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.

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.

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.

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).

Survival of Pathogens During Storage of Livestock Manures

Posted in: Ontario Pork, Pork Insight Articles by admin on July 16, 2007 | No Comments

This study looks at the effects of different manure storage systems and how pathogens survive in each different system. Methods were developed to sample and analyses the manure. Several different storage systems and manure types were reviewed, and they were: dairy and swine liquid manures, dairy solid, poultry solid, and beef solid. For each type typical and modified methods were compared. For liquid manure, storage without fresh manure additions appeared to reduce some of the pathogens. Results from the dairy solid trials indicated that storage of calf manure separate from the milking herd manure resulted in a much greater degree of pathogen decline. The poultry manure composeted very quickly to the point that E.coli was below detection level. Pathogen decline in the solid beef manure piles appeared to be greater in covered piles, but the results varied depending on locations of the piles.

Evaluation of the prevalence of coccidia in Ontario suckling piglets and identification of a preventive treatment

Posted in: Ontario Pork, Pork Insight Articles by admin on July 6, 2007 | No Comments

In Europe, coccida has been found to cause enteritis, diarrhea and varying weight gain in suckling pigs. Most countries use the drug Baycox as a prevention to coccida, but in Canada the drug was banned in 2005. Also there is little to no information on the prevalence and impact of the parasite. The objectives of this study are to determine the importance of coccidia infections in suckling pigs, identify the preventative treatments used by Canadian veterinarians for coccidia infected pigs and to evaluate the efficacy of the most practical method. For objective one 50 swine herds were selected, the sizes of the operations ranged from 30-1700 sows. About 10 litters were randomly selected on each farm. A fecal sample was collected on 3-5  pigs in every litter and then tested to see if it was diarrheic and if coccidia was present. Coccidia was found in 70% of farms and on those farms the infection rate ranged from 5-100%. On farms that had tested positive for coccidia the average weight at 21 days of age was 400g less compared to negative farms. Discussions with swine vets revealed that the two most common treatment protocols were ad libitum provision of Deccox mixed with oral iron throughout the suckling period and a single treatment of Clinacox in the first week of the pigs life. These two treatments were evaluated and found that neither reduced the risk of coccidia infections or the risk of diarrhea. Also neither had beneficial effects on growth rates. The research concluded by saying coccodia is common among piglets aged 7-21 days of age and causes diarrhea and the current treatment methods appeared to not have any beneficial impact.

Environmental Characterization of Selected Dead Animal Disposal Methods

Posted in: Ontario Pork, Pork Insight Articles by admin on June 29, 2007 | No Comments

Disposal of dead farm animals has seen changes in the past few decades. Formally a farmer would get paid to have his dead animals picked up because there was value in the by products. Now a farmer must pay to have dead animals removed from the farm because of prion-related diseases that have almost eliminated the market for bone meal and meat products of dead animals. Many farmers have turned to cremation or composting. This study looks at the environmental impacts of on farm disposal of dead stock. Multiple cremation sights were tested for several contaiminets using ta consistent methodology. For contaminants that have provincial or federal emission guidelines or limits, the emissions from the units were typically close to or do better than the standards when a secondary chamber was installed that had sufficient temperature and residence time. Insufficient time and temperature and poorly designed facilities were found to have increased toxic contaminants in the stack discharge.

The Effects of Gender and Feeding Strategy on Growth Performance and Pork Quality

Posted in: Ontario Pork, Pork Insight Articles by admin on June 12, 2007 | No Comments

In this study three experiments were carried out to determine the effect that gender and feeding strategy had on growth performance and pork quality. The first trial consisted of 108 pigs in pens of six. They were either fed freely until they reached market or given a restricted diet of 70% or 85% of the free diet until they weighed 60kgs, at which point they were put on the free diet. Pigs on the restricted diet took longer to reach 60kgs than pigs on the free diet. But pigs on the restricted diet had faster growth after they reached 60kgs and were switched to a free diet, so in the end the days to market were fairly similar. The pigs on the restricted diet had less feed intake so feed efficiency was better. During the trail, compensatory gain during the finishing phase for barrows was more than gilts, but feed intake and feed efficiency was similar.Hot carcass weight, dressing percent and loin depth (final probe) were similar for each feeding strategy. Indicators revealed that meat tenderness was better for limit fed pigs. A disease outbreak made the second trials results uncompilable so a third trail was undertaken.The third trial consisted of one restricted diet of 70% of free diet based on body weight and one conventional diet that was free fed. Again it was found that the free diet had better growth results up to 60kgs, and the limited diet pigs had better gains after reaching 60kgs. Overall gains were less for the limited pigs as they were on a sustained limited feeding period. Overall intake was similar for each diet. Feed costs were lower for the restricted diet but after accounting for increased days to market the costs were similar. A proposed hypothesis was confirmed, stating that there should be 42 days of full feeding to maximize muscle protein degradation and improve meat tenderness.

Investigation of exposure to swine influenza viruses in Ontario (Canada) finisher herds in 2004 and 2005

Posted in: Ontario Pork, Pork Insight Articles by admin on May 30, 2007 | No Comments

The epidemiology of influenza in the North American swine population has changed since the emergence of a triple-reassortant H3N2 influenza virus. Although seen previously in North America, the Ontario swine population had likely been free of viruses of the reassortant H3N2 lineage until 2005. The objective of this study was to investigate the frequency and distribution of exposure to H1N1 and H3N2 subtypes in the Ontario finisher pig population prior to and after the H3N2 outbreak that occurred in 2005. This included investigating prevalence and spatial distribution of positive herds, assessing proportion of

random variation at different hierarchical levels, and evaluating selected demographic factors and management procedures as potential risk factors.