Six 1-year-old farmed red deer were used to compare physiological and behavioural responses to a range of doses of 5% xylazine with or without the addition of 0.4 mg of fentanyl citrate and 3.2 mg of azaperone per ml. Each deer was randomly assigned to one of six treatments: xylazine alone at 0.4 and 0.6 mg/kg, the xylazinelfentanyl citrate/azaperone combination containing 0.2, 0.4 and 0.6 mg/kg of xylazine, or a sterile water control. Injections were given intramuscularly in the anterior neck, operator blind, on each of 6 sampling days between October and January, such that each deer received all treatments with 9-28 days between each treatment. Measurements included heart rate and respiration rate. A 0-3 scoring system (normal to nil response, respectively) was devised to record sedative responses (body stance, head position, degree of eye closure, palpebral reflex, resistance to movement of the head, response to noise) and analgesic responses to touch and pinching of the ear, and response to a needle prick in the gluteal region. Scores were added to produce a sedation score and analgesia score, respectively, for each treatment. Records were taken immediately prior to injection and thereafter at 5, 14, 25, 35, 60, 90, 120, 150, 180, 210, 240 and 300 minutes. All deer given each dose rate of the xylazine and the xylazine/fentanyl citrate/azaperone combination became recumbent. There was a tendency for the time to recumbency and variation of time to recumbency to be shorter at higher dose rates and with the addition of fentanyl citrate and azaperone to xylazine, particularly with xylazine at 0.4 mg/kg. These trends were not statistically significant (p>0.05). The duration of recumbency was shorter with the low dose of the xylazine/fentanyl trateiazaperone combination (0.2 mg/kg of xylazine) than for the higher doses of xylazine alone or the combination of drugs (p<0.05). There were no significant differences in heart rates or respiration rates between treatments, although all treatments significantly reduced both heart and respiration rates (p<0.01). The sedation scores showed similar peak responses and timing to peak responses (14-25 min) to both drug treatments and all dose rates, but the responses were less persistent for lower doses. The analgesia scores showed a similar pattern, with peak responses 14-35 minutes after administration and more persistence at higher dose rates of both xylazine alone and the xylazine/fentanyl citrate/azaperone combination. This study has shown that most physiological and behavioural responses to a range of doses of xylazine or the xylazine/fentanyl citrate/azaperone combination were statistically similar. However, there was a tendency for recumbency to occur more rapidly and with less variation in timing when the mid-range dose of the drug combination was used, supporting the observation by practitioners that the drug combination results in a more rapid and reliable state of recumbency at a lower dose rate of xylazine. 相似文献
Examination of 25 cases of multiple benzimidazole and levamisole resistance, identified in sheep by faecal egg count reduction testing at the Batchelar, Lincoln and Invermay Animal Health Laboratories, showed that benzimidazole-levamisole combinations provided effective control in eight (47%) of 17 cases in which they were tested. Overall, the use of combination drenches resulted in average improvements in faecal egg count reductions of 25.6% (p<0.01) and 23.2% (p<0.05), respectively, over those achieved by the use of benzimidazole or levamisole drenches alone. The results suggest that instances of multiple resistance in which combination drenches might be effective are unlikely to be predictable either by identification of the parasites involved, or from the levels of benzimidazole or levamisole resistance present. 相似文献
1. The ostrich industry in South Africa (and elsewhere) experiences a high rate of embryo mortality during artificial incubation of eggs. Most of this mortality takes place in the last 10–14 d of incubation.
2. We carried out post‐mortem examinations on 111 embryos that died within this period to assess the causes of this mortality.
3. Malpositioning and severe oedema were the predominant symptoms of dead‐in‐shell embryos with 55% being malpositioned and 41% showing severe oedema. Of these, 22 embryos (24%) showed both symptoms. Malpositioning generally results from incorrect setting of the eggs or inadequate turning and oedema was significantly correlated with the amount of water lost from the eggs which in turn was correlated with egg size.
4. Myopathy, gross lesions of internal organs, haemorrhage, bacterial infections and congenital deformities were found in less than 10% of chicks examined for these symptoms. 相似文献
1. Floor eggs are a problem in non‐cage systems for laying hens, as they require secondary egg collecting. Failure to lay in a well‐defined nest site may also be a welfare problem for the hens, but only if their nesting motivation has been thwarted.
2. We investigated the relationships between a hen's prelaying behaviour and its tendency to lay on the floor by recording the behaviour of 20 hens housed individually in wire cages with single littered nest boxes.
3. Most floor eggs (80%) were laid by the same 6 hens. These 6 “floor‐layers” performed more nest seeking behaviour, less nest‐building behaviour and less sitting prior to oviposition than the 14 hens that consistently laid in nest boxes.
4. The incidence of floor eggs declined with age. Both nest and floor laying hens performed less nest seeking behaviour with age. Floor layers, however, increased their performance of nesting behaviour, whilst nest layers performed less nesting behaviour with age.
5. Floor laying hens behaved as if they found the nest box less attractive than nest‐laying hens; perhaps because they had lower nesting motivation, or perhaps because their nesting motivation was as high, but they less readily perceived the nest box as an appropriate nest site. 相似文献
1. Commercial pullets were grown at cool (10°‐20°C) or hot (25°‐35°C) temperatures to similar bodyweights at 18 weeks of age. Between 18 and 50 weeks the birds were either kept at the same temperatures as during growth or transferred to the alternate temperature.
2. Birds kept at the cool temperatures throughout life ate most food and gave the best production during lay. Minimum food intake and poorest performance were obtained with birds kept at the hot temperatures throughout life.
3. Performance in the hot environment during lay was improved by rearing birds in the cool environment, the response being related to an increased food intake. Food intake in the cool environment during lay was reduced, with only minor effects on performance, in birds which had been reared in the hot environment.
4. The results of the present study show that production responses during lay are affected by the temperatures experienced by hens during both growth and lay. 相似文献
Four groups of five Romney lambs were treated by plunge dipping with one of four registered organophosphorus flystrike preventatives. Untreated lambs acted as controls. The sheep were challenged at weekly intervals with larval implants of organophosphate-susceptible and -resistant strains of Lucilia cuprina. All four treatments provided 19-21 weeks protection against susceptible larvae but chlorfenvinphos provided the longest protection (16-17 weeks), followed by propetamphos (15-16 weeks), dichlofenthion (10-13 weeks) and diazinon (9-13 weeks), against the resistant strain. 相似文献
The coding sequences in RNA2 for the coat proteins (CP) of strawberry latent ringspot virus (SLRSV) were modified and amplified using polymerase chain amplification reactions (PCR) to facilitate their expression inAgrobacterium tumefaciens-transformedNicotiana tabacum Xanthi-nc. The coding sequences for the smaller capsid protein (S, 29kDa) and that for the theoretical precursor of L and S (P, 73kDa) had ATG initiation codon sequences added at the 5-proximal Ser/Gly (S/G) cleavage site in the unmodified sequence. The sequence coding for the larger of the two proteins of mature SLRSV capsids (L, 44kDa) had an ATG codon added at its 5 S/G site and a TAG stop codon sequence added at the 3-proximal S/G site. The P, L and S proteins were expressedin planta to a maximum concentration of 0.01 % of total extractable proteins but did not assemble into virus-like particles. When challenged by mechanical inoculation with virus particles or viral RNA, and compared with control plants, tobacco plants (primary transgenic clones or S1 and S2, kanamycin-resistant seedlings) expressing the virus capsid subunits separately, or their precursor, decreased the accumulation of SLRSV particles in inoculated leaves and fewer plants became invaded systemically. In experiments in which the roots of seedlings were exposed to SLRSV-carrying vector nematodes (Xiphinema diversicaudatum), SLRSV was detected in the roots of non-transformed control tobacco plants (6/20) and in transgenic tobacco expressing the L protein (7/40), but not in any of 25 tobacco plants expressing the S protein or in 35 expressing the P protein. This is the second example of CP-mediated resistance to virus inoculation by nematode vectors. 相似文献
The cause of a streak disease of pearl millet (Pennisetum glaucum), originating from Nigeria, has been attributed to a geminivirus belonging to the African streak virus cluster. A full-length, infectious clone of the virus was obtained which was transmissible by the vectorCicadulina mbila (Naudé). Analysis of the complete nucleotide sequence of the coat protein gene of this virus shows it to be most closely related to sugarcane streak virus. The possible evolutionary implications of this finding are discussed. 相似文献
Diseases caused by lymphoid leukosis virus (LLV), a retrovirus, take a long time after infection to develop and have a wide variety of pathological manifestations. This long latent period is characteristic of persistent virus infections. Disease produced by LLV infection and its underlying mechanisms is compared with persistent infections caused by other retroviruses in birds and mammals of veterinary importance. The diseases considered for comparison are those caused by reticuloendotheliosis, feline leukaemia, bovine leukosis and equine infectious anaemia viruses. There are significant changes in the immunological status in all diseases caused by these viruses. LLV infections follow this trend with, in manifestations of neoplastic disease, a perturbation of the normal switch that occurs from IgM to IgG synthesis. There are also indications of other immunological disturbances.Factors other than immunological disturbances may contribute to the length of time after infection required for the many forms of LLV infection to appear. Such additional factors may include the operation of biological clocks, such as the arrival of sexual maturity, and also the very nature of retroviruses. These factors, like the immunological changes, play major roles in the maintenance and progression of persistent retrovirus infections.Abbreviations ACTH
adrenocorticotropic hormone
- AEV
avian erythroblastosis virus
- AMV
avian myeloblastosis virus
- BLV
bovine leukaemia virus
- CAV
chicken anaemia virus
- EBL
enzootic bovine leukaemia
- EIAV
equine infectious anaemia virus
- env
envelope gene
- FeLV
feline leukaemia virus
- FeSV
feline sarcoma virus
- FOCMA
feline oncovirus membrane-associated antigen; gag, group antigen gene
- HTLV
human T-cell leukaemia virus
- LLV
lymphoid leukosis virus
- L/S
leukosis/sarcoma
- LTR
long terminal repeat
- MAV
myeloblastosis-associated virus
- MDV
Marek disease virus
- MuLV
mouse leukaemia virus
- ORF
open reading frame; pol, polymerase gene
- REV
reticuloendotheliosis virus
- RIF
resistance-inducing factor
- RSV
Rous sarcoma virus 相似文献
Extreme eosinophilia with disseminated eosinophilic granulomatous disease is described in a 4-year-old Arabian mare. Clinical signs included weight loss, coughing, jugular distention, and ventral edema. Cutaneous lesions were not observed. Eosinophilic inflammation was observed in cytologic specimens from the respiratory tract, body cavities, and lymph nodes. At necropsy, a 20-cm diameter intrathoracic mass was observed. Smaller nodules were present in the lymph nodes, liver, spleen, adrenal glands, pancreas, and skeletal muscle. Histologically, these masses and nodules were characterized by infiltrates of eosinophils, macrophages, and multinucleated giant cells, reactive fibroplasia; and multifocal eosinophilic coagula. Microscopically, mild eosinophilic infiltrates were observed in sections of stomach, small intestine, colon, and pleura; however, gross lesions were not observed in these tissues at necropsy. The etiology of the extreme eosinophilia and disseminated eosinophilic granulomatous disease in this horse was not determined. 相似文献