Chemical Composition and Ruminal Digestibility of Ceratoides,a Salt-tolerant Perennial Plant,at Different Years

It has been proposed that salt-tolerant plant could be used as a feed resource for ruminants whereby salt would be removed from salinized land (Asian-Aust.J.Anim.Sci.(2002) 15:998-1001).Ceratoides arborescens (Losinsk.) Tsien et C.G.Ma is known as a drought-and salt-tolerant plant,a kind of shrubs,growing in semi-arid land of Inner Mongolia.Because the covering effect of the perennial plant as a mulch over the soil might be expected,the optimum covering effect would be obtained after the growth period.The perennial plant produces seeds around summer and end its growth thereafter.Nutrient value of the perennial salt-tolerant plant,however,had not been reported in flowering period at different year.It is necessary to know the ruminal degradability of the plants of each growing year in order to determine the regimen to diet for ruminants.The present experiment,therefore,was undertaken to analyze the digestibility and chemical composition of Ceratoides arborescens as feed for ruminants.     

Histofarcin test for the diagnosis of epizootic lymphangitis in Ethiopia: development, optimisation, and validation in the field

Histofarcin, a skin test antigen for the diagnosis of epizootic lymphangitis, was locally produced from the mycelial form of Histoplasma capsulatum var. farciminosum (HCF) in disease-endemic districts of Ethiopia and tested for its application in the field between April 2002 and May 2003. The test was evaluated using 108 mules, 84 in endemic and 24 in disease-free districts. Microscopic and mycological examinations of clinical lesions were used as the "gold standard" for the validation of the test. The concentration of histofarcin that caused an optimum reaction was 0.2-0.4 mg/mL in a 0.1 mL dose and this was attained 24-48 h post-injection. The sensitivity and specificity of the histofarcin test were 90.3% (CI = 73.1, 97.5) and 69% (95%, CI = 48.1, 84.9%) in disease-endemic districts. On the other hand, specificity was 100% (CI=94.8, 100) in disease-free districts. Positive and negative predictive values of the histofarcin test were 77.78% (95% CI = 60.4, 89.3) and 85.71% (95% CI = 62.6, 96.2), respectively. A marginal substantial agreement (kappa = 0.61, P = 0.0000) was observed between the clinical status and the result of the histofarcin test. A large proportion (31%) of 'false positives' was recorded in endemic districts, which could be due to the pre-clinical stage of the disease. The latter ended in lower specificity and positive predictive value of the test since the true infection status of a 'false positive' could not be known on the basis of clinical features. Therefore, standard test validation procedures including slaughtering and isolation of HCF is required. After proper validation, we conclude that the histofarcin test could play a significant role in detecting early infection, and differentiating of EL from glanders, ulcerative lymphangitis, and sporotrichosis.     

Effects of stress on endocrine and metabolic processes and redirection: cross talk between subcellular compartments

Recent advances in genome analysis and biochemical pathway mapping have advanced our understanding of how biological systems have evolved over time. Protein and DNA marker comparisons suggest that several of these systems are both ancient in origin but highly conserved into today's evolved species. However, remnants of some of the more ancient functions of these chemical systems can run in conflict with the functions that those same pathways serve in complex organisms and tissue systems today. Relevant to the present topic, nitric oxide (NO) and superoxide anion (O₂^•−), ancient cellular molecules in evolutionary terms, are recognized today as both necessary for the well-being and stable health of cells but also injurious to cells as elaborated in conjunction with the cellular stress response. Why the dichotomy? This question underlies one of the basic issues challenging researchers as well as practitioners in their approach to disease management. The fundamental proinflammatory response of the innate immune system of the host is needed for pathogen control but can be injurious to tissues from “collateral damage” from NO- and O₂^•−-derived reactive molecules capable of affecting protein function via post-translational chemical modification. This review highlights newer aspects of the biochemistry of the NO- and O₂^•−-mediated innate proinflammatory response and further show how protein and tissue damage via overproduction of reactive nitrogen and oxygen intermediary molecules such as peroxynitrite (ONOO⁻) might be targeted to specific epitopes of proteins. Changes in the regulation of metabolism in response to proinflammatory disease states are discussed for GH signal transduction and tissue specificity.     

CliniTox: the computer-based information system for poisoning in farm animals

Poisonings can cause reduced performance and severe economic loss in farm animals. A swift and targeted action is required from veterinarians. We have established a computer-based decision support system for poisonings in ruminants and pigs. The system offers access to the most recent information available in clinical toxicology of farm animals. Towards this goal, relevant reports from the peer-reviewed literature were evaluated and organised according to the requirements of a structured database. The information provided for each toxic substance includes a summary of its chemical and physical properties, sources, commercial uses or natural occurrences, toxicokinetic data, mechanisms of action, threshold doses, clinical symptoms with brief case reports, sampling and analytical results, post-mortem abnormalities, differential diagnoses, therapeutic guidelines and references to the literature. This decision support system has been programmed with two user-friendly search functions: a search tool that allows the choice of clinical and pathological findings, and another function that serves to find a substance using its chemical name, the class of compounds to wich it belongs, a possible source or one of its main applications. CliniTox can be accessed directly via our webserver (http://www.clinitox.ch).     

Predictive values of serum and bulk milk sampling for the presence of persistently infected BVDV carriers in dairy herds

The aim of this study was to examine whether it is possible to predict the presence of persistently infected (PI) animals with bovine viral diarrhoea virus on dairy farms in The Netherlands, based on a few blood samples of the herd, possibly in combination with a bulk milk test for antibodies. In 25 herds with, and 24 herds without, PI animal(s) the probabilities of obtaining at least x antibody positive animals out of a sample of n animals were calculated, with n varying from 3 to 7 and values for x that were considered were n, n - 1 to n - x. This probability, among animals 9-24 months old, ranged from 0.70 to 0.96 for herds with PI animals and from 0.13 to 0.37 for herds without. Using the result of bulk milk testing in addition did not add to the prediction. It was concluded that, due to the high percentage and large variation of antibody positive animals in herds without PI animals, it is not possible to predict the presence of PI animal(s) in dairy herds in The Netherlands using these methods.     

Evaluation of the diagnosis of subclinical endometritis in dairy cattle using ultrasound

The aim of this study was to determine signs of subclinical endometritis found by ultrasound that are associated with reduced fertility in dairy cows.The maximum diameter of the uterine lumen was determined by ultrasound in 324 cows without clinical signs of endometritis after evaluation of the genital tract 21 to 27 days postpartum. Cows were classified into healthy or with subclinical endometritis by three threshold values for the maximum uterine lumen diameter of 0.2 cm, 0.5 cm or 0.8 cm. Examinations by rectal palpation and ultrasound as well as classifications were repeated 14 days later. In addition, ovaries were scanned by ultrasound to determine the stage of the estrous cycle. In a subgroup of 103 cows the echotexture of the uterus and its contents was evaluated. In these cows the diagnosis of subclinical endometritis was performed by a scoring system. The diameter of the uterine lumen was significantly affected by stage of the estrous cycle at the time of examination. However, no effects were found for the stage of the cycle at the time of examination on subsequent reproductive performance. A uterine lumen with a maximum diameter of more than 0.2 cm showed a significant negative association with conception rate and proportion of cows pregnant. Classification based on higher threshold values did not reveal an association with reproductive performance. Echogenic content in the uterus also decreased reproductive performance. A classification based on the echotexture of the uterus and its contents revealed significant differences between healthy cows and cows with subclinical endometritis regarding the proportion of cows inseminated and pregnant.The results of this study showed that the diagnostic of bovine endometritis should be broadend by ultrasonography. The definition of subclinical endometritis diagnosed by means of ultrasonography has to be evaluated in further studies.     

Airway hypersensitivity induced by Ascaris suum extract in New Zealand Romney sheep

Sheep from local farms with and without previous exposure to pigs were tested for their skin and airway responses to a commercial Ascaris suum antigen. There was an immediate reaction to intradermal injection of the antigen in 90% of 101 sheep. A bronchial provocation test by aerosol of the same antigen was undertaken on 43 of the sheep with a positive skin reaction. About 70% of sheep showed an immediate airway response to the antigen as an aerosol, reflected as a significant increase in airway resistance and/or decrease of dynamic lung compliance. The mean peak airway resistance and mean lowest dynamic lung compliance were 165% above and 61% below their baselines, respectively. No significant changes were recorded when the same animals were given an aerosol of phosphate buffered saline. Similarly, no correlation was found between the degree of skin reaction and the magnitude of bronchoconstriction (p>0.05). The sheep with previous exposure to pigs showed no significant differences in airway responses to antigen challenge, although they showed significantly greater skin reactions than those without exposure to pigs. These results indicate that the majority of Romney sheep in the Manawatu have a natural skin and airway sensitivity to A. suum antigen and may therefore be used as an animal model to study human airway hypersensitivity. The origin of this sensitivity has yet to be determined.