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The Pig Journal Vol 50 - November 2002
The Pig Journal Vol 50 - November 2002
Order forms: Complete volumes Individual papers fron vols. 42-51 CD Offer
| Refereed Section |
EVALUATION OF THE EFFICACY OF A SINGLE DOSE MYCOPLASMA HYOPNEUMONIAE VACCINATION PROGRAMME IN CHALLENGED PIGS
p.8-27
Authors: D. Llopart, J. Clota, R. March, I. Navarra, P. Riera and C. Artigas
Abstract
The efficacy of a single dose vaccination programme using an inactivated vaccine against M. hyopneumoniae (MYPRAVAC SUIS - Laboratorios Hipra) was evaluated in pigs when challenged by an intratracheal route with 10 ml of M. hyopneumoniae virulent strain culture (106 ccu/ml) (ref. 3371.[Dr. N. Friis, Denmark]). Forty M. hyopneumoniae seronegative pigs of seven to 10 days of age were used. Four experimental groups of 10 pigs each were established. Group One was vaccinated twice (day 0 and 21) and challenged at day 70. Group Two was vaccinated once (day 0), a PBS sterile solution was injected at day 21 and they were also challenged at day 70. Group Three was not vaccinated but injected with a PBS solution (day 0 and 21) and challenged at day 70. Group Four was neither vaccinated, injected with a PBS solution at day 0 and 21 nor challenged. All pigs were slaughtered at day 98. Clinical signs of pneumonia were observed in two pigs from Group Three, 21 days post challenge. Groups One, Two and Four did not show any signs of pneumonia during the post-challenge period. Although daily weight gain during the post-challenge period was higher in the vaccinated groups (Group One: 0.61 kg; Group Two: 0.64 kg; Group Three: 0.48 kg; Group Four: 0.59 kg), no significant differences were found between groups. Blood samples showed that the percentage of positive animals was higher in Group One than Two at days 42 (80% vs 20% respectively) and 70 (90% vs 10% respectively).
The administration of two doses of vaccine induced higher inhibition percentage (IP) values against M. hyopneumoniae than the administration of one dose in a competitive ELISA test. The percentage of positive animals was similar between Groups One and Two (vaccinated) but higher than Group Three at 28 days post challenge. Macroscopic pulmonary lesions scored at day 98 showed that Group One presented a significant reduction of the pulmonary lesions attributed to M. hyopneumoniae when compared with Groups Three and Four (p=0.036 and 0.011 respectively), but no significant differences were found between Groups One and Two (p=0.197). Histopathology confirmed that Group One presented a lower incidence and severity of pulmonary lesions than Groups Two and Three. The trial concluded that the administration of a single dose vaccination programme induces a humoral immune response and reduces pulmonary lesions when compared with a non-vaccinated group of pigs when challenged, though best results were obtained with the two dose vaccination programme.Order: Article by email or post
A COMPARATIVE FIELD STUDY OF THE EFFICACY OF CEFQUINOME AND AMOXYCILLIN AGAINST ACUTE MENINGITIS OF WEANED PIGLETS
p.28-41
Authors: E. Thomas, G. Martin, B. Voss, A. Boettner, P. Pommier, W. Loehlein, and K. Hellman
Abstract
This study compared the efficacy of two antibiotics (cefquinome and amoxycillin) for the treatment of bacterial meningitis, primarily caused by Streptococcus suis, in weaned piglets. The study was performed in piglets from farms with a history of meningitis due to S. suis. Meningitis was diagnosed on clinical grounds, and affected piglets randomly treated once daily intramuscularly with cefquinome (Cobactan®, 2mg/kg) or amoxycillin (Clamoxyl®, 7.5mg/kg). Response to treatment was evaluated clinically, and deaths were investigated by necropsy and bacteriological examination. A total of 110 weaned piglets with clinical signs of meningitis were treated, 55 with cefquinome, and 55 with amoxycillin. Cure rates at the end of the study (Study day 21) were 67% in the cefquinome group, and 58% in the amoxycillin group, and clinical scores reduced significantly more rapidly in the cefquinome-treated group.
Mortality rates were 24% in the cefquinome treated group and 33% in the amoxycillin group. Piglets with abnormal demeanour, paralysis, paddling, or four or more abnormal values of the six clinical signs measured were less likely to survive or be cured. A variety of bacteria were isolated from the central nervous systems of the piglets at necropsy, including S. suis. Cefquinome once daily for three to five days is an effective treatment for bacterial meningitis in piglets.Order:
THE INFLUENCE OF LACTATION LENGTH ON THE OCCURRENCE OF NON-INFECTIOUS REPRODUCTIVE FAILURE IN A LARGE COMMERCIAL HERD
p.42-52
Authors: K. Van Gelder and G. Bilkei
Abstract
The trial was conducted on an East European breeding company farm with 5600 sows. Based on length of lactation, a large number of healthy, parity 2-5 sows were randomly assigned to 9 different weaning age groups (weaning at 5- 7; 8-10; 11-13; 14-16; 17-19; 20-22; 23-25; 26-28 or 29-35 days).The parameter: A: "regular returns to oestrus," B: "irregular returns to oestrus," C: "anoestrus," and D: "other reproduction related reasons of reproduction failure (RF)/culling," were evaluated.
Compared with those lactating 17-19 days, sows lactating 5- 7, 8-10 or 11-13 days had a higher (P<0.01) proportion of "regular returns to oestrus," "irregular returns to oestrus" and "anoestrus." These parameters had a tendency to decrease as lactation length increased. Sows with lactation lengths of 20-22 and 26-28 days showed significantly less (P<0.05) anoestrus when compared to the sows lactating 17-19 days. Sows lactating 14-16 days had a significantly higher (P<0.01) proportion of animals returning to oestrus due to "other reproduction related reasons of RF/culling."
Anoestrus was found in 20.62 % of RF cases. No oestrus was shown in 17.14 % of sows in the <16 days weaning groups but only 3.48 % of sows weaned >20 days had anoestrus. Sows weaned >20 days showed markedly higher "other reproduction related reasons of RF/culling" than sows weaned at <16 days of lactation.
The results indicate that in healthy sows in this unit, a lactation length of 17-19 days compared with shorter lactation lengths, results in lower RF rates.Order:
RISK ASSESSMENT - CAMPYLOBACTER INFECTION TRANSMISSION FROM PIGS TO MAN USING ERYTHROMYCIN RESISTANCE AS A MARKER
p.53-58
Author: D.G.S. Burch
Abstract
The transmission of campylobacter infections from meat to man is considered one of the major routes of spread, along with water contamination, of this increasingly common form of infectious intestinal disease. To make a risk assessment of the likely transmission from pigs to man, a database was established from a variety of references, as there was much variation in the data and few were sufficiently complete to allow for a quantitative assessment to be made. It was noted that erythromycin resistance was very high in pigs for both C. jejuni and C. coli in comparison with man and chicken, thought to be one of the major sources of infection and that this would act as a possible marker to determine the transmission rate of campylobacter spp. from pigs to man.
There was no evidence of transmission of C. jejuni from pigs to man, as the organism was rarely isolated in pigs (4%) in comparison with chicken (90%) and man (92%) and erythromycin resistance rates were very low at 2% in man, in chicken (4%) and 35% in pigs. With regard to C. coli, isolation in pigs is very high (96%) but low in chicken (10%) and man (8%) and erythromycin resistance in man (15%) is similar to chickens (15%) but much lower than in pigs (57%). This confirms that pig meat and environmental contamination by slurry/waste from pigs can be considered either a no risk or very low potential risk in the transmission of campylobacter infections to man and therefore also a no risk or very low risk in the transmission of antimicrobially resistant strains to man.Order:
PASSIVE TRANSFER OF MATERNAL ANTIBODIES TO PCV2 PROTECTS AGAINST DEVELOPMENT OF POST-WEANING MULTISYSTEMIC WASTING SYNDROME (PMWS): EXPERIMENTAL INFECTIONS AND A FIELD STUDY
p.59-67
Authors: G.M. Allan, F. McNeilly, I. McNair, B. Meehan, M. Marshall, J. Ellis, C. Lasagna, G. Boriosi, S. Krakowka, G. Reynaud, L. Boeuf-Tedeschi, M. Bublot and C. Charreyre
Abstract
The results of an experimental infection study and a field trial to elucidate the effects of natural passive transfer of antibodies to PCV2 in colostrum to piglets on the development of clinical PMWS are reported. In the experimental disease model, suckled piglets derived from sows with high serum antibodies to PCV2 were protected against PMWS, but not infection with PCV2 following exposure to a cell culture grown isolate of PCV2. Piglets derived from sows with low levels of serum antibody to PCV2 were not protected against PMWS. In the field trial, serum antibody levels to PCV2 were determined in 8 randomly selected sows/gilts on a PMWS-affected farm and the progeny from these animals individually tagged, bled at 3 days of age and monitored for disease until 12-13 weeks of age.
Diagnosis of PMWS was based on clinical signs, histological lesions and the demonstration of an abundance of PCV2 antigen associated with these lesions. None of the 36 piglets derived from 3 mothers with PCV2 serum antibody levels of >1/1280 developed PMWS. Six piglets derived from two mothers with PCV2 serum antibody levels of 1/50 and four piglets derived from 3 mothers with PCV2 serum antibody levels of 1/250-1/500 developed PMWS.Order:
THE "PORCINE INTESTINAL DISTENSION SYNDROME"
p.68-82
Authors: J.R. Buddle and D.E. Twomey
Abstract
There are several gastro-intestinal accidents and haemorrhagic diseases in pigs that cause 'sudden' death. There has been some confusion about the definition of and relationship between these diseases. One, the porcine intestinal distension syndrome (PIDS), previously called "intestinal haemorrhage syndrome," should be recognised as a distinct syndrome. It occurs most frequently in pigs aged 2-6 months, and is characterised by a short clinical course of abdominal distension with associated discomfort. A small proportion of affected pigs die because the extreme distension causes asphyxiation. 'Sudden death' may be the first indication of the disease. At necropsy, there is a pale carcase and abdominal distension. The distended intestines (jejunum, ileum, caecum, and colon) bulge from the incised abdominal wall because of the pressure of the gas within them, and are markedly reddened because of congestion and/or haemorrhage by diapedesis (but not because of haemorrhage by rhexis). The wall of the ileum is thin. Inflammation is absent. Stomach and duodenum are normal. Usually, there is a clockwise (anti-clockwise when viewed from the ventral aspect) torsion of the whole jejunum, ileum, caecum, and colon. The torsion is easy to miss and should be specifically looked for. The stomach is normal and usually full of feed.
The cause of PIDS is unknown but observations suggest that, contrary to some previous reports, excessive gas production precedes venous congestion, and that knowledge of the disease will be advanced by studying the cause of excessive gas production in the caudal intestine.Order:
THE DURATION OF IMMUNITY AFTER VACCINATION WITH A SINGLE DOSE MYCOPLASMA HYOPNEUMONIAE VACCINE AND THE EFFECT OF SEROLOGICAL STATUS ON LUNG LESION SCORES
p.83-92
Authors: A. Dawson, S. Thevasagayam, J. Sherington, J.D. Mackinnon, L.P. Stipkovits and A.R. Peters
Abstract
The duration of immunity induced by a single dose Mycoplasma hyopneumoniae vaccine (StellamuneÔ Once) was investigated in pigs vaccinated at approximately 3 and 5 weeks of age. Liveweight gains, coughing rates and lung lesions at post-mortem examination were compared between controls and vaccinates challenged at approximately 21 and 26 weeks of age. Three of four vaccinated groups showed significant reductions in lung lesions (55-86%) compared with their contemporary controls. In a fourth comparison, the induced lung lesion scores in the controls were relatively low and the reduction was not statistically significant in the vaccinates (4.4 vs 1.1%; P<0.07).
There were significant beneficial effects on liveweight gain and coughing rate in 2/4 vaccinated groups. In a second study, the lung lesion response to vaccination was assessed in groups of seronegative and seropositive pigs 4 weeks after challenge. Overall, there were significant reductions of 50-60% in lung lesion scores in vaccinates compared with controls <0.05). The interaction between serological status and vaccination was not significant (P=0.3) showing that the effects of vaccination were not influenced by the presence of maternal antibody. It is concluded that the vaccine confers a duration of immunity of up to 23 weeks and that protection can be induced in the presence of maternally derived serum antibodies.Order:
| Short Communication |
COMPARISON OF EFFICACY AND COSTS BETWEEN REAL TIME ULTRASONOGRAPHY (RTU) AND GONADOTROPIN ESTIMATION FOR PREGNANCY DIAGNOSIS
p.93-100
Authors: D. Kruger and G. Bilkei
Abstract
In a large pig production unit, two methods of early pregnancy diagnosis between days 16-19 of pregnancy were compared. In Group one (246 sows): the sows were trans-rectally pregnancy tested at day 16-19 post-mating (PM) with real time ultrasonography (RTU). Pregnancy was confirmed either by visualising embryonic vesicles, embryos or corpora lutea. Sows tested non-pregnant received a gonadotropin injection (PG 600â Intervet, Munich, Germany) immediately after testing. At subsequent oestrus, these animals were artificially inseminated (AI) on three consecutive days. Sows in Group two (201) received one injection of gonadotropin (PG 600â Intervet, Munich) on day 17 PM. When showing subsequent oestrus, they received AI in the same way as the animals in group one.
The following parameters were evaluated:The time allotted showed marked differences between the groups (group one 8.4 minutes vs. group two 0.4 minute per sow). The accuracy of pregnancy diagnosis did not differ significantly between the groups (group one revealed 17 (6.9%), group two 13 (6.4%) non-pregnant sows. Subsequent farrowing rate did not differ significantly between the groups. Although both RTU and gonadotropin-performed pregnancy diagnosis result in similar results, the gonadotropin-performed pregnancy diagnosis is cheaper as it requires less labour and time.
A: time allotted for treating a sow.
B: accuracy of pregnancy diagnosis.
C: subsequent farrowing rate.
Order:
Proceedings Section This section includes the Proceedings of the Pig Veterinary Society meeting held at Burleigh Court, Loughborough, on 23rd and 24th May 2002 VETERINARY SURVEILLANCE - WHAT WE REQUIRE
p.101-105
Author: R. Hancock
Abstract
This paper sets out the Veterinary Laboratories Agency's (VLA) veterinary surveillance objectives against the background of Government objectives. It highlights the importance of so-called "passive" surveillance in detecting outbreaks of disease. It introduces the concept of a "pyramid of scrutiny" which is needed to ensure that the competent authority, charged with national disease control, is made aware of outbreaks of new or emerging diseases occurring on livestock farms. The importance of the existence of a synergistic relationship between farmers, their veterinary surgeons and diagnostic laboratories is emphasised.Order:
DISEASE SURVEILLANCE WHAT DO BREEDING COMPANIES REQUIRE?
p.106-110
Author: R.A. Potter
Abstract
Genetic improvement made by the Breeding Companies needs to be protected, if all its benefits are to be realised. This puts extra emphasis on disease prevention and, in turn, the necessity for high standards of biosecurity throughout the whole of the livestock industry. The author re-examines the basics of such control systems and draws on the failures, which occurred with regard to the spread of Foot and Mouth Disease (FMD) and, prior to that, with the re-emergence of Sheep Scab, to illustrate his points.Order:
SURVEILLANCE: WHAT WE REQUIRE THE MEAT AND LIVESTOCK COMMISSION
p.111-118
Author: D. Armstrong
Abstract
Monitoring and surveillance of animal disease is of national socio-economic importance because of the potential impact of disease-causing and zoonotic organisms on animal health, animal welfare and food safety and because of the impact that disease problems have on the economic viability of the pig production units. National legislation is the basis for surveillance and control of notifiable diseases; but there is heavy reliance on passive surveillance for the detection of new outbreaks. There is no national strategy for monitoring and surveillance of non-notifiable diseases and an absence of co-ordinated strategies to improve the overall health status of the national pig herd. Improvements in this area would lead to better animal welfare and to cost savings through more efficient production.
There is consumer pressure for high standards of animal welfare and food safety. The farm assurance schemes in Great Britain provide an effective monitoring and surveillance system for compliance with animal welfare standards. The British pig industry is committed to a proactive whole chain approach to food safety and is introducing a Salmonella monitoring programme as part of its risk reduction strategy. Monitoring and surveillance systems require commitment and involvement of all stakeholders; but it is important that they are properly resourced and integrated in co-ordinated risk reduction strategies.Order:
POST-WEANING MULTISYSTEMIC WASTING SYNDROME (PMWS) - TWO POINTS OF INTEREST
a. The role of Parvovirus
b. A case of Post-weaning Multisystemic Wasting Syndrome (PMWS) in unvaccinated pigs
p.119-123
Author: W.A. Nash
Abstract
The value of serology and the use of vaccines in the control of Porcine Parvovirus (PPV), together with its possible impact on other disease entities, are discussed by the author and the paper concludes with the description of a case of Post-weaning Multisystemic Wasting Syndrome (PMWS) in an unvaccinated herd.Order:
POST-WEANING MULTISYSTEMIC WASTING SYNDROME (PMWS) IN FRANCE: SEROLOGICAL PROFILES OF AFFECTED VERSUS NON-AFFECTED HERDS AND PRELIMINARY ANALYTICAL EPIDEMIOLOGY
p.124-134
Authors: N. Rose, P. Blanchard, G. Larour, G. Le Diguerher, E. Eveno, J.P. Jolly, A. Oger, M. Le Dimna, A. Jestin and F. Madec
Abstract
The serological characteristics of Post-weaning Multisystemic Wasting Syndrome (PMWS) affected and non-affected farms were studied through a case/control survey. This study involved 138 farrow-to-finish farms located in France and selected according to their PMWS status defined according to mortality rate, clinical observations and laboratory findings. Blood samples were taken from different categories of pigs including sows and growing pigs and several serological analyses were carried out for Porcine Circovirus type 2 (PCV-2), PRRS virus, parvovirus, influenza viruses and Lawsonia intracellularis antibody detection. The serological profile of the farm was related to the PMWS status with a multivariate logistic regression model.
It came out that PMWS farms were characterised by a higher seroprevalence for PCV-2 in growing pigs at the beginning of the fattening period and a lower seroprevalence in young sows. A strong association was found between PRRS virus and parvovirus active circulation in the herd. A quantitative variation in expression of the disease was observed, suggesting the need for the next analysis of the circumstances related to the syndrome.Order:
POST-WEANING MULTISYSTEMIC WASTING SYNDROME (PMWS) - FIELD OBSERVATIONS IN SPANISH HERDS
p.135-142
Author: E. Marco
Abstract
The aetiology of PMWS is still not completely clear. Clinical signs and lesions observed in affected farms are variable, but some of them are repeatable in all cases. Some of these signs and lesions are characteristic of a Porcine Circovirus type II, and they can be reproduced in experimentally infected pigs, but some of them would indicate the presence of congestive heart failure in affected animals. The heart function is altered, as could be detected through ultrasound scanning and Doppler technology. Myocarditis seems to be a common histological finding in such animals and this could be a primary cause of congestive heart failure. Myocarditis and lymph node enlargement are also found in one week-old piglets which would be an indication of an early infection. Different control strategies and treatments are described.Order:
DANISH VIEWS ON CURRENT PIG PRACTICE
p.143-147
Author: J. Lindahl
Abstract
This paper sets out the experiences of a Danish pig specialist, highlighting many of the problems faced in practice and relating them to (a) the measures taken nationally, through Government legislation, and (b) procedures adopted in the field.Order:
RECENT DEVELOPMENTS IN PIG IMMUNOLOGY
p.148-156
Authors: M. Bailey, S. Wilson, K. Haverson and C. Stokes
Abstract
The basic mechanisms and intricacies of the immune systems of vertebrate animals form the introduction to this comprehensive paper. Studies by the authors and others into the acquisition and true role of active and passive immunities in the pig are described in detail, with particular reference to the overlapping status of both dam and progeny in the building up of overall disease resistance. The problem of allergic diseases in humans, relating to immune dysregulation is also described, as are the diseases in growing pigs, also linked to such dysregulation.Order:
THE PIG LUNG - TARGET AND DEFENCE
p.157-161
Author: N. Stockhofe-Zurweiden
Abstract
Although remarkable progress has been achieved in combating infectious diseases in the last century, pneumonia continues to be one of the most important diseases in farm animals. In a recent German study of pigs sent for post-mortem, about forty percent of the cases had pneumonia, which was the same level as 50 years ago. Hence, a thorough investigation into the microbial and environmental factors affecting the lungs and a knowledge of the pathogenesis of associated diseases are necessary if better preventive strategies are to be evolved. This presentation focuses on the lower respiratory tract and the innate defence systems of the lung. Different examples will show the effects of environmental factors and micro-organisms on structure and function of the lower respiratory tract.Order:
General Section
THE 17TH IPVS CONGRESS, AMES, JUNE 2-5 2002 - A PERSONAL REVIEW
p.162-173
Author: S.H. Done
Order:
Members' Papers
PORCINE RESPIRATORY DISEASE COMPLEX (PRDC)
p.174-196
Author: S.H. Done
Abstract
This is a detailed, comprehensive paper outlining the history of Porcine Respiratory Disease Complex (PRDC), the delicate juxtaposition and interaction of its possible viral and bacterial components and the necessary steps that need to be taken, i.e. therapeutic, vaccinal, managemental and environmental, to control its severity and movement within an infected herd.Order:
PORCINE CIRCOVIRUSES AND POST-WEANING MULTISYSTEMIC WASTING SYNDROME (PMWS): FACTOIDS
p.197-220
Authors: S.H. Done, A. Cook and A.C.J. Gresham
Abstract
The purpose of this short paper is to review what is known and not the myths surrounding PMWS. The facts are presented in the form of tables. The most common differential diagnosis of PMWS is Porcine Respiratory Disease Complex (PRDC) due to PRRSV and M.hyopneumoniae (M.hyo). Some authors have also implicated PCV-2 and opportunistic bacteria, and many authorities would now consider PRDC and PMWS as part of a continuing spectrum of disease (Thacker, 2001).Order:
