Relationships between behavioral and meat quality characteristics of pigs raised under barren and enriched housing conditions.

In this study the effects of barren vs enriched housing conditions of pigs on their behavior during the lairage period (2-h holding period before slaughter), carcass characteristics, postmortem muscle metabolism, and meat quality were studied. The barren housing system was defined by common intensive housing conditions (i.e.

Assessment of protective efficacy of live and killed vaccines based on a non-encapsulated mutant of Streptococcus suis serotype 2.

The protective efficacy of a live and killed non-encapsulated isogenic mutant of Streptococcus suis serotype 2 was determined in pigs, and compared with the efficacy of the capsulated wild-type strain. SPF pigs were vaccinated twice intramuscularly at 4 and 7 weeks of age with a dose of 1 x 10(9) formalin-killed CFU of the wild-type (WT-BAC), formalin-killed non-encapsulated mutant (CM-BAC) or live non-encapsulated mutant (CM-LIVE) strain. After 2 weeks, vaccinated pigs and non-vaccinated controls were challenged intravenously with 1 x 10(7) CFU of the homologous, wild-type S.

Rescue of infectious bursal disease virus from mosaic full-length clones composed of serotype I and II cDNA.

Infectious Bursal Disease Virus (IBDV) is the causative agent of one of the most important and wide-spread infectious diseases among commercial chicken flocks. IBDV causes a depletion of B-lymphoid cells in the bursa of Fabricius, inducing immunosuppression, morbidity, or even acute mortality. Because currently used live IBDV vaccines are derivatives from field isolates no serologic discrimination between field isolates and live vaccines can be made.

Determination of the circadian rhythm in plasma corticosterone and catecholamine concentrations in growing broiler breeders using intravenous cannulation.

This paper describes a fast and simple technique for cannulation of the vena cutanea ulnaris (wing vein) in ad libitum fed growing broiler breeders of 5 weeks of age. Twenty-four hours after cannulation, blood was sampled every 4 h during 24 h. The circadian rhythm in plasma corticosterone and catecholamine concentrations was determined for the first time in growing broiler breeders.

Genetic correlations among body condition score, yield, and fertility in first-parity cows estimated by random regression models.

Twenty type classifiers scored body condition (BCS) of 91,738 first-parity cows from 601 sires and 5518 maternal grandsires. Fertility data during first lactation were extracted for 177,220 cows, of which 67,278 also had a BCS observation, and first-lactation 305-d milk, fat, and protein yields were added for 180,631 cows. Heritabilities and genetic correlations were estimated using a sire-maternal grandsire model.

Translocation activity of C-terminal domain of pestivirus Erns and ribotoxin L3 loop.

The pestivirus envelope glycoprotein E(rns) has RNase activity and therefore was suspected to enter cells to cleave RNA. The protein contains an RNase domain with a C-terminal extension, which shows homology with a membrane-active peptide. The modular architecture and the C-terminal homology suggested that the C terminus could be responsible for the presumed translocation.

The role of the individual amino acids of a GnRH-tandem-dimer peptide used as an antigen for immunocastration of male piglets determined with systematic alanine replacements.

Immunocastration targeting gonadotropin releasing hormone (GnRH) can be obtained in male piglets using native GnRH conjugates. However, due to insufficient efficacy of these conjugates, improved GnRH antigens, like peptides existing of repeats of the GnRH amino acid sequence, have been designed. We previously reported about a dimerised GnRH-tandem peptide with a D-Lys at position 6 of the native GnRH sequence (G6k-TD) being highly effective.

Respiratory and systemic humoral and cellular immune responses of pigs to a heterosubtypic influenza A virus infection.

The level of heterosubtypic immunity (Het-I) and the immune mechanisms stimulated by a heterosubtypic influenza virus infection were investigated in pigs. Pigs are natural hosts for influenza virus and, like humans, they host both subtypes H1N1 and H3N2. Marked Het-I was observed when pigs were infected with H1N1 and subsequently challenged with H3N2.

Viable porcine arteriviruses with deletions proximal to the 3' end of the genome.

In order to obtain attenuated live vaccine candidates of porcine reproductive and respiratory syndrome virus (PRRSV), a series of deletions was introduced at the 3' end of the viral genome using an infectious cDNA clone of the Lelystad virus isolate. RNA transcripts from the full-length cDNA clones were transfected into BHK-21 cells. The culture supernatant of these cells was subsequently used to infect porcine alveolar macrophages to detect the production of progeny virus.

Evaluation of diagnostic tests for the detection of classical swine fever in the field without a gold standard.

Knowledge of the sensitivity of diagnostic tests for infectious diseases under field conditions can be used to design a surveillance program that increases the effectiveness of the control policy. In this study, the sensitivity of tests for the detection of classical swine fever (CSF) virus (CSFV) under field conditions was estimated without knowledge of the true disease status of the animals tested. During the CSF epidemic of 1997-1998 in The Netherlands, tonsil samples from pigs of CSF suspect farms were collected for laboratory diagnosis of CSE These specimens were tested in a fluorescence antibody test (FAT1) for the presence of CSFV antigen.

Differentiation of Campylobacter species by AFLP fingerprinting.

The fluorescent amplified fragment length polymorphism (AFLP) fingerprinting method was tested for its ability to identify and subtype the most important Campylobacter species found in veterinary infections. Sixty-nine reference strains and 19 clinical isolates of Campylobacter jejuni subsp. jejuni, Campylobacter jejuni subsp.

The nature of the bond between peptide and carrier molecule determines the immunogenicity of the construct.

The influence of the nature of the bond between a peptide and a (lipidic) carrier molecule on the immunogenicity of that construct was investigated. As types of bonds a thioester-, a disulfide-, an amide- and a thioether bond were investigated. As carrier molecules a peptide, an N-palmitoylated peptide or a C(16)-hydrocarbon chain were used.

Definition of neutralizing sites on African horse sickness virus serotype 4 VP2 at the level of peptides.

The antigenic structure of African horse sickness virus (AHSV) serotype 4 capsid protein VP2 has been determined at the peptide level by PEPSCAN analysis in combination with a large collection of polyclonal antisera and monoclonal antibodies. VP2, the determinant for the virus serotype and an important target in virus neutralization, was found to contain 15 antigenic sites. A major antigenic region containing 12 of the 15 sites was identified in the region between residues 223 and 400.

Interaction of classical swine fever virus with membrane-associated heparan sulfate: role for virus replication in vivo and virulence.

Passage of native classical swine fever virus (CSFV) in cultured swine kidney cells (SK6 cells) selects virus variants that attach to the surface of cells by interaction with membrane-associated heparan sulfate (HS). A Ser-to-Arg change in the C terminus of envelope glycoprotein E(rns) (amino acid 476 in the open reading frame of CSFV) is responsible for selection of these HS-binding virus variants (M. M.

Analysis of the quality of protection induced by a porcine influenza A vaccine to challenge with an H3N2 virus.

Antigenic drift of swine influenza A (H3N2) viruses away from the human A/Port Chalmers/1/73 (H3N2) strain, used in current commercial swine influenza vaccines, has been demonstrated in The Netherlands and Belgium. Therefore, replacement of this human strain by a more recent swine H3N2 isolate has to be considered. In this study, the efficacy of a current commercial swine influenza vaccine to protect pigs against a recent Dutch field strain (A/Sw/Oedenrode/96) was assessed.

Active surveillance of BSE in cattle in The Netherlands.

Since January 2, 2001 a large-scale active surveillance programme for BSE started in the Netherlands in addition to the passive surveillance programme of cattle with clinical symptoms compatible with BSE. Based on decisions of the Council of European Ministers of Agriculture, the European Union launched an active surveillance system for BSE in cattle of 30 months and older. Until April 1, more than 100,000 head of cattle were tested in this scheme, including all cattle slaughtered and a large part of the cattle that died on the farm.

Present and future of veterinary viral vaccinology: a review.

This review deals briefly with some key developments in veterinary vaccinology, lists the types of vaccines that are used for vaccinations commonly performed in food animals as well as in companion animals, and indicates that the practising veterinarian can select the best vaccine by comparing the results of efficacy studies. Diva (Differentiating Infected from Vaccinated Animals; also termed marker) vaccines and companion diagnostic tests have been developed that can be used for progammes aimed to control or eradicate virus infections. Vaccine-induced herd immunity, which can be measured relatively easily when diva vaccines are used, is a crucial issue in such programmes.

Adaptation to social isolation. Acute and long-term stress responses of growing gilts with different coping characteristics.

The present experiment studied the acute and long-term stress responses of reactive and proactive prepubertal gilts to social isolation. Gilts with either reactive or proactive features were identified according to behavioral resistance in a backtest at a young age (2-4 days), respectively being low (LR) and high resistant (HR) in this test. At 7 weeks of age, 12 gilts of each type were socially isolated.

Minimization of rate of inbreeding for small populations with overlapping generations.

We propose a method that minimizes the rate of inbreeding (delta F) for small unselected populations with overlapping generations and several reproductive age classes. It minimizes the increase in coancestry of parents and optimizes the contribution of each selection candidate. The carrying capacity of the population is limited to a fixed number of animals per year.

Detection of bovine herpesvirus 4 glycoprotein B and thymidine kinase DNA by PCR assays in bovine milk.

A polymerase chain reaction (PCR) assay was developed to detect bovine herpesvirus 4 (BHV4) glycoprotein B (gB) DNA, and a nested-PCR assay was modified for the detection of BHV4 thymidine kinase (TK) DNA in bovine milk samples. To identify false-negative PCR results, internal control templates were constructed, added to milk samples, and co-amplified with viral DNA using the same primers for both templates. Specificity, sensitivity, and reproducibility of the two PCR assays were examined.

Comparison of RNA and cDNA transfection methods for rescue of infectious bursal disease virus.

Specific alterations in the genetic material of RNA viruses rely on a technique known as reverse genetics. Transfection of cells with the altered generic material is a critical step of this procedure. In this report we have compared RNA and cDNA transfection methods for the efficiency of transient protein expression and rescue of (recombinant) infectious bursal disease virus (IBDV).

Transgenesis may affect farm animal welfare: a case for systematic risk assessment.

This paper considers (potentially) harmful consequences of transgenesis for farm animal welfare and examines the strategy of studying health and welfare of transgenic farm animals. Evidence is discussed showing that treatments imposed in the context of farm animal transgenesis are by no means biologically neutral and may compromise animal health and welfare. Factors posing a risk for the welfare of transgenic farm animals include integration of a transgene within an endogenous gene with possible loss of host gene function (insertional mutations), inappropriate transgene expression and exposure of the host to biologically active transgene-derived proteins, and in vitro reproductive technologies employed in the process of generating transgenic farm animals that may result in an increased incidence of difficult parturition and fetal and neonatal losses and the development of unusually large or otherwise abnormal offspring (large offspring syndrome).

Disease-induced variability of genetic correlations: ascites in broilers as a case study.

Breeding against a production disease is complicated by multiple relationships between productivity, disease, and environment. Ascites in broilers is such a disease. The combination of the reasonably well understood etiology (a physiological/pathological cascade due to inadequate oxygen supply) and the practical relevance makes ascites a relevant case for demonstrating and partly revealing these complex relationships.

Persistence of herpesvirus of eel Herpesvirus anguillae in farmed European eel Anguilla anguilla.

Herpesvirus of eel Herpesvirus anguillae (HVA) was isolated repeatedly from farmed eel of an outwardly healthy stock, but virus isolation was much greater in an experimental group of fish that were injected with dexamethasone. The results suggest that HVA can establish a latent infection in eel. Previous exposure of these eels to HVA virus was shown by detection of HVA-specific antibodies.