Holstein Association
USA study shows clear relationship between desirable functional conformation and
economically
important
traits.
What should a dairy cow
look
like?
How does physical conformation in today's dairy industry relate to economically important
traits? A recent study completed by Holstein
Association
USA
staff aimed to answer these questions using a large dataset with matching data from official
linear
classification evaluations and DHIA production records. The dataset covered almost 20 years of
data
and
included
over 1 million cows*.
Final
Score Major Breakdowns
Final score for first lactation cows can range from 50 points to 89 points, with higher scores being more desirable. For all
analyses, all cows were divided into four quartiles based on final score where the highest 25% of cows were in the
top quartile and the lowest 25% in the bottom quartile.
Figure 1. Lifetime ECM By Final Score
Quartile
How does physical conformation
impact longevity and lifetime production?
We all want to breed cows that produce
large
quanties of high component milk across their lifetime. Comparing the top quartile to the bottom
quartile,
the
highest scored cows produced 13,389 more pounds of energy-corrected milk (ECM) across
their
lifetimes
than cows in the bottom quartile (Figure 1).
Using a long-term milk price, of
$20/cwt, this
difference represents $2,678 more in lifetime gross revenue per cow.Cows
with
better
physical conformation provide more lifetime revenue to a dairy.
Figure 2. Lifetime
DIM By
Final
Score Quartile
The data tells us
that part
of
this difference in lifetime ECM is because those cows in the highest quartile based on first
lactation
classification score simply stayed in the herd longer.
In Figure 2, cows in the top quartile had142 more lifetime days-in-milk
(DIM) than cows in the bottom quartile, or almost five
extra months. Getting several extra months of lactation out of cows
helps spread the fixed cost of raising each heifer over more time, reducing the effective cost
of
raising
heifers.
The bottom line is - the data clearly shows that cows with more correct,
functional
conformation live longer and make more milk.
Click the links below to view the complete and detailed results of our study