Book reviews

The T.M.E. System of Feed Evaluation. I.R. Sibbald, Animal Research Centre Contribution 83‐1, Animal Research Centre, Ottawa, Ontario, Canada.

Physiology and Behaviour of the Pigeon, edited by M. Abs. 1983. 360 pages, illustrated. London, Academic Press Ltd. Price £34.00. ISBN 0 12 042950 0.     

A note on the amino acid composition of the Turkey

1. The amino acid composition of the whole body protein of 28‐ and 56‐d‐old turkeys is reported.

2. There were some differences between the two ages; these could largely be reconciled by considering the likely differences in the proportion of feather protein.

3. The results were compared with similar values for the chicken and goose; overall there is a striking similarity, both in absolute concentrations and relative proportions of amino acids.     

Mode of action of the systemic fungicides furalaxyl,metalaxyl and ofurace

The systemic fungicides furalaxyl, metalaxyl and ofurace,

1 Ofurace is the proposed BSI and ISO common name for α-(2-chloro-N-2,6-xylylacetamido)-γ-butyrolactone.

used to control diseases caused by phycomycetes, were extremely active in vitro against Pythium ultimum, Phytophthora nicotianae and Phytophthora palmivora. Sporangia production was reduced more than mycelial growth but germination of sporangia and zoospores was relatively unaffected. Less than 1% of the metalaxyl or furalaxyl, present in media at the ED₅₀ for hyphal growth, was firmly absorbed by Phyt. palmivora mycelium; uptake was against a concentration gradient and was characterised by a rapid accumulation followed by a more gradual release. Respiration and wall synthesis were not inhibited, whilst membrane permeability was unaffected. Lipid patterns were altered but these changes were probably of secondary importance. The fungicides inhibited protein and nucleic acid synthesis; RNA production was particularly affected. There was some evidence of a reduction in nuclear division. The primary effect of furalaxyl and metalaxyl probably involves impaired biosynthesis of RNA so that mitosis is inhibited; ofurace may act in the same way.     

A comparison of the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts after calving in cows also given internal teat sealants

AIM: To compare, in cows treated with an internal teat sealant, the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts (SCC) after calving.

METHODS: Cows from a spring-calving, pasture-based dairy farm in the Manawatu-Whanganui region of New Zealand were randomly allocated to receive either a short-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=291) or a long-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=288) at the end of lactation. Cows were managed on-farm with routine husbandry procedures through the dry period and following calving. A multivariable logistic regression model was used to determine the association between length of action of dry-cow therapy and the proportion of cows with a SCC >150,000?cells/mL at the first herd test after calving.

RESULTS: Age of cow, mean SCC for the preceding season and interval from calving to the first post-calving herd test were all associated with the proportion of cows with an individual SCC >150,000?cells/mL at the first herd test (p<0.001) Treatment with the short-acting dry-cow therapy was not associated with decreased odds of cows having a SCC >150,000?cells/mL at the first herd test compared with treatment with long-acting dry-cow therapy (OR=0.724; 95% CI=0.40–1.30).

CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, which routinely used internal teat sealants, the use of short-acting cloxacillin-based dry-cow therapy did not result in an increased proportion of cows with elevated SSC post-calving. This was a single farm, single year study but indicates that in this herd, changing from a long-acting to a short-acting antimicrobial may have no impact on the prevalence of subclinical mastitis.     

Presentation,clinical pathological and post‐mortem findings in three related Scottish terriers with ligneous membranitis

Ligneous conjunctivitis and gingivitis were diagnosed in three related Scottish terrier dogs presented for investigation of severe conjunctivitis and respiratory signs. Hypoplasminogenaemia was confirmed in one of the three affected dogs. Supportive treatment was not effective, and the dogs died or were euthanased because of the disease. Post‐mortem analysis of two of the dogs revealed multiple abnormalities including severe proliferative fibrinous lesions affecting the conjunctiva, gingiva, trachea, larynx and epicardium and multiple fibrous adhesions throughout the thoracic and abdominal cavities. One dog had internal hydrocephalus and lacked a cerebellar vermis. Ligneous membranitis was confirmed on histopathology. This is a rare condition in dogs but an important differential diagnosis for severe conjunctivitis and gingivitis.