Quote:
The quote you provided is overstates the issues just a bit.
First, the amount of vitamin degradation is an issue, but not enough to worry about especially with new coatings used to protect vitamins now.  Plus, the cost of the "extra" vitamins pales in comparison to the high prices of the commodities used to manufacture the remaining 99% of the feed.
Second, the quote does not address the improved digestibility of pelleted feeds due to the gelatinization of the starches in the grains.  With the ever increasing price of feed commodites more and more feeds will/should be pelleted to gain further efficiencies.
Third, not all feeds require a binder to produce a high quality product.  However, if a binder is needed it is used at a very low level that would not affect the cost or nutritional value of the feed much.
Finally, pelleting of feeds prevents separation of feed ingredients during transportation and feeding.  This is typically not an issue in traditional Corn-Soy feeds, but when we use other feed ingredients with varying particle sizes the use of pelleting improves the feeding characteristics of feeds.
A "mash" feed is simply the feed that is a mixture of feed ingredients that has not been processed after mixing, much like a cake mix.   To produce a pellet the feed (mash) is heated and conditioned with steam just before the mash is forced through a die that produces the pellet.  The length of the pellet is regulated by a scalping knife on the pellet mill.  A crumble is produced by processing the pellet between two rollers.  
To determine which form of feed to use a producer must weight the economic and phisical advantages of a processed feed agains the simple ground feed (mash).
Jim