Lythrum hyssopifolia (lesser loosestrife) poisoning of sheep in Victoria     

MJ Lancaster  JS Nimmo  C Lenghaus  IJ Gill  RD Crawford  RT Badman  JL Samuel  CJ Werner  C Button  N Kvalheim 《Australian veterinary journal》2009,87(12):476-479

Objective To document an ovine disease attributed to the consumption of Lythrum hyssopifolia (lesser loosestrife). Procedures Historical and histological review of field and experimental cases. Results 1–20% mortality occurred in sheep flocks grazing paddocks where L. hyssopifolia was the predominant green vegetation. Well‐documented disease outbreaks occurred in summer on nine farms across Victoria between 1974 and 2002. Liver damage occurred in all nine outbreaks, with kidney damage in at least eight. Hepatocyte necrosis was usually zonal to midzonal (zone 2) in the liver samples from four farms and periacinar (zone 3) in those from three farms, but some livers showed only single‐cell necrosis. Multinucleate hepatocytes near necrotic areas were a feature in six cases. Proximal tubular epithelium appeared to be the primary renal target and brown granules were often present in renal tubules. Biochemical and histological evidence of liver and kidney damage was obtained from two sheep experimentally pen‐fed harvested L. hyssopifolia. Conclusion Chemicals in L. hyssopifolia are toxic to ovine hepatocytes and renal tubular epithelial cells.  相似文献   

Binding of insecticides to macromolecules in the blood of the rat and American cockroach     

H.L. Skalsky  F.E. Guthrie 《Pesticide biochemistry and physiology》1975,5(1):27-34

This investigation concerns transport of DDT, dieldrin and parathion in the blood of the rat and roach. Using gel filtration, ion-exchange chromatography, and disc gel electrophoresis, a method for the isolation of some of the plasma proteins that bind DDT and dieldrin has been demonstrated. By a variety of staining procedures, these macromolecules were shown to be of a lipoprotein nature. A tentative molecular weight of 520,000 was obtained for one of the binding proteins in roach hemolymph.  相似文献   

Lateral transmission of equine arteritis virus among Lipizzaner stallions in South Africa     

Guthrie AJ  Howell PG  Hedges JF  Bosman AM  Balasuriya UB  McCollum WH  Timoney PJ  MacLachlan NJ 《Equine veterinary journal》2003,35(6):596-600

REASONS FOR PERFORMING STUDY: A serological study conducted in 1995 revealed that 7 stallions at the Lipizzaner Centre, Gauteng, South Africa, were seropositive for antibody to equine arteritis virus (EAV). A Lipizzaner stallion imported into South Africa from Yugoslavia in 1981 had previously (1988) been confirmed to be an EAV carrier. Despite being placed under life-long breeding quarantine, EAV had been transmitted between stallions at the Lipizzaner Centre. OBJECTIVES: To investigate the phylogenetic relationships between the strain of EAV shed in the semen of the original carrier stallion and strains recovered from the semen of 5 other stallions; and to investigate the means whereby lateral transmission of EAV occurred among 7 in-contact, nonbreeding stallions at the Centre. METHODS: EAV was isolated from semen collected from the seropositive stallions using RK-13 cells. Viral RNA was reverse transcribed and amplified by polymerase chain reaction using ORF 5-specific primers, subjected to sequence and phylogenetic analysis. RESULTS: Phylogenetic analysis of strains of EAV recovered from the semen of 6 persistently infected stallions confirmed that all viruses were closely related and probably derived from a common ancestor, i.e. the stallion imported from Yugoslavia. Lateral transmission subsequently occurred among 7 in-contact, nonbreeding stallions at the Centre. It is speculated that these stallions may have been exposed to virus from bedding or fomites contaminated with semen. CONCLUSIONS: These data confirm that lateral transmission of EAV can occur from shedding stallions to susceptible, in-contact horses, including other stallions, which may become persistently infected with the virus. POTENTIAL RELEVANCE: The findings are consistent with lateral spread of a single, unique strain of EAV among a group; and suggest that transmission of EAV may be initiated by infection of one or more stallions with virus on bedding or other fomites contaminated with EAV- infected semen.  相似文献   

Effect of adenosine infusion on isoflurane MAC in dogs.     

M Asakawa  JW Ludders  B Badgley  HN Erb  LP Posner  RD Gleed 《Veterinary anaesthesia and analgesia》2005,32(4):12-13

Adenosine is a potent analgesic in people and reduces the MAC of halothane in dogs. The purpose of this study was to determine whether adenosine reduces the MAC of isoflurane in dogs. Seven beagles (four males and three females) were anesthetized and randomly assigned to receive adenosine (0.3 mg kg^–1 minute^–1; 6 mL kg^–1 hour^–1, IV) or saline (0.9%, 6 mL kg^–1 hour^–1IV). After an interval of ≥7 days, each dog was reanesthetized and treated with the alternate infusion. Anesthesia was induced and maintained with isoflurane in oxygen. Dogs were intubated and instrumented for measurement of mean systemic arterial blood pressure and airway concentration of isoflurane and end‐tidal partial pressure of carbon dioxide. The MAC for isoflurane was determined using the tail‐clamp technique. Baseline MAC values were 1.25 (1.15, 1.35)% [median (minimum, maximum)] and 1.25 (1.05, 1.45)% before the saline and adenosine treatments, respectively. After 2 hours of infusion with saline or adenosine, MAC values were not different (p = 0.156) and were 1.25 (0.95, 1.35)% and 1.05 (1.00, 1.25)%, respectively. Two hours following the end of each infusion, the MAC values for saline and adenosine treatment groups differed significantly (p = 0.015), but by no more than the normal variation inherent in this study, and were 1.15 (1.15, 1.35)% and 1.05 (1.05, 1.25)%, respectively. Mean arterial blood pressure was 93 (74, 123) mm Hg for saline treated dogs and 67 (52, 72) mm Hg (p = 0.008) during adenosine infusion. End‐tidal carbon dioxide was not different between the two treatment groups. We conclude that adenosine administered at 0.3 mg kg^–1 minute^–1had no effect on isoflurane MAC in dogs, but decreased mean arterial blood pressure.  相似文献   

Second Oestrus Synchronization and Precocious Embryo Viability after Puberty Induction in Gilts by the Use of Gonadotrophin Treatment     

V do Lago  WL Vianna  RD Gama  A de  Campos Rosseto  ME Pinese  A de  Sant''Anna Moretti 《Reproduction in domestic animals》2005,40(2):141-144

The use of exogenous gonadotrophins in puberty inducement and ovulation synchronization is a technique that has a positive influence on the management of swine. The purpose of this study was to verify the effects of a second gonadotrophin treatment [equine chorionic gonadotrophin (eCG) and luteinizing hormone (LH), intramuscularly (i.m.)] upon the second oestrus synchronization and fertility in gilts. Seventy-one NAIMA (Pen Ar Lan) gilts had their first oestrus (puberty inducement) induced by a hormonal treatment (eCG and LH). Then, they were randomly distributed into two treatments, with (T1) and without (C) gonadotrophin treatment at the second oestrus. The animals were fed with a single ration (16% of crude protein and 3286.73 kcal ME/kg), and timed artificial insemination performed at the second oestrus. Gilts were slaughtered for embryo recovery and ovary examination about 5 days after insemination. There was no evidence of a difference in the percentage of the second oestrus expression (T1 - 90.90% and C - 86.84%), the duration of the oestrus cycle (T1 - 19.62 +/- 0.82 days and C - 19.67 +/- 4.14 days), the percentage of follicular cysts (T1 - 15.15% and C - 18.42%) and number of ovulations (T1 - 14.60 +/- 5.7 and C - 13.23 +/- 4.8) between treatments (p > 0.05). However, the hormonal treatment (T1) showed minor oestrus dispersion and embryo viability (T1 - 8.4 +/- 5.6 and C - 11.2 +/- 4.6) (p < 0.05). These results indicate that the better synchronization and expression of the second oestrus when using gonadotrophins (eCG and LH) is followed by a lower embryo viability, which is probably the consequence of the heterogeneous follicle recruitment during the injection of eCG.  相似文献   

Cyanobacterium Cylindro-spermopsis raciborskii as a probable cause of death in cattle in northern Queensland     

AD THOMAS  ML SAKER  JH NORTON  RD OLSEN 《Australian veterinary journal》1998,76(9):592-594

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Pesticides in aquatic environments: Mohammed Abdul Quddus Khan,Ed. No. 10 in Environmental Science Research. Plenum Press,New York and London, 1978. 257 pp., $29.50     

Frank E. Guthrie 《Pesticide biochemistry and physiology》1978,9(3):352

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Functional Activity of Frozen Thawed Chinchilla lanigera Spermatozoa Cryopreserved with Glycerol or Ethylene Glycol     

MF Ponzio  JM Busso  M Fiol de Cuneo  RD Ruiz  AA Ponce 《Reproduction in domestic animals》2008,43(2):228-233

The cryopreservation of spermatozoa constitutes a valuable tool for the captive breeding management of valuable and/or threatened species. Chinchilla lanigera is a species almost extinct in the wild, and the domestic counterpart has one of the most valuable pelts in the world. The objectives of this study were to: (i) compare the functional activity of post‐thawed chinchilla spermatozoa cryopreserved at ?196°C either with glycerol (G) or ethylene glycol (EG) as cryoprotectants (1 m final concentration) and (ii) investigate the effects of incubating the gametes for 4 h in the presence or in the absence of the cryoprotectants; evaluations were performed taking into account motility, viability, response to hypo‐osmotic shock and acrosome integrity of the cells. Parameters reflecting post‐thaw (0 h) sperm functional activity were significantly lower than those of freshly ejaculated gametes. When comparing the cryoprotectant efficiency of G vs EG, neither cryoprotectant agent offered appreciable advantages. After 4 h of incubation, in the presence or absence of the cryoprotectant agent, a rapid and significant decrease was found in all functional parameters and remained at ～ 20–30% motile, viable and viable acrosome intact cells. Viability was significantly lower when the cryoprotectant was removed from the media (possibly due to the centrifugation process). With respect to the maintenance of sperm membrane integrity, only ～ 10% of cells showed membrane resistance to hypo‐osmotic conditions after the 4 h incubation period. These results constitute new insights for cryopreservation protocols and the development of assisted reproductive techniques in this species.  相似文献   

Grassland vegetation changes and nocturnal global warming   总被引：4，自引：0，他引：4  

RD Alward  JK Detling  DG Milchunas 《Science (New York, N.Y.)》1999,283(5399):229-231

Global minimum temperatures (TMIN) are increasing faster than maximum temperatures, but the ecological consequences of this are largely unexplored. Long-term data sets from the shortgrass steppe were used to identify correlations between TMIN and several vegetation variables. This ecosystem is potentially sensitive to increases in TMIN. Most notably, increased spring TMIN was correlated with decreased net primary production by the dominant C4 grass (Bouteloua gracilis) and with increased abundance and production by exotic and native C3 forbs. Reductions in B. gracilis may make this system more vulnerable to invasion by exotic species and less tolerant of drought and grazing.  相似文献   

Vertical movements of Atlantic salmon post-smolts relative to measures of salinity and water temperature during the first phase of the marine migration     

N. PLANTALECH MANEL-LA  E. B. THORSTAD  J. G. DAVIDSEN  F. ØKLAND  R. SIVERTSGÅRD  R. S. MCKINLEY  & B. FINSTAD 《Fisheries Management and Ecology》2009,16(2):147-154

Abstract  The migratory behaviour of hatchery-reared Atlantic salmon, Salmo salar L., post-smolts during the first phase of the marine migration was examined to assess their susceptibility to salmon lice, Lepeophtheirus salmonis (Krøyer), infestations. Swimming depths of eight post-smolts relative to the measured salinity and temperature were monitored for an average of 11.4 h following release outside the mouth of the River Eio using depth sensitive acoustic transmitters. Vertical salinity and temperature distributions were simultaneously recorded along the migratory route. Mean swimming depth was 1.7 m (individual mean 0.5–2.1 m). There was no overall preference among all the post-smolts for specific salinity concentrations. Typically post-smolts migrated the majority (68%) of their time at salinities <20 psu (brackish water), and as a result outside the reported salinity tolerances of sea lice. Furthermore, post-smolts chose the warmest water layer during their coastal migration.  相似文献