Effect of electrical stunning on somatosensory evoked potentials in chickens

The spontaneous EEG and somatosensory evoked potentials (SEPs) were examined in chickens before and after electrical stunning using a waterbath stunner. Fifty-four per cent of the birds became epileptic and lost their SEPs, and 17% were non-epileptic and appeared to retain their SEPs. It was concluded that there was a reasonably close association between the presence of epileptiform activity in the EEG and the absence of SEPs following electrical stunning, but that the absence of SEPs could be preferred as an indicator of an effective stun on conceptual grounds.     

Prevalence of Dirofilaria immitis and Dipetalonema reconditum in greyhounds

Blood samples from 331 greyhounds in the Hunter Valley and nearby coastal areas of New South Wales were examined for microfilariae using a filtration technique. Species were identified by histochemical staining; 10.9% of the greyhounds were infected with Dirofilaria immitis and 3.6% with Dipetalonema reconditum. The prevalence of infection of both species was significantly greater in summer than in winter (p = less than 0.05). Infection with D. immitis was correlated with differences in age, sex, bodyweight and coat colour, and a reported lack of stamina and the presence of a cough. No significant association was found. Diethylcarbamazine citrate was used for prophylaxis in 8.8% of all the greyhounds examined.     

Immunocytochemical study of tissues from clinically normal dogs and of neoplasms, using keratin monoclonal antibodies.

Three commonly used keratin monoclonal antibodies (MAB)--AE1:AE3, CAM 5.2, and MAK-6--were compared with routinely used cytokeratin antibody. The expression of these antibodies was analyzed in several tissues obtained from clinically normal dogs and in a variety of neoplasms from dogs. Using appropriate enzymatic digestion, paraffin-embedded tissues processed in routine manner retained their typical keratin expression. Differentiated and poorly differentiated epithelial neoplasms, lymphomas, and melanomas were studied by use of the avidin-biotin-peroxidase technique. All 4 of the aforementioned antibodies had similar staining profiles. Of 3 anaplastic carcinomas, 2 had positive reaction to all 4 antibodies. All lymphomas, plasma cell tumors, and amelanotic melanomas had negative reaction to MAK-6, CAM 5.2, AE1:AE3, and cytokeratin MAB. Three basal cell epitheliomas had positive reaction to all 4 antibodies, whereas 1 basal cell tumor with a solid pattern had negative staining reaction. Two carcinoids had negative reaction to all markers and 1 of 2 malignant chemodectomas and 1 transitional cell carcinoma had staining reaction to only AE1:AE3 MAB. Comparing the 4 antibodies, use of AE1:AE3 MAB produced the strongest staining intensity followed by cytokeratin, MAK-6, and CAM 5.2 MAB. All 4 antibodies had low background staining. In conclusion, AE1:AE3 and MAK-6 MAB are as useful as cytokeratin MAB for identification of poorly differentiated epithelial neoplasms in dogs and cats.     

Effect of endocytic and metabolic inhibitors on the internalization and intracellular growth of Brucella abortus in Vero cells.

Uptake, transfer to rough endoplasmic reticulum, and intracellular growth of Brucella abortus were studied in Vero cells treated with endocytic and metabolic inhibitors. Infection of Vero cells was suppressed when inhibitors of energy metabolism (iodoacetate, dinitrophenol), receptor-mediated endocytosis (monodansylcadaverine, amantadine, methylamine), or endosomal acidification (chloroquine, ammonium chloride, monensin) were added to the inoculum. Inhibition was not observed when these drugs were added after the inoculation period. Infection of Vero cells by B abortus was inhibited by dibutyryl-cyclic adenosine monophosphate and Vibrio cholerae enterotoxin, but was stimulated by dibutyryl-cyclic guanosine monophosphate and escherichia coli heat-stable enterotoxin a. Uptake of B abortus by Vero cells was not prevented by colchicine, but was abolished by cytochalasin B. Uptake of heat-killed B abortus and noninvasive E coli was similar to that of viable brucellae. Intracellular growth of B abortus was not affected by cycloheximide. Results indicate that: B abortus may be internalized by a receptor-mediated phagocytic process; transfer of B abortus from phagosomes to rough endoplasmic reticulum may require endosomal acidification; and replication of B abortus within the rough endoplasmic reticulum may not depend on protein synthesis by the host cell.     

BR农用荧光灯补光育苗的研究

对黄瓜、番茄在育苗前期进行短时间的人工补光有明显促进生长的效果。农用荧光灯(BR)的补光效果优于日光型荧光灯(W)。早春育苗进行人工补光的时间以下午自然光照强度稍高于光补偿点、叶片气孔尚未关闭之前为好,呼和浩特、包头3月份16:00、4月份17:00开始补光为宜。补光的光强度在500～800lx 效果明显。光源距幼苗的距离以10cm 为宜。     

The cardiorespiratory effects of morphine and butorphanol in horses anaesthetised under clinical conditions

Twenty-five horses admitted for minor orthopaedic or soft tissue surgery were anaesthetised with detomidine, ketamine and halothane. Heart rate, arterial blood pressure, respiratory rate, tidal volume, minute volume, blood gases and occlusion pressures were measured before and for 30 mins after intravenous (iv) injection of saline, butorphanol 0.05 mg/kg bodyweight (bwt) or morphine 0.02 or 0.05 mg/kg bwt. Drug or saline treatment induced no significant changes from pre-treatment values within a group for arterial blood pressure, heart rate, respiratory rate, arterial carbon dioxide tension, arterial oxygen tension and occlusion pressure. In conclusion, both morphine and butorphanol at the stated doses cause no adverse effects on the cardiovascular and respiratory systems of anaesthetised horses.     

Sedative and cardiovascular effects of romifidine, alone and in combination with butorphanol, in the horse

The behavioural and sedative effects of intravenous (iv) romifidine (40 and 80 μg/kg bodyweight [bwt]) alone or in combination with iv butorphanol (50 μg/kg bwt) were investigated in four ponies and one Thoroughbred horse. Apparent sedation, as judged by the lowering of the head, and by the response to imposed touch, visual and sound stimuli was assessed. The combination with butorphanol reduced the animals' response to imposed stimuli when compared with the effect of the same dose of romifidine alone. Following the administration of romifidine/butorphanol combinations muzzle tremor was noted and some animals attempted to walk forward. In a separate series, the cardiopulmonary effects of iv romifidine (80 μg/kg bwt) alone, or in combination with butorphanol (50 μg/kg bwt) were investigated. Romifidine and the romifidine/butorphanol combination caused similar cardiovascular changes, these being bradycardia with heart block, and hypertension followed by hypotension. Romifidine caused a transient decrease in arterial oxygen tensions and arterial carbon dioxide tensions had increased significantly by the end of the 90 min recording period. Romifidine/butorphanol combinations produced significantly higher arterial carbon dioxide tensions during the first 15 mins after drug administration than did romifidine alone. Butorphanol at 50 μg/kg bwt iv reduced the response to imposed stimuli in horses sedated with romifidine. The combination produced no cardiovascular changes beyond those induced by romifidine alone, but did increase the degree of respiratory depression.     

Genetic Engineering Approaches to Pig Production*

Modern biotechnology promises a number of new applications in animal breeding and production. Although conventional pig breeding has achieved a high level of efficiency and productivity numerous problems have been encountered with animal health and the loss of meat quality. Selection based on phenotypic performance data of individual animals does not take into account the importance of specific genes and their relevance within a complex regulatory system. In most cases it is therefore difficult to trace back the genetic origins of clinically important disorders. The application of genetic engineering techniques in pig production will facilitate diagnosis, improvement of productivity, and animal health by allowing direct genetic manipulation. Attention must be focussed on the physical and genetic analysis of the procine genome. The isolation and characterisation of genes, DNA-markers, polymorphic DNA-fragments, and their chromosomal assignment will be important prerequisites and tools for the elucidation of genetic disorders. Especially the detection of heterozygous carriers of recessive disorders and their elimination from the breeding stock will increase selection accuracy and decrease the generation intervals. But also the rapid and simple detection of infectious diseases, which is sometimes difficult if not impossible at present, will improve animal health and welfare. Although the production of transgenic animals either by DNA-microinjection into zygotes or the use of embryonal stem cells manipulated in vitro is less straightforward than DNA-based diagnosis it will play an important role in the direct manipulation of the porcine genome and genes. Breeding programmes including the use of transgenic livestock have already been developed. There is no doubt that genetic engineering has reached a degree of practical feasibility, allowing it to play an important role in pig breeding in particular and animal production in general.     

Viral respiratory disease of the horse.

The diagnosis of any viral respiratory disease relies on laboratory procedures to isolate the virus and demonstrate a significant rise in serum antibody titers. To isolate viruses from the upper respiratory tract, it is imperative that nasopharyngeal swabs are obtained from animals in the early acute stage of illness, i.e., during the pyrexic phase when the virus is replicating. Nasopharyngeal swabs must be placed in a virus transport medium and forwarded immediately to the laboratory at refrigerated temperature. Equine influenza, rhinopneumonitis, and equine viral arteritis are the three viral infections causing outbreaks of respiratory disease in North America. African horse sickness, although foreign to North America, could be introduced despite stringent horse importation regulations. Specific antiviral therapy is not available to treat viral respiratory disease in the horse. A variety of inactivated and modified live vaccines, however, are available to prevent clinical disease and the spread of infection caused by the common viral respiratory pathogens. A considerable amount of research is underway to enhance the potency and duration of immunity of the present vaccines against influenza and rhinopneumonitis. This research is directed at defining and characterizing the importance of specific glycoprotein antigens on the surface of the virus, which trigger the various host immune responses, and determining whether they are stimulatory or suppressive.