Health advantages of transition to batch management system in farrow-to-finish pig herds

Sow batch management systems have become more popular due to advantages in labour planning, piglet batch sizes, all-in all-out practices and health management. The present study investigated the potential health advantages of 10 selected farrow-to-finish pig herds before and after transition from a one week batch management system to a four or five week batch management system. Five different animal categories (gilts, sows, piglets, growers and finishers) were sampled at three time points (T0, T1 and T2) before and after transition to a four or five week batch management system. Different matrices of the animals were collected: blood, nasal swabs and faeces. Several economically important diseases were monitored through serology: Lawsonia intracellularis, Porcine Reproductive and Respiratory Syndrome virus (PRRSv), Mycoplasma hyopneumoniae, Actinobacillus pleuropneurnoniae; and PCR-testing: Pasteurella multocida dermonecrotic toxin (DNT) and Brachyspira species, especially the major pathogenic Brachyspira hyodysenteriae. Following serological analysis, the percentage of positive animals per category and sampling occasion were calculated. Health improvement based on serology was defined as the reduction in the percentage of positive animals for a specific disease in a specified animal category. All samples were negative for P. multocida DNT and B. hyodysenteriae. Little to no improvement could be observed for PRRSv. For L. intracellularis an improvement could be observed in piglets (71%) and growers (56%; P < 0.05). For both of the respiratory pathogens, M. hyopneumoniae and A. pleuropneumoniae, significant improvement was observed in finishers (34 and 24%, respectively). In growers, only M. hyopneumoniae showed a significant improvement (34%). In conclusion, the transition from a one week batch management system to a four or five week batch management system in the present herds resulted in a reduction of the percentage of seropositive animals for three of the monitored economically important diseases: L. intracellularis, M. hyopneumoniae and A. pleuropneumoniae

Proteolysis in milk during experimental Escherichia coli mastitis

This work consisted of the intramammary infections (IMI) of 8 heifers by high doses of Escherichia coli to study both the proteolytic activity in milk and the resulting peptides. Therefore, a milking kinetic has been followed, and several parameters have been studied, such as proteose peptones ( PP) fraction ( quantitative and qualitative changes), plasmin activity (PA), milk somatic cell count (SCC), and bacterial count. A qualitative study of milk proteins and PP was performed by sodium dodecyl sulfate-PAGE, and the peptides recovered in PP during the acute phase of inflammation were amino-terminal micro-sequenced. A BSA increase in milk over time supported the hypothesis of an increase in the permeability of the epithelial barrier. A significant increase in PP content, considered to be an indicator of proteolysis, was observed from postinfusion hours (PIH) 12 to 48. Both the E. coli bacterial count and the SCC increased from PIH 3 to 216. Plasmin activity was increased noticeably from PIH 15 to 24. The respective increases in SCC, bacterial count, and PA suggest their involvement in a global mechanism responsible for the increase in proteolysis in milk after E. coli challenge. Somatic cell count and E. coli may be involved from PIH 3 to 216, and PA involvement might be highlighted during the maximum proteolysis, from PIH 15 to 24. A qualitative study of PP fraction by electrophoresis revealed the apparition of 5 peptide bands: P1 and P2 previously recovered during the lipopolysaccharide challenge, and E1 (27.0 kDa), E2 (15.5 kDa), and E3 (9.0 kDa) were specific to E. coli challenge; E1, E2, and E3 contained casein fragments. The roles played by leukocytes and E. coli are discussed

Hygienograms for evaluation of cleaning and disinfection protocols in pig facilities

Cleaning and disinfection (C&D) is already well established in the daily routine of modern Flemish pig herds. Correct application of cleaning and disinfection protocols is however not always performed. To evaluate the efficiency of the applied cleaning and disinfection protocols, the use of hygienograms - as already widely used in poultry - should be promoted. Therefore, a study was conducted by Animal Health Care Flanders and CID Lines to evaluate the relevance of a hygienogram scoring system in pigs following cleaning and disinfection according to the farmers\u27 routine procedures and a protocol as prescribed by CID Lines

The role of the infection status of sows on the assignment as Salmonella risk farm in the Belgian Salmonella control program

Salmonella surveillance and control programs arc generally based on results of samples taken from the fattening pigs and intervention measures are limited to the fattening unit. To evaluate the role of the sows in the assignment as Salmonella risk herd we compared the serological status from sows at risk herds to the status of sows at non-risk farms. From this study it is clear that the role of the sows and their serological Salmonella status is a potential influencing factor for the assignment of Salmonella risk farms in the Belgian Salmonella control program, which is principally based on sampling of fattening pigs. More insight in the role of the sow as a reservoir for Salmonella infections might help to define important intervention measures at pre-harvest stage

Bacteriological prevalence in finishing pig farms assigned as Salmonella risk farms by serological screening

The Belgian Federal Agency for the Safety of the Food Chain (FASFC) installed a National Salmonella surveillance and control program in pigs, the Salmonella Action Plan (SAP), which became compulsory by means of a Royal act in July 2007. Assignment as Salmonella risk farm is based on serological analysis of blood samples collected from the fattening pigs. The knowledge of prevailing serovars of Salmonella by bacteriological methods is essential to develop and/or evaluate the serological method. In 57% of all the assigned farms, based on serological screening (~ mean SIP-ratio\u27s), there is \u27firm evidence\u27 by bacteriological isolation. This suggests that a sufficient correlation is achieved at herd level in the first stage of the Salmonella Action Plan

Effectiveness analysis of resistance and tolerance to infection

<p>Abstract</p> <p>Background</p> <p>Tolerance and resistance provide animals with two distinct strategies to fight infectious pathogens and may exhibit different evolutionary dynamics. However, few studies have investigated these mechanisms in the case of animal diseases under commercial constraints.</p> <p>Methods</p> <p>The paper proposes a method to simultaneously describe (1) the dynamics of transmission of a contagious pathogen between animals, (2) the growth and death of the pathogen within infected hosts and (3) the effects on their performances. The effectiveness of increasing individual levels of tolerance and resistance is evaluated by the number of infected animals and the performance at the population level.</p> <p>Results</p> <p>The model is applied to a particular set of parameters and different combinations of values. Given these imputed values, it is shown that higher levels of individual tolerance should be more effective than increased levels of resistance in commercial populations. As a practical example, a method is proposed to measure levels of animal tolerance to bovine mastitis.</p> <p>Conclusions</p> <p>The model provides a general framework and some tools to maximize health and performances of a population under infection. Limits and assumptions of the model are clearly identified so it can be improved for different epidemiological settings.</p