Here is an interesting result which illustrates the impact of variation on the optimal selling weight of finisher pigs. The optimal weight of a single pig can be readily calculated if you know the approximate feed efficiency and adg for the last couple of weeks of finishing as well as an expected market price. In general you want to add the next lb as long as the value received for that lb is in excess of the cost.
As you add lbs each day in late finishing, adg tends to stablize around 2 lbs per day but feed efficiency begins to deteriorate. Therefore, each additional lb will cost a little more to put on. As you add weight, at some point you will begin to incur a discount to the base price and lean percent will begin to deteriorate. If you know how these things change, you can estimate the optimal selling weight of a single pig.
