03/26/2026
Myostatin 2-Copy Piedmontese
– Muscle At Birth Scoring
(For those who didn't see this in the NAPA breed magazine)
One of the reasons that the Piedmontese breed has been
successful in selecting towards improved calving ease, is
the fact that – when everything is working as it should – the
calves are born with very limited muscle development. We
call it the “late muscle development” feature.
We have all seen the slender Piedmontese calf at 1 day of
age become a completely “new” animal by 1 month of age,
when the muscle growth is becoming obvious. Even at 10
days of age, we begin to see the loin and rump fill and expand.
(This is important, as it is entirely possible for calves
to go over-due in gestation by 10 days or more.)
Muscle development at birth is one of the easiest things
for breeders to take note of, and use to “score” their own
calves. Writing down a score for each calf on the day of
birth will help you immensely later on when the calves
have bloomed into their full muscle expression. Sometimes
it is hard to recall how much muscle a calf was expressing
at birth, after he’s turned into a super-hero.
However, there may be real value in scoring this particular
trait of “late expression of muscling” (post birth expression)
and using your records to cull breeding animals that
expressed excess muscle at birth. After all, those extra
inches of girth, especially at the shoulder and hip, can cause
serious issues in birthing. Bulls that express significant
muscle at birth may be better suited to commercial crossbreeding
use (producing those easy-born 1-copy-Myostatin
calves) than they are for seed stock improvement.
Obviously, you need to make note of the many other factors
involved: s*x of calf can make a difference in birth weight
and gestation length, and corresponding muscle development
at birth. So, if you have an ET bull calf that went 10
days “over-due” and he carries more muscle at birth than
you like, make sure you record the fact that he was 10 days
over !
Ideally, a Piedmontese calf is born long and lean. They are
relatively “tall” calves, but the fine bone and lack of muscle
expression give them an extremely fine and streamlined
body – from shoulder through hips. Birth weight is not the
discussion here, but rather birth conformation. It is easier to
deliver a 90 pound “snake” than a 50 pound “square box”.
Length of neck is desirable, with smoothness in the shoulder,
as it allows for an easy transition once the head has
entered the birth canal. Short, abrupt calves with a blocky
shoulder can get hung up.
The images shown represent a fullblood heifer calf, at 10
hours old. The pictures have been “edited” to add or subtract
muscle in varying degrees – to use as a guideline for
the scoring system. ----- by Vicki Johnson.
Score 1: represented by Calf
# 1
Light muscle throughout
entire body, long very slender
neck.
Score 2: represented by Calf
# 2
Normal muscle throughout
entire body, long slender
neck.
Score 3: represented by Calf
# 3
Heavier muscle, slightly
more in the hips than in the
shoulder, some crest (thickness)
of the neck is apparent,
with increased mass in the
shoulder.
Score 4: represented by Calf
# 4
Excess muscle throughout
the entire body, crested neck
and increased shoulder mass.
piedmontese.org
