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Prairie Swine Centre is an affiliate of the University of Saskatchewan
Prairie Swine Centre is grateful for the assistance of the George Morris Centre in developing the economics portion of Pork Insight.
Financial support for the Enterprise Model Project and Pork Insight has been provided by:
Dehydrated Chicory Root Powder for Modulating Intestinal Fermentation to Reduce Odor Impact: Study Phase-I with Post-weaned Pigs
Posted in: Ontario Pork, Pork Insight Articles by admin on October 17, 2008 | No Comments
This paper discusses the impacts of implementing graded chicory root powder into a pig diet and how it effects fecal odour, productive growth, and nutrient digestibility. Six diets of soybeans and corn were given one of six doses of chicory root powder ranging from 0-1%. The root powder at 0.2% was found to reduce H2S in the fecal matter by 40%, while higher levels of the root powder had no effect on fecel matter content. The implementation of the root powder resulted in imporved average daily gain but had a negitive effect on digestibility. The chicory root had improved efficiency of P retention. The use of chicory root in a diet at levels of 0.2% may be beneficial for reducing fecal excretion of volatile sulfides and improve efficiency of dietary calcium and phosphorus utilization without adversely affecting growth performance and efficiency of whole body nitrogen utilization in weanling pigs fed corn and soybean meal-based diets. However levels higher than 0.2% can have negative impacts on growth performance and efficiency of dietary nutrient utilization without decreasing fecal excretion of volatile sulfides in weanling pigs.
Comparison of Immune Cell Recruitment and Function in Endometrium During Development of Epitheliochorial (Pig) and Hemochorial (Mouse and Human) Placentas
Posted in: Ontario Pork, Pork Insight Articles, Production by admin on September 30, 2008 | No Comments
The role of maternal immune cells in early implantation sites has received special attention from reproductive biologists because immune cells participate in tissue transplant rejection. During normal pregnancy, endometrial immune cells differ from those in blood by subset distribution and appear to be activated but non-destructive of conceptuses. The immune system evolved well before placental mammals. By comparing the regulation and functions of endometrial immune cells between species in two phylogenetic clades that model differently evolved placental types (pig (Sus scrofa) versus mouse (Mus musculus) and human (Homo sapiens)), we seek to understand how ‘‘non-self’’ trophoblast cells
thrive in most pregnancies. Our studies suggest recruitment of specific immune cells to conceptusassociated endometrium and immune cell-promoted endometrial angiogenesis are of key importance for mammalian conceptus well-being.
Learning from 2006 to reduce future impacts of Fusarium epidemics to stakeholders of the corn industry
Posted in: Ontario Pork, Pork Insight Articles by admin on August 24, 2008 | No Comments
Recently mycotoxins in corn have had tighter limits as to what is acceptable, this increases the impact of a disease like fusarium on a crop. In 2006 an outbreak of fusarium in the corn crop was not detected until harvest, this caused a loss of $60 million for corn producers, hog producers also suffered as the amount of clean grain became limited. The lack of communication and lack of an early detection system created a misunderstanding among stakeholders and the problem was not addressed until it was to late. Some reasons why the 2006 crop had such bad fusarium was that not enough attention was paid towards hybrids. Some hybrids were partially resistant to DON but because in nature the disease changes year to year the corn was not protected from the certain kind of fusarium. It is recommended that a controlled environmental corn hybrid screening program on campus be created. Wet conditions are ideal for fusarium to thrive, it is recommended that weather conditions like that should be tracked and posted on a web-based log so producers can have early warning about a potential fusarium outbreak. Improved communication is key to controlling fusarium in corn crops.
The Negative Effects of Exogenous DNA Binding on Porcine Spermatozoa are Caused by Removal of Seminal Fluid
Posted in: Ontario Pork, Pork Insight Articles by admin on August 23, 2008 | No Comments
Sperm-mediated gene transfer (SMGT) might become the most efficient and cost effective technique to generate transgenic animals, which will significantly increase their application in biomedical research and in commercial production. Despite some successes, the technique has remained controversial for almost 20 years and despite number of studies the reasons for poor reproducibility of this promising technology has not been understood. We suggest that the reason for poor reproducibility is the presence of natural defences against exogenous DNA invasion acting in spermatozoa or in embryo. Based on previous reports we have investigated the effect of foreign DNA binding on spermatozoa by monitoring motility, viability and genomic DNA damage. Evaluation of DNA binding in sperm collected from 16 boars demonstrated that 28–45% of the added pEGFP plasmid was bound to spermatozoa with 9–32% being internalized in sperm nucleus. In agreement with previous reports, our results demonstrated that the pEGFP-treated sperm show an average a 2-fold decrease in motility ( p < 0.05), 5-fold decrease in progressive motility ( p < 0.05), and 1.4-fold increase in number of sperm with highly damaged DNA ( p < 0.05) as detected by Comet assay. In contrast with previous reports, we demonstrate that all such changes were associated with the removal of seminal plasma during the washing step and not with foreign DNA binding per se. We suggest that poor reproducibility of SMGT most likely result from selection against DNA-loaded sperm at later stages of fertilization.
Expression of Bioactive Porcine Interferon-gamma by Recombinant Lactococcus lactis
Posted in: Ontario Pork, Pork Insight Articles by admin on August 20, 2008 | No Comments
Lactococcus lactis is an immunomodulator and candidate live mucosal delivery vehicle for vaccine antigens and for
biologically active molecules, including immunoregulatory cytokines such as interferon-gamma (IFN-g). To provide a tool for investigating downregulation of allergic predisposition of pigs to experimental food allergy, porcine IFN-g was cloned and expressed as a fusion protein with the usp45 secretion signal. Immunoblot analysis with polyclonal anti-pIFN-g-antibody demonstrated that the recombinant porcine IFN-g (rpIFN-g) protein was expressed in the L. lactis transformants as a secreted product. Activity of rpIFN-g was confirmed by ability to upregulate class II major histocompatibility complex (MHC) on cells of the porcine monocytic cell line 3D4/31. The L. lactis producing biologically active rpIFN-g will be used to investigate its possible ability to modulate the allergic immune response phenotype of pigs. Biologically active rpIFN-g was produced in L. lactis and upregulated MHC class II expression on porcine monocytic cells suggesting that the modified L. lactis might be able to enhance type 1 immune response and reduce susceptibility to allergy in animals/humans. The researchers have engineered and expressed afunctional rpIFN-g gene in L. lactis that would allow delivery to the pig’s intestinal mucosa. Although use of this construct is limited by lack of control over quantity and conditional expression of recombinant protein production, containment of live genetically modified L. lactis secreting human IL-10 in pigs is possible using an auxotrophic thymidine mutant (Steidler et al., 2003). However, the presently described construct will be used as a heat-killed bacterial vehicle expressing the recombinant porcine IFN-g protein, for delivery both orally and systemically.
Dietary Lysine Requirement for Maintenance is 49 mg/kg0.75 in a Population of Modern, High Productivity Sows
Posted in: Ontario Pork, Pork Insight Articles by admin on August 19, 2008 | No Comments
The recommended daily lysine requirement of non-pregnant sows at maintenance, 36 mg/kg, was estimated from research in the 1960’s with growing pigs and sows. The current estimate was hypothesized to be too low for modern, high producing sows. Non-pregnant Hypor Hybrid (Hypor Inc) sows (n=4; 222.6±0.7 kg BW) were adapted to 2.2 kg of a semi-synthetic diet containing 14.0 MJ ME/kg and 1.09 g/kg lysine. Each sow received 6 test diets, in random order, providing lysine intakes of 19.8, 25.2, 30.6, 41.4, 46.8 and 52.2 mg/kg. After adaptation to each diet, indicator amino acid oxidation using L-[1-13C]-PHE was determined simultaneously with indirect calorimetry for 4 h. Plateaus in oxidation were achieved within 1.5 h. PHE oxidation decreased as lysine intake increased and was lowest (P<0.05) at 46.8 mg/kg. Heat production was linearly correlated (r2 = 0.54) with PHE oxidation and was lowest (P<0.05) at lysine intake of 46.8 mg/kg. The mean RQ (1.029±0.028) showed that dietary energy was not limiting. RQ was also lowest (P<0.001) at lysine intake of 46.8 mg/kg. Maintenance lysine requirement, calculated by regression analysis, was 49 mg/kg. The dietary lysine requirement for this population of sows was determined to be 49 mg/kg; this exceeds the current recommendation by 30%. HP and RQ were lowest when sows received adequate intake of dietary lysine, demonstrating that energy metabolism was also most efficient at this intake. Amino acid requirements of modern sows must be redetermined during maintenance, gestation and lactation.
Energy Metabolism and Leucine Oxidation in Early and Late Lactation in Sows
Posted in: Ontario Pork, Pork Insight Articles by admin on | No Comments
Energy metabolism and leucine oxidation were measured in lactating sows as part of a long-term research program designed to redefine the protein, amino acid, and energy requirements of modern, high producing sows. Leucine oxidation was used to estimate the catabolism of dietary and body protein for energy. The data showed that sows actively stored energy through lipogenesis during the overnight period, but were forced to utilize those reserves during the day when piglets were most actively suckling. Leucine oxidation was greater (P<0.0001) on d 17 than d 7 (28.8% vs. 21.8% of dose). Milk (5.4 kJ/g; 5.2% crude protein) production per piglet (656 g/d vs. 940 g/d) increased (p<0.05) while feed intake (kg/d) tended (P<0.10) to increase from early to late lactation. In conclusion, feed intake during lactation was insufficient to meet energy requirements of these sows, based on measurements of energy metabolism. Amino acid oxidation increased between early and late lactation, indicating that more protein was being catabolized, probably to provide additional energy. Therefore, the amino acid intake of these sows in late lactation was insufficient to meet the demands for both protein synthesis and energy utilization.
Nutrient Utilisation and Intestinal Fermentation are Differentially Affected by the Consumption of Resistant Starch Varieties and Conventional Fibres in Pigs
Posted in: Ontario Pork, Pork Insight Articles by admin on | No Comments
This study examined the influence of different resistant starch (RS) varieties and conventional fibres on the efficiency of nutrient utilisation and intestinal fermentation in pigs. Thirty-six pigs (30 kg) were fed poultry meal-based diets supplemented with 10% granular resistant corn starch (GCS), granular resistant potato starch (GPS), retrograded resistant corn starch (RCS), guar gum (GG) or cellulose for 36 d according to a completely randomised block design. Distal ileal and total tract recoveries were similar (P.0·05) among the RS varieties. Distal ileal starch recovery was higher (P,0·05) in pigs consuming the RS diets (27–42%) as compared with the control group (0·64 %). Consumption of GCS reduced (P,0·05) apparent total tract digestibility and whole-body retention of crude protein in comparison with the control group. Consumption of GPS reduced (P,0·05) total tract Ca digestibility and whole-body retention of Ca and P compared with the control group. However, consumption of RCS increased (P,0·05) total tract Ca digestibility compared with the control group. Caecal butyrate concentration was increased (P,0·05) following consumption of RCS and GG in comparison with the control group. Consumption of all the RS varieties reduced (P,0·05) caecal indole concentrations compared with the control. Caecal butyrate concentrations were positively correlated (P,0·05; r 0·63–0·83) with thermal properties among the RS varieties. In conclusion, nutrient utilisation and intestinal fermentation are differentially affected by the consumption of different RS varieties and types of fibres. Thermal properties associated with different RS varieties may be useful markers for developing RS varieties with specific functionality.
Methicillin Resistant Staphylococcus aureus Colonization in Pigs and Pig Farmers
Posted in: Ontario Pork, Pork Insight Articles by admin on | No Comments
The objectives of this study were to evaluate the prevalence of MRSA colonization in pigs and pig farmers in Ontario, Canada and to characterize MRSA strains. Nasal and rectal swabs were collected from 285 pigs from three different age groups from 20 pig farms. The prevalence of MRSA colonization in farms was 45% (9/20) whereas the prevalence in pigs was 24.9% (71/285). There was no difference in MRSA colonization between age groups. The prevalence of MRSA colonization in pig farmers was 20% (5/25). There was a correlation between the presence of MRSA in pigs and humans on farms (P value = 0.001). The results of spa typing revealed the predominant strain in pigs and humans was eGenomics spa type 539 (Ridom t034, clonal complex 398) which accounted for 59.2% of isolates and has been reported in pigs in Europe. A common human epidemic clone, CMRSA-2 (USA100, clonal complex 5) was also found in both pigs and pig personnel. Indistinguishable strains were found in pigs and pig personnel on all five farms with a colonized human. This study demonstrates that MRSA is common in pigs in Ontario, Canada, and provides further support to concerns about transmission of MRSA between pigs and humans. The reasons for the high prevalence of MRSA colonization in pigs both in Canada and in other countries remain uncertain. The presence of similar strains in pigs and their human contacts, the high prevalence of colonization of pig farmers and the possible emergence of ST398 strains as a cause of clinical infections in humans indicates that MRSA in pigs may pose a public health risk to human contacts.
Cellular and Molecular Evaluation of Mechanisms at the Maternal-Fetal Interface that Promote Porcine Fetal Survival.
Posted in: Ontario Pork, Pork Insight Articles by admin on August 15, 2008 | No Comments
In commercial hog barns sows during early and mid gestation experience spontaneous fetal loss reaching 30-45%. It is not clear why these losses occur but poor blood supply to the developing conceptus is suspected to be the cause. This study documented that type 1 cytokines dominate early pregnancy, while type 2 cytokines are more common after mid-gestation. Type 1 cytockines were more common at arresting conceptus attachment sites comapred to healthy ones. It was also noted that chemokines and their decoy receptor was significantly higher in arresting sites at mid-gesstation. Using an intra-uterine infusion of MCC (Bioniche life sciences, Inc.), litter size was increased by 3 piglets in treated sows compared with control. Runts were very rare in treated compared with placebo animals. Other effects of MCC include stimulation of maternal fetal vasculature and numbers and size of corpora lutea. Overall this proposal made significant advances towards the understanding of embryo loss during porcine pregnancy and therapeutic promotion of litter size.