Treatment randomisation at animal or pen level? : Statistical analysis should follow the randomisation pattern!

Random treatment assignment is essential in demonstrating a causal relationship between a treatment and the outcome of interest. Randomisation ensures that animals assigned to different treatment groups do not differ from each other systematically, except for the randomly assigned treatment. The randomisation pattern should also dictate the statistical analysis.

Vaccination with an F4/F18 Vaccine Improves Piglet Performance Combined with a Reduction in Antimicrobial Use and Secondary Infections Due to .

Post-weaning diarrhea (PWD) due to () remains a major cause of economic losses for the pig industry. Therapy to combat PWD typically consists of antibiotic treatment or supplementation of zinc oxide to the feed. The emergence of antimicrobial resistance to and new EU regulations prompt the need for alternative control strategies, such as immunization.

Seasonal Variation in Prevalence of and Other Respiratory Pathogens in Peri-Weaned, Post-Weaned, and Fattening Pigs with Clinical Signs of Respiratory Diseases in Belgian and Dutch Pig Herds, Using a Tracheobronchial Swab Sampling Technique, and Their Associations with Local Weather Conditions.

Besides (), many other viruses and bacteria can concurrently be present in pigs. These pathogens can provoke clinical signs, known as porcine respiratory disease complex (PRDC). A sampling technique on live animals, namely tracheobronchial swab (TBS) sampling, was applied to detect different PRDC pathogens in pigs using PCR.

Supplementation of a β-mannanase enzyme reduces post-weaning diarrhea and antibiotic use in piglets on an alternative diet with additional soybean meal.

Enzyme supplementation with a β-mannanase to degrade β-mannan fibers present in the diet has been shown to restore and improve performance in swine. The current study was conducted on a farm which had historical episodes of post-weaning diarrhea. In total, 896 newly weaned piglets were enrolled in two consecutive trials.

Short communication: J-5 Escherichia coli vaccination does not influence severity of an Escherichia coli intramammary challenge in primiparous cows.

The objective of the present study was to evaluate the efficacy of a J-5 Escherichia coli vaccine in a mild to moderate inflammatory challenge model using primiparous dairy cows for inoculation only. We hypothesized a clinical difference between placebo and J-5 E. coli vaccinated animals with the mild to moderate inflammatory challenge model.

Evaluation of a zinc chelate on clinical swine dysentery under field conditions.

Background: is the primary cause of swine dysentery, characterized by bloody to mucoid diarrhea due to mucohaemorhagic colitis in pigs and primarily affects pigs during the grow/finishing stage. Control and prevention of consists of administration of antimicrobial drugs, besides management and adapted feeding strategies. A worldwide re-emergence of the disease has recently been reported with an increasing number of isolates demonstrating decreased susceptibility to several crucially important antimicrobials in the control of swine dysentery.

Use of trachea-bronchial swab qPCR testing to confirm seropositivity in an SPF breeding herd.

Background: A dedicated program to monitor for freedom of several economically important diseases is present within most of the breeding companies that currently deliver high health breeding animals to their customers. Serology is therefore the preferential approach in order to screen for most of these diseases, including (). However, in case of positive serology, further decisions on farm health status and the related consequences should be based on additional confirmation tests.

Good vaccination practice: it all starts with a good vaccine storage temperature.

Background: Recent introduction of strategies to reduce antibiotic use in food animal production implies an increased use of vaccines in order to prevent the economic impact of several important diseases in swine. Good Vaccination Practice (GVP) is an overall approach on the swine farm aiming to obtain maximal efficacy of vaccination through good storage, preparation and finally correct application to the target animals. In order to have a better insight into GVP on swine farms and the vaccine storage conditions, a survey on vaccination practices was performed on a farmers' fair and temperatures in the vaccine storage refrigerators were measured during farm visits over a period of 1 year.

Prevalence of virulence factors in enterotoxigenic isolated from pigs with post-weaning diarrhoea in Europe.

Background: Post-weaning diarrhoea (PWD), due to , is an important cause of economic losses to the pig industry primarily as a result of mortality and worsened productive performance. In spite of its relevance, recent data about the prevalence of virulence genes and pathotypes among isolates recovered from cases of PWD in Europe are scarce.

Results: This study investigates the prevalence of fimbrial and toxin genes of by PCR among 280 farms with PWD across Europe.

An evaluation of gonadotropin-releasing hormone analogue administered to gilts and sows on subsequent reproductive performance and piglet birth weight.

Background: The present study investigated the effect of peforelin (Maprelin®), a gonadotropin-releasing hormone (GnRH) analogue, administration in gilts, primiparous and pluriparous sows in a high productive farm on sow reproductive performance and piglet quality at birth.

Methods: In a 400 sow herd, gilts, primiparous and pluriparous sows were randomly allocated to 2 groups: peforelin treated (peforelin = P-group) or no treatment (control = C-group). Animals were injected 48 h after the last altrenogest treatment (gilts) or 24 h post weaning (sows).

Assessment of litter prevalence of Mycoplasma hyopneumoniae in preweaned piglets utilizing an antemortem tracheobronchial mucus collection technique and a real-time polymerase chain reaction assay.

The swine industry currently lacks validated antemortem methods of detecting baseline herd prevalence of Mycoplasma hyopneumoniae. The focus of our study was to evaluate alternative antemortem detection techniques and to determine baseline litter prevalence in preweaned pig populations utilizing the selected technique and a real-time polymerase chain reaction (qPCR) assay. Preliminary data was analyzed on weaned piglets with evidence of respiratory disease (n = 32).

Evaluation of a serodiagnostic test using Ascaris suum haemoglobin for the detection of roundworm infections in pig populations.

The significant economical consequences of infections with Ascaris suum in pigs are already well documented. However, due to the subclinical nature of the disease and the lack of practical diagnostic means, ascariasis often remains undiagnosed. Here we describe the development and evaluation of a novel indirect ELISA using the purified A.

Evaluation of the Salmonella surveillance program in Belgian pig farms.

Since July 2007, Belgium has implemented a national surveillance and control program for Salmonella in pigs. Pig farms are designated as Salmonella high risk farms based on serological profiles and are obliged to subsequently take part in a Salmonella specific action plan (SSAP). The SSAP was evaluated and potential risk factors for the persistence of Salmonella on the farm were investigated.

Arcobacter population dynamics in pigs on farrow-to-finish farms.

Healthy pigs are an important reservoir for the emerging human pathogen Arcobacter which can result in contamination of porcine carcasses and pork and the spread of arcobacters into the environment. Up to now, the excretion of arcobacters by pigs has been studied, but information about the transmission routes in fattening pigs is lacking. The present study aimed to elucidate the Arcobacter population dynamics in pigs during the fattening period on four farrow-to-finish farms.

The effect of an experimentally induced acute mastitis on the test results of an Ostertagia ostertagi milk ELISA.

Antibody levels against Ostertagia ostertagi in the milk are a promising parameter to identify dairy cows or herds with production losses due to gastrointestinal nematodes. However, milk antibody levels can be influenced by udder-related factors. In this study, the effect of an experimentally induced mastitis on the test results (ODR) of a milk O.

Prevalence, enumeration and strain variation of Arcobacter species in the faeces of healthy cattle in Belgium.

Arcobacter species were isolated from faeces of healthy cattle on three unrelated Belgian farms, using a quantitative isolation protocol. Isolates were identified by m-PCR and characterized by modified ERIC-PCR. The Arcobacter prevalence on the three farms ranged from 7.

Occurrence and strain diversity of Arcobacter species isolated from healthy Belgian pigs.

In this study, Arcobacter species were isolated from clinically healthy porkers and sows on four unrelated pig farms, using a quantitative isolation protocol. Isolates were identified by m-PCR, and fingerprints were distinguished by modified ERIC-PCR. The prevalence of Arcobacter in pigs ranged from 16 to 85%.

Potential mechanism of action of J5 vaccine in protection against severe bovine coliform mastitis.

Coliform mastitis is one of the most difficult diseases to treat in the modern dairy industry. Curative therapy with antibiotics remains only moderately effective and depends on the stage at which the disease is treated. The most successful strategies for combating coliform mastitis appear to be prevention by hygienic management or prophylactic immunization.