TMR or corn silage (CS) types


TMR - Type 1: carbohydrate pool digestion rates

•    CB1 Kd 18-20%/hr

•    CB3 Kd 5-6%/hr

•    Ideal ‘fast pool’ and ‘slow pool’ rates


•    Good manure consistency

•    High dry matter intake (DMI)

•    Excellent milk yields

•    Exceptional feed conversion 

Actions to Consider

•    Watch for (prevent) sudden changes in feed delivery or consistency.

•    Ensure adequate peptide and degradable crude protein to feed rumen microbes.

Corn Silage - Type 1 

•    Rapid fibre digestion.

•    Rapid starch digestion.

•    DMI will be good.



TMR - Type 2: carbohydrate pool digestion rates

•    Small pool of CB1 that disappears quickly

•    CB3 Kd: 5-6%/hr

•    A small ‘fast pool’ but ideal ‘slow pool’ rate, resulting in insufficient energy supply


•    Grain in manure

•    Low milk protein

•    Milk yield lower than expected

•    Rough hair coats

•    Poor reproduction

Actions to Consider

•    Increase supply of rumen-available starch and sugar (CB1 Kd of 20-22%/hr)

•    Grind grains finer

•    Ensure adequate supply of peptide and NPN protein

Corn Silage - Type 2

•    Fibre digestion is slow and not extensive.

•    Rapid starch digestion over a short period.

•    Potential Acidosis


TMR - Type 3: carbohydrate pool digestion rates

•    CB1 Kd: >25%/hr

•    A fast ‘fast pool’ and a slow ‘slow pool’, resulting in a high acidosis potential


•    High acidosis potential

•    Sore feet, reproductive problems, poor DMI

•    Ketosis in early lactation cows

•    Fibre in the manure - low rumen pH

•    Variability in body condition

•    Fat/Protein inversion in >10% of the herd

Actions to Consider

•    Increase NDFD by adding non-forage fibre sources

•    Slow CB1 Kd to <5%/hr

Corn Silage - Type 3

•    Good fibre digestion over a long time period.

•    Slow Starch digestion.



TMR - Type 4: carbohydrate pool digestion rates

•    CB1 Kd: <15%/hr

•    CB3 Kd: <5%/hr

•    A slow ‘fast pool’ and a slow ‘slow pool’


•    Cows look “ok”

•    Poor milk production

•    Early peak / Poor peak milk

•    Average milk components

•    Stiff manure despite adequate dietary CP

•    Reproduction - delayed, but not too bad

Actions to Consider

•    Increasing rumen available starch and sugar

•    Grinding grains finer

•    Increase NDFD by adding more non-forage fibre (beet pulp, brewers, soyhulls, etc), and/or more digestible forages.

Corn Silage - Type 4 

•    Fibre digestion is neither rapid nor extensive.

•    Starch digestion is neither rapid nor extensive.

•    DMI may suffer.