High dietary calcium to phosphorus ratio and alkali-forming potential as factors promoting silica urolithiasis in sheep

Sheep were used to study factors previously found to promote silica urolithiasis in a rat model. In addition to high silica, these dietary factors included elevated calcium, a high calcium to phosphorus ratio and alkali-forming effects. Wether lambs had ad libitum access to a diet of 50% of grass hay and 50% ground oats plus supplement. Diet analysis was 3.4% total SiO2, .29% calcium, .25% phosphorus, 11.3% CP and 28% ADF. Treatments (40 lambs/treatment) consisted of a control (C), limestone to increase dietary calcium to .6% (L), L + 1% sodium bicarbonate (LS) and L + 1% ammonium chloride (LA). After a 91-d experimental period followed by a 56-d postexperimental finishing period, silica kidney deposits were found in all treatments, and SiO2 made up 74% to 97% of the urolithic ash. Kidney urolith incidences in the four treatments were C, 7/40; L, 12/40; LS, 20/40; and LA, 9/40. A higher urolith incidence in LS (LS vs C, P less than .05) and a trend toward a higher incidence in L (L vs C, P less than .2), accompanied by elevated urine pH (L = LS greater than C greater than LA, P less than .01), lend support to the concept that high-silica diets having high calcium to phosphorus ratios and alkali-forming potentials contribute to silica urolithiasis.     

Terminal ileitis in lambs

Terminal ileitis was diagnosed in three flocks of lambs in different areas of Alberta. Salient clinical features in affected lambs were progressive emaciation with diarrhea, and in some lambs, frequent abdominal stretching. Postmortem findings included thickening of the ileal, and in some animals, the jejunal, cecal and colonic mucosa as a result of mucosal infiltrates of many lymphocytes and fewer plasma cells, eosinophils, globular leukocytes, and neutrophils. Hyperplasia of intestinal lymphoid tissue was prominent in most affected lambs. The cause of the condition is unknown.     

Routes of transmission and consequences of small ruminant lentiviruses (SRLVs) infection and eradication schemes

Small ruminant lentiviruses (SRLV = maedi-visna in sheep and caprine arthritis encephalitis in goats) are distributed throughout most countries of the world, particularly Europe. Laboratories from 16 European countries established collaborations within the framework of a COST (CO-operation in the field of Scientific and Technical Research) action sponsored by the European Union in order to (i) better organize their research programmes on SRLVs and (ii) to coordinate efforts to combat these two diseases. After five years, a consensus conference--the first one in the veterinary medicine field--concluded the work of this network of laboratories by reviewing the present position and discussing three important questions in the field of SRLVs: routes of transmission, consequences of infection and potential role of eradication programmes at either a European or local level, according to the situation in each country or region. This paper brings together existing information regarding these questions and identifies areas for future research.     

Chlamydiosis in workers at a duck farm and processing plant

SUMMARY An outbreak of chlamydiosis was Investigated in workers at a duck farm and processing plant during winter 1989. Chlamydia psittaci was isolated from ducks, but there was little evidence of clinical chlamydiosis in the ducks. Serological tests showed that 76% of workers had been exposed to Infection, 12% recently, 16% had not been exposed and 8% had inconclusive test results. There was a strong association (P < 0.05) between years of employment and exposure to Infection. Infection appeared to be contracted during the first year of employment. Measures were Implemented to reduce shed contamination and control rodents and wild birds. At the same time, ducks were medicated, the processing plant was modified, work practices were altered and workers were advised about chlamydiosis to reduce the risk of human infection.     

Associations between membership of farm assurance and organic certification schemes and compliance with animal welfare legislation

Animal health (AH) defines the outcome of their inspections of livestock holdings as full compliance with the legislation and welfare code (A), compliance with the legislation but not the code (B), non-compliance with legislation but no pain, distress or suffering obvious in the animals (C) or evidence of unnecessary pain or unnecessary distress (D). The aim of the present study was to investigate whether membership of farm assurance or organic certification schemes was associated with compliance with animal welfare legislation as inspected by AH. Participating schemes provided details of their members, past and present, and these records were matched against inspection data from AH. Multivariable multilevel logistic binomial models were built to investigate the association between compliance with legislation and membership of a farm assurance/organic scheme. The percentage of inspections coded A, B, C or D was 37.1, 35.6, 20.2 and 7.1 per cent, respectively. Once adjusted for year, country, enterprise, herd size and reason for inspection, there was a pattern of significantly reduced risk of codes C and D compared with A and B, in certified enterprises compared with the enterprises that were not known to be certified in all species.     

Assessing seed desiccation responses of native trees in the Caribbean

New Forests - Native trees from the Caribbean were tested for seed desiccation responses, by adapting the “100-seed test” protocol. Ninety-seven seed lots of 91 species were collected...     

Estimating Disease Prevalence Using Inverse Binomial Pooled Testing

Monitoring populations of hosts as well as insect vectors is an important part of agricultural and public health risk assessment. In applications where pathogen prevalence is likely low, it is common to test pools of subjects for the presence of infection, rather than to test subjects individually. This technique is known as pooled (group) testing. In this paper, we revisit the problem of estimating the population prevalence p from pooled testing, but we consider applications where inverse binomial sampling is used. Our work is unlike previous research in pooled testing, which has largely assumed a binomial model. Inverse sampling is natural to implement when there is a need to report estimates early on in the data collection process and has been used in individual testing applications when disease incidence is low. We consider point and interval estimation procedures for p in this new pooled testing setting, and we use example data sets from the literature to describe and to illustrate our methods.