It's the same at all trucking companies. JBS is no different. Do a forum search on per diem. There are several threads on the topic.
Trucking per diem is not like normal per diem. They don't pay you anything. Instead of getting $59 a day, they give you a tax break on $59 of your own money you earned. It's just another way truckers are mislead and screwed because we are exempt from many labor laws.
You are better off opting out from per diem. It looks like you made less on your W-2, which cuts down on your Social Security, Medicare, 401K, Disability and Unemployment. Companies love it because it cuts down their matching shares and payments to the gov't.
You get the tax break come tax time anyways when you figure your per diem there. The only difference is getting $40 a week now in saved tax money or waiting until your tax return and getting it. I'd rather get the most out of my benefits and wait until tax time and get a bigger return.
My niece works on the road doing fiber optics. She started a new job out of state in Denver last month. She gets $60 a day per diem, paid with a seperate tax free check on top of her paycheck. That's the way it's suppose to be.