Evaluation and Management of Nutritional Status
written by Tyler Melroe South Dakota State University
We all have different perspectives. From the way our government approaches challenges, to the way two different judges may sort cattle we should realize that everyone has their own unique world view. This has certainly become prevalent in the beef industry as we see everything from operations promoting decreasing mature cow size to seedstock being marketed for maximum performance. Obviously your world view of the beef business is going to affect the type and kind of cattle that you raise.
Evaluating Nutritional Status Whether you like big ones, little ones or anything in between, maintaining the appropriate body condition score (BCS) is critical to the reproductive success of your cowherd. Evaluating the BCS of a set of cattle, most typically cows
and replacement heifers, can tell you a lot about their energy status in relation to daily requirement. The most common system in the beef industry utilizes a scoring system that ranges from 1 to 9. Table 1 indicates factors in evaluating BCS. Managing your herd’s reproductive success will primarily work around the evaluation of BCS. In an era where the term “efficiency” has become vogue it is important to define the context in which we are using the term. Are you feeding cattle, looking to reduce the amounts of inputs required to attain an optimum average daily gain? What if your business is the cow business? In what context do you use the term efficiency? In the cow business it revolves around reproductive success. No matter what their level of condition is, the cow that can
provide the greatest output over her maintenance requirement AND breed back early is the most efficient. Table 2 shows where body condition plays into the reproductive equation. From an economic standpoint targeting a moderate BCS (4-6) likely optimizes the efficiency equation. Evaluation of the efficiency in the showring has essentially led to selecting for greater levels of body condition, in nearly every case attained by grain feeding. The accuracy of that assumption could be argued exhaustively. However, it will be critical when making your management decisions you understand full well what your resources are, what they cost and what they return.
Making the Adjustment First, your environment, goals and genetics make a significant difference. You must define where
Table 1. Physical evaluation of Body Condition Score BCS)
Condition Score Reference Point
1
2
3
4
5
6
7
8
9
Muscle Atrophy
yes
yes
slight
no
no
no
no
no
no
Visible Spine
yes
yes
yes
slight
no
no
no
no
no
Visible Ribs
all
all
all
3-5
1-2
0
0
0
0
Fat in Brisket and Flank
no
no
no
no
no
some
full
full
extreme
Visible Hip and Pin Bones
yes
yes
yes
yes
yes
yes
slight
no
no
*Adapted from Pruitt and Momont, 1990 182
May/June/July 2011