Meat inspection in New Zealand: prospects for change

Regulatory authorities are facing increasing challenges with respect to the newly-recognised public health risks associated with meat products. Meat inspection resources should be allocated according to their maximum ability to reduce food-borne hazards, rather than according to the classical rules of meat inspection. Scientific evaluation of routine post-mortem inspection procedures for each class of livestock, introduction of the Hazard Analysis Critical Control Point approach to process control, on-line testing for microbiological hazards and residues, and effective management of production, processing and inspection data are central to this process. The meat inspection system that has evolved in New Zealand reflects a response to non-scientific forces such as market requirements and industrial practices rather than scientific discipline. In the future, the daily routine of meat inspectors will be extended well beyond their current slaughterfloor responsibilities, and veterinarians will require specialist skills. Science should be the basis for international food regulation and policy concepts such as equivalence or mutual acceptance are achievable on this basis.     

Comparative studies of BHV-1 variants by in vivo--in vitro tests.

The new encephalitogenic BHV-1.3 and previously characterized BHV-1 strains were studied with reference to their immunogenic and protective potency and their antigenic relationships using "in vitro" and "in vivo" tests. The "in vitro" results obtained by neutralization kinetics showed that the Los Angeles (LA) strain (BHV-1.1) and a vaginal isolate L-114 strain (BHV-1.2) had antigenic similarities. Conversely, the behavior of the encephalitogenic strain A-663 (BHV-1.3), was significantly distinct. The "in vivo" protection test was carried out in calves using LA and A-663 strains. Post-vaccination antibodies and challenge with A-663 strain showed that the immunogenic behavior and protective capacities of both strains were similar. Neutralization kinetics differences between BHV-1.1 and BHV-1.3 did not alter the "in vivo" protection against BHV-1.3 challenge.     

Comments on the method to test side effects of pesticides on the predatory mitePhytoseiulus persimilis Ath.-Hen

A paper published byKniehase & Zoebelein (1990) describes a new laboratory method to test the side effects of pesticides on the predatory mitePhytoseiulus persimilis and criticizes the laboratory test developed by the International Working Group pesticides and beneficial organisms of the International Organization for Biological Control (IOBC), West Palaearctic Regional Section (WPRS). The present publication discusses the advantages and disadvantages of both methods, responds to the criticism and mention the overall concept of the IOBC/WPRS Working Group including semifield and field test methods.In einer Arbeit vonKniehase undZoebelein (1990) wird ein neues Laborverfahren zur Prüfung der Nebenwirkung von Pflanzenschutzmitteln auf die RaubmilbePhytoseiulus persimilis beschrieben. Die genannten Autoren äußern sich kritisch über das seither von der Arbeitsgruppe Pflanzenschutzmittel und Nutzorganismen der International Organization for Biological Control (IOBC), West Palaearctic Regional Section (WPRS) praktizierte Verfahren. In der vorliegenden Arbeit werden die Vor- und Nachteile der beiden Prüfmethoden diskutiert. Einer Reaktion auf die Kritik folgt eine kurze Beschreibung der gesamten Konzeption der genannten Arbeitsgruppe, die auf einer Kombination aus Labor-, Halbfreiland- und Feldprüfverfahren beruht.     

A study of periodontal disease in sheep over a twelve month period

Sheep affected by broken mouth periodontal disease (P.D.) were examined over a twelve month period for different clinical parameters. It is suggested that P.D. in sheep is an episodic phenomenon similar to human P.D., and that only a few animals with signs of P.D. may undergo clinically significant destruction over a yearly period. No single parameter could reliably predict future deterioration in other parameters.     

The detection of Mycobacterium paratuberculosis in bovine faeces by isolation and the comparison of isolation with the examination of stained smears by light microscopy

The detection of Mycobacterium paratuberculosis organisms in bovine faeces by isolation was compared with that by the microscopical examination of Ziehl-Neelsen stained faecal smears for the presence of clumps of acid-fast M. paratuberculosis organisms. Faeces were obtained from cattle naturally or experimentally infected with M. paratuberculosis as well as from uninfected cattle. Microscopical examination was an unreliable method for the detection of M. paratuberculosis organisms, since the organisms were only detected in 99 (=55.9%) of 177 culturally positive faecal samples. 1111 addition, clumps of acid-fast organisms indistinguishable from M. paratuberculosis were also observed iin three of 18 samples from cattle free from Johne's disease and in 18 of 37 culturally negative samples from paratuberculous cattle. When M. paratuberculosis organisms were added to faeces from an uninfected cow, results showed that isolation attempts should be positive when 15 or more M. paratuberculosis organisms per gram of faeces are present.     

Immunological control of hematophagous arthropod vectors: utilization of novel antigens

Immunological control of ixodid ticks requires development of a vaccine that stimulates an effective anti-tick response. However, it is important to avoid induction of intense host skin reactivity to tick feeding. Salivary-gland-derived molecules are introduced into the host during ixodid engorgement; therefore, use of these moieties might not be an optimal immunization strategy. Antigens not normally involved in acquired resistance can be used to induce anti-tick immunity. These "novel" antigens, obtained from tick gut absorptive surface, are not introduced into the host during tick feeding, but are exposed to host-immune effector elements in the blood meal, resulting in ixodid rejection, prevention of ova production and death. Anti-tick immunity is induced with microgram quantities of this ixodid gut antigen preparation. Sera obtained from immunized animals were used to identify antibody-reactive components of the resistance-inducing extract. Tick gut absorptive surface antigen glycoconjugates were identified by lectin blotting, using a series of probes with different carbohydrate specificities. The lectins, peanut and wheat germ agglutinin, and immunized host antibodies bound extract components with similar molecular weights. Solubilization and fractionization of tick gut proteins with the non-ionic detergent Triton X-114 is described.     

Bile duct obstruction secondary to chronic pancreatitis in seven dogs

Seven icteric dogs were determined to have bile duct obstruction secondary to chronic pancreatitis. All dogs had histories of intermittent vomiting and diarrhea. Alkaline phosphatase and alanine aminotransferase activities and total bilirubin concentrations were markedly elevated. Diagnosis was based on exploratory laparotomy and histological examination. Each dog had a 3 to 10 cm mass in the body of the pancreas and obstruction of the common bile duct. Three dogs treated with pancreatectomy, gastrojejunostomy, and cholecystojejunostomy died within five weeks. Three dogs treated with conservative surgical procedures were alive at 8, 16, and 26 months postoperatively. One dog was euthanized because of suspected neoplasia. Hepatic enzyme activity and bilirubin levels decreased markedly in the surviving dogs. Histological examination of the pancreatic masses indicated chronic pancreatitis. Hepatic biopsies revealed evidence of cholestasis. Chronic pancreatitis should be included in the differential diagnoses of icterus, bile duct obstruction, and masses in the pancreas.