FORMULATION – Diets with a high dry matter content will have a reduced intake especially if they are over 50% DM. The dryer the diet then the more the cow must chew, and she has to produce more saliva to digest the fibre slowing the passage through the rumen and reducing it efficiency. The ideal Dry Matter for a dairy cow diet is 40% to 45% to maximise intakes. If silages are dry using moist feeds like brewers’ grains will help with DM and adding water or Molasses will make a big difference.
The NDF percentage of the diet is important when formulating and key to getting the diet right for high yielding cows and there DMI. If the NDF is too high, then intakes will reduce and can cause acidosis especially when a large amount of dairy compound feed is being fed in one go. This is caused by the lack of effective fibre in the rumen to balance the rapidly fermenting dairy compound.
QUALITY – Cows need high quality feed which is fresh and palatable to keep their DMI as high as possible. They have a very refined sense of smell and taste and can reject feed quickly as their Rumen contains bacteria which are very sensitive. Spoilage or moulds quickly heat up the diet and reduce the DMI and feeding cheaper by products which will go off quickly can be a false economy.
Cows like consistency and is the reason why a TMR works well and getting the same feed every day increases the DMI. The chop length is also important cows can easily sort feeds greater than the width of their muzzle which is about 8 cm long. Longer dryer feeds can sort out by more dominant cows, and this can lead to those cows getting more concentrates and not enough fibre which will cause sub-acute acidosis. Other cow’s which are less dominant will therefore get more fibre in their diet and their intakes will be reduced.
PRESENTATION – Ensuring cows always have access to feed and water all the time outside of milking is key to maximum DMI intakes. Pushing up the TMR is very important but pushing it up again 20 minutes later will allow the dominate cows to get up the first time and fill up. Then the second time the less dominate cows and heifers will have a chance
CONCLUSION
Maximising DMI is key to profitability, a well formulated diet using high quality ingredients which is well presented to cows will ensure that they have every chance to maximise their potential. One of the most important ways to check DMI is to monitor what the cows are really eating compared to what they should be eating according to the formulated diet. This can be done easily by weighing how much forage is actually going into the feeder wagon or feed bunker, even a small difference can have a big impact.