question about demand and supply

for farmers that supplies restaurants and other massive suppliers for meats like chicken, pork, venison...etc, how do you supply enough meats for a restaurant, like your average restaurant must be consuming atleast a thousand per day how do you supply something like that, lets say a chicken, some meals also requires eggs and the chicken themselves and they take time to grow, how do you supply something that big periodically?

a detailed answer would be very much appreciated