10 June 2007

4 minute read

As mentioned in the December, 2006 newsletter the common one being asked was how much can or should I feed. Let’s be clear there are a number of factors which should be considered in answering this question. Let’s review those.

First, what stage of production is the cow in--, mid or late pregnancy or the beginning of nursing a calf? The difference in energy needs between these three stages is substantial. For instance, cows nursing a calf will need 50% more megacalories of Net Energy for maintenance than a cow in the middle of pregnancy.

Second, what feeds are being fed along with the distillers grains? Recently at a meeting one producer asked about supplementing a corn stover based ration versus another producer wanting to supplement a limit fed mixed corn silage and ground hay ration. These are two completely different situations.

A third consideration that was covered in the December, 2006 newsletter was the difference in distillers grains moisture levels. Don’t forget dry distillers only contain about 10% moisture while wet distillers grains typically contain 60 to 70% moisture. The table included in this article shows how to adjust distillers feeding rate for moisture.

So let’s look at four different rations and see how much dried distillers it takes for wintering a 1350 lb late pregnancy cow. First, a ration using poor quality brome hay, 10% crude protein and 52% TDN. You will find that meeting protein needs is not a big problem with this ration, but we need about 4.5 lbs daily of dried distillers grains for energy. This ration contains almost 50% more protein than is needed. As we move into lactation this ration would need 10 lbs of dried distillers grains.

A second ration asked about is supplementing harvested corn stalks. For the 1350 late pregnant cow it would take 5.5 lbs of dried distillers grains and all the corn stalks the cow will eat. This ration would need some Calcium supplementation from the mineral program, but no Phosphorus will be necessary. To move this up to a ration for nursing cows will require about 12 lbs of dried distillers grain daily. A caution here. IF the distillers grains are over .75% Sulfur this ration may be too high in total Sulfur intake.

A third ration combination is stretching hay with both harvested corn stalks and distillers grains and limiting intake. For instance, a 2 part corn stalks to 1 part good quality hay on a limited basis and supplemented with 3 to 3.5 lbs of dried distillers grains works well for a late pregnancy cow. To move this into a lactation situation one will need to feed 15 lbs of dried distillers grains. Again, take note of the Sulfur issue here.

Finally, a number of producers are looking at limit feeding corn silage mixed with ground corn stalks or poor quality hay. Again, for a 1350 lb late gestating cow an example would be 40 lbs of corn silage, 15 lbs of ground corn stalks and 3.5 lbs of dried distillers grains. To make this work for early lactation the ration would need 10 lbs of dried distillers grains. Keep in mind both silage and stalks are low in Calcium and would need some help in that area, plus vitamins and trace minerals.

In summary, keep in mind the amount of distillers grains needed varies according to forages fed and be sure to adjust for moisture content of the distillers that you purchase.