A recent issue of Holstein
International had an article discussing the industry trend toward an
ever- straighter hind legs and the decline in quality of mobility
leading to higher young cow culling rates.
The trend in Holsteins has
alarmed Holstein USA to announce an entirely new formula for “Foot and Leg
Composite” (FLC), removing linear scores for “rear legs side view” and adding
linear scores for stature in its place.
Linear scoring has very
little to say about legs and feet, basically ignoring front legs and feet,
putting emphasis on foot angle, then measuring the degree of “set” to the hock
from side and rear views. We are now
looking at the fourth version of “FLC” since linear scoring was introduced in
1972. Across four decades, the expert
recommendation on set of hind leg has failed to reduce foot and leg problems.
So what does
“stature” have to do with Foot and Leg structure? It appears that the young cows that leave
our herds with stiff, straight hind legs also are quite tall. Ironically, “stature” not only has been
highly correlated with positive type values, it is increasingly
associated with superior milk yields.
The current sources of the straightest legs are also among the elite
Genomic levels for GTPI and GNM$.
(Of course, a couple
generations of “sires of sons” have yet to show progeny production data.) On the data graphed by Holstein
International the generational trend for “straight” was unmistakable.
Will this latest FLC solve
everyone’s problems? I have watched
the trends in “indexing” for forty years and expect nothing will change,
especially as a majority of sires already selected for AI show in their own
physiques the potential for siring legs too straight, joints too stiff, feet
not standing sturdy.
Not including “leg set
side view” in FLC means straighter-legged examples can persist in the mating
population due to selection for udder, milk yield, fat and protein and somatic
cell levels in the indexes.
Solving the mobility
Which cows exhibit the
best mobility? Cows who stand
comfortably on four feet. “Sturdy”
cows with “central” thurls have proper weight bearing on their feet both front
and rear. They have supple, flexible
hock joints and springy pasterns (demonstrating an equal distribution of shock
absorption from walking). They do not
stand on toes nor shuffle their heels—their weight bearing is at the center of
the hoof. They are not pigeon toed—their
weight bearing is even from inner to outer toe.
Have you ever tried to
stand up on your toes for any period of time?
How about walking with extended toes?
It is painful, from your ankles up into your calves. Yet in preferring “steep” foot angle we
have asked our cows to walk like ballerinas, in spite of slippery concrete. This foolishness continues in the latest
FLC. If you look up the greatest
progenitors of Productive Life (eg,Rudolph and Ramos) you are likely to find
sires criticized for “low” foot angle (based on herdmate deviation).
Our fixation on extreme
linears (reinforced by typical linear mating system formulas) keeps us breeding
extreme physical character in our young cows.
We never stop with “good enough”, we keep seeking a “gooder than good”
mating combination that produces more extreme frame expressions. Feet and legs are the extremities furthest
from the body core and thus tend to show the results of extreme mating first.
Linear theories of the
physique were focused on defining the traits that correlated with a faster
maturity of production volume. For 45
years we have followed these, and have culled millions of failures
Consider the “aAa”
The “aAa” Breeding Guide
(Weeks Analysis) preceded linear type traits by 20 years. Scientists who developed linear measurement
thought their new program would make “aAa” obsolete. Instead we find “aAa” still going strong
around the dairy world, after 45 years of linear confusion. How does a program that thrives without
breed association (classification) or AI stud (Genomic) support or subsidy
persist? Because it understands
physical heritability and it solves problems of physical
Specific to Legs and
Feet: Quality of mobility in “aAa” methods is
analyzed as an integrated whole rather than the average of a few individual
parts. The entire skeletal structure is
considered; muscling activating the
skeleton is considered; cartilage and tendon structures in all joints are
considered. Both front and rear legs
and feet are analyzed, as a functional unit and as they are attached to the
A crucial defect in modern
high-genetic cows is the “square” thurl position. When the thurl is back from center in the
pelvic structure, angling hind legs out towards the rear, you find it thrusting
pins up and shifting rear end weight onto the loin (a structure which is not
designed to carry added weight).
In an attempt to be
sturdy, feet are thrust forward (on legs with “set” hocks) or posty backwards
(on legs with tight hocks) and cows then walk “flat footed” and ‘spread
toed”—all in an attempt to redistribute weight. As cows age, loins flatten out and
stiffness in the back impedes mobility.
Another defect in modern
high-genetic cows is the confusion of “dairyness” with angularity
leading to narrowing of the chest. This
narrowing brings the forelegs closer together.
Again, with all the front end weight to support, on a narrowing
pedestal, cows learn to turn their feet out in an attempt for more
stability. Weight is then carried on
the inside toe, leaving the outer toe to grow and curl. Again, the quality of mobility is
impeded. Chronic lameness can result,
no hoof trimming can fix this.
“Narrowing” of the frame is a side effect of
the selection in favor of more stature (such heifers show more angularity from
longer bones and stretched muscling across the skeletal extension). If the loin is narrow, the entire body will
be narrow (ribs will lose the ability to “spring” as rumen and abomasums try to
fill with feed). The difficulty
classifiers have with cows lacking stature is “they just don’t look dairy
enough to score higher”. Showring
judges have the same visualization problems.
Yet loss of body capacity will result in loss of productive ability – a
“loss of dairy function”.
Think about the combination
of square thurls and narrow front ends.
Take it a generation further and lose the depth and spring of rib. Put that narrow, anorexic heifer up on her
toes by stiffening all her joints. In
each generation you have a highly-ranked sire, but you are losing function and
producing young-age culls. You have
to adopt a breeding guide that protects you from going too far so that all
this genetic “potential” on which you have been selecting mating sires can
still be harvested in fully functioning physiques. This is why “aAa” Breeding Guide (Weeks
Conclusion: selecting on index rank and mating on linear
traits is doubling your emphasis on data that leads to limitations of the
physique. Loss of mobility is just one of the many
limitations that are causing too many promising young cows to have short herd
life. Consider adding a mating
method that understands transmission of physical qualities and
experience the freedom from agonizing over genetic theories that promise much
but deliver little sustainable improvement.
Linear traits help you
sort which bulls to use, but have proven ineffective in telling you which cow
fits which bull. “aAa” matches cows
to bulls for improved function. It can fix your mobility problems.
with feet and legs by
If a problem persists long enough, with all efforts to
fix it basically unsuccessful, it is easy to assume (as some geneticists feel)
that foot and leg problems are “normal” to the high production dairy herd—at
least for Holsteins, which is 90% of all milk cows.
Why then do a handful of cows remain highly productive
into teen ages, while more seem to fail at younger ages? Nothing seems to have more impact on early
culling today than “failure of mobility”.
These are definably genetic differences, NOT the fault of facility or
herd management. Our methods of
genetic selection are not consistently producing cows that are adaptable to
the physical environment where they must walk every day.
There is a mating system that is focused on quality
of mobility as part of overall physical adaptability to
the cow environment you have. This
program does not require you to change AI studs or give up on your genetic
goals. It just answers the question
that your current breeding approach does not address. Check it out inside this newsletter.
Service, Inc. PO Box 661 Ovid,
MI 48866 ph (989) 834-2661