饲料粉碎粒度和调质温度对肉鸡养分消化率及生长性能的影响

饲料制粒可以提高采食量和缩短采食时间,以提高肉鸡生长性能和饲料转化率.而原料的粉碎和调质是制粒过程中非常重要的环节,不仅直接影响到饲料的营养价值和肉鸡的消化吸收,还会影响加工成本和产品质量.粉碎粒度过大会导致混合不均匀、颗粒品质欠佳等不利影响,并且对动物的采食及采食后的物理性消化产生影响,粒度过小则会对动物健康产生不利影响.调质过程主要是使饲料受到水热作用,使其蛋白质变性、淀粉糊化等,调质温度是调质环节的关键参数,温度的高低对蛋白质变性及淀粉糊化程度有直接影响,从而间接影响到动物的生长性能和养分消化利用率.同时,调质温度过高会导致饲料中添加的酶制剂及维生素等严重失活,反而会降低饲料的营养价值.本文综述了肉鸡饲料粉碎粒度和调质温度的研究进展,阐述了粉碎粒度、调质温度与肉鸡生长性能和养分消化率的重要关系.     

机柜式微型机房在银行营业网点的应用研究

为了简化和规范银行网点设备间的建设,建议引入机柜式微型机房中心,使用含精密空调的一体式机柜,把所有设备均安放在机柜里,成为一个微型机房,实现了绿色节能。     

Effect of Conditioning Zinc Sulfate Heptahydrate (ZnSHH) with Zinc Oxide (ZnO) and Neem Oil on Growth,Productivity, Zinc Biofortification of Grain and Zinc Uptake by Basmati Rice

Commercial grade zinc (Zn) sulfate hepta hydrate (ZnSHH) is the most widely used source of Zn in India and several other countries for amelioration of Zn deficiency in crops. However, it releases water of hydration at temperature above 30°C and forms lumps on storage, which make it difficult to handle it and apply in fields. Therefore, conditioning of ZnSHH with ZnO and neem oil reduces the release of water of hydration and prevents lumps formation and can be well stored. Field experiments were conducted at the research farm of the Indian Agricultural Research Institute, New Delhi, India during rice growing seasons (July-November) of 2009 and 2010 to study the effect of conditioning ZnSHH with ZnO and neem oil on growth, productivity and Zn fortification of rice (Oryza sativa) grain and uptake by Basmati rice ‘Pusa 1121’. The experiment was conducted in a randomized block design with 3 replications comprised of 9 treatments of Zn fertilization. The present study shows that when conditioned with 2% ZnO and 4% neem oil ZnSHH improved yield attributes, grain and straw yields, Zn uptake and partial factor productivity (PFP), agronomic efficiency (AE), recovery efficiency (RE), and physiological efficiency (PE) of Zn in Basmati rice ‘Pusa 1121’. In general, ZnO was inferior to ZnSHH. Application of ZnSHH conditioned with 2% ZnO and 4% neem oil can be a better source of Zn for transplanted puddled Basmati rice on Zn deficient soils.     

办公建筑中空调形式对室内外PM2.5浓度相关性的影响

室外PM2.5可通过新风及围护结构缝隙渗透至室内,室外PM2.5较高时尤为明显,结果导致室内空气中的PM2.5浓度上升。为了研究空调形式对室内外PM2.5浓度相关性的影响,在2015年夏季对重庆某办公建筑中采用不同空调形式的室内外PM2.5浓度进行了实测。实测结果发现：集中式空调、分体式空调和非空调房间室内外PM2.5浓度比变化范围分别为0.59～0.76、0.47～0.76、0.71～0.91。室内外PM2.5浓度相关性系数的排序为：集中式空调环境（0.94）> 非空调环境（0.92）> 分体式空调环境（0.77）,研究结果表明,办公建筑的空调形式,对室内外PM2.5浓度的相关性有影响。     

Broodstock conditioning of the Portuguese oyster (Crassostrea angulata,Lamarck, 1819): influence of different diets

The Portuguese oyster Crassostrea angulata shows great potential in oyster farming. The conservation of pure populations of this species is important for production diversification and biodiversity preservation. In this way, the zootechnological development for seed hatchery production is extremely important. Broodstock conditioning is a key step in the process of rearing bivalves in a hatchery. Many factors regulate the reproductive cycle, being food one of the most important ones. To evaluate the effect of different diets on C. angulata reproductive performance, broodstock were conditioned with different food regimes formulated fundamentally by flagellates (Diet 1 – Pavlova lutheri and Isochrysis galbana clone T‐ISO; Diet 2 – P. lutheri, T‐ISO and Skeletonema costatum) and constituted fundamentally by diatoms (Diet 3 – S. costatum and Chaetoceros calcitrans; Diet 4 – P. lutheri, S. costatum and C. calcitrans). During conditioning, samples of oysters were collected to evaluate condition index, gonadal development and biochemical composition. At the end of the conditioning period, oysters were induced to spawn to evaluate reproductive output (fecundity, fertilization rate and D‐larvae development). The diets had an impact on the gametogenesis process, energy storage and reproductive output performance, being the best results those obtained in broodstock fed with the diatoms‐predominant diets. However, those fed with diets majority flagellates had an unsuccessful performance. Holistic approaches incorporating all results in this study reveal and reinforce the idea that the diatom species used presented the nutritional requirements to C. angulata broodstock, being essential in the conditioning phase.     

Germination response of Orobanche seeds subjected to conditioning temperature, water potential and growth regulator treatments

Broomrapes (Orobanche spp.) are parasitic weeds that cause significant losses of crop yield. Experiments were conducted to investigate the seed response to the artificial germination stimulant GR₂₄ in three species of Orobanche subjected to preconditioning under various temperatures, water potentials and with plant growth regulators. The highest germination percentages were observed in Orobanche ramosa, Orobanche aegyptiaca and Orobanche minor seeds conditioned at 18°C for 7 days followed by germination stimulation at 18°C. With the increase of the conditioning period (7, 14, 21 and 28 days), the germination percentage of O. ramosa and O. aegyptiaca progressively decreased. When conditioned at −2 MPa, the germination percentage was lower than at 0 and −1 MPa, especially at 13 and 28°C. Orobanche minor seeds could retain relatively high germination if conditioned at 18, 23 or 28°C, even after significantly extended conditioning periods (up to 84 days). GA₃ (30–100 mg L⁻¹), norflurazon and fluridone (10–100 mg L⁻¹), and brassinolide (0.5–1.0 mg L⁻¹) increased seed germination, while 0.01 mg L⁻¹ uniconazole significantly reduced germination rates of all three Orobanche spp. The promotional effects of GA₃ and norflurazon and the inhibitory effect of uniconazole were evident, even when they were treated for 3 days. Germination of Orobanche seeds was much lower when the unconditioned seeds were directly exposed to GR₂₄ at 10⁻⁶ m . This early GR₂₄-induced inhibition was however alleviated or even eliminated by the inclusion of GA₃ or norflurazon (10–50 mg L⁻¹) in the conditioning medium. On the contrary, the inclusion of uniconazole increased the inhibitory effect of GR₂₄, particularly in the case of O. ramosa.     

Stimulating effects of the insecticide chlorpyrifos on host searching and infestation efficacy of a parasitoid wasp

Hymenopterous parasitoids play an important role in the control of insect populations. During oviposition, Hymenopterous parasitoids use cues such as odours from their environment to locate their specific host. Leptopilina heterotoma (parasitoid of Drosophila larvae) locate their host by probing the substrate with the ovipositor. This behaviour can be induced by the odour of the host substrate alone. We analysed the sub-lethal effects of chlorpyrifos at LD20 on the probing activity in response to a fruit odour (banana). The insecticide increased the percentage of females spontaneously probing in response to the odour. Parasitoid females were then conditioned to associate banana odour with the oviposition in host larvae. This conditioning enables parasitoids to memorize the odour and to increase their probing response to this odour. During the olfactory conditioning, females exposed to the insecticide found and oviposited in host larvae more quickly than control females. One hour after the olfactory conditioning, females exposed to the insecticide presented a higher increase of their probing response to the odour than controls. Twenty-four hours after conditioning, the stimulation produced by chlorpyrifos was no longer perceptible, but the level of response of conditioned females was still higher than that of non-conditioned females, showing that odour memory was not impaired by the insecticide treatment. These sub-lethal effects, that stimulate host searching by parasitoids without impairing odour memorization, could increase their parasitic efficiency.     

Effects of 2 training methods on stress-related behaviors of the dog (Canis familiaris) and on the dog–owner relationship

Instrumental learning plays an important role in dog–human interactions. The recent demand for pet dog training has resulted in the development of various training methods. The present exploratory study aims to compare the effects of 2 training methods on both the behavioral welfare of the dog and the dog–owner relationship: the first method is based on positive reinforcement (appearance of an appetitive stimulus), whereas the second method is based on negative reinforcement (disappearance of an aversive stimulus). The study compared behaviors linked to signs of stress and attentive behaviors toward the owner in 2 dog training schools, which used different methods. Walking on-leash activity and obeying the “sit” command were studied. The results show that dogs from the school using a negative reinforcement–based method demonstrated lowered body postures and signals of stress, whereas dogs from the school using a positive reinforcement–based method showed increased attentiveness toward their owner. However, neither method affected avoidance behaviors. This exploratory study reveals the differential effects of the 2 training methods on dogs' behaviors; it suggests that training methods based on positive reinforcement are less stressful and potentially better for their welfare.     

基于PID的饲料制粒调质温度控制系统设计与试验

为解决颗粒饲料在制粒过程中调质温度依赖人工辅助控制问题,该研究设计了基于PID控制算法的调质温度控制系统。采用开环阶跃响应法建立电动比例调节阀与调质温度之间的控制模型。为了得到最优的PID控制参数(比例系数K_p、积分系数T_i、微分系数T_d),通过Simulink仿真试验对比了Ziegler-Nichols整定法、衰减曲线法和临界比例度法的PID响应曲线,确定PID最优控制参数为K_p=52.7,T_i=6.4,T_d=1.6。对小型制粒机调质温度控制系统进行试验,选用哺乳母猪配合粉料,调质温度分别设定为75、80和85℃,稳定后的调质温度均能维持在设定范围内;选取调质温度为80℃进行稳定性试验,每1 min记录调质温度,整个试验过程中调质温度基本稳定在(80±1)℃范围内,调质温度平均相对误差小于1%,调质温度变异系数小于0.5%,系统温度控制稳定,可自动采集制粒生产数据,实现了制粒过程中调质温度的快速响应和实时控制。研究结果可为颗粒饲料制粒机的自动化控制提供参...