Nutrition
The “How” of Body Condition Modification
By Tyler Melroe, M.S., Beef Nutritionist, Hubbard Feeds
Managing a herd’s fertility is a continuous
process in which one must plan for changing
variables, such as weather and lactation.
Developing a strategy as you plan for the next
calving season will help you to get a head
start on managing body condition score (BCS)
in your bred cows. This article is not about
why body condition score is important, but
about how — and why — we manage it. Lactation and pregnancy
Managing maintenance Table 2. Additional feedstuffs (pounds, as fed)
per cow to maintain BCS, weaning at
148 vs. 240 days*
The simplest way to reduce a lactating cow’s
maintenance requirement is to wean her calf.
The first question that should be asked is, “How
much feed will be saved by early weaning?”
While lactation declines from mid- to late
lactation, energy is still required to produce
milk. Table 2 describes the additional inputs
needed to maintain BCS during late lactation.
Whether we are looking to maintain cows or add
condition, the first step is understanding what
factors influence maintenance requirements.
To keep this practical, we will relate these
changes to three common feed ingredients
(Table 1) and how many pounds of feed a
good-milking, 1,300-pound cow would need
to consume to maintain a proper BCS.
Table 1. Net energy (Mcal/cwt) values for grass
hay, corn grain and corn silage (dry matter basis)
a
a
a
DM% NEg NEm
Grass hay 85 26 58
Corn grain 85 65 98
Corn silage 35 47 75
a DM: dry matter; NEg: net energy for
gain; NEm: net energy for maintenance
52 | JUNE/JULY 2018
Days Since Calving
148-
168 169-
189 190-
210 211-
240 Total
Grass
hay 178 141 108 81 508
Corn
grain 94 74 57 43 267
Corn
silage 300 238 183 137 857
*Not providing these additional resources
would cause a cow starting at BCS 5 to
lose about half a condition score during this
timeframe.
Weather’s role
Another influencer is the weather. In parts of the
country where winter is more pronounced, the
changes in daily requirements can be significant.
Table 3 describes the additional feed needed for a
clean and dry cow on a day that is slightly windy
and has a temperature of 10 degrees Fahrenheit.