Cloning and expression of porcine complement C3d for enhanced vaccines

Posted in: Ontario Pork, Pork Insight Articles by admin on October 31, 2007 | No Comments

Young pigs have immature immune systems, this causes vaccines to have limited effects on neonatal piglets. Also after pigs ingest colostrum there immune system suppresses maternal antibodies. This creates a need for vaccines that can induce active immune responses in piglets before maternal antibodies decline to non-protective levels. Tests done on lab mice have shown that the complement component C3d has potent immune stimulating properties.  In addition, biochemical studies in lymphocytes suggest that C3d should block the suppressive effects of maternal antibodies, stimulating active immune responses. Researchers were able to clone the gene fragment coding for “porcine complement C3d” and have introduced modifications into the DNA sequence to allow expression of C3d in E. coli, for subsequent use in vaccines.

Aerosol transmission of PRRSV: Is it time to start watching the weather vane?

Posted in: Air Filtration, Pork Insight Articles by admin on October 30, 2007 | No Comments

The spreading of the PRRS virus has recently been assumed to travel further in cold weather conditions. This was proven in past experiments and has since been considered the meteorological factor involved in PRRS spreading. Although it is true that cold weather is a factor in the survival of the virus it may  not be the only factor. The tests done to uncover weather factors involved a swine operation which was PRRS positive and 3 outlying facilities located 120 meters away in the direction of the prevailing winds. Two conclusions drawn from the research was that the virus was aerosol transported in all months except August and July and parameters other than temperature were a factor. It was noticed that air spreading viruses occurred not only in the winter but in the spring and summer months of April, May, and June. Also, meteorological parameters such as wind direction, relative humidity, barometric pressure and ultraviolet light index were found to be significant predictors of the PRRS virus in air. Although more work is required to legitimize some of these findings, producers can take away that prevailing winds should be a factor when deciding where to build new facilities.

Lymphocyte contributions to altered endometrial angiogenesis during early and midgestation fetal loss

Posted in: Ontario Pork, Pork Insight Articles by admin on October 26, 2007 | No Comments

20-30% of fetuses are lost 15-30 days into gestation in pigs, and an additional 10-15% are lost in days 50-70. In mammals an uterine leukocyte (uNK) recruits during endometrial decidualization, and expand in early gestation, then decline mid-gestation. For humans and mice uNK produces HIF-1α, VEGF, and PIGF. In pigs, uNK is first detected at day 12, and is triggered by the attachment of conseptuses since the endometrium does not decidualize. This study aimed to determine if leukocytes like uNK can have a proangiogenetic result in mid-gestation, and to trace the difference between day 20 to 50. Proinflammatory cytokines (IFN-γ
and TNF-α) transcription levels were analyzed at gestation day 20 and 50, as these have been present when fetuses have been aborted. The transcription levels were compared between peri-implantation and mid-gestation pregnancy failures. The results found pig leukocytes produce VEGF and PlGF, like other mammals. PIGF aids in uNK maturation, which produce VEGF, and VEGF levels were higher at day 50 than 20 in healthy cells. Pregnancy failures corresponded with low levels of VEGF and HIF-1α transcription, but not with low levels of PIGF. Healthy sites transcribed IFN-γ
and TNF-α, a day 20 arrest had higher IFN-γ
transcripts, and day 50 arrests had a higher level of TNF-α. The implication of the results is that pig leukocytes play a role in angiogenesis until mid-gestation.

ACTUALlTE: EUROVENT : Les filtres 11 air mis a’ nus

Posted in: Air Filtration, Pork Insight Articles by admin on October 25, 2007 | No Comments

ACTUALlTE: EUROVENT : Les filtres 11 air mis it nus 1 2>t1Ql2oo7
• Oepuis revrier 2007, la filtration de “air a rejoint la grande majorite des composants et des ensembles aerauliques en adherant aun programme commun de certification des performances. Etre certifie Eurovent, constitue une garantie pour “utilisateur.
1. Ce que contrOle EUROVENT :
. Le programme de certification Eurovent couvrent les filtres a poches. les fillres compacts et les panneaux des classes FS a F9, testes selon la norme EN779 :2002.

Pilot Plant for Electrolytic Deodorization of Liquid Hog Manure

Posted in: Ontario Pork, Pork Insight Articles by admin on October 9, 2007 | No Comments

This project attempts to deodorize liquid hog manure by using direct-current electrolysis which was tested in a 1800 L pilot plant that was constructed. The project wanted to limit the smell and intensity of the manure while not eliminating it. The electrochemical cell had anodes that were titanium metal coated with a thin layer of iridium dioxide and it had cathodes made of steel grids. Two different electrode configurations were look at over six experiments each lasting a week. The electrolysis were initiated after filling the pilot plant and allowing it to equilibrate for several days, and the experiments were concluded by allowing the electrolyzed manure to stand without further treatment for 1 week, to demonstrate that the odour did not come back. All experiments were successful at meeting the criteria of reducing the odour from an “offensive smell” to a “barn odour”, the odour did not come back after 7-10 days, and bacteria that causes the odour was found to be reduced. The objectives of the experiment were met and further testing will be carried out in a on farm setting.

Evaluation of methicillin-resistant Staphylococcus aureus (MRSA) colonization in pigs and people that work with pigs in Ontario Veterinary College

Posted in: Ontario Pork, Pork Insight Articles by admin on September 22, 2007 | No Comments

Methicillin-resistant Staphylococcus aureus (MRSA) causes diseases in people and certain animals. It is called a ‘superbug’ because it is a bacterium that is highly resistant to drugs. Recent evidence out of Europe has found a link between carriage of MRSA in pigs and carriage by people who work with pigs. There is now evidence that MRSA may cause disease in pigs. This study looked at MRSA carriage by pigs and pig farmers. In the study MRSA was found on 45% of farms and 25% of pigs on those farms were carriages. Although non of the people or pigs studied were infected with MRSA. There is little risk of MRSA being transferred to people through consuming pork, but there is concerns for people  who come into contact with pigs. Europeans are concerned that pigs may be the cause of humans becoming infected with MRSA. There is little evidence about about the role of pigs in human disease in Canada, but this study has proven that there is a large amount of pigs who carry the disease. The findings of this study were unable to determine if the disease was always present and undetected or if it has recently emerged in pigs. MRSA may be a occupational hazard to pig farmers and people in contact with pigs although further study is required to determine if the concern is significant and how the risk should be handled.

SRRP performances d’un système de filtration d’air québécois

Posted in: Air Filtration, Pork Insight Articles by admin on August 28, 2007 | No Comments

Ne pas oublier que le bon sens devrait faire partie de l’équation.

On a passablement d’information sur la transmission de pathogènes par l’air et sur les systèmes de filtration.

MAIIS la localisation et l’application d’’une biosécurité effective et non “psychologique” est très importante.

Analysing Livestock Farm Odour Using an Adaptive Neuro-Fuzzy Approach

Posted in: Ontario Pork, Pork Insight Articles by admin on August 23, 2007 | No Comments

In this paper, a neuro-fuzzy-based method for analysing odour generation factors to the perception of livestock farm odour was proposed. The proposed approach incorporates neuro-adaptive learning techniques into fuzzy logic method. Rather than choosing the parameters associated with a given membership function by trail and error, these parameters could be tuned automatically in a systematic manner so as to adjust the membership functions of the input/output variables for optimal system performance. A multi-factor livestock farm odour model was developed, and both numeric factors and linguistic factors were considered. The proposed approach was tested with a livestock farm odour database.  It can incorporate non-numeric data and subjective human expert knowledge, which allows prior knowledge to be included in the model. In addition, the membership functions can be tuned during the learning according to input/output data to optimise performance. This feature is important as it can avoid inappropriate predetermination of membership functions, thus minimising errors resulting from the limited knowledge of the livestock farm odour system. A livestock farm database collected by our research team has been used in this study. The results show that the proposed approach is effective and provides a much more accurate odour prediction in comparison with a typical multi-layer feedforward neural network.

A Review of Molecular Contrasts Between Arresting and Viable Porcine Attachment Sites

Posted in: Pork Insight Articles, Production by admin on August 14, 2007 | No Comments

Significant spontaneous fetal loss of unknown cause occurs in North American commercial swine. About 30% of conceptuses, thought to be genetically normal, are lost during the peri-attachment period. An additional 20% are lost at mid-pregnancy. Littermate endometrial and trophoblast biopsies were studied by quantitative real-time PCR for gene expression, and immunohistochemistry for protein expression at gestation day (gd)15–23 and 50. RNA analyses were also conducted on endometrial lymphocytes and arterial endothelial cells removed from biopsies by laser capture microdissection. Genes were selected for study from human literature and cloned as required. As in humans, angiogenic, cytokine, chemokine and chemokine decoy receptor gene expression occurs at the porcine maternal–fetal interface. In each tissue studied, distinct patterns of expression are found between early and mid-pregnancy, as well as between viable and arresting conceptus attachment sites. These changes involve both endometrial lymphocytes and dendritic cells. Restriction in endometrial angiogenesis, reduction in expression of the chemokine decoy receptor D6, and reduction in dendritic
cell numbers contribute to fetal arrest. In peri-attachment loss, interferon- c is more abundantly transcribed than tumor necrosis factor-a, but this ratio is reversed during midgestation failure. Further characterization of spontaneous fetal loss in pigs will identify targets for modification by hog producers and may provide a model for identification of antecedents to fetal loss in humans.

Our studies also characterize spontaneous fetal loss in pigs as an excellent animal model to assist in understanding the maternal–fetal interactions leading to pregnancy failure in humans. We have found porcine and human endometria, as well as trophoblasts, express similar cytokines, chemokines, and chemokine decoy receptors. The large amount of material available for study from porcine attachment sites, the reliability of spontaneous fetal arrest and its consistency of timing, the accessibility to timed pregnant reproductive tracts, and the ability to conduct paired sampling of littermates with different survival potential are all strong features that should complement studies in patients where these features are limiting.

Nonruminant Nutrition symposium: Understanding protein synthesis and degradation and their pathway regulations

Posted in: Ontario Pork, Pork Insight Articles by admin on August 13, 2007 | No Comments

A review of papers published to follow-up on the corresponding presentations at the Nonruminant Nutrition Symposium, “Understanding protein syntheis and degradation and their pathway regulations,” held on June 10 2007 at the  annual meeting of the American Society of Animal Science, the American Dairy Science Association, the Asociación Mexicana de Producción Animal, and the Poultry Science  Association in San Antonio, Texas. Topics include: hormonal and nutritional factors regulating postnatal mucle protein synthesis through protein translation pathways and signaling molecules in the postnatal pig  (Davis, et. al., 2008), challenges and methodological considerations for measuring intracellular protein degradation in animals (Bergen, 2008), major pathways of protein degradation with emphasis on the nonlysosomal Ca²⁺-dependent protein degradation system in muscle and implications for meat quality (Goll, et. al., 2008), and mamailian target of rapamycin (mTOR) as a central regulator in regulating cellular metabolism, hyperplasic-hypertrophic protein growth, and ribosome biogenesis at transcriptional and translational levels by sensing and inegrating signals from mitogens, stressors, and nutrients (Yang, et. al., 2008).