This message is from: [EMAIL PROTECTED]
On Sun, 08 Aug 1999 13:25:09 -0800 Jean Ernest <[EMAIL PROTECTED]>
writes:
>I have a question for Brian J: how much does early nutrition affect the
ultimate height in a FJord? . What I am asking, is there an increase
in size/ height in North America due to better nutrition perhaps, rather
than selecting for taller fjords?>
Jean,
I have wondered the same thing. I really think the answer is some of
both.
The conventional wisdom when I went through vet school was that better
nutrition does not change mature size. Except for cases of severe
deprivation, a horse is going to reach the size he/she was genetically
programmed to reach. Good nutrition can speed it up. Poor nutrition can
slow it down. But eventually the pre-programmed size will be reached.
Prolonged starvation is an exception to this as it can permanently stunt
bone growth.
I will say, however, I have wondered at times if this conventional wisdom
is always true. I hear enough examples like you gave about Bjorken,
Jean, of horses getting tall, that it makes me wonder. Similarly, the
Quarter Horses and Paints that we see around here that are pushed so hard
for the show ring are getting absolutely huge before they are even two
years old! Are we finally learning how to let them reach their full
genetic potential as Dr. White mentioned?
Concerning the effects of better nutrition over a period of years, this
does seem to change mature size of a breed of animals. Or take people
for example. The average height in the US is quite a few inches taller
than it was just 100 years ago. Although I don't know that it has ever
been proven, the best explanation out there is a more widely available
and better-balanced diet.
Is our nutrition here better than Norway though? I'm sure we have more
feeds and hays to choose from. But that doesn't necessarily mean the
nutrition in the US is better. We used to live at 6200 feet in the
mountains of Colorado, and I have rarely seen better hay than the high
altitude hay that was grown there. I am willing to bet they can grow
some pretty darn nice hay in the mountains of Norway. Was it Anneli that
told us that many people in Sweden and other parts of Europe make and
feed haylage, which is even higher in protein and energy than dry hay?
Also, they have oats and corn just like we do, and I'm sure there are
commercial horse feeds to choose from which are probably just as good as
ours. I guess it is probably safe to say that most Fjords' feeds in the
US today are more balanced than what most Fjords' diets USED TO BE in
Norway. I feel safe saying that because most horses' diets in the US
today are better balanced than they used to be in the US also. So
perhaps there has been a gradual change over the years due to an
improvement in diet.
Finally, to me, there is no question that some people/breeders in North
America have made a concious effort to increase the size of Fjords. And
that change can be made fairly quickly really, over just a few
generations with selective breeding. I believe there are several reasons
that they generally do not have the larger Fjords in Norway like we have
in the US. First, they've already been there and done that, and they
didn't like the results. Granted, it was by adding Dolehest blood, so it
was changing a little more than just size. But as Steve McIlree
straightened me out on, there used to be a lot of Dole Horse blood in
Fjords, and the result was a bigger Fjord. The Norwegians purposely bred
them back down to what we think of as more the traditional size, which
was around 14 hands.
Secondly, there is a certain size of animal that best fits a certain
environment. There are many factors that play into this, among them
availability of food, relative amount of heat loss due to body size,
ability to handle difficult terrain, etc. The traditional size of the
Fjord was what best fit their environment. Even if they can grow good
hay in Norway, the amount they can grow is limited (short growing season,
mountainous terrain), so they probably had just enough hay (or haylage)
to feed the cows and relatively small horses, not some big draft horses.
Also, in a cold climate like much of Norway has, conserving heat is
important. A bigger animal has more surface area per unit mass than a
smaller animal does, and loses heat easier when it's cold. Finally,
smaller animals are, in general, more nimble on difficult terrain than
larger ones. This is why elephants are plains dwellers and don't usually
vacation in the mountains. All of this means that the more traditional
sized Fjords just did better, all things considered, than the larger
ones.
We here in this country, though, are not necessarily worried about what
size is best suited for our area. Many of us are looking for a Fjord
with certain characteristics. We've heard it here on the List in the
last few days; Some want a larger Fjord because they think they will feel
