Milk Fat Troubleshooting Checklist

Best Axis has complied a quick summary of the causes for milk fat depression. Milk fat depression is an old story, but it does manifest on dairies at inconvenient times. When brought in to help correct a low milk fat case, below is the checklist we go through with our clients to help determine the root of the problem. This is the order of how we examine the ration together and start finding the solution:

CHECKLIST:

• • Dietary polyunsaturated fat load-Unsaturated fatty acid intake should ideally be under
    1.5 pounds per day. This is often from corn oil in silages and distillers’ grain
  • Carbohydrate type and degree of processing
  • TMR particle size
  • Particle size sorting of the TMR (Caused by moisture level, poor mixing, forage length)
  • Rumensin/ionophore level
  • Mold or mycotoxins from forages or wet byproducts
  • Rate of fiber digestibility
  • Physical exposure of liquid fat versus oilseed fat
  • Unknown liquid fat specs and subsequent polyunsaturated fat load
  • Effective neutral detergent fiber (NDF) of the ration and actual chewing time
  • Feeding management (Time of delivery, amount delivered, forage selection, empty bunks, slug
    feeding, competitive eating, bunk displacements)
  • Acid load of the TMR (pH) and amount of ensiled low-pH/rapidly fermenting forage that is being fed. Consider very rapid carbohydrate fermentation rates, which all the other factors will not overcome even if balanced (a common problem with lush grass, wheat grain, and high-moisture corn)
  • High water sulfates
  • Accuracy and consistency of the actual formulation mixing, including dry matter adjustments
  • Mixer wagon scale accuracy
  • Moisture monitoring for humid and dry weather fluctuation
  • Fermentation profile of the silage

Adapted from Mullins for Progressive Dairyman September 29, 2017