历经时间不长,部属公益二类事业单位的承接能力与政府购买服务的要求还不完全相适应,还存在着一些需要研究解决的矛盾。文章对承接能力的概念、内涵和基本特征进行了创新性分析界定,在此基础上,结合当前部属公益二类事业单位政府购买服务承接能力的现状与问题,提出了加强承接主体能力建设的思路与对策。     

Heat stress: A major contributor to poor animal welfare associated with long-haul live export voyages

Recent investigations by the Australian Department of Agriculture, Fisheries and Forestry into high mortalities on live export voyages from Australia to the Middle East during the Northern hemisphere summer suggest that animal welfare may be compromised by heat stress. The live export industry has generated a computer model that aims to assess the risk of heat stress and to contain mortality levels on live export ships below certain arbitrary limits. Although the model must be complied with under Australian law, it is not currently available for independent scientific scrutiny, and there is concern that model and the mandated space allowances are inadequate. This review appraises the relevant literature on heat stress in sheep and cattle, including laboratory studies aimed at mimicking the ambient temperatures and humidity levels likely to be encountered on live export voyages. Animal welfare is likely to be very poor as a result of heat stress in some shipments.     

How do visual and auditory cues influence calf stress reactions at weaning?

We investigated the effects of visual and auditory information related to cow and calf stress responses at weaning. Three weaning conditions were established with physical separation only (PS), physical and visual separation (VS), and physical, visual and auditory separation (VAS). Stress responses such as vocalization and self‐grooming, and changes of three maintenance behaviors (lying, walking and grazing) were recorded for experimental cows and calves in the respective conditions. Comparison of the data revealed that the cow responses differed slightly among groups. However, the peak frequency of vocalization was higher in the PS calves than in those of either VS or VAS. Self‐grooming frequency was significantly different in calves and was high in the order of VAS, VS and PS calves. Furthermore, the percentage of time spent lying down was greater, and that of walking was less, in VAS calves than in either VS or PS calves. These results demonstrate that different information at weaning might strongly affect the stress responses of calves but not those of cows. Relative impacts of different types sensory information on stressors must be considered to plan animal‐friendly weaning.