U.S. farms hold 68.4 million head of hogs, up 4 percent from a year ago when the sector began to recover from the Porcine Epidemic Diarrhea virus that killed millions of piglets and drove pork prices to record highs, said the USDA in a quarterly report. The Hogs and Pigs report, which estimated the hog population as of Sept. 1, was the second in a row to show a larger hog population. “This is the highest inventory of all hogs and pigs since quarterly U.S. estimates began in 1988,” said the department. There were 62.4 million hogs being fattened for slaughter, up 2 percent from June 1. The number of breeding sows and boars was up by 1 percent from June. The pig crop during June, July and August was 1-percent larger than the same period in 2014.