In less than three years, the gross debt of the top five Chinese pork producers increased by nearly threefold, S&P Global Ratings said in a report Wednesday.The outbreak of African swine fever beginning in 2018 decimated herds, and lured many businesses into China’s hog industry to take advantage of high prices, government subsidies and easy financing.But the rush to expand pork production means the indebted companies now face pork prices that have lost half their value in less than two years. $S&P Global Infrastructure Index Ishares (IGF.US)$