A new skin condition of broilers which results in the downgrading of up to 15-30% of broiler carcases/week is described. Unsightly brown-black coloured erosions and ulcers occur on the breast, hock and foot skin. Histopathological examination of these revealed acute inflammation with necrosis of the epidermis and in more severe cases, the upper dermis. A study of the condition has shown a strong association between the appearance of lesions and poor litter conditions and that birds as young as 9 days may be affected. It is suggested that the condition is a contact dermatitis. A study of the development of lesions in one flock is also described.

The isolation of a number of strains of infectious bursal disease (IBD) virus from fowl, turkeys and ducks is described. These isolates could be grouped into two serotypes using the neutralisation test. It is proposed that the cell culture adapted vaccine strain from fowl should be the prototype virus for serotype 1 and that the TY89 isolate from a turkey should be the prototype for serotype 2. The isolates in serotype 2 consisted of an antigenically homogeneous group of viruses from turkeys and fowl. However, within serotype 1, which represented isolates from fowl and ducks, some isolates showed only a 30% cross reaction with the vaccine strain. If cross protection mirrors cross neutralisation, then infection with viruses belonging to serotype 2 or with antigenically distant strains from serotype 1 provides one explanation for the apparent failure of the vaccine on certain sites. However, if cross protection does not mirror cross neutralisation, then a virus from serotype 2 could be used as a heterotypic vaccine for young birds with high levels of maternally derived antibody to serotype 1.

Three groups, each of five calves, four to seven months old, were inoculated intranasally with different numbers of Mycobacterium bovis. Infection was established readily in the calves which received an inoculum containing either 10(6) or 10(4) colony forming units (cfu). After every infection there was a lag period during which the organisms could not be isolated from specimens of nasal mucus. All the animals excreted M bovis and the time of commencement, quantity and duration of excretion appeared to be related to the inoculation dose. Excretion continued for many weeks, and for two calves excretion became intermittent over many months. All the calves which were given inocula of 92 cfu failed to develop the disease and no immunological responses were detected; however, M bovis was isolated from nasal secretions from one of these animals 100 days after inoculation.

Depletion of the nitrofuran antibiotics furazolidone, furaltadone, nitrofurantoin and nitrofurazone and their tissue-bound metabolites AOZ, AMOZ, AHD and SEM from pig muscle, liver and kidney tissues is described. Groups of pigs were given feed medicated with one of the nitrofuran drugs at a therapeutic concentration (400?mg?kg(-1)) for ten days. Animals were slaughtered at intervals and tissue samples collected for analysis for six weeks following withdrawal of medicated feed. These samples were analysed both for parent nitrofurans (using LC-MS/MS and HPLC-UV), and for tissue-bound metabolites (using LC-MS/MS). The parent drugs were detectable only sporadically and only in pigs subjected to no withdrawal period whatsoever. This confirms the instability of the four major nitrofuran antibiotics in edible tissues. In contrast, the metabolites accumulated to high concentrations in tissues (ppm levels) and had depletion half lives of between 5.5 and 15.5 days. The metabolites of all four drugs were still readily detectable in tissues six weeks after cessation of treatment. This emphasizes the benefits of monitoring for the stable metabolites of the nitrofurans.

SUMMARYA virus, designated 132 virus, was isolated from the faeces of chickens in chick embryo liver cell cultures. The morphology and morphogenesis of 132 virus were indistinguishable from that of rotaviruses. The nucleic acid of 132 virus had the nuclease resistance of double-stranded RNA, and was separated by polyacrylamide gel electrophoresis into 11 segments with mol. wt. ranging from 2.07 × 106 to 0.20 x 106. SPF chickens were susceptible to oral infection with 132 virus, which replicated in the villous epithelial cells of the small intestine. 132 virus was therefore a rotavirus by morphological, biochemical and biological criteria. However, by immunofluorescence it was not possible to demonstrate an antigenic relationship between 132 virus and known avian and mammalian rotaviruses, indicating that 132 virus does not possess the group antigen shared by all previously characterized rotaviruses. This finding has implications for the diagnosis of rotavirus infections by serological tests.