Matt Lamberson

by Matt Lamberson


Upon attending the Forage Club meeting on 3-6-18 and listening to Pat Hoffman, with Vita Plus, discuss his Corn Silage: A 2020 View presentation, I left the meeting with a new perspective on how we need to view corn silage’s roll in today’s ration formulations.

One important focus during my time in the nutrition world has been to improve forage quality whether it is in the form of haylage or corn silage. For the most part we have succeeded very well in improving many things such as amount of protein harvested in our haylages, digestibility of the fibers and starches, reduction of ash, particle size and corn processing scores, improved fermentation and storage management. In addition, we do inventory planning with the goal to achieve enough carry over to allow the feeds to have a long enough fermentation time so all of the “goodies” become more available during the digestion period in the cow.

When we think of corn silage we must consider what is the make up of whole plant corn silage. Well it is a pretty simple concept initially, there is a seed (grain) portion and a fiber portion that we chop up and put into storage and call it a forage…but is it a true forage?

Looking back at where grain yields were in the 1940’s at around 30-40 bushels to where they are today at around 170-180 bushels (these are averages from the USDA-NASS) we need to consider how this “forage” is going to feed. There are numerous variables to consider when the focus is on the starch portion of the corn silage: amount, particle size, moisture, quantity being fed. Along with this we need to consider the other sources of energy in the diet: dry vs. wet corn, snaplage, distillers, other oil/fat products, and let’s not forget the endosperm type…what is the starch-protein matrix? And to top it off what are the kd rates (how fast does the starch digest). So as grain yields increase the ratio to forage changes dramatically and as we look to feed this forage there are underlying implications we must work through to balance the ration correctly.

Below is a chart showing how the % True Forage decreases as the starch % increases.

One of the more recent implications we as nutritionist have been working through is the amount of TFA’s (total fatty acids) in our rations, with this in mind we are attempting to balance the ration to produce the most economical RCM (revenue corrected milk). The higher the starch levels in the corn silage the higher the TFA content in that feedstuff; in addition to what the other ingredients being used to formulate the diet contribute. As the levels of TFA increase in the diet there becomes a higher potential to depress butter fat levels in the milk. In addition to the TFA we must monitor how much UFA (unsaturated fatty acids) there are, which comes from corn/soy oils and indirectly suppresses milk fat synthesis. The worst bad guy we need to look out for is the amount of CLA (conjugated linoleic acid) of which are bioactive at the mammary gland and suppress de-novo milk fat synthesis…and it only takes a tiny amount (2-3 grams) to have a negative impact.

As a part of our ration balancer software we get a report that estimates total dietary TFA, RUFALS (rumen unsaturated fatty acid load), CLA and to what degree they are accessible. With this information we can then determine what impact the current ration ingredients may have on rumen health and milk fat production, thus giving us an awesome model to analyze what options work best to create the most healthy and economical ration. Other considerations we must ponder while formulating the ration are having discussions with the producer about what and when certain feedstuffs should be utilized for optimal performance. Such as using up higher digestible and available starch feeds during the cooler weather months before heat stress increases the risk of butter fat depression instances. Can we feed more corn silage in the winter and more legume silages in the summer? Need to be aware of byproduct feeds and their affects on the ration when other higher starch and oil feeds are being fed.

In conclusion, I’ve come to the recognition that when grabbing a sample of corn silage to send in to the lab for analysis I will continue to have a new perspective of how this “forage” will affect the ration I’m trying to formulate as I realize this is not my grandfathers or fathers corn silage.