The changes coincide with the shift to three-site production, one for farrowing, another a nursery and a third for finishing hogs to market weight.
The survey found that in 1992, only five per cent of hogs were produced under contract. Now it’s 69 per cent.
In North Carolina, where the three-site, large-scale revolution began, it’s now 91 per cent.
From 1992 to 2015, the average number of hogs sold per farm rose from 945 head to 8,721 head.
In 1992, 97 per cent of hog operations were independent but by 2015 it was down to 47 per cent.