Corn silage processing score (CSPS) or kernel processing score is a tool that is talked about a lot in the dairy industry and is useful for evaluating corn harvest management and starch availability to cows. I  recently received questions about the variability of CSPS when tested on the same corn silage and the difference in CSPS score in fresh versus fermented corn silage.   

 

Corn silage processing score represents t he percentage of starch that passes through the coarse sieves ( particles < 4.75 mm) derived from the adequately processed kernels. The percentage of starch passing through the 4.75 mm sieve is determined by subtracting the amount of starch that did not pass through the 4.75 mm sieve from the total starch in the sample. The percentage of starch that passed through the 4.75 mm sieve is the CSPS. The guidelines for interpreting the results are:  

Variability of CSPS through a harvest day 

As part of a project in Fall 2015 , the Forage Lab analyzed CSPS on fresh corn silage sample d four times through out a harvest day on four different farms (Table 1).  Each farm used a different chopper. On average, CSPS was adequately processed on all the farms (Table 1) . The largest within - farm difference of CSPS was seen at Farm 3 (15.4 %) and the smallest difference was at Farm 4 (5.3 %) . There was no trend on any of the farms for CSPS to decrease or increase through out the sampling day (Table 1) . Sampling one time during corn silage harvest does not look like a good way to evaluate CSPS. However, multiple samples in a day are not practical, but sampling every day or every few days during harvest will provide a better evaluation of processing performance and be a good tool for management.