Feeding Strategies, Part 4 - What to watch for

The first major challenge to implementing “densified” grain mixes is to realize that cost per ton of grain mix will be higher. However, if the feeding rate per cow is less, the cost per cow per day can be lower than before. (Don’t assume – do the math to determine this.)

Also, sometimes animal performance can be better on these denser grain mixes, so accounting for increased milk production by calculating milk income over purchased feed costs should be done.

When feeding less purchased grain in total to the cow, it is important to realize that a cow will likely attempt to still maintain her daily dry matter intake. It is important to ensure that there is forage available for her to eat to maintain this intake, and preferably, good forage. Offering additional forage will give the best chance for additional milk response an will ensure that no body condition is lost due to reduced total energy intake once grain intakes are lowered.

Another challenge in feeding nutrient denser grain mixes is providing enough minerals. If you choose to put all of the minerals in one of two feeds, low feeding rates can make it a challenge to get enough minerals in the cow each day. While minerals can be “densified,” as well, there is a point at which you can run into palatability problems with the grain mix. Palatability enhancers, like molasses, can be used to overcome this problem. Some farmers choose to put minerals into both mixes, or choose a grain that is fed in greater quantities (usually the energy mix or corn meal). Minerals that can be of particular concern are salt and calcium, both of which are required in large quantity. Cows should be offered at least ¼-pound of salt each day and shorting cows of salt can really cut production. Salt can easily be top dressed loose or offered free choice if it can’t be delivered in the grain mix. One salt block to more than 10 cows does not constitute free choice.

Lastly, feeding a concentrated mix in component fed herds, if not done carefully, can lead to challenges in managing protein levels in the diet. A small change in the amount of grain fed can make a big change in the amount of protein consumed and can lead rot excess protein fed (which is expensive and detrimental to the cow, especially body condition and reproduction). This can be a challenge, especially when forage quality is changing often. Using MUN (milk urea nitrogen) analysis is an invaluable tool for monitoring dietary protein inadequacy. Whole herd average MUN should run between 10 and 14 mg/dl. It is not uncommon to see well-managed diets running 8 to 11. Lower than 8 may signify too little protein in the diet. Individual cow MUN levels should not be running about 18 mg/dl. If you see many cows over 18, there is probably too much protein or too little rumen fermentable carbohydrate in the diet. Most creameries now offer MUN analysis, and it can be obtained through DHI.

Does it work?
Using this strategy in 2007, one PFM farm lowered its grain purchases as percent of milk receipts 10 percentage points n one year, while milk production per cow continues to increase.