Circuit and Noise Analysis of Odorant Gas Sensors in an E-Nose

Posted in: Ontario Pork, Pork Insight Articles by admin on February 28, 2005 | No Comments

In this paper, the relationship between typical circuit structures of gas sensorcircuits and their output noise is analyzed. By using averaged segmenting periodical graphand improved histogram estimation methods, we estimated their noise power spectra andoptimal probability distribution functions (pdf). The results were confirmed through experiment studies.

Assessing Mycoplasma hyopneumoniae aerosol movement at several distances

Posted in: Air Filtration, Pork Insight Articles by admin on January 15, 2005 | No Comments

Modern developments in pig production such as segregated production, early weaning and strategic medication have eliminated some of the risks associated with the spreading of pathogens. Although there have still been certain pathogens able to penetrate herds despite these improvements. Enzootic pneumonia (EP) is one disease that still causes reductions in production performance of swine herds. One of the main agents of EP is M hyopneumoniae, which is very difficult to grow in a lab causing a need for nested PCR technology to aid in the detection of the organism in tissue and air samples. The spreading of M hyopneumoniae is mainly through infected pigs and aerosols. This disease is assumed to travel up to 3km making dense pig operations and roadways that transport hogs risk factors for spreading the disease. But these assumptions are based on retrospective epidemiological studies, no scientific studies have been conducted to see if the disease can actually travel through the air for various distances. To test for the spreading of M hyopneumoniae a model was used that had previously been designed to test for the spreading of PRRS. This model consisted of three components: dispersal, dissemination and detection. The dispersal phase involved spraying units of M hyopneumoniae through a aerosol can, similar to a cooking oil spray. A blower was used to disseminate the samples, and a portable air centrifuge was used to collect samples at 1, 75 and 150 m from the dissemination area. The study was replicated twice at each distance. After each test, the centrifuge was sanitized. Samples were taken after each tests at each distance. All of the samples from each distance were found to be positive with M hyopneumoniae DNA. All the samples consisted of non-specific bacteria making it difficult to determine  if any samples had M hyopneumoniae-like colonies. Further studies need to be carried out to find out the maximum distance the particles can travel and to see if different weather conditions play a role in the distance traveled.

Battling PRRS virus Aerosol Spread

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Researchers were able to determine that the PRRS virus transfers between pigs by way of aerosol. It was also determined that the more virulent the disease was the higher chances it has of shedding and infecting other pigs. Identifying these factors has led to a need to develop an air filtration system capable of stopping the PRRS virus from traveling from an infected herd to a non-infected herd. A filtration system put in place by French hog farmers was able to eliminate PRRS outbreaks in an area that was once commonly infected with the virus. This method involved three filters one being high efficiency particulate air (HEPA) filter capable of filtering particles as small as 0.3 microns. To prove the effectiveness of this method American researchers ran a series of  tests involving PRRS infected pigs. The PRRS infected pig was put in one room and a PRRS negative pig was put in a room beside it with the filter placed between them. In 20 trials the PRRS negative pig was not infected with the virus, when the same test was done without the filter the negative pig was infected 6 out of 20 times. To intesify the study the researchers used 2 pints of solution containing PRRS to create a “virus fog” which was put through the filter. When the filter was in place for 10 trails the negative pig was not infected once, where as in the control when the filter was removed the negative pig was infected 9 out of 10 times. This HEPA filter was put in place in a  barn in Iowa that consistently suffered from PRRS outbreaks annually between November and February. After a year of having the filter in place the barn suffered no out breaks and the staff veterinarian said that the overall environment of the barn had been improved.


New ideas about gilt development and management

Posted in: Production by admin on January 1, 2005 | No Comments

Replacement gilts are important in any herd because they determine the future productivity of the herd. Today the visual selection criteria used may not be the best indicator of reproductive potential. The aim of this paper is to introduce some relatively new management techniques for gilt development. It is important to maintain health during ovarian development at the piglet stage. In piglets that exhibit diarrhea, age at puberty is unaffected for the most part, but the proportion of gilts exhibiting puberty, farrowing rates, and number of pigs born alive are consistently lower. At the nursery stage, growth of specialized glands from uterine tissue must be maximized. First off, sows must not be exposed to estrogen-containing mycotoxins in feed. This results in poor embryonic survival of the replacement gilts coming from that sow. Replacement gilts cannot be crowded or there will be detrimental effects on weight of ovulation and born alives.

The first lactation is widely agreed as the most important time of a gilts reproductive life. The number and size of piglets nursing have a direct effect on the amount of milk produced, and the amount of milk produced is directly related to the weaning weight. Analysis can be done on a per farm basis to determine the amount of piglets the average gilt can rear without experiencing a reduction in subsequent breeding performance.

If gilts fail to reach a timely first estrus, work should be done to ensure that future gilts experience minimal environmental stresses, minimal competition with pen mates, and minimize lactation stress by reducing the number of nursing pigs.

Panel Presentation: The Financial Perspective Opportunities in Contract Finishing

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Contract finishing in Canada and the US has been growing in popularity for the past decade Hytek in Manitoba contracts finishing barns in Iowa and Minnesota. The advantage to a farrowing facility contracting a finisher is the savings in facility costs, which operation of these facilities accounts for 20% of costs. Contract C is the most common purchased because it includes the facilities, labour, utilities, maintenance, taxes, insurance, and manure removal. The contractor of the barn must provide adequate facilities (biosecurity, design, etc.), environmental compliance, maintain financial records, have a good location, a good contract and fee, be a low cost operator, give a proposed term, and have a high reputation. In addition to all of that, the contractee must be able to provide quality pigs that can grow to genetic potential.

Micro-Organisms as Feed Additives – Probiotics

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For many decades antibiotics have been used as feed additives in various species of farm animals to reduce the frequency of diarrhoea under certain conditions. It can also improve body weight gain or feed conversion ratio. These antibiotics modify the intestinal bacteria and their interaction with the host animal. Public concern has risen over the potential increase of bacterial antibiotic resistance. Some alternatives to antibiotics include probiotics, prebiotics, organic acids and herbs, as well as essential oils. Probiotics are commonly defined as viable microbes that lead to beneficial effects for the host by modifying the intestinal microbial population. It must survive throughout processing, pelleting, storage, and stomach. Some research trials have shown that alternative growth promoters can enhance animal performance. 80% of experiments show that piglets fed probiotics see a reduction in piglet diarrhoea.

DEVELOPMENT OF THE OFFSET MODEL FOR DETERMINATION OF ODOR-ANNOYANCE-FREE SETBACK DISTANCES FROM ANIMAL PRODUCTION SITES: PART I. REVIEW AND EXPERIMENT

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You can feed fusarium-contaminated barley to pigs

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While the full extent of the fusarium problem in the 2005 Manitoba cereal grain crops has yet to be determined, preliminary reports highlight the potential for significant infection rates. For pig producers, this could mean another season of coping with DON. The mycotoxin DON (deoxynivalenol or vomitoxin), when present in swine diets above 1 to 2 ppm, can suppress feed intake and lead to reductions in average daily gain and increase days to market. At the University of Manitoba.s Department of Animal Science, we have been conducting research to A) better understand how fusarium contaminated cereal grains impact swine performance and B) develop strategies to reduce the negative impacts observed when feeding these grains. With respect to point B, the attention have been focused on the use of pearling techniques, or abrasive dehulling, to remove DON (and other mycotoxins) from the grain. Our initial studies with a laboratory-scale pearling machine showed that pearling was quite effective at removing DON from hulled barley: The removal of 15% of the outer kernel, approximately equal to the hull fraction, resulted in the removal of 65% of the DON. Similar results were obtained when we tested a commercial-scale pearling unit. The commercial-scale unit provided an opportunity to assess the impact of pearling on the feeding value of fusarium-contaminated hulled barley. We showed that pearling 1) removed the feed refusal factor from contaminated barley and 2) increased the digestible energy value of barley by an average of 15%, due to the removal of the fibrous hull fraction. The next phase in our studies included the investigation of whether DON-contaminated barley, once it had been pearled, could serve as a suitable feed ingredient for starter pigs. The effect of commercial pearling of DON-contaminated barley diets was evaluated with respect to the performance of early-weaned pigs. Three sources of barley were used, each with a different level of initial DON contamination: Barley 1 = 1.2 ppm (low); Barley 2 = 4.4 ppm (medium); and Barley 3 = 7.6 ppm (high). Each barley source was subjected to a commercial pearling procedure, using a Satake cereal grain abrader, to remove approximately 20% of the outer portion of the grain. As a result, the final DON levels in the pearled barley samples were: Barley 1 = 0.42 ppm; Barley 2 = 1.54 ppm; Barley 3 = 2.70 ppm. These barley samples were used in the formulation of two phase diets for starter pigs. Phase I diets contained 44% pearled barley, 25% soybean meal (48% crude protein), 15% dried whey, 10% lactose, 6% spray dried plasma, 1.8% vegetable oil, plus supplemental lysine, methionine, and a vitamin-mineral premix to provide sufficient nutrients to meet or exceed the requirements of the young pig. The phase II diets consisted of 67% pearled barley, 27% soybean meal, 1.5% vegetable oil, plus supplemental lysine, methionine, and a vitamin-mineral premix to provide sufficient nutrients to meet or exceed the requirements of the young pig. As a control, corn-based diets were formulated to the same nutrient specifications for the two phases. Based on these results, we conclude that the commercial pearling of DON-contaminated, hulled barley yields a feed ingredient that is well tolerated by young pigs. The removal of the mycotoxins, in particular DON, as well as the fibrous hull fraction creates a feed ingredient that supports average daily gains and feed efficiency values that are similar, if not better, than a corn-based control. Therefore, the pearling or dehulling of barley should be considered as an effective strategy to increase the utilization of fusarium-contaminated grains by the swine industry. Pearling requires capital inputs (pearling machine, grain handling and storage), as well as the input of energy. However, the costs associated with pearling should be offset by the reduction in transportation costs associated with the importation of DON-free grains, as well as the improvement in the digestible energy value that is obtained through the removal of the fibrous hull fraction (ie: less added oil required in the diets). Further work to optimize the process, as well as the determination of the cost-effectiveness of the procedure will indicate the economic conditions when this process is viable at the commercial level.

Effect of water spinach and fresh cassava leaves on intake, digestibility and N retention in growing pigs

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Effects of estradiol implantation on growth, carcass traits and circulating concentrations of insulin-like growth factors (IGFs) and IGF-binding protein-3 in finishing barrowsB

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Only limited information is available as to the effect of each of the androgen and estrogen on growth measures in barrows. It has been reported that estradiol-17h implant (CompudoseR) had varying effects on growth and its efficiency measures in finishing barrows depending on the dose and duration of the implant as well as animal’s body weight at the time of implantation. This study was therefore undertaken primarily to delineate the effect of a low dose of
the Compudose implant on growth and carcass characteristics in finishing barrows. It was found that implantation of Compudose containing 24 mg of estradiol-17h is effective for decreasing backfat thickness without significantly affecting live weight gain, FCE and muscle characteristics including protein and fat contents in finishing barrows. Suppression of backfat deposition thus appears to be a major effect of the implant in the pig. The Compudose
implant also causes a decrease in feed intake and an increase in serum concentration of the insulin-like growth factor. Collectively, these effects of estrogen may be mediated in part by the insulin-like growth factor in finishing barrows.