A:   The short answer to your question is that we don't believe ration DM has much impact on conversion, DMI, or ADG, and certainly not at these levels of DM or moisture. I believe some of that thinking started with higher moisture grains and higher moisture corn silage. It is possible that higher moisture fermented feeds like silage and high-moisture corn may decrease DMI, but the mechanism is not directly related to too much water in the diet, as you point out. The likely explanation is that the starch is more fermentable in these feeds when fermented at higher moistures, causing some rumen metabolism challenges (potentially).

Further evidence for this is the moisture content of lush pasture is less than 20% DM and cattle perform well on lush pastures. More evidence is that the rumen contents are normally 85% water. We believe cattle just tend to drink less (and still have to consume water). There are some challenges with greater moisture in finishing diets, but too much water for optimum performance is not one of them (in our opinion). Real challenges are potentially bunk spoilage (maybe freezing in your part of the world), and some increase in feeding costs due to hauling more water. For smaller beef producers, this is likely not an issue.

Now, you may observe decreased DMI intake with wet byproducts at high levels, but that mechanism could be different and is likely at very high inclusions. You should watch S content as that can depress intake, especially if S is high in the drinking water.

If you want to see our data on feeding very high levels of wet byproducts, you can download a recent extension publication we have on the web at the internet address on my address line below. On the left side there is a tab for "byproduct feeds". If you go there, there some different things for producers and the publication (item 1) can be downloaded as a pdf or viewed online as html format. This is our best summary to date for producers. From that, we have observed improved ADG and conversions out to 40% of diet DM for traditional wet distillers grains plus solubes (35% DM, 65% water). We have also recently completed a study using modified wet distillers grains plus solubles (43% DM). That is also in a new beef report article (2008 Nebraska Beef Report).