The impact of the PED virus in swine was felt most strongly during the unusually harsh winter months of December through February, Purdue University agricultural economist Chris Hurt said Monday (March 31).
He said this means the losses of baby pigs probably will decrease as the weather warms this spring.
Hurt said the U.S. Department of Agriculture's report showing how much the nation's inventory of market hogs decreased in the past six months was perhaps the most anticipated report for the pork industry in decades. It was the industry's first opportunity to get a national, comprehensive measure of the baby pig losses since porcine epidemic diarrhea virus was first identified in the spring of 2013.
PED is a virus of swine that is fatal to nearly all infected piglets less than 2 weeks old. There is no vaccination or treatment. Health experts say the virus causes no harm to humans and is not a threat to food safety.
"While PEDv was in some hog herds last summer, the national data does not pick up any impact on pigs per litter during the warm weather," Hurt said.
The USDA Hogs and Pigs report, released March 28, was based on a random survey of 6,100 pork operations across the country in early March.
The nation's losses of baby pigs over the past six months appears to have been about 5 percent of the total herd, according to Hurt's analysis of data from the report. The market expectations had been for about a 7 percent loss. His analysis would suggest that about 600,000 baby pigs were lost in the fall and 2.1 million were lost during the winter because of PEDv and the weather.
Hurt said the best way to evaluate the magnitude of losses is to examine the number of pigs per litter, which measures the number of pigs that were alive when the survey was conducted. As expected, the losses were greater in the winter quarter, which spanned December 2013 through February 2014. During that period, the national average number of pigs per litter dropped to 9.53, compared with an expected rate of 10.3, a decline of more than 7 percent.
During the warmer quarter of September to November, baby pig losses were running about 2 percent.
As the weather cooled, the percentage of losses increased monthly from 2 percent in October to 8 percent in February.
"The large losses experienced in February probably mean that losses will continue to be large into March but may lighten as the weather warms into April and the rest of spring," he said.
Hurt said it was not possible to determine how much of the lower rates were the result of PEDv and how much were from the unusual weather.
The report, which has data on 16 of the major pig production states, indicated that states with very large losses of pigs over the winter were Ohio, Missouri, Colorado, North Carolina, Oklahoma and Michigan. Indiana along with Iowa, Kansas, Illinois and Nebraska had moderate reductions. States showing little or no losses were Minnesota, Pennsylvania, Texas, Utah and South Dakota.
The USDA report is available at http://usda01.library.cornell.edu/usda/current/HogsPigs/HogsPigs-03-28-2014.pdf.