Case Study: A Nutritionist’s Strategy for Solving a Starch Discrepancy in the Delivered TMR

Written by: Kevin Buttles, MAT. PAS Sometimes it is easy to get lulled to sleep when there is not much going on at a client’s farm – forages are the same, no fresh cow problems, no real health problems, and components are right on target.  A closer look at the farm’s historical data and a frank discussion regarding goals and expectations with the herd owner revealed a recent slump, or at least a stall, in pounds of milk produced.  My first step was to take a TMR sample for analysis and to compare the results to the formulated diet.  We have all done that.  Many of the nutrients were right on, but when the results showed four whole percentage points less in starch (22.5% instead of 26.5%), I knew I had to attack this problem from multiple angles right away.  I implemented the following investigative strategies during the next six weeks to assess big picture items and to scrutinize the smallest of details. First I retested on-farm forages and HMSC and tested the purchased corn and starch containing commodities. Dry matters needed to be corrected. When I updated the diets, I juggled around different corn sources to take advantage of different starch fermentation rates. I closely evaluated RD starch, kd rates, CHO B3 pdNDF, and uNDF in the CNCPS model.  All seemed to be good. Then I utilized the oven-dried, 7hr lab procedure on the starch containing feeds to take advantage of one of the newer starch digestibility lab procedures to improve accuracy of reporting starch kd rates.  I felt confident that I was supplying sound nutrient data for...