Beef Cattle Mythbuster
By Dr. Don Llewellyn, Livestock Extension Specialist Director, WSU Lincoln County Extension
via The Ritzville Adams County Journal (WA) - 9/15/2022
Myth: It makes no difference if one calculates cow feed intake on a dry matter basis or an as-fed basis.
Answer: Oh, but it does matter!
Okay, here we go! This is one of those topics that probably caused more confusion among my students than most any question I asked them (or had them calculate on an exam!). Let’s make some practical sense of this and how it applies to the real world for cattle producers.
Before we can address this concept, we define our terms: As-is (or as-fed) basis refers to selling or using feed with no adjustments made for moisture content. On the other hand, feed sold or used with adjustments made to account for variation in moisture content is referred to as dry-matter basis. So why does this really matter? Two reasons come to mind that we need to address here: 1) when calculating projected intake, we do so on a dry matter basis and 2) it is also important when determining if the cows’ nutritional requirements are being met.
Being able to systematically figure out how much a cow will eat is useful in determining how much hay or other commodities will be needed for winter feeding. Table 1 provides some ‘rules of thumb’ for dry matter intake of nonlactating, pregnant cows in the winter:
Table 1. Expected intake of nonlactating, pregnant, spring calving cows during the winter (% of body weight [BW]).
Feed quality | Estimated intake (% BW)
Low-quality forages (< 7% crude protein) 1.5
Moderate quality hay (8 - 10+% crude protein) 2.0
High quality hays, silages, and pastures 2.5