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Biomedical subjects

M Bisgaard

Publications and source records attributed to M Bisgaard.

100 records · Page 6Linked to original sources
PubMed1978

Prevalence of precipitating antibodies against mycoplasmas and viruses in egg-laying flocks in Northern Jutland.

Antibodies against infectious laryngotracheitis virus, influenavirus and Newcastle disease virus were not demonstrated. The prevalence of infections caused by adeno- and reovirus in egg-laying flocks was 85 and 74% respectively. Approximately 25% of the flocks had antibodies against infectious bronchitis virus and infectious bursal disease virus. A raised prevalence of antibodies against mycoplasmas was found with increasing age.

Animals↗
PubMed1977

[Tentative organisation of disease recording in the poultry production. Collection and processing of condemnation results from 6 poultry slaughterhouses in Northern Jutland (author's transl)].

According to condemnation lists collected from 6 poultry slaughterhouses in northern Jutland there has been an increase in condemnation rate for broilers from 0.8 to 1.0% (Table I). The most important causes of condemnation have been emaciation, CRD, hock disorder and enteritis (Table II). Only a few slaughterhouses were involved in processing of hens, turkeys and web-footed birds showing inconstant distributions (Tables III and IV). Variation among slaughterhouses appears from Tables II-IV. The cause of variation and the value of central disease recording are discussed.

Abattoirs↗
PubMed1977

[Increased frequency of CRD in the broiler production in northern Jutland. I. Possible connexion between increased frequency of CRD and recently started vaccination with live infectious bronchitis vaccine (Massachusetts type) in egg producing flocks (author's transl)].

An increased condemnation rate due to CRD (chronic respiratory disease) is documented by means of condemnation lists collected in collaboration with directions and veterinarians at 6 poultry slaughterhouses. The geographic distribution of the 41 affected farms appears from Fig 1. The first outbreaks occurred around the turn of the year 1975/1976 and reached its climax in the 12th period (Table I). The increase in percent CRD of slaughtered chickens culminated in week 23/1976 amounting 0.64% (Fig 2). The increased total condemnation rate closely corresponds to an increase in CRD (Fig 3). These facts are intimately connected with the high number af consultations about respiratory diseases. Although not provable it seems possible and not unlikely that the broiler production has been exposed -- to increased directly or indirectly -- risk of infection from a raised number of IB vaccinated egg producing flocks.

Animals↗
PubMed1977

[Increased frequency of CRD in the broiler production in northern Jutland. II. Influence on production and economy (author's transl)].

The consequences for production and economy caused by an increase in CRD outbreaks in broilers in northern Jutland are estimated by comparing production results from book-keeping farms to the average results of the whole country, where an improvement of 19 gram was found, while a similar increase did not occur in northern Jutland (Table I). The condemnation rate has risen 0.4% in northern Jutland. For the whole country 0.1% rise has been registered. Production results from 6 book-keeping farms with CRD have been compared to the results from all book-keeping farms in the region. It appears from Table III that the 6 farms were lacking 60 gram weight increase and 0.03 in feed conversion. Gross margins for production without problems have been calculated to 0.70 kr. per chicken against 0.42 kr. per chicken in the 71 CRD attacked flocks (Tables IV and V). If in addition also slaughterhouse expenses are added the total loss due to CRD in the 71 flocks sum up to 510.144 kr.

Abattoirs↗
PubMedDate not supplied

A voluntary Salmonella control programme for the broiler industry, implemented by the Danish Poultry Council.

In the light of data and experience gained over the last two decades, initiatives made to combat and control Salmonella in the Danish broiler industry are described and the results obtained so far are discussed. The main elements include evaluation of the establishments, procedures and processes used, including bacteriological assessment, advice and guidance, routine bacteriological monitoring, and also research. Results obtained are used in the control of breeding stock, parent stock, hatcheries, broiler farms, slaughterhouses, feedmills and transport systems.

Abattoirs↗
PubMedDate not supplied

Phenotypic characterisation of Australian sheep and cattle isolates of Mannheimia haemolytica, Mannheimia granulomatis and Mannheimia varigena.

OBJECTIVE: To perform a comprehensive phenotypic characterisation of 35 isolates of bacteria previously identified as haemolytic Pasteurella-Actinobacillus and obtained from cattle and sheep. DESIGN: The 35 isolates that had been obtained from Australian animals, 30 from cattle and five from sheep, were compared with reference strains of the five recognised species of the genus Mannheimia--M. haemolytica, M. glucosida, M. granulomatis, M. ruminalis and M. varigena. RESULTS: Thirty-four of the isolates could be confidently assigned to three species of the genus Mannheimia. Twenty-nine were M. haemolytica, with 25 being isolated from cattle and four from sheep. All but three of the bovine M. haemolytica were isolated from pneumonic lungs. Of the three remaining bovine M. haemolytica isolates, one was obtained in pure culture from a bovine milk sample and the other two as part of a mixed flora associated with a middle ear infection of a calf suffering mucosal disease. Of the four ovine M. haemolytica isolates, two were isolated in pure culture from milk and two, also in pure culture, from pneumonic lungs. Three bovine isolates were identified as M. granulomatis--one from a tongue abscess, one from a jaw abscess and one from a lung showing suppurative bronchopneumonia. Two bovine isolates were identified as M. varigena--one coming from an udder and the other from a spleen. The available diagnostic records provided no information on whether these isolates were associated with a disease process. The remaining isolate was obtained from an ovine tongue abscess and could not be assigned to a recognised species within the genus Mannheimia. CONCLUSION: The study represents the first time that M. haemolytica, M. granulomatis and M. varigena have been recognised as being present in cattle and sheep in Australia. Veterinary laboratories that encounter Pasteurella-Actinobacillus-like organisms from cattle and sheep should attempt as complete a characterisation as possible to help improve our knowledge of the disease potential of these organsims.

Animals↗
PubMedDate not supplied

[The influence of infectious bronchitis virus on egg production, fertility, hatchability and mortality rate in chickens (author's transl)].

In 35 flocks comprising almost 100,000 White Plymouth Rock birds producing hatching eggs, infectious bronchitis (IB) caused a decline in production which appeared to be connected with the age of the birds, when the outbreak started (table I). In outbreaks of IB in pullets 3-4 weeks before they are ready to lay there is a considerable risk of delay of production and a generally too low yield (fig 1). Egg laying birds, 25-34 weeks of age, suffered a drop in production from 20-80% (on an average 40%) and normal yield was never regained. After 6-8 weeks the production rate usually stabilizes around 6-12% below normal production. IB outbreaks in the middle of the production period (35-45 weeks) resulted in a decline of egg production of 40-90% (on an average 55%). Recovery of production usually occurred after 6-8 weeks (fig. 2). Observations of clinically typical outbreaks without any laboratory verification indicate that IB outbreaks at the end of the egg production period resulted in irreparable decline of production. Marked alterations in exterior and interior quality of the egg have been observed. Both mishapen appearance, rough and thin shell, bleached shell color and watery albumen have occurred. These facts did sometimes cause transient increased "sorting out" of haching eggs. Also fertility rate was noticed to be affected temporarily during and after an attack of IB. In 17 flocks drops of 1.7-22.4% (on an average 7.4%) were registered (fig. 3). Also hatchability decreased 3.0-43.8% (on an average 13.7%) (fig. 4). In most of the registered outbreaks of IB the weekly mortality remained below 1%, but in single cases the figure could rise up to about 4% (fig. 5), most often in flocks where complicating factors such as secondary infections caused by E. coli or M. gallisepticum were present.

Animals↗
PubMedDate not supplied

[Respiratory diseases in poultry caused by viruses--occurrence and diagnosis (author's transl)].

The highly intensive conditions, that economic necessity has forced upon the poultry industry, have resulted in strongly changed environmental conditions and management which combined with the use of a constantly increasing number of live vaccines has highly complicated clearing up the etiology in diseased flocks. This is true not least as far as respiratory diseases concerns, which thereby often run an atypical course. A review, however, not complete, is given of the occurrence and diagnostic procedures in respiratory diseases caused by viruses, the greatest importance attached to infections caused by adeno- and infectious bronchitis virus.

Animals↗