Domestic pigs alter their social strategy in response to social group size

Posted in: Welfare by admin on October 2, 2009 | No Comments

In a series of studies, we investigated the concept that domesticated pigs may adopt cost efficient social strategies, in which individuals become less aggressive due to a higher number of potential competitors, in large social groups. Six blocks, each comprising four pens of 18 pigs (small group, SG) and two pens of 108 pigs (large group, LG)were used. Pigs were 11 weeks old at the initial group formation. Weeks 1, 6 and 12 following SG and LG formation, two randomly selected pigs with SG or LG social experience were incorporated into another SG or LG for a period of 2 h and the aggressive behaviour of pigs was observed. Four test combinations were used (SG to SG (SS), SG to LG (SL), LG to SG (LS) and LG to LG (LL)). There was less aggression in the LL compared to SS, SL and LS combinations (1.6% versus 2.5, 2.3, and 2.5% of time, respectively, P = 0.009). Furthermore, 8 weeks following

SG and LG formation, a total of 200 pigs were regrouped for 2 h in groups of four in a neutral test arena to assess the effect of prior social experience (SG vs. LG) on aggressive behaviour. Pigs were regrouped with their own group members (familiar), or with unfamiliar non-group members either from SG or LG. Five test combinations were used (four pigs from the same SG (S), four pigs from the same LG (L), two pigs from a SG and two pigs from a LG (SL), two pigs each from two different LG (LL) and two pigs each from two different SG (SS)). Pigs derived from SG fought aggressively (duration, s) with unfamiliar pigs, compared to those derived from LG (4.9, 6.7, 16.1, 12.1 and 9.5 s for S, L, SS, SL and LL test combinations respectively, P < 0.001). In addition, the latency to initiate first aggressive interaction was shorter (duration, s) in SS than LL treatment combination (23.3, 22.5, 10.8, 11.8 and 19.2 s for S, L, SS, SL and LL test combinations respectively, P = 0.008). Taken together, our results suggest that pigs become less aggressive and may shift to a low-aggressive social strategy in large social groups. This may provide potential benefits for welfare of pigs under commercial production situations.

Making Fusarium-Resistant Plants from Pollen

Posted in: Ontario Pork, Pork Insight Articles by admin on October 1, 2009 | No Comments

Researchers at the University of Guelph are finding new ways to produce fusarium-resistant corn plants from pollen. The process involves extracting pollen from mature plants and holding it in a dish where it can be exposed to screenings. The millions of pollen grains being held are exposed to  acids found in fusarium that help the disease break down plants to help penetrate it and to UV lights which kills most of the pollen grains but some are mutated and remain. The researchers then select the pollen grains that are able to survive the screening and have the desired traits they are after. The surviving embryos are then grown to maturity in a lab and put through test to see how resistant they are. This process allows for creating disease resistant plants while not altering the genes, meaning they are not transgenic. Not being transgenic allows the plants to avoid the regulations and scrutiny that comes with other mutated plants.

Angiogenic DC-SIGN+ cells are present at the attachment sites of epitheliochorial placentae

Posted in: Ontario Pork, Pork Insight Articles, Production by admin on September 15, 2009 | No Comments

Spontaneous early and mid-gestation fetal losses occur in swine. At both stages, endometrial lymphocytes associated with smaller, paler conceptuses have fewer pro-angiogenic and more pro-inflammatory cytokine transcripts compared with robust conceptuses. We hypothesized that similar differences occur in conceptus-associated dendritic cells (DCs). Using laser capturemicrodissection, dendritic cell-specific intercellular adhesion molecule-grabbing non-integrin (DC-SIGN)+ cells were isolated from attachment sites of healthy and arresting conceptuses at gestation day (gd)20 and 50. DC-SIGN+ cells were screened using real-time PCR for vascular endothelial cell growth factor (Vegf), its receptors, semaphorins (Sema) and plexins (Plxn), and for toll-like receptor (Tlr) transcripts to address potential activation pathways. Homogenized endometrial and trophoblast biopsies were quantified for type 1/type 2 cytokine transcripts/proteins. DC-SIGN+ cells from healthy and arresting conceptuses had more Vegf transcripts at early than mid gestation whereas transcripts for Vegfr1 and Vegfr2 were stable. In gd20 arresting site DC-SIGN+ cells, Neuropilin-2 transcripts were elevated, whereas at gd50 arresting sites, Plxn-A2 increased and Sema3A transcripts were lost. Tlr-1, Tlr-4 and Tlr-6 transcript abundance was independent of conceptus health. At gd20, type 1 cytokines were prevalent, whereas at gd50 type 2 cytokines predominated in endometrium and trophoblast. Thus, gestational features, characteristic of haemochorial placentation, are present in species with distinctly different placentation.

Development of a Plant-Based, Low Cost, Orally Administered Vaccine against Porcine Reproductive and Respiratory Syndrome Virus (PPRSV)

Posted in: Ontario Pork, Pork Insight Articles by admin on September 14, 2009 | No Comments

The objective of this study was to develop a plant based product that can be fed to pigs to help induce the immune system to combat PRRSV. The GP5 neutralizing epitope and CTB were the parts of the plants that the researchers want to extract. It was found that  plant-produced CTB-GP5NE could efficiently bind to the mucosal GM1 acceptor, demonstrating it is biologically active. Taken together these results prove that CTB-GP5NE is an excellent candidate for oral vaccine against PRRSV. The researches state that the system to extract the plant products must be improved it if were to be introduced at a commercial level.

Intensive hog farming operations and self-reported health among nearby rural residents in Ottawa, Canada

Posted in: Environment by admin on September 10, 2009 | No Comments

Background: In 2004, hog farming operations were introduced in the village of Sarsfield in the
eastern part of Ottawa, Canada. This study evaluates the health-related quality of life (HRQOL),
and the prevalence of respiratory conditions among adults and children who lived in proximity to
this farm.
Methods: A cross-sectional survey was administered to a random sample of residents from seven
rural communities in the eastern part of Ottawa, Canada. We analyzed self-reported questionnaire
data obtained from 723 adults and 285 children/adolescents. HRQOL was assessed using the SF-
36 survey instrument, while data were also collected for sociodemographic characteristics, the
prevalence of selected health conditions, and lifestyle related behaviours (e.g., smoking) of
participants. Variations in self-reported health according to the residential distance to the hog farm
were evaluated using logistic regression and analysis of variance methods.
Results: For the most part, the prevalence of selected health conditions among adults and children
was not associated with how far they lived from the farm. No associations were observed with
migraines, respiratory conditions (asthma, rhinitis, sinusitis, and chronic bronchitis), and allergies.
However, a higher prevalence of depression was noted among those who lived within 3 km of the
farm relative to those who lived more than 9 km away (odds ratio = 2.01, 95% CI = 1.11, 3.65).
Furthermore, individuals who lived closer to the IHF were more likely to worry about
environmental issues such as water quality, outdoor and indoor smells, and air pollution. This level
of worry also contributed to lower HRQOL scores for individuals who lived closer to the farm. It
was also observed that the prevalence of depression was much higher among those who indicated
a concern about environmental issues (18.2%) when compared to those who did not (8.0%).
Conclusion: While our findings suggest that living in close proximity to an IHF may adversely
affect HRQOL these should be interpreted cautiously due to a lack of direct measures of
environmental exposures, and possible biases inherent in the use of self-reported health measures.

Dust concentration variation in relation to animal activity in a pig barn

Posted in: Environment by admin on September 2, 2009 | No Comments

The contribution of animal activity to dust concentration in a pig barn, was evaluated through the continuous monitoring of animal activity. PM₁₀ concentrations were measured during a three months observation period, from April to July, in a mechanically ventilated fattening room in Northern Italy. Pigs of 60 kg and with a mean age of 150 days were fed with liquid feed and were lodged on concrete fully slatted floor. PM₁₀ concentration was monitored continuously by a dust sampler. From April 12 at 13:42 until April 13 at 15:09, 33 pigs housed in two of the 16 pens of the barn were monitored using a video camera placed at the height of 5 m above the pen floor. A comparison of data related to dust measurement and to activity index was performed on the hours of recorded images. PM₁₀ concentration reached maximum values at feeding times, during feed release and with lights turned on. An increase in dust concentration took place within an hour after increased animal activity. PM₁₀ concentration decreased until it reached the nocturnal mean concentration (316 μg m⁻³) after 1 h from feeding time. As expected, correlation analysis showed that particulate matter concentration was associated with ventilation rate (70%, P < 0.001), with relative humidity (−93%, P < 0.001), with inside and outside temperatures which determine ventilation rate a priori, and finally with animal activity (99%, P < 0.001). These results confirmed the strong association that exists between animal activity and particulate matter concentration in animal houses. An increase in PM₁₀ concentration from 316 μg m⁻³ (the mean value of dust levels was observed at night when the recorded animal activity showed the lowest values) to 624 μg m⁻³ corresponded to the dust raised by 343 animals (with an increase in animal activity of 0.018 units), in a mechanically ventilated barn with fattening pigs fed with liquid feed, and lodged on a fully slatted concrete floor.

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Protein Turnover in Lactating Sows

Posted in: Ontario Pork, Pork Insight Articles by admin on August 14, 2009 | No Comments

Protein turnover and energy metabolism was simultaneously measured in sows on d 7 and 17 of lactation. Sows were fed a lactation diet ad libitum (14 MJ DE/kg, 20.7% crude protein, 1.02 % total lysine). On days 7 and 17 of lactation, 24 h energy expenditure was measured by indirect calorimetry while a primed-constant infusion of L-[1-13C]leucine (1.0 mg/kg/h) was delivered intravenously over 24 h to measure
rates of protein synthesis and breakdown. Milk yield and composition were also measured. Leucine intake varied due to differences in feed intake, but leucine flux was not significantly different between days of lactation. Protein synthesis and leucine appearance from body protein breakdown, as % of flux, were higher (P<.001) on d 7 than d 17 (81.1 vs. 76.9 % and 25 vs. -10 %), respectively. The protein and leucine content of milk were also higher on d 7 than d 17 (5.3% vs. 5.1% CP and 3.0 vs. 2.0 g/kg), respectively. Negative protein breakdown on d 17 indicates utilization of leucine by the mammary gland that was neither oxidation or protein synthesis. The higher dietary intake
of energy and protein on d 17 reduced both whole body protein breakdown and protein synthesis. The higher dietary energy intake on d 17 (13.4 MJ/d) was entirely accounted for by milk energy output (13.8 MJ/d). These data indicate that sows were in greater protein deficit during early lactation than late lactation; therefore diets higher protein, or with a better balance of amino acids, are required in early lactation to reduce the loss of body protein.

Protein Turnover and Heat Production of Sows Varies at Day 30, 45 and 105 of Gestation

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

The objective of this study was to determine the protein turnover and heat production rate of sows at day 30, 45 and 105 of gestation. Gravid sows (n=4) were fed 2.4 ± 0.1 kg of a barley-wheat-SBM diet of 12.5 MJ ME/kg, 0.65% total lysine, and 15% crude protein twice daily throughout gestation. Heat production was measured by indirect calorimetry and a primed-constant infusion of L-[1-13C]leucine (1.0 mg/kg/h) was simultaneously delivered intravenously over 24 h. All measurements were made at d 30, 45, and 105 of gestation. Respiratory quotient (RQ) was calculated to determine nutrient utilization. Energy retention (intake minus heat production) (MJ/d) was greatest (P<0.01) on d 45 (6.1 ± 0.9) compared to d 30 (3.7 ± 0.9) or d 105 (1.4 ± 1.5) of gestation. The RQ was greater than 1 and highest on d 45 indicating lipogenesis. Leucine flux, appearance from breakdown, and incorporation into protein were highest (P<0.0001) on d 45 compared to days 30 or 105 of gestation. However, as a result of the significant increase in protein breakdown (9.3 vs. 1.0 g/d) protein gain was lower (P<0.05) for sows on d 45 (165.2 g/d) compared to d 30 (172.4 g/d and). Therefore, energy was preferentially stored by these sows on d 45 at the expense of protein. The correct utilization of phase feeding would improve productivity and provide positive economic returns.

Threonine Requirement of Sows in Early, Mid- and Late Gestation

Posted in: Ontario Pork, Pork Insight Articles by admin on August 13, 2009 | No Comments

The objective of this study is to determine the Threonine requirement of sows in early, mid- and late gestation. The THR requirement in early (35–53d),mid- (63-70d) and late (92–110d) gestation was determined by indicator amino acid (IAAO) oxidation in six second parity sows fed THR from 60 % to 150 % of NRC (1998) estimated requirements. L[1-13C]phenylalanine was given orally at 30 min intervals for 8 meals and expired 13CO2 was quantified. The nonlinear Mixed model in SAS was used to determine the THR requirement for each period by breakpoint analysis. Plasma THR was also used to estimate requirement. Sows responded differently to increasing levels of dietary THR in early and late gestation. Preliminary breakpoint analysis resulted in a THR requirement of 6.1 g/d in early gestation (R2=0.59), 7.0 g/d in mid gestation (R2=0.55) and 13.6 g/d in late gestation (R2=0.56). The THR requirement based on plasma THR was 7.2 g/d (R2=0.90) in early gestation and 14.0 g/d (R2=0.76) in late gestation. The current recommended THR intake during gestation is 10 g/d.  Feeding to a single amino acid requirement value during gestation will result in overfeeding in early gestation and underfeeding in late gestation. Feeding excess AA in early gestation will unnecessarily increase feed costs. Whereas, underfeeding AA in late gestation will have negative effects on sow body condition at parturition and on lactation performance. Phase feeding in gestation can reduce feed costs and may improve sow reproductive performance.

Using Data Collected for Production or Economic Purposes to Research Production Animal Welfare: An Epidemiological Approach

Posted in: Featured, Ontario Pork by admin on August 12, 2009 | No Comments

Epidemiological approach to studying finisher pig deaths during transport. Evaluation of using the epidemiological approach to study finisher pigs during transport. Emphasis put on approach to the research and time spent and importance of evaluating data as 50% to 75% of research time. Researchers conclude that epidemiology is a useful tool to study animal welfare issues in production animals.