Feedstuffs Analysis

The Feedstuffs magazine I received  recently contained the Feedstuffs Ingredient Analysis Table: 2017 Edition.  This summary is published every year and contains basic nutritional data on most commonly available feedstuffs. I knew I had the 1977 Edition in my files and surmised that a comparison of some of the data would be interesting.   Little did I realize that it would raise more questions than it answers.

Here is a comparison chart of three common feedstuffs.  

I anticipating that there would be some changes in nutritive value  but found only four is this admittedly small sample.

  • There was a 10 percent increase in phosphorus levels in corn.
  • There was a 16 percent decline in crude protein in corn.
  • There was a 19 percent decline in crude protein in wheat.
  • There was a 27  percent decline in ash or mineral content in corn.

The most astounding thing to me was the absence of change.  In 40 years, the analysis of dehydrated alfalfa meal was exactly the same - ditto for all the rest of the data in the chart. 

Specifically, I am curious to know how crude protein in corn and wheat  can decline 16 to 19 percent respectively and  the ruminant digestible protein not vary at all?.   

I know there could be some difference because of changes in analysis techniques and I know they are averages - but almost everything being identical after 40 years makes me suspicious of the validity of this data.  If at all possible, we should rely on individual testing of any feedstuffs included in out livestock rations.