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To have the best pig production, health is king. Healthy pigs grow faster, are more efficient, and have a higher survival rate, while ultimately keeping pig costs low. Once the disease is introduced into the sow herd or growing-finishing group, the exact opposite will happen. The severity and its impact on performance and economic results actually boil down to two main factors: health issues and animal husbandry.

Porcine Reproductive and Respiratory Syndrome (PRRS) was first discovered in the United States in 1987-88 and quickly became one of the diseases that had the greatest economic impact on the pig industry. The latest PRRS break was identified as 1-4-4 lineage 1C, touted as the most challenging and costly of all the previous strains.

In this article, an analysis will be conducted to understand the severity of the interruption of positive PRRS in nurseries in 2020/2021 compared to previous years. The nursery analysis is carried out using the MetaFarms Ag platform and only focuses on the United States (US) customers. In the 2020 calendar year, the clearance volume of US MetaFarms customers was slightly more than 9,000 heads (9,085 heads), and the total number of pigs started was close to 17 million heads. 

In order to minimize the spread of PRRS, every stage of production has been modified, and the biggest changes have taken place in the sow farm. Some sow farms have been modified by filtering to change airflow, enhancing biosecurity measures at supply and personnel entry points, and changing the way animals are transported and moved. One of the main reasons why sow farms have and will continue to undergo so many changes is the trickle-down effect on nursery and fattening performance and the resulting economic impact.

When PRRS was first introduced to the sow farm, the impact on sows was much smaller than the impact on piglets. Generally, PRRS affects sows with low piglet survival rates, abnormal abortions, and higher than normal mortality rates. After a period of time, the impact on the sow is minimized. However, the impact on weaned piglets will continue until the sow is healthy and stable.

In this article, we will use the latest closing performance to focus on the kindergarten performance in the beginning months before and after the PRRS season. Figure 1 shows the average mortality percentage broken down by month. The gray line indicates that in 2020, there will be a clear separation from October to December, which shows us the severity of the 1-4-4 strain. In this 40-month analysis, the average value in December 2020 is 4.98%, which is 0.66% higher than the next highest month in January 2018 (a change of 15.3%). It lasts until the first few months of the next year. 

Figure 2 shows the average annual mortality rate broken down into three different percentiles. The top 10% represents the best 10% of the groups that closed within that time frame, while the bottom 10% shows how the worst groups are closed. This chart shows the severity of PRRS interruption when the nursery is closed. All regions except the top 10% are higher than those in the previous three years. For 2021, the month involved is the group starting from January 1 to April 30. 

Digging deeper into the performance and economic differences of the nursery mortality groups, Figure 3 shows three different breakdowns of mortality percentages between 2019 and 2021. The nursery closing groups with mortality rates below 2% are grouped together to provide the same logical analysis of the other two brackets. In 2021, 24.5% of the groups ended with mortality rates exceeding 5%, compared with 14.9% in 2019. Note that not only is the average mortality rate different in 2021, but also the increased feed cost per pound compared to 2019. Compared with 2019, the cost of feed in 2021 has increased, but the difference between these groups is $0.1047, which is 38% higher, which cannot be ignored because it shows how high the cost of cultivating these health challenge groups is.

In July 2021, the National Pork Industry Conference (NPIC) held a meeting chaired by Dr. Chris Sievers and Dr. Ryan Strobel of the Swine Veterinary Center, focusing on some of the best ways to manage PRRS-positive pigs in nurseries. The conference has some very simple but valuable topics that can help producers and caregivers understand the core foundations of animal husbandry, namely feed, water and air. Both veterinarians pointed out that keeping pigs warm and dry will in turn stimulate water consumption and feed intake, thereby giving pigs a chance to survive. 

One aspect that can also be overlooked is the impact of unhealthy pigs on breeders. Receiving multiple batches or batches of these health-challenged pigs can be frustrating, so if you are an on-site supervisor, we recommend that you praise these breeders for doing well during the challenge.  

The mystery behind why the 1-4-4 lineage 1C PRRS strain is so widespread and challenging is still unsolved, so what can pig managers do every day? Everyone must assume their own role in slowing the spread of the disease. Have you cleaned your vehicle correctly, including the floor mats and other places? Are all products entering the farm properly cleaned and disinfected? With a possible outbreak of exotic animal diseases in the United States, now is the best time to strengthen biosecurity measures, and everyone needs to participate.

MetaFarms Analytic Insights is used to provide the background and trends of this article. If you want to see an analysis of how PRRS affects the performance of your nursery, or if you have suggestions for the production area where you want to write an article, please contact Bradley Eckberg or Ron Ketchem.

Source: Bradley Eckbergy, MetaFarms, they are fully responsible for the information provided, and they own the information completely. Informa Business Media and all its subsidiaries are not responsible for any content contained in this information asset.

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