Re: Feeding a yearling

["Susan Garlinghouse" <suendavid@worldnet.att.net>]

> I recently purchased a yearling colt and would like some impute as to what
> feeding guidelines some of you have followed with "the younger ones"!!  I
> currently feed vita-flex's Accel as an all around supplement to my
> horses,(mixed with COB and my own mixture of Purina Athlete)  along with
good
> quality grass hay.  I have never had a horse quite this young and would
> really appreciate some advice on feeding.  Grass vs. alfalfa, grain vs. no
> grain, supplements vs. none or better supplements, etc.  I would GREATLY
> appreciate any advice.  Thank you so very much.
> Johnna
> "He who is impatient waits twice." -- Mack McGinnis "


There was a recent discussion on RC that'll be in the archives that had some
good suggestions, so I'll just add a few more.  My suggestion would be
rather than mixing COB and Purina Athlete (which is probably deficient in
copper and zinc, possibly lysine), feed a good-quality grain mix formulated
*specifically* for young horses---the vitamin and mineral levels and ratio
requirements are different for a youngster than they are for adults, and you
really want to get them right.  Omolene 300 is good, All-American has a foal
mix I particularly like---there are lots of good mixes formulated for
babies.  If you are feeding more than about five pounds of grain per day,
then you don't need to add additional supplements, and more is not better.
If you are feeding less than five pounds, then adding a little of a good
quality vit/min mix is okay.  I happen to have a preference for Grand Vite,
especially for youngsters, as it contains a particular yeast strain
(Yea-Sacc) that I'm particularly fond of (and actually has some real
research behind it).

A little alfalfa is okay, but shouldn't be overdone due to mineral
imbalances---too much calcium (as well as other things) can contribute to
developmental orthopedic disease.  If you feed it at all, an average
yearling shouldn't be getting more than about 6-8 pounds a day, tops, plus
all the grass hay he wants.

I've pasted below a page of the lecture notes I used when I taught nutrition
at Cal Poly a few years ago---theyre a little cryptic (since I wrote them to
lecture from, not for general reading), but you'll get the idea.  A few
things about DOD and a few guidelines about how much you can feed.  If you
have any other questions, throw them this way. :-)

Hope this helps.

Susan G


Nutritional Management of Developmental Orthopedic Disease

DOD is also known as epiphysitis, osteochondrosis, angular limb
deformity-different manifestations of metabolic bone disease which disrupts
normal bone formation in young growing horses.  Most common in large,
fast-growing, light horse breeds, but can occur in any breed.

May manifest different ways, but all DOD are or are related to a failure of
growth cartilage to properly ossify into bone tissue.  When bones are
growing, cartilage is laid down in growth plates either along diaphysis of
long bones or epiphysis at end of long bone.  Cartilage gradually calcifies
into bone tissue.  If disturbed or disrupted, DOD results.  Usually
diagnosed by swelling at joints and lameness, confirmed by radiographs.
Majority occur in limbs, or cervical vertebrae, though not all result in
lameness.

Primary causes of DOD are
1) rapid growth (major cause)
2) trauma to growth plates
3) genetic predisposition (demonstrated in people, dogs, swine, horses)
4) nutritional imbalances - primarily energy, protein, calcium, phosphorus,
zinc and copper

Focus in this lecture is in horses, but also occurs in large breeds of dogs,
cattle, poultry and swine (big part of why all the pigs at the swine unit
are lame by the time they reach market weight).

Relationship between rapid growth and nutritional imbalance - let's say you
have a young animal that you are feeding a high energy ration.  You get
rapid growth, but if mineral intake is not sufficient to meet additional
requirements, bone quality is compromised => DOD

DOD most commonly occurs in overfed horses, but can also occur in underfed
horses as result of inadequate protein.  Used to be thought that excess
protein was the cause, now we know this is NOT the case, at least not
directly.  Protein itself will not cause DOD, but if fed in sufficient
quantities, excess protein goes towards energy production, which will
contribute to DOD.   So excess protein is not the problem, excess energy is.

If insufficient protein is fed, with adequate energy, then the results are
decreased bone growth, but no decrease in weight gain.  This puts additional
stress on the bone (trauma as listed above) and again predisposes to DOD.

Calcium-phosphorus imbalances - The primary minerals in bone tissue are
calcium and phosphorus, so no surprise that for optimal bone growth, you
need adequate Ca/P in the diet.  But, important not only that minerals be
provided in diet, but that they be absorbed.  Many interactions between
minerals, which may decrease availability.  Excess P will decrease Ca, but
also excess Ca will decrease P.  If diet/absorption is deficient in either
mineral, DOD might result.  In species other than horses, high calcium also
decreases absorption of zinc, manganese and iron (zinc deficiency a factor
in DOD).

Copper-zinc imbalances - copper a factor in stabilizing collagen and in
elastin synthesis, deficiency may result in DOD.  Most commonly affects
ruminants, but also occurs in horses.  Animals with deficient copper/zinc do
not have a decreased growth rate, just DOD lesions.  When copper and zinc
increased, growth rate still remains the same, but incidence of DOD
significantly decreases.  Therefore, copper and zinc do not affect growth
rate, just incidence of DOD.

Most common feeding practices which lead to DOD in young horses are:
1) feeding too much grain (excess energy)
 - continuous access to creep feed
 - feeding grain in excess of recommended amounts
 - why do people feed excess energy?
  - desire for animal to reach market/mature size as quickly as possible
  - belief among horse owners that high energy plane will result in bigger
mature horse (not true--if energy is sufficient, mature size will be equal,
just not as quickly)
  - desire for rapid, early growth in halter horses ( produces larger
yearlings, but crippled two year olds)
2) unlimited access to legume hays such as alfalfa (excess energy and
excessive calcium leading to possible P deficiency)
 - source of excess energy unimportant, just as likely to get DOD from
excess alfalfa as excess grain (the important point is excess energy, not
where the energy came from)
3) feeding ration inadequate in utilizable calcium, phosphorus, copper,
zinc, protein (particularly lysine).

Recommendations to minimize DOD in growing horses:
1) Feed as much good-quality grass hay as will be consumed without waste.
2) Legume hay:
 Weanlings: restrict legume hay intake to 0.5 lbs/100 lbs of expected mature
weight.
 Example: You have a 6 month old weanling foal that you expect will grow to
1200 lbs mature weight. => maximum alfalfa intake should be no more than 6
lbs alfalfa per day.

 After 10 months of age, can feed an additional 1 lb per day until 12 months
of age until 1 year.  Published recommendations state after 1 year, can feed
ad libitum any type of hay.  I prefer limiting alfalfa until two years, and
ideally after that as well (preferably 25% or less of total forage ration,
never more than 50% under most circumstances).
3) Grain mix:
 Nursing foals (age 0-4 months) - 0.5 - 0.75 lbs/100 lbs of present BW
 Weanlings - (age 4-12 months) - 1.7 - 2.0 lbs/100 lbs of BW
 Yearlings (12-18 months) - 1.3 - 1.7 lbs/100 lbs of BW
 Long yearlings (18-24 months) - 1.0 - 1.25 lbs of BW
 two-year-olds (24-36 months) 1.0-1.25 lbs/100 lbs of BW

*NEVER feed more than 0.9 lbs of grain per 100 lbs of expected mature BW
(this takes precedence over above recommendations)*.

Example: You have a 16 month old yearling that weighs 800 lbs, that you
expect will mature at 1100 lbs.  Based on 1.3 - 1.7 lbs of grain/100 lbs of
BW, you should be feeding 10.4 - 13.6 lbs of grain per day.  However, based
on a mature body weight of 1100 pounds, this horse should be fed no more
than 9.9 lbs of grain (11 x .9 = 9.9)

4) Make sure grain mix/total ration is properly formulated to provide
adequate minerals in correct ratio
 Requirements: Protein, Ca, P, Cu, Zn
Nursing   16%, 0.9%, 0.6%, 60 ppm, 50 ppm
Weanling   14.5%, 0.8, 0.5, 60, 25
Yearling   12.5, 0.5, 0.3, 40,  25
Long yearling  12, 0.4, 0.24, 40, 10
Two year old  11, 0.3, 0.20, 15, 7
Mature   8, 0.25, 0.20, 15, 7

All of the above nutrients are on a dry matter basis, NOT as-fed.
There is no harm in adding more copper/zinc (this applies to horses only,
not other species), so rather than calculating how much copper/zinc is
already present in forage, recommended to just add additional copper/zinc at
above levels when formulating a ration.

Yeast cultures - research by Glade demonstrated that addition of yeast
culture Yea-Sacc decreased incidence of DOD in young, growing horses.
Hypotheses is that microbes secrete phytase, which increases P
bioavailability and absorption.  Recommended addition to young horse
rations, especially those at risk of DOD.  Species investigated was
Saccaromyces cerevisiae (brewers yeast).  There is a difference between live
yeast cultures and dead yeast cultures.  Brewers yeast is dead, no probiotic
benefits.  Yeast culture is live (freeze dried), reconstituted when
introduced to aqueous/warm environment.  Also increases butterfat
production, increase fiber digestion.  Two latter benefits are primary
advantages in supplementing other livestock species.

In poultry species, probiotic cultures are being used to decrease
Salmonella.  Newly hatched chicks are sprayed with probiotic solution.  When
chicks preen, GI tract is colonized with "friendly" bacteria, which crowd
out Salmonella species.  No Salmonella in GI tract means no contamination of
eggs and less incidence of contamination of broiler carcass (though both can
still be contaminated from other sources).