Not really the same thing, but it did remind me, my brother works at Walmart and they have employee discounts (I think for 'nonessential items' is what they say) and the discount covers sugary and junk food items, but not meats or fresh produce. Employees (at least at his store last I heard him...
We only have actual green grass for about a month and a half out of the year where I live, and the rest of the year they need to be almost exclusively supplimented We think they get so excited and know it will go away quickly and just gorge themselves on it.
Absolutely. Sheep are worse though. We can't even let them graze in the spring because they will actually eat too much grass when it's green and actually tasty.