Snaplage ‘recipes’ to minimize milk fat depression – Pat Hoffman, Vita Plus

By Pat Hoffman, Vita Plus dairy technical specialist
This past summer at Vita Plus, we evaluated a new ration formulation sub-model that accounts for the rumen unsaturated fatty acid load (RUFAL) in the ration.  Research has demonstrated that feeding dairy cows excessive levels of RUFALs has a negative effect on milk fat test.  In fact, in our summer project, more than 50 percent of the variance in milk fat percent across herds could be explained by accessible RUFAL concentrations in the diet.

So where do these RUFALs come from?  Well, unfortunately, the majority of accessible RUFALs in our dairy cow diets come from corn silage, high moisture corn or snaplage.

We’ve all heard of corn oil, right?  Corn has an abundance of RUFALs located in the corn germ.  Regrettably, these RUFALs in corn silage and snaplage are easily accessible to rumen microbes.  Sometimes rumen microbes improperly convert the RUFALs in corn to a family of fats called conjugated linoleic acids.  These bioactive fats have demonstrated an ability to suppress milk fat production in numerous research trials.

So here is the rub.  Are we planning to feed a high corn silage diet with snaplage?  This may work in the fall and winter when RUFALs are less accessible in corn silage or snaplage, but this could be a sure path to milk fat test depression next spring and summer when the RUFALs are fully accessible.  This past spring and summer, we evaluated 16 high corn silage rations (rations with more than 20 pounds of corn silage per cow per day) in which snaplage was also fed.  The mean milk fat percentage of cows fed these diets was 3.53 percent, and all diets exhibited some level of milk fat suppression.

It is understood that snaplage does have many well-defined feed production advantages.  We can use regular corn silage harvesting equipment to harvest snaplage and it can be harvested earlier than dry corn.  This opens up land earlier for fall manure applications and cover crop plantings.  So, if snaplage is going to be made, here are some “recipes” to help minimize milk fat suppression.

Recipe 1:  Don’t feed snaplage in combination with high levels of corn silage in the late spring through the end of summer because the RUFALs are too accessible in both.  Make only enough snaplage to last eight months and feed dry corn during the late spring and summer.

Recipe 2:  Ensile snaplage in storage units that can be easily shut down.  For example, snaplage stored in bags is easier to shut down and stop feeding than snaplage stored in a wide bunker silo.  This gives us the option to shut down the snaplage storage unit for the summer and pair the fully fermented snaplage with less fermented new crop corn silage at a later date.

Recipe 3:  Do everything to make snaplage as aerobically stable as possible.  Use Crop-N-Rich^® Buchneri or Stage 2 inoculant to improve aerobic stability.  The reasoning is, in the event that snaplage feeding rates have to be reduced to maintain milk fat test, the face of the ensiled snaplage can withstand the reduced removal rate and remain stable.

Recipe 4:  Don’t make too much snaplage.  In fact, it may be more beneficial to make less snaplage than needed because having too much snaplage often forces a higher feeding rate to manage the storage systems and inventory.

One recipe may not fit all, but these recipes serve as a template you can use to feed a diet with high corn silage and snaplage and minimize milk fat depression.