IMPROVING BONE DENSITY
- the role of nutrition
Nia O’Malley
Connolly’s Red Mills
Tendrleen Horse Feeds
Accelerated Growth

Youngstock production dictated by industry
trends

Industry has strong desire to accelerate growth
for the sales ring

Australian study found intensively fed horses
were consistently heavier, taller and better
developed in the cannon bones than horses on
lower nutrition levels
Skeletal Growth
Mature Height
Mature Weight
6 months
84%
46%
12 months
94%
65%
22 months
97%
90%
* BMC: 68% complete at 6 months, 76% complete at 12 months
Bone Mineralisation

Bone mineralisation begins
during the last three
months of pregnancy

Foetal liver stores minerals
needed for mineralisation
after birth

The newborn foal born
with 17% of its adult BMC
Balance is Key!

Very high calcium supplementation leads to a
depression of zinc absorption

Very high phosphorus levels will negatively
influence calcium absorption

High zinc levels interferes with the uptake of
copper

Low magnesium levels affect calcium absorption
Oats Alone?

High grain diets immediately unbalance
bone metabolism, as grains are low in
calcium and magnesium and reasonably
high in phosphorus

While a calcium deficiency may not reduce
size, the skeleton is weak, porous and
fragile, and prone to breakdown
Feeding the Broodmare

If the mare’s calcium intake is not adequate
during gestation and lactation, it will result in
skeletal mineral loss in the foal

Foals born of calcium deficiency have smaller
cannon bone diameters at birth

Mare’s milk drops significantly at about the
seventh week of lactation, which could
negatively influence foal growth rates
Vitamins & Mineralisation

Vitamin D acts by increasing the intestinal
absorption of calcium and phosphorus

Deficiency of vitamin D will exacerbate an
existing imbalance in calcium : phosphorus

Vitamin A deficiency leads directly to loss of
bone strength and thinning of the bone cortex
Bone Strength & Protein

However bone strength does not only depend
on bone mineralisation

But also on the quality and quantity
of protein

Protein provides the framework base
upon which minerals are deposited
What are amino acids?

Proteins are comprised of
chains of amino acids

Essential Amino Acids



12 amino acids can be
synthesised within the
horse’s body






However 10 need to be
supplied by the diet



Arginine
Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine
Protein

Provision of high-quality protein is important
to support optimal growth and weight gain in
young horses

A deficiency of certain
amino acids will do more
to depress growth rate
than any other nutrient
Study in Finland:

Two groups of weanlings fed different
protein supplements

The weanlings fed higher-quality protein
had more growth of the circumference of
their cannon bone

Due to greater intake of essential amino
acids
Broodmares & Protein

Maintenance
requirements for the first
8 months

However the protein
requirement increases
greatly during the 9th, 10th
and 11th month

The first three months of
lactation are equally as
important
Exercise: Also a factor!

Bone is constantly
remodelling itself in response
to the forces of impact and
loading

Remodelling increases bone
density by removing existing
bone and adding new bone to
areas where forces are greatest
Effect of Exercise on Bone

Weanlings paddock raised & exercised
daily vs. box raised


Paddock raised weanlings had 33% higher
bone densities
Arab weanlings kept: in stalls 24/day, on
pasture 12/day, on pasture 24/day

Pasture weanlings had increased bone
mineralisation
To Conclude!

Maximising bone density by building
stronger bone is achieved through a
combination of both nutrition and exercise

Nutrients such as protein, calcium,
phosphorus, other minerals and vitamins
must be provided in the correct amounts
relative to each other, and in balance with
the amount of energy being fed
Thank you for your attention!
Any questions?
M: 087 9902651
E: nomalley@redmills.ie