Evaluation of the influence of supplementing the diet with mannose or palm kernel meal on salmonella colonisation in poultry

1. The dietary inclusion of 15 and 25 g/kg mannose was associated with a reduction in the numbers of Salmonella enteritidis (PT4) in the caecal contents of chicks challenged by the food. The same benefit was not recorded for S. infantis, possibly because this strain, unlike S. enteritidis PT4, lacked mannose‐sensitive fimbriae.

2. The addition of 25 g/kg palm kernel meal (PKM), but not 20 g/kg desiccated coconut, to the food reduced the degree of salmonella colonisation in the intestinal tract of broiler chicks given diets contaminated with S. kedougou or S. enteritidis from the day of their arrival from the hatchery.

3. The beneficial effect of PKM was also demonstrated at an inclusion rate of 5 g/kg and was similar for preparations with a particle size of either < 150 μm or < 300 μm.

4. Day‐old birds challenged orally with S. enteritidis and given food supplemented with 25 g/kg PKM, became clear of infection by 3 weeks of age while birds given unsupplemented food remained infected.

5. These preliminary results suggest that the inclusion of PKM, which contains inter alia, oligosaccharides containing mannose, in the diet of chicks may reduce the extent to which the intestine is contaminated with salmonellas.     

Antigenic relatedness and partial amino acid sequences of pili of Escherichia coli serotypes O1, O2, and O78 pathogenic to poultry

Pilus proteins from Escherichia coli serotypes O1, O2, and O78 pathogenic to poultry were compared with regard to their antigenic relatedness and partial amino acid sequences. Agglutination, immunodiffusion, and immunoblot assays with polyclonal antibodies to these pili showed that these pili not only share some common antigens but also contain antigens unique to each pilus. The partial amino-terminal amino acid sequences support our earlier findings that the pili are different but contain some structural homologies.     

Rapid detection of viral-specific antibodies by enzyme-linked immunosorbent assay (ELISA)

The development of three separate rapid ELISAs for detecting antibodies in host serum to three different viruses is described. These include: 1. A direct antigen assay using enzyme labelled anti-canine Ig for detecting antibodies to canine parvovirus, 2. A competitive ELISA using a feline infectious peritonitis virus-specific monoclonal antibody labelled with enzyme, and 3. A competitive ELISA using an equine infectious anemia virus-specific monoclonal antibody and enzyme labelled antigen, p. 26. The utility and benefits of each of the three approaches is emphasized.     

In vitro viral expression as a criterion for development of control procedures for enzootic bovine leukosis

In a university beef herd of 304 cattle in which six died of lymphosarcoma between 1980 and 1984, 77% of the Angus and 26% of the Charolais cattle were determined to be infected with bovine leukemia virus (BLV). Changes in iatrogenic procedures were initiated as early control measures. In vitro viral expression (VE) was used as a criterion to identify cattle for subsequent segregation or culling. This involved determinations of percentages of BLV-associated lymphocyte profiles among thin-sectioned Ficoll-Paque-isolated blood lymphocytes that were processed into plastic after culture for 48 h. Cattle retained until completion of nutritional studies or as breeding stock were separated into two groups. The BLV-seronegative cattle, BLV-seropositive cattle with 0% VE, and BLV-seropositive cattle with 1% to 4% VE were placed in group 1. Seropositive cattle with greater than or equal to 5% VE were placed in group 2. In 1985, evaluation of in vitro VE in 108 mature BLV-seropositive cattle retained for breeding revealed 36 (33%) had no observable VE. In 1986, 58 of 108 cattle were available to be reexamined, and 21 (36%) had 0% VE in both years. The VE expression values for individual cattle were generally comparable over the 2-year period. Of 48 initial seronegative breeding stock housed in group 1 with BLV-seropositive cattle with low or no VE, 21 (44%) seroconverted during 1985 to 1986. A positive correlation of 0.585 was found between VE and age-related absolute lymphocyte number.     

Vaccination of swine against H3N2-influenza field isolates using the human Philippines-strain

Intratracheal inoculation of 2 Belgian H3N2-influenza viral strains, isolated from sick swine in the field, caused high fever, anorexia and dyspnoea in unvaccinated swine. The strains are related to the human A/Port Chalmers/1/73 (H3N2)-strain. In a limited study, 2 subunit vaccines, both derived from the human A/Philippines/2/82 (H3N2)-strain, were tested for efficacy in protecting swine against these Belgian field isolates. Vaccine A was a commercial vaccine, vaccine B an experimental vaccine. For evaluation of the efficacy of the vaccines, clinical as well as virological parameters were used. It was found that 2 spaced injections of the experimental vaccine (B) resulted in very high serum hemagglutination-inhibition (HI) titres against the Philippines-strain. Nevertheless, only partial protection was obtained, as indicated by the milder clinical signs and the decreased viral replication at challenge. One injection of the experimental vaccine (B) and 2 spaced injections of the commercial vaccine (A) did not result in any protection at challenge, even though moderate HI titres against the Philippines-strain were obtained. It was concluded that if an H3N2-strain is included in vaccines for use in swine, a strain should be selected which is identical or very closely related to the strain(s) prevalent in the swine population of the country in which the vaccine will be used.     

Appearance of slow-reacting and complement-requiring neutralizing antibody in cattle infected with Akabane virus

Slow-reacting complement-requiring neutralizing (NT) antibody was detected in sera from cattle 2 weeks after infection with Akabane virus. Bovine sera obtained 3 or 4 weeks after infection contained slow-reacting noncomplement-requiring NT antibody. The slow-reacting complement-requiring NT antibody was sensitive to 2-mercaptoethanol (2-ME), whereas the slow-reacting noncomplement-requiring NT antibody was resistant to 2-ME. The initial phase may represent the IgM response and the later phase a change to IgG. A NT test was developed in which virus-serum mixtures were incubated at 4 degrees C for 48 h and then with complement at 37 degrees C for 60 min; this gave an improved sensitivity over the previous incubation at 37 degrees C for 60 min.     

Equine chronic diarrhea: Traditional Chinese veterinary medicine review

Chronic diarrhea is a common problem in equine practice. Herbal medicine has been used for the treatment of gastrointestinal disease in horses for at least one thousand years. In present-day equine practice in China, the most common approach to treat chronic diarrhea is herbal medicine, or a combination of herbal medicine and acupuncture. Three types of chronic diarrhea in horses will be described in detail in term of symptoms, diagnosis and herbal treatments in this paper. Nineteen herbal formulas for treatment of different types of diarrhea will be introduced. Clinical results of each herbal formula will be evaluated. Acupuncture treatment of this problem will also be included.     

A zinc-containing intraruminal device for facial eczema control in lambs

A zinc-containing intraruminal device has been developed for protecting lambs against facial eczema. The rate of release of zinc from the device has been optimised, and its safety in use established. Under both experimental and farm conditions, the device gave excellent protection against the liver injury associated with facial eczema. The device relies upon erosion for release of zinc, and disappears completely when its charge of zinc has been released, leaving no metal or plastic residue in the rumen. This device has the potential to greatly ameliorate the problem of facial eczema in New Zealand.     

Duration of immunity in foxes vaccinated orally with ERA vaccine in a bait.

Red foxes (Vulpes vulpes) vaccinated orally with the ERA strain of rabies vaccine in a bait were challenged after 83 mo. Ten of 11 foxes that had seroconverted following vaccination resisted challenge with a virulent rabies virus which produced clinical signs of rabies in 6 of 6 unvaccinated foxes. Five of 11 vaccinated animals retained titers of rabies virus neutralizing antibody throughout the period. Although 6 of 11 had no detectable antibody at the time of challenge, 5 of these 6 resisted challenge and had an anamnestic response, as indicated by elevated titers of antibody when measured at day 77 postchallenge. These results show that foxes can be immunized successfully with a single oral dose of ERA vaccine, probably with protection against a lethal rabies challenge, for at least 7 y.