Environmental and behavioural factors affecting the prevalence of foot lameness in New Zealand dairy herds - a case-control study     

Chesterton RN  Pfeiffer DU  Morris RS  Tanner CM 《New Zealand veterinary journal》1989,37(4):135-142

A case-control study of environmental and behavioural factors influencing foot lameness was undertaken on 62 dairy herds comprising an average of 185 milking cows in Taranaki, New Zealand. Thirty two case herds were identified as having had at least 10 per cent of the cows lame during the milking season in which the herd was studied, and thirty control herds were selected on the basis that no more than 3 per cent of cows in these herds had been lame per year for at least two years immediately prior to investigation. Each herd was visited at both a morning and an afternoon milking, and 58 risk factors were measured between the time the farmer began to assemble the cows for milking and the completion of milking. Comparison of single variables between case and control herds identified 24 which showed differences (p<0.10). These variables were then subjected to stepwise multivariate logistic regression, and statistically significant variables in this analysis were used to create a tentative path diagram of possible causal web relationships between the various risk factors and the outcome variable, the lameness prevalence level. Information from a review of the published literature was used to include further variables to the 24 into the initial (or null hypothesis) path model. Logistic path analysis was then used to eliminate non-significant paths from the diagram, leaving 19 arrows joining 13 variables in the final path diagram, compared with 33 joining 20 variables in the initial version. The most influential variables in explaining variation between case and control herds were the average level of maintenance of the track and the degree of patience shown by the farmer in bringing the cows in for milking. Overall, factors associated with the movement of animals to the milking shed explained 40 per cent of the variation (deviance) with regard to the lameness prevalence level. Risk factors associated with characteristics of the milking process explain 24 per cent, and risk factors associated with characteristics of the cows in the herd explain 9.5 per cent. Recommendations are made on management changes which deserve further investigation as ways of reducing lameness problems in dairy herds.  相似文献   

Effect of embryonic and neonatal administration of tamoxifen on adiposity in the broiler chicken     

I. Rozenboim  B. Robinzon  E. Arnon  N. Snapir 《British poultry science》1989,30(3):607-612

1. The effect of early exposure of heavy breed (HB) chicks to an anti‐oestrogen (tamoxifen—TAM) on later adiposity was studied.

2. TAM administration at the embryonic stage, but not at the day of hatching, reduced adiposity in females but not in males, at 8 to 9 weeks of age. This reduction in adiposity in females minimised or even alleviated the excess of fat in females compared to males.  相似文献   

Ultrastructural analysis of platelets and megakaryocytes from a dog with probable essential thrombocythemia     

F Tablin  N C Jain  C P Mandell  P E Hopper  J G Zinkl 《Veterinary pathology》1989,26(4):289-293

Blood platelets and bone marrow megakaryocytes from a dog with essential thrombocythemia were analyzed by transmission electron microscopy and compared with those of control dogs. Platelets varied in size and shape and contained enlarged and dilated open canalicular systems. Megakaryocytes were dysmorphic and had evidence of abnormal maturation, with large numbers of megakaryoblasts containing alpha granules and poorly organized and reduplicated demarcation membranes. The fewer, more mature megakaryocytes lacked normal cytoplasmic organization. Most notable was the absence of well-demarcated "platelet fields," due to the excessive and disorderly array of demarcation membranes.  相似文献   

What Is Your Diagnosis?     

Lowseth LA  Herbert RA  Muggenburg BA  Gillett NA  Rebar AH 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1989,18(3):57-57

  相似文献   

An epidemiological investigation into the reported incidents of dog biting in the City of Guelph   总被引：2，自引：1，他引：1       下载免费PDF全文

Szpakowski NM  Bonnett BN  Martin SW 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(12):937-942

  相似文献   

The influence of a premating injection of gonadotrophin-releasing hormone on sow and gilt fertility          下载免费PDF全文

Kirkwood RN  Thacker PA 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(12):959-960

  相似文献   

Glasser's disease and prevalence of subclinical infection with Haemophilus parasuis in swine in southern Ontario          下载免费PDF全文

Smart NL  Miniats OP  Rosendal S  Friendship RM 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(4):339-343

Glasser's disease accounted for less than 1% of total swine mortalities in an 11 year retrospective postmortem survey of swine submissions at three provincial government diagnostic laboratories in southern Ontario. However, Glasser's disease was suspected in 17 of 83 boar mortalities at the Record of Production Boar Test Station between 1983 and 1985 and was much more common in specific-pathogen-free (SPF) boars than in conventional boars. The prevalence of the causative organism, Haemophilus parasuis, was determined for 19 SPF herds in Ontario classified as "Excellent" under the Ontario Swine Herd Health Policy. Nasal swabs from two-month-old pigs were cultured on chocolate agar containing 1.5 mug/mL lincomycin, 5 mug/mL bacitracin, and 0.1 mug/mL crystal violet. Three herds were negative for H. parasuis infection; 16 herds contained clinically healthy carrier pigs.  相似文献   

AIDS awareness          下载免费PDF全文

Neumann N 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(5):387

  相似文献   

Evaluation of postoperative complications following elective surgeries of dogs and cats at private practices using computer records.   总被引：2，自引：1，他引：1       下载免费PDF全文

F L Pollari  B N Bonnett 《The Canadian veterinary journal. La revue veterinaire canadienne》1996,37(11):672-678

This study was designed to determine the frequency of postoperative complications following elective surgeries (castration, ovariohysterectomy, onychectomy) of dogs and cats from private practices and to evaluate the use of electronic medical records for this type of research. All elective surgeries performed during the study period at 5 private practices were included. The surgical techniques and materials used for each procedure were similar across practices, but the interpretation of "complication," the amount of detail recorded on the primary medical record, and the intensity of follow-up varied. The frequencies and types of complications varied by species and procedure. The postoperative complication frequencies ranged from 1% to 24% for all complications and 1% to 4% for severe complications. The results of this study describe populations of elective-surgery patients at private practices, provide data for educating clients about the risks associated with these procedures, and demonstrate how computerized records can be used to collect practice-specific medical information.  相似文献   

Prevalence and duration of insensibility following electrical stunning in calves     

Gregory NG  Anil MH  McKinstry JL  Daly CC 《New Zealand veterinary journal》1996,44(1):1-3

Sixty-one calves were electrically stunned with 100-250 V currents (103-1806 mA) and the prevalence and duration of insensibility was assessed from their physical behaviour, the presence of epileptiform activity in their electrocorticograms, and the absence of visual evoked responses in their electrocorticograms. A current applied at 100 V across the head for 3 s failed to induce insensibility in all cases. Currents at 150-250 V induced insensibility in all calves and the shortest duration of insensibility was 44 s. It is recommended that a 150-200 V current would be appropriate for commercial use.  相似文献