The use of electronarcosis as anaesthetic in the cichlid, Oreochromis mossambicus (Peters). I. General experimental procedures and the role of fish length on the narcotizing effects of electric currents

Procedures to narcotize fish by means of alternating or direct electrical currents are described and a method of evaluating the narcotic effects on fish of electrical currents is detailed. The role of fish length on the narcotizing potential of electrical currents was investigated. The results indicate that there is a positive correlation between fish length and the duration of narcosis.     

The use of electronarcosis as anaesthetic in the cichlid, Oreochromis mossambicus (Peters). III. The effects of changing physical and electrical parameters on the narcotizing ability of half-wave rectified currents

The narcotizing potential of various rectified current configurations on Oreochromis mossambicus was investigated. A 50 Hz, 200 Vp. half-wave rectified current, applied for 30 s, was found to be a suitable configuration for electronarcosis.     

Effects of electrical water bath stunning current frequencies on the spontaneous electroencephalogram and somatosensory evoked potentials in hens

1. The effectiveness of water bath electrical stunning of chickens with a constant root mean square (rms) current of 100 mA per bird delivered for 3 s using 100, 200, 400, 800 and 1500 Hz sine wave alternating current (AC) was investigated in layer hens. The quantitative changes occurring in the electroencephalogram (EEG) and somatosensory evoked potentials (SEPs) were used to determine the effectiveness of stunning. The changes occurring in the EEG were evaluated using Fast Fourier Transformations (FFT) and the SEPs were averaged to determine whether they were present or abolished. 2. The results of FFT indicated that stunning of chickens with a constant rms current of 100 mA per bird using 100 or 200 Hz induced epileptiform activity in all the hens, immediately followed by a reduction in the total (2 to 30 Hz) and relative (13 to 30 Hz) power contents in the EEG frequency bands indicative of unconsciousness and insensibility. The SEPs were abolished in the majority of hens stunned with 100 Hz and all the hens stunned with 200 Hz. 3. By contrast, stunning using 400, 800 or 1500 Hz failed to induce epileptiform activity in all the birds, the total and relative power contents in the EEG frequency bands showed a substantial increase, rather than reduction, and the SEPs were also retained in the majority of chickens. It is therefore suggested that stunning using these frequencies failed to stun them satisfactorily. In these birds, occurrence of a painful arousal, rather than unconsciousness, could not be ruled out. 4. It is therefore suggested that water bath electrical stunning of chickens with a minimum rms current of 100 mA per bird delivered using 100 or 200 Hz would be adequate to ensure bird welfare under commercial conditions, provided both the carotid arteries in the neck are severed at slaughter. On humanitarian and bird welfare grounds, a rms current of greater than 100 mA per bird should be applied whilst using frequencies of 400 Hz or more of sine wave AC for water bath electrical stunning of chickens.     

Some observations on the narcotizing ability of electric currents on the common carp Cyprinus carpio

Some effects of alternating current electronarcosis and of rectified current electronarcosis on C. carpio were investigated. In all instances recovery from narcosis was accompanied by convulsive spasms. Haemorrhaging of the gills was also observed to occur. Carp do not appear to be suitable candidates for electronarcosis.     

Pharmacokinetics of ampicillin and pentobarbital in the course of subclinical fascioliasis in sheep

Pharmacokinetics of two common veterinary drugs, ampicillin and pentobarbital, were determined in sheep before and four, eight, 12, 17 and 21 weeks after infestation of animals by an oral administration of 150 metacercariae of Fasciola hepatica. The parasite infestation was ascertained by clinical observation of the animals. The pharmacokinetics of ampicillin were not significantly affected by the liver parasitism but the disposition of pentobarbital changed. A significant increase in elimination half-life (around 180 per cent), volume of distribution (130 per cent) and mean residence time (154 to 170 per cent) was observed in sheep infected by the parasite for four to 12 weeks. In these animals, duration of narcosis caused by pentobarbital was prolonged 1.8-fold. The results suggested that both reduced elimination of pentobarbital and impaired distribution of the drug would be responsible for the prolonged duration of narcosis in infected animals.     

Interactions Among Different Devices and Electrical Stimulus on the Electroejaculation of Captive Agoutis (Dasyprocta leporina)

The interactions among different electroejaculation devices associated with serial or continuous stimuli were investigated to improve the efficiency of the electroejaculation for semen collection in agoutis. Ten sexually matured male Dasyprocta leporina were restrained by the intramuscular administration of xylazine–ketamine association. Each individual was randomly subjected to four electroejaculation protocols, by combining two devices (one presenting longitudinal electrodes emitting square waves and other presenting ring electrodes emitting sine waves) and two electrical stimuli protocols (serial or continuous). A total of 40 attempts for electroejaculation were conducted in agoutis, being 10 per treatment. The most efficient treatment in providing ejaculates containing sperm (p < 0.05) was that using and electroejaculator connected to a probe with ring electrodes and associated with serial stimuli (4/7; 57%). In spite of semen parameters obtained by sine waves were adequate for using the samples for assisted reproduction, higher values for sperm motility and functional membrane integrity were obtained in the use of the square wave, independently of the electric stimulation protocol used (p < 0.05). In conclusion, we verified that the use of a device presenting a probe with ring electrodes and emitting sine waves, associated with a serial stimuli protocol, improves the efficiency for semen obtaining by electroejaculation in adults D. leporina.     

Effect of rapid decompression and associated hypoxic phenomena in euthanasia of animals: a review.

Documentation in the literature indicates that death is as painless following the induction of hypoxia by rapid decompression as by other methods that lead to hypoxia, such as exposure to high altitude, carbon monoxide, and inert gases (nitrogen, xenon, and krypton). Many of the signs and symptoms of hypoxia are the same as those for alcoholic intoxication and inert gas narcosis. Moreover, there is good evidence that analogous relationships or mechanisms may exist for hypoxia, inert gas narcosis, and anesthesia.     

Evidence of the development of ‘domain‐restricted’ expertise in the recognition of asymmetric motion characteristics of hindlimb lameness in the horse

Reasons for performing study: Visual assessment of horses' movements is subjective, affected by bias and dependent on the level of experience of the assessor. However, to date there are no data available on the ability of the human visual system to recognise (a)symmetry in moving objects. Objectives: To investigate, using visual lameness assessment, the limits of human perception and the ability of experienced and nonexperienced individuals to detect asymmetry in 2 moving objects simulating hindlimb lameness in the horse. Methods: Twelve experienced individuals (equine and small animal clinicians), and 24 nonexperienced individuals (undergraduate veterinary students) were presented with computer simulations showing 2 ‘tuber coxae markers’ created using data from both lame and nonperceptibly lame horses, as well as artificial data based on a sine wave. Individuals were asked to classify as symmetrical or asymmetrical, and then rank based on the grade of perceived asymmetry. Repeatability and learning effect were evaluated by repeating the tests on a subset of subjects. Results: The threshold for detection of movement asymmetry was found to be approximately 25% difference in amplitude between the 2 moving objects for all individuals. There was no significant difference between experienced and nonexperienced individuals in the ability to detect asymmetry in the simulations based on artificial data. However, the percentage of correct answers was higher for experienced compared to nonexperienced individuals for simulations based on data from real lame horses. Conclusions: There was a significant difference between experienced and nonexperienced individuals in the ability to identify asymmetric movement based on the pattern seen in a lame horse, as opposed to an artificial pattern for which all individuals showed similar performance. Potential relevance: The study provides the basis for the development of computer simulations that could aid in training veterinarians in the diagnosis of lameness and, even, the objective assessment of expertise in this field.     

桑树不同品种生态特性的研究

为依据生态学的原理和规律建设高产优质桑园,研究了湖桑32号、农桑12号、新一之濑、选792号等不同品种桑园的土壤温度、土壤含水量、土壤呼吸强度、CO_2浓度、空气温度、空气相对湿度、光合有效辐射等生态特性。4个品种的土壤呼吸速率依次为农桑12号>湖桑32号>新一之濑>选792号;增加空气相对湿度的大小顺序为农桑12号>选＊蛇号>湖桑32号>新一之尬湖桑32号周围的地浓度显著高于其它3个品种;农桑12号降低气温的生态特性较为显著。对不同品种桑园与空旷地气候因素进行差异性分析认为,夏季桑园具有降低气温、增加空气相对湿度、降低土壤温度、减少土壤蒸发、增加土壤含水量的生态作用。     

Use of acupuncture in the resuscitation of animals

In the present work fundamental experience is summed up regarding the acupuncture resuscitation of animals. The results are based on examination of 243 cases of 17 different species of domestic and exotic animals and birds. The apnoea condition, or only deep narcosis, has been induced with the use of different kinds of narcotics, above all Thiopental. A review of four most effective acupuncture points and the proper way of resuscitation are given. The acupuncture resuscitation has shown up to 100% results in clinically healthy dogs, whereas in animals affected with different diseases the success of intervention showed to be smaller (77.47%). In zoo animals in narcosis induced by medicines, the resuscitation effectiveness achieved 92.6%. The resuscitation effect is based not only on strictly determined points but also on diffusive irritation of respective point and its surroundings by acupressure. Discussion deals with the factors on which the acupuncture resuscitation and its success are dependent.     

干旱胁迫及复水对入侵植物节节麦幼苗生长及生理特性的影响

以节节麦幼苗为试材,采用盆栽称重控水法,进行了28 d干旱及7 d复水处理,研究干旱胁迫及复水对节节麦幼苗叶、根生物量比等形态参数、保护酶活性等生理参数的影响。旨在探讨节节麦形态和生理特征可塑性对土壤水分变化的响应特性,为其耐旱机制研究提供参考依据。结果表明:1)干旱胁迫过程中,叶片相对含水量、相对电导率、丙二醛和脯氨酸含量均呈持续增加的变化趋势;叶绿素含量呈先升后降变化趋势;轻度及中度干旱胁迫下超氧化物岐化酶(SOD)活性持续增加,而重度干旱胁迫中则呈先升后降的变化趋势;2)干旱胁迫致使节节麦幼苗叶生物量比、比叶面积下降,根生物量比及根冠比增加;3)复水后,叶片相对含水量、脯氨酸等多数指标均能迅速恢复至正常水平,表明节节麦对干旱胁迫造成的损伤具有较高的修复能力。节节麦通过一系列形态及生理特征的可塑性变化适应土壤干旱生境,从而表现出较强的耐旱性。此外,生理参数可塑性指数的均值明显大于形态参数,说明节节麦主要通过调整生理代谢以适应短期干旱胁迫。     

Survival of Salmonella strains differing in their biofilm-formation capability upon exposure to hydrochloric and acetic acid and to high salt

Acidic and osmotic treatments are part of hurdle systems to control pathogens such as Salmonella in food. In the current study, Salmonella enterica isolates previously shown to differ in their ability to form biofilms were grown in diluted tryptic soy broth (TSB) (1:5 dilution in distilled water) and subsequently exposed to phosphate-buffered saline (PBS) adjusted to pH 3.0 with HCl, PBS adjusted to pH 3.9 with acetic acid or rice vinegar diluted 1:15 with distilled water (pH 3.9). Cells grown in diluted TSB were also exposed to distilled water, pH 7.6, containing 5 M NaCl. No differences in survival upon exposure to PBS adjusted to pH 3.0 with HCl or distilled water containing high salt were observed between the isolates; however, exposure to acetic acid and rice vinegar resulted in lower survival levels of isolates previously shown to be poor biofilm formers. The numbers (log(10) cfu/ml) of surviving cells after exposure for 36 hr to acetic acid and rice vinegar were 4.43 ± 0.24 vs. 2.27 ± 0.87 (P<0.05) and 5.19 ± 0.12 vs. 2.33 ± 0.93 (P<0.05) for isolates with a high vs. low biofilm-forming ability. The survival data could be fitted with the Weibull model. The data suggest that the ability of Salmonella strains to survive in the presence of acetic acid and rice vinegar parallels their ability to form biofilms. Thus, Salmonella with a high biofilm-formation capability might be more difficult to kill with acetic acid found in foods or cleaning solutions.     

Xylazine-ketamine-oxymorphone: an injectable anesthetic combination in swine

A xylazine, ketamine, and oxymorphone combination was investigated to determine its effectiveness as an injectable anesthetic regimen for use in swine. The combination was found to provide good narcosis, analgesia, and muscle relaxation, and was considered to be adequate for minor surgery. The intravenous dose rate was xylazine, 2mg/kg; ketamine, 2mg/kg; and oxymorphone, 0.075mg/kg. The dose of each component was doubled when the intramuscular route was used.     

Commercial slaughter methods used on Atlantic salmon: determination of the onset of brain failure by electroencephalography

This study investigated the effect of exsanguination without prior stunning, or carbon dioxide narcosis followed by exsanguination, or percussive stunning or spiking the brain, on the time taken to abolish the visual evoked responses (VERS) of farmed Atlantic salmon. Only percussive stunning and spiking killed the fish immediately and the other two methods resulted in aversive reactions by the fish. The VERS were lost between 148 and 440 seconds after exsanguination without stunning, and between 300 and 554 seconds after carbon dioxide narcosis followed by exsanguination. During both these procedures the fish showed strong aversive behaviour. In contrast, percussive stunning and spiking the brain could result in the immediate loss of VERS and no aversive reactions from the fish if the stun was applied correctly.     

重庆市蚕桑生产组织模式的调查分析与调整建议

重庆市现有的蚕桑生产组织模式主要包括农户分散经营模式、公司规模化经营模式、公司+农户模式、专业合作社模式。对这4种生产组织模式的运行状况进行了调查分析,认为4种模式分别存在规模小风险大、投入大成本高、制度设计有缺陷、服务功能有限等问题。调整与完善重庆市现阶段的蚕桑生产组织模式建议从3个方面入手:(1)通过桑园流转等方式,重点发展蚕桑生产基本户;(2)构建使农户与龙头企业或合作社成为真正的利益共同体——干、鲜茧利益共同体的新型生产组织模式;(3)以蚕桑资源高效利用和提高蚕桑产业总体经济效益为目标,充实蚕桑生产合作社的生产与经营内容,提高合作社的自我发展能力。     

引入青海的辽宁绒山羊A—B导联心电图

对34只引入青海的辽宁绒山羊A－B导联心电图进行了描记和分析。结果发现绒山羊A－B导联心电图有波形大，波型和波向一致好等优点，是山羊描记心电图时的首选导联。     

An analysis of the spatial and temporal patterns of highly pathogenic avian influenza occurrence in Vietnam using national surveillance data

The objectives of this study were to describe the spatio-temporal pattern of an epidemic of highly pathogenic avian influenza (HPAI) in Vietnam and to identify potential risk factors for the introduction and maintenance of infection within the poultry population. The results indicate that during the time period 2004-early 2006 a sequence of three epidemic waves occurred in Vietnam as distinct spatial and temporal clusters. The risk of outbreak occurrence increased with a greater percentage of rice paddy fields, increasing domestic water bird and chicken density. It increased with reducing distance to higher population density aggregations, and in the third epidemic wave with increasing percentage of aquaculture. The findings indicate that agri-livestock farming systems involving domestic water birds and rice production in river delta areas are important for the maintenance and spread of infection. While the government's control measures appear to have been effective in the South and Central parts of Vietnam, it is likely that in the North of Vietnam the vaccination campaign led to transmission of infection which was subsequently brought under control.     

The Influence of the Halothane Test on Heart Parameters,Oct-Activity,Acid-Base Balance and Blood Electrolytes in Halothane-Sensitive Pigs and in Pigs Pre Medicated with a β-Blocker (Propranolol)

The heart and liver functions, blood electrolytes and acid-base balance were studies in halothane-sensitive and nonsensitive pigs. An inhibition of the hyperthermia reaction was attempted by an i.v. injection of propranolol. The pulse rate of sensitive pigs was shown to be elevated already at the beginning of halothane narcosis. No other differences between sensitive and nonsensitive pigs were observed from the electrocardiogram. Ectopic beats and arythmia appeared only in 1 halothane-sensitive pig which died soon after the test. The serum OCT-activity showed no abnormalities. Hyperkalemia and acidosis occurred but the Ga⁺⁺ was not elevated in halothane-sensitive animals. The slight elevation in Na⁺ was thought to be caused by hemoconcentration. A propranolol injection only delayed but did not inhibit the halothane reaction.     

Anaesthesia with Fentanyl–Metomidate in the cat and its effects on respiration and circulation

Narcosis with Fentanyl–Hypnodil was evaluated in 14 cats. Four were given Lorfan at the end of the narcosis. Clinical variables such as induction, narcotic and awakening phase were recorded. Respiratory variables such as Pao₂, Paco₂, pH and frequency of respiration, as well as circulatory variables such as pulse frequency, blood pressure and cardiac output were measured.
Narcosis with Fentanyl–Hypnodil had a marked respiratory depressive effect but did not interfere with circulation. As a morphine antagonist Lorfan was appropriate for terminating the period of anaesthesia and to control respiratory depression.     

结缕草属植物抗旱生理机理

选择抗旱种源Z125和干旱敏感种源Z098,对其干旱胁迫期间的叶片相对含水量、SOD酶活性、脯氨酸和可溶性总糖含量的变化进行研究,同时观察叶片的萎蔫情况,结果表明:随着干旱胁迫时间的延长,叶片相对含水量呈逐渐下降的趋势,开始时缓慢,Z125在干旱胁迫到第12 d,Z098在第9 d,下降趋势增加;可溶性总糖的含量逐渐增加,在15 d期间,Z125始终高于Z098;脯氨酸含量逐渐增加,大部分时间内Z125均大于Z098;SOD酶活性先增加后降低,不同种源出现峰值的时间不同,Z125在第12 d,而Z098在第9 d,前15 d中,Z125都高于Z098;干旱胁迫下,结缕草(Zoysia Willd.)水分平衡的保持、SOD酶活性的增加以及渗透调节物质(脯氨酸和可溶性总糖)的积累,是结缕草抗旱的重要生理机制。