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Biomedical subjects

J Svendsen

Publications and source records attributed to J Svendsen.

At least 55 records · Page 3Linked to original sources
PubMed1975

Occurrence of K88-negative escherichia coli serotypes in pigs with post weaning diarrhoea.

Faecal swabs from pigs with post weaning E. coli diarrhoea in 43 different herds were bacteriologically examined. A survey of the isolated haemolytic E. coli strains showed that only 1 of the examined strains possessed the K88 antigens and that E. coli strains belonging to serogroup O149:K91 were most frequently isolated. The results suggest that the K88 antigen is of minor significance in the development of post weaning diarrhoea associated with E. coli serotype O149:K91.

Animals↗
PubMed1975

Preweaning mortality in pigs. 4 Diseases of the gastrointestinal tract in pigs.

The incidence of fatal gastroenteropathies in sucking pigs was studied during a 2-year period in 17 sow herds involving 2,936 litters. The results showed that 2.8 per cent of the liveborn pigs died with gastroenteropathies during the sucking and immediate post weaning period. The incidence was lowest in offspring from second-litter sows (Table I) and the progeny from large litters tended to have the highest incidence (Table II). Fatal gastrointestinal diseases were observed in a total of 17.6 per cent of the examined litters, and the average number of death per affected litter was 1.5 (Tables III and IV). The progeny of sows with post parturient diseases had significantly higher death losses than had the progeny from normal healthy sows (Table V). Climate had no apparent influence on death losses, but they were lowest during the warmer period of the year (April-September) (Tables VIII and VI.) The incidence varied considerably from herd to herd, but was not influenced by herd size (Table III). However, the level of hygiene exerted a pronounced influence on the incidence (Table VII), and self-contained herds had significantly lower death losses than had herds where female breeding stock was occasionally brought in (Table IX). Approximately 65 per cent of the pigs which succumbed due to gastrointestinal diseases died during the first week of life, which means that 1.8 per cent of the pigs at risk died during this period (Table X). The material was grouped according to the results of the post mortem and bacteriological examinations (Table XI). Approximately 50 per cent of the fatal cases were associated with an intestinal bacterial infection, which in most instances was caused by pathogenic strains of E. coli (Tables XII and XIII), while approximately 14 per cent had distinct gross pathological lesions which alone were indication of a diagnosis. In the remaining one third of the fatal cases the aetiology and pathogenesis remained by and large unexplained; however, nutritional and dietetic disorders played a role in many of these cases. Aetiological, epidemiological and pathological aspects of the fatal gastrointestinal diseases are discussed, and it is concluded that a high level of hygiene, the prevention and treatment of post parturient diseases, "closed" management systems, and the avoidance of unsuitable or damaged sow feed would be instrumental in keeping the level of fatal gastrointestinal diseases low among sucking pigs.

Age Factors↗
PubMed1975

Preweaning mortality in pigs. 5. acute septicaemias.

A 2-year study on preweaning mortality revealed that 2.1 per cent of the liveborn pigs succumbed to acute bacterial septicaemias. The most frequently encountered causative organisms were haemolytic streptococci and E. coli.

Animals↗
PubMed1975

Preweaning mortality in pigs. 7. Polyarthritis.

The incidence and causes of polyarthritis in sucking pigs were studied in herds with 2,936 litters during a 2-year period. Among pigs more than 3 days old, the average morbidity rate was 3.3 per cent and the mortality rate amounted to 1.5 per cent (Table I). Among herds the morbidity ranged from 0.9 to 7.0 per cent and the mortality due to polyarthritis from 0.5 to 2.8 per cent. The incidences of polyarthritis were higher in the progeny of gilts than in the progeny of sows of other age groups (Table II). No consistens correlation between litter size at birth and the mortality rate due to polyarthritis was found (Table III). Cases of polyarthritis were observed in 17.8 per cent of the examined litters. Death due to polyarthritis occurred in 10.8 per cent of the litters (Table I); 67.3 per cent of the fatal cases occurred sporadically with only one pig lost per litter (Table IV). The mortality due to polyarthritis appeared to be higher in male pigs (Table V). An analysis of some possible contributory factors showed that the frequency of polyarthritis was adversely affected by new introduction of female breeding stock, clipping of the canine teeth and tail docking in the new-born, and by occurrence of skin diseases in individual piglets (Table VI, IX & XII). No obvious relation was found with such factors as: season of the year, sow's health condition, herd size (Table I), or hygiene level in the individual herds (Table VIII). Death due to polyarthritis occurred most frequently in pigs 2--4 weeks of age (Table X). The pathological lesions, which varied according to the duration of the inflammation and to the aetiology, are described. Arthritis was most frequently observed in the larger limb joints, although every joint may be affected (Table XI). In the majority of the cases a meningoencephalitis was present. A survey of other concomitant, complicating or possible predisposing lesions are presented (Table XII). The bacteriological examination of joints and other organs Table XIII) showed that haemolytic streptococci by far dominated as causative organism. Staphylococci species and E. coli were isolated from affected joints in 6.4 per cent and 4.3 per cent of the pigs, respectively. C. pyogenes and E. rhusiopathiae were rarely encountered in these sucking pigs with polyarthritis. Aspects of the epidemiology and pathogenesis are discussed in regard of minimizing the losses due to polyarthritis/meningitis in sucking pigs.

Animals↗
PubMed1975

Causes of culling and death in sows.

Over a 4-year period, the annual number of culled sows in 9 Danish herds averaged 54.8 per cent of the year-sows and the number of culled sows in per cent of total number of farrowings averaged 25.8 (Table I). -- The culling rate varied considerably from herd to herd within the same year and from year to year (Tables I and II); however, the average annual culling rate for all the herds only presented small variations (Table II). The average number of litters reared per sow before culling was 3.6. The culling rate was higher in pedigree herds than in commercial herds, and it was highest in the small pedigree herds (Table III). The hygiene level in the herds and the introduction of new female breeding stock did not influence the culling rate (Table IV). A proportionally lower percentage of the sows was culled in herds where the dry and pregnant sows were housed in stalls and/or were tethered, as compared to herds where these sows were housed in pens (Table V). -- The culling rate in the age groups of sows with less than 8 farrowings remained at approximately the same level (Table VI). The main reason for culling was infertility problems, which were recorded in 41.4 per cent of the culled sows, while 16.7 per cent of the sows were culled because their litters were poor and/or small (Table VII). The mortality rate among the culled sows was 11.9 (Table VII), and the main causes of death were chronic pyogenic infections, which occurred in 25.5 per cent of the fatal cases (Table VIII). Certain aspects concerning the recording and calculation of culling rates in the different herds are discussed and it is emphasized that the culling rate per se may not have any direct relationship to the productivity in the herd.

Age Factors↗
PubMed1972

Immunity to Escherichia coli in pigs: serum gamma globulin levels, indirect hemagglutinating antibody titres and bactericidal activity against E. coli in pigs up to five weeks of age.

Serum gamma globulin levels, indirect hemagglutinating antibody titres and bactericidal activity against the 0149:K91;K88ac:H10 Serotype of Escherichia coli were determined in pigs up to five weeks of age from vaccinated and non-vaccinated sows. Gamma globulin levels at two days of age were approximately twice adult levels, by three weeks of age they were one quarter of adult levels and remained so until five weeks of age. Indirect hemagglutinating antibody activity was highest at two days of age, fell until three weeks of age and then rose. Little or no indirect hemagglutinating antibody activity was detected in sera taken at two days of age from pigs from non-vaccinated sows. Only three of 26 two day old pigs had demonstrable bactericidal activity; by three weeks of age 16 of 26 had bactericidal activity. Serum from piglets of vaccinated sows had no more bactericidal activity than did sera from non-vaccinated sows.

Animals↗
PubMed1972

Immunity to Escherichia coli in pigs: antibody secretion by the mammary gland after intramammary or intramuscular vaccination with an E. coli vaccine.

Indirect hemagglutinating antibody titres in individual gland samples of colostrum and milk from 13 sows were measured. Five of the sows were vaccinated via a mammary gland and five by the intramuscular route with a live formalinised Escherichia coli vaccine and three remained as non-vaccinated controls. Antibody titres were higher in colostral and milk whey from the vaccinated sows than from non-vaccinated groups. The inoculated gland in the group of sows given vaccine by the intramammary route secreted milk containing markedly more antibodies to the vaccine E. coli strain than did the non-vaccinated glands. Milk from the vaccinated gland did not contain higher titres to heterologous E. coli O antigens than milk from non-vaccinated glands. Serum titres were the same or higher than the titres in colostrum from non-vaccinated glands.

Animals↗
PubMed1971

Immunity to Escherichia coli in pigs. The role of milk in protective immunity to e. coli enteritis.

Milk whey from immunized sows increased the survival time of gnotobiotic piglets infected with Escherichia coli. The survival time of infected piglets fed milk whey from non-vaccinated sow's was the same as that of similar pigs fed condensed cow milk. The significance of milk antibodies in immune protection against E. coli enteritis is discussed and compared with that of absorbed colostral antibodies. From calculations presented it would appear that seven day old piglets receive approximately 1 g of gamma globulin daily from milk and that this is equal to the piglets total serum gamma globulin content. After seven days of age the gamma globulin content of piglet serum falls, whereas that of milk remains constant; milk is, therefore, potentially a major source of immunoglobulins with protective activity against E. coli associated enteritides.

Animals↗