Genotypic Prevalence of the Adhesin Involved in Diffuse Adherence in Escherichia coli Isolates in Pre-weaned Pigs with Diarrhoea in Korea

Posted in: Welfare by admin on January 1, 2004 | No Comments

New Information on Regional Transmission of PRRSV and its Potential Impact on Swine Farm Biosecurity Protocols

Posted in: Air Filtration, Pork Insight Articles by admin on August 31, 2003 | No Comments

One of the biggest challenges faced in pig biosecurity is the spreading of the PRRS virus by aerosols. Currently biosecurity protocols are successful at preventing the introduction of other swine pathogens, such as transmissible gastroenteritis virus, but they have limited, if any efficacy against PRRSV. This was mostly because no one knew exactly where the virus was coming from and it was believed that once the disease left the host it was harmless to others. The purpose of this article is to summarize attempts to identify regional vectors and routes of PRRSV spread and discuss how these new data may impact future biosecurity protocols and facility designs on swine farms. It has been proven that PRRSV can be transmitted by biological vectors like mosquitoes and house flies. Also both mosquitoes and flies have shown that PRRS can remain viable in their GI tracts. Tests done that invovled infected flies who were released and then baited and trapped at various distances found that flies caught as far as 2.3 km away were PCR-positive. Another possible transmitter of the PRRS virus is transport carriers. Pigs are shipped long distance to slaughter and also come into close contact with other pig herds and cross international and state boarders. Little information exists on this subject so a test was designed to find the potential risks involved with the spreading of PRRS through transport trailers. The experiment involved four treatments: Treatment 1 consisted of a manual scraping of the interior to remove soiled bedding. Treatment 2 consisted of bedding removal, washing, and disinfecting. Treatment 3 consisted of bedding removal, washing, disinfecting as described; however to simulate cold weather conditions, trailers were then frozen overnight at -20 0 C and allowed to thaw. Treatment 4 consisted of bedding removal washing, disinfecting and drying. Following each treatment, naive sentinel pigs were housed in trailers for 2 hours. Only treatment 4 prevented pigs from becoming infected with PRRSV. Scott Dee believes biosecurity for PRRS comes down to four things 1. Having a naive source of breeding stock and semen. 2. Insuring that the interior of the transport vehicle is always dry in every case. 3. Controlling the risk of insect entry. And 4. Controlling the risk of PRRSV-contaminated aerosols. Dee goes on to propose questions that should be asked about biosecurity such as: Should we have different protocols based on season? Do we need to reconsider barn design?  Can we still live with naturally ventilated facilities? and other questions that should be addressed as we battle the PRRS virus.

Accurate screening for porcine reproductive and respiratory syndrome

Posted in: Air Filtration, Pork Insight Articles by admin on August 30, 2003 | No Comments

The PRRS virus is very detrimental to a swine herd and can be very costly to producers. Being able to test for PRRS is crucial, the IDEXX HerdChek* PRRS 2XR test kit which can detect antibodies from European and North American strains of PRRS in pig serum, is a good tool for producers to have for early detection of the PRRS virus. This tool  has a 1:40 dilution of serum with 30,30,15 minute timing. The IDEXX HerdChek provides a fast, accurate, sensitive and easy to use tool due to the incorporation of diagnostically important epitopes representing the two major type strains of PRRSV.

Evaluation of mosquitoes, Aedes vexans, as biological vectors of porcine reproductive and respiratory syndrome virus

Posted in: Air Filtration, Pork Insight Articles by admin on August 29, 2003 | No Comments

This study tries to determine if mosquitoes are able to transport the PRRS virus form one swine herd to another. To achieve this the study looked into the duration of viability and the site of PRRS virus within the mosquitoes. The researchers evaluated if PRRS could be transported to a susceptible pig by mosquitoes who had fed on an infected pig 7-14 days earlier. The tests consisted of 100 mosquitoes that fed on a pig which was experimentally induced with PRRS. The mosquitoes were then kept alive under lab conditions. 10 mosquitoes were then collected a various time intervals: at 0 hour (h), 6 h, 12 h, 24 h, 48 h, 72 h, 5 days (d), 7 d, 10 d, and 14 d post-feeding. Samples of various mosquito parts were taken to determine if they were PRRS positive. Infectious PRRS that would infect pigs was only found on the gut homogenates of mosquitoes collected at 0 and 6 hours post feeding. The second experiment involved 30 mosquitoes who feed on  PRRS infected pig and then after 7, 10 and 14 days after feeding the mosquitoes were allowed to feed on a PRRS negative pig. The PRRS negative pig did not contract the virus nor did the mosquitoes have any traces of PRRS on them. This lead to the indication that mosquitoes are not a likely source of biological vectors for PRRS.

The Financial Impact of PRRS Virus

Posted in: Air Filtration, Pork Insight Articles by admin on August 28, 2003 | No Comments

Some of the financial losses from a PRRS infection are more deaths, poor growth performance, increases of other diseases, and the use of more medications and vaccines. Outbreaks among the sow herd have been estimated to be around $250 per sow and as high as $302 per sow. The costs involved with persistent infections in the breeding herd or growing pigs are difficult to quantify, some authors believe it to be around $6.25 to $15.25 per pig. Following a PRRS outbreak the chances of other diseases infecting the herd can be increased significantly, which can cause huge losses to producers. Most producers spend more money on diagnostic testing and herd monitoring after their herd becomes infected. Budget analysis can provide a simple method for estimating the cost of the diseases on a farm and help justify the money spent developing control strategies.

Costs of PRRSV in Commercial Production

Posted in: Air Filtration, Pork Insight Articles by admin on August 27, 2003 | No Comments

The PRRS virus is a serious problem for hog producers but it is often difficult to understand the economic impact of PRRS on a herd. In order to acquire a solid understanding of the impacts of a PRRS outbreak, researchers looked at hog operations in the mid-west United States to gain data. Sites were ranked based on there PRRS infection rates: 0 – consistent production of PRRS negative pigs, 1 – PRRS infected herds with no sign of PRRS in the nursery, and 2 – PRRS positive pigs in the nursery. Pig flows were tracked over seven months, and nursery data and finishing data was collected. Analysis of the data was able to provide a good look at the cost of PRRS, stating that:  Income per pig weaned for status 0 was $42.64, for status 1 $40.46 and for status 2 it was $35.57. Also the PRRS status of each site moved linearly with wean-finish performance.

Evaluation of 4 intervention strategies to prevent the mechanical transmission of porcine reproductive and respiratory syndrome virus

Posted in: Air Filtration, Pork Insight Articles by admin on July 14, 2003 | No Comments

Four intervention strategies were tested on their ability to help prevent the spreading of PRRS. The four methods were: the use of disposable boots to prevent contamination of personnel footwear, the use of a boot bath to sanitize plastic boots, the use of plastic slated floor in the anteroom to prevent the spreading of PRRS to other peoples footwear, and the use of bag-in-a-box shipping methods to prevent PRRS virus contamination of the contents of a container destined for a swine farm. Ten tests were done with PRRS positive replicates as well as ten PRRS negative replicates were done. Swabs were collected from different sites and tested by a TaqMan polymerase chain reaction for PRRSV RNA and by swine bioassay to confirm the presence of infectious PRRS virus. The results showed that disposable boots, the boot bath and bag-in-a-box were all very effective in preventing the spreading of the PRRS virus. The slated floor did not do a good job in preventing the virus as it was an area where outside footwear could contact it and leave traces of the virus behind. This information is interesting although the study was not large or took statistical significance into consideration, therefore it is recommend as a pilot study rather than a biosecurity protocol.

Wastewater treatment system for pressure wash equipment

Posted in: Air Filtration, Pork Insight Articles by admin on June 12, 2003 | No Comments

Three new filtration systems are showcased in this publication by filtsep.com. They are:

• The PressureClear system from Turnkey Solutions Inc – A wastewater treatment system for pressure wash equipment
• The FEG™ Plus tubular membrane from Koch Membrane Systems – A high temperature/pressure tubular membrane system
• DelPore™ synthetic HEPA media, from DelStar Technologies Inc – A synthetic HEPA media that prevents dust overloading

The ‘Alaskan pipeline: A new model for evaluating aerosol transmission of swine pathogens

Posted in: Air Filtration, Pork Insight Articles by admin on May 29, 2003 | No Comments

There has been debate about the transmission of the PRRS virus through the air, some do not believe it is possible while other state that PRRS can be transmitted by aerosols. One test to prove if PRRS transmission by aerosols was possible involved pigs being held in  a transport trailer 30 meters from the side of a swine barn that had fans blowing in the direction of the trailer, and inside the barn there was PRRS positive pigs. There were no air samples that tested positive for PRRS inside or outside of the barn and obviously no pigs in the trailer became infected. This experiment didn’t shed any evidence towards proof  of PRRS being transported through the air, but the experiment did have a large number of variables that could have possibly manipulated the results such as the weather and the types of fans used. To make the experiment less subject to variables, Scott Dee used a 150m long PVC pipe with an air collector on one end and a fan on the other end. A  spray can of PRRS solution was sprayed into the fan side of the tube and collected on the other side. Air samples on the other side of the pipe were tested and were found to be PRRS positive. Then two pigs were held in a box on the non-fan side of the tube and sprayed with the solution, one of the pigs contracted the PRRS virus. This experiment was eye opening to the people who did not believe that the transmission of PRRS was possible by aerosols.

Quantitative Selection for Piglet Survival as A Safe Way to Reduce the Cost of Weaners

Posted in: Production by admin on January 1, 2003 | No Comments

Improving piglet survival has three reasons, including general success in selection for increased litter size; larger litters increase the necessity of fostering, and concern for animal welfare. Losses in litter size occur in the uterus, farrowing, and pre-weaning. The survivability depends on the piglet’s genes, the maternal genes, and the milking sows genes (if fostered). Simultaneous selection for litter size and birth weight will increase birth weight dramatically, but will not increase survival nor increase litter size. Eight years of selection for litter size and piglet survival can increase litter size and survivability. Almost all economically important traits can be improved genetically. Even for a trait with a very low heritability (such as piglet survival) genetic progress can still be made. Some work being done is on survival and birth weight, survival and fatness, survival and feed intake, and survival and mothering ability.