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Part I: What's the Score in Your Herd?
Body condition scores (BCS) describe the relative fatness or body condition
of a cow herd through the use of a nine-point scale. A body condition score
five (BCS 5) cow is in average flesh and represents a logical target for most
cow herds, whereas a BCS 1 cow is extremely thin and a BCS 9 cow is extremely
fat.
Body condition score (BCS) of beef cows at the time of calving has a dramatic
impact on subsequent rebreeding performance (table below). The postpartum
interval is the length of time from calving to first estrus (heat) after
calving. For a cow to maintain a 365 day calving interval, she must rebreed
by 82 days after calving (283 day gestation + 82 day postpartum interval = 365
days). On the average, cows that calve in a BCS 3 or 4 have difficulty
exhibiting their first heat by 80 days after calving. Whereas cows that calve
in BCS 5 or 6 tend to exhibit heat by 55 days after calving and therefore
have a better opportunity to maintain a 365 day calving interval. Although
cows that calve in a BCS of 7 have a short postpartum interval, it is not
economical to feed cows to a condition score of 7.
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In addition, thin cows at calving (BCS 4 or thinner) produce
less colostrum, give birth to less vigorous calves that are slower to
stand and these calves have lower immunoglobulin levels (bar graph below),
thus impairing their ability to overcome early calf-hood disease challenges.
This illustrates the importance of targeting mature cows to calve in a BCS
of at least 5. Because 1st-calf-heifers are still growing after calving, they
need to be fed so they are a BCS of 6 at calving.
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The Look and Feel of Body Condition Scoring
Body condition scoring can be done using only visual indicators or a combination
of visual and palpation of key bone structures for fat cover during routine
processing of cows through a chute. The key areas for evaluation are the backbone,
ribs, hips, pinbones, tailhead and brisket. Palpation of cows for fatness along
the backbone, ribs, and tailhead will help refine your skill to visually score
body condition.
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If body condition scoring is new to you, just focus on separating
cows into thin, moderate and fat groups without worrying about the numerical
score. With experience, you will connect the ''look and feel'' of your cows
to a body condition score that you can consistently determine.
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Body condition scores should be recorded so that links to productivity and
herd management (particularly nutritional management) can be examined. Several
years of such information could reveal, for example, needed management changes
for a given age group (i.e., thin three-year-olds) of cows or might identify
a sire group of females that simply didn't fit your resources.
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When visually scoring body condition, you must "look through the hair coat"
on cows. This is often difficult due to a long winter hair coat. It is good
training to re-evaluate your body condition scores when cattle are wet. You
may be surprised at the impact hair coats can have on visual scores. Long, thick
winter hair coats are obviously highly desirable (at least in the Northern plains),
thus actual palpation for fatness of cows may be the best choice to produce
consistent body condition scoring. Drawings of cows in BCS 1 to 9 can give an
indication of how these cows would look if they were without hair.
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Other factors in addition to hair coat that can affect visual body condition
scores are age of cow, rumen fill, and stage of pregnancy. The goal of body
condition scoring is to evaluate fatness independent of these factors. At first,
one or more of the above factors may mislead you, but careful study of your
herd through the production year will sharpen your focus so that body condition
can be scored independent of the above factors.
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When to Condition Score Cows
The greatest single factor influencing rebreeding performance of beef cows
is body condition at calving. However, if producers wait until calving to manage
body condition of their cows, they will find it very difficult and expensive
to increase the body condition of a lactating cow.
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Although evaluation of body condition can be looked at as an ongoing process,
there are several key times when body condition scoring should be considered:
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Weaning Time
Pay particular attention to young cows weaning their first calves, as they
are most likely to be thin at this time. May need to consider early weaning
calves from young cows and giving higher quality grazing.
45 Days after Weaning
Gives a good idea how fast cows are ''bouncing back'' after weaning. Thin cows
should be gaining back condition if cow type is matched with the feed resources.
90 Days before Calving
Last opportunity to get condition back on cows economically. This would be
the time to separate thin cows from cows in good condition.
Calving Time
If cows are thin, breeders may want to change the pre-calving feeding program.
It is difficult to get condition on cows after calving economically. It takes
large amount of high-quality feed.
Beginning of Breeding Season
Thin cows may indicate a poor match of calving season to feed sources. Maybe
calving is held too early in the spring. The period from weaning to 90 days
pre-calving is the best time to get serious about body condition scoring and
planning the nutrition/ management program because the manager's strategy
can have great impact. The period from calving to re-breeding may help explain
the productivity (or lack thereof!) but it is mostly too late to have much
impact on herd productivity and profitability.
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