Cobalt deficiency in sheep and diagnostic reference ranges

Abstract

Extract

In the last 2 years, two papers have been published suggesting that current New Zealand reference criteria for diagnosing cobalt deficiency should be reviewed (Grace et al 2003), and they are conservatively high and lead to the over-diagnosis of vitamin B₁₂ deficiency and ill-thriftiness in sheep (Gruner et al 2004). The comments refer to reference ranges cited by animal health diagnostic laboratories. These reference ranges were derived from the paper by Clark et al (1989 Clark, RG, Wright, DF, Millar, KR and Rowland, JD. 1989. Reference curves to diagnose cobalt deficiency in sheep using liver and serum vitamin B₁₂ levels.. New Zealand Veterinary Journal, 37: 7–11. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]), which reviewed data from published and unpublished weight gain response trials preceding that date. The review included all published trials in New Zealand and as many unpublished trials that the authors could obtain. They involved serum vitamin B12 data from 54 trials and liver vitamin B₁₂ data from 21 trials. It was stated that more data from trials conducted in autumn were required to reliably determine an autumn response curve. In addition, it was envisaged that as other trial data became available the reference curves could be upgraded (Clark et al 1985 Clark, RG, Wright, DF and Millar, KR. 1985. A proposed new approach and protocol to defining mineral deficiencies using reference curves. Cobalt deficiency in young sheep is used as a model.. New Zealand Veterinary Journal, 33: 1–5. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]).     

Distribution of leptospirosis in possums from New Zealand and its offshore islands

Extract

As part of a larger project investigating methods of brushtail possum (Trichosurus vulpecula) biocontrol, possum sera were collected from 15 sites throughout New Zealand and its offshore islands. These sites were selected to cover the original release sites of possums in New Zealand.     

Osteosarcoma in a woma python (Aspidites ramsayi)

Osteosarcoma of the axial skeleton in an 18-month-old woma python (Aspidites ramsayi) is described. A subcutaneous mass overlying the costal arches enlarged progressively over a period of 5 months and, in that time, became ulcerated and more invasive of surrounding tissues. A punch biopsy of the lesion under general anaesthesia provided tissue for histopathology and diagnosis of low-grade osteosarcoma.     

The primary structure and heterogeneity of tau protein from mouse brain

Tau protein is a family of microtubule binding proteins, heterogeneous in molecular weight, that are induced during neurite outgrowth and are found prominently in neurofibrillary tangles in Alzheimer's disease. The predicted amino acid sequences of two forms of tau protein from mouse brain were determined from complementary DNA clones. These forms are identical in their amino-terminal sequences but differ in their carboxyl-terminal domains. Both proteins contain repeated sequences that may be tubulin binding sites. The sequence suggests that tau is an elongated molecule with no extensive alpha-helical or beta-sheet domains. These complementary DNAs should enable the study of various functional domains of tau and the study of tau expression in normal and pathological states.     

Impact of farming intensity and water management on nitrogen dynamics in intensive pond culture: a mathematical model applied to Thai commercial shrimp farms

A mathematical model is used to investigate the impact of farming intensity and water management on nitrogen dynamics in the water column of intensive aquaculture ponds. The model describes the input of ammonia, its assimilation by phytoplankton or nitrification, and the loss of nitrogen through sedimentation, volatilization, and discharge. The model is calibrated for two commercial shrimp (Penaeus monodon Fabricius) farms in Thailand. Assimilation by phytoplankton with subsequent sedimentation or discharge is the principal process of ammonia removal. When inputs of ammonia exceed the algal assimilation capacity (carrying capacity), nitrification and volatilization of excess ammonia become significant. Carrying capacity is negatively affected by non-chlorophyll turbidity, and was estimated as 6 t ha^?1 cycle^?1 at a non-chlorophyll extinction of 2.6 m^?1. In ponds managed within their carrying capacity, ammonia concentrations are lowest at no water exchange, reach a maximum at exchange rates between 0.2 and 0.4 day^?1, and decline again at higher rates. When the carrying capacity is exceeded, excess ammonia concentrations decline continuously with increasing water exchange. Average exchange rates used in intensive shrimp farms (up to 0.2 day^?1) reduce phytoplankton abundance and sedimentation within ponds, but not ammonia concentrations. Discharges are high in particulate nitrogen at water exchange rates up to 0.3 day^?1, but contain mainly dissolved nitrogen at higher rates.     

AFLP fingerprinting in <Emphasis Type="Italic">Capparis</Emphasis> subgenus <Emphasis Type="Italic">Capparis</Emphasis> related to the commercial sources of capers

A genetic fingerprinting technique (AFLP) was used to determine the relationships among Capparis spp. Genetic distances, based on AFLP data were estimated for 45 accessions of Capparis species, from Spain, Morocco and Syria. The results of this analysis support the differentiation of four of the five taxa involved. The group of plants recognised as C. spinosa on the basis of morphological characters, includes several cultivars and appears in an intermediate position between C. orientalis and C. sicula and overlaps with C. orientalis. The other two species C. aegyptia and C. ovata are separate from the rest. Capparis spinosa had a low number of unique bands in comparison with the other species. Although these results cannot confirm the hybrid origin of C. spinosa, the distribution of the bands supports this hypothesis, the most likely parental species being C. orientalis and C. sicula.     

Effects of bacterial infection and castration on prostatic tissue zinc concentration in dogs

An Escherichia coli bacterial prostatitis was experimentally induced to determine the effect of bacterial infection on prostatic tissue zinc concentrations in castrated and gonadally intact male dogs. Five of the 22 mixed-breed dogs (group 1) had no culture evidence of infection 2 weeks after the instillation of bacteria into the prostate gland. The remaining 17 infected dogs were allotted to 2 groups; 1 group of dogs was subjected to castration (group CA, 7 dogs), and the other group of dogs was subjected to sham operation (group SO, 10 days). The groups were divided into groups of dogs with prostatic infection at necropsy (groups CA-I and SO-I), and those dogs without prostatic infection at necropsy (groups CA-N and SO-N). Urine, prostatic fluid, and prostatic tissue (week 0, 7, +/- 12) specimens were obtained for bacteriologic culturing to determine whether prostatic infection was present. Prostatic tissue was obtained at necropsy (week less than 6, 7, or 12) for analysis of zinc concentration by atomic absorption spectrophotometry. The logarithmic mean prostatic tissue zinc concentrations were compared between groups. Group CA had a significantly lower prostatic zinc concentration than all other groups. Zinc concentrations were not statistically different between any of the other groups. Castration did decrease the prostatic tissue concentration of zinc, a known natural antibacterial factor. However, resistance to infection and resolution of infection were not correlated with prostatic tissue zinc concentrations in this experimental model.