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 Youngstock production dictated by industry trends Industry has strong desire to accelerate growth for the sales ring 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 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 Bone mineralisation begins during the last three months of pregnancy Foetal liver stores minerals needed for mineralisation after birth Foetal liver stores minerals needed for mineralisation after birth The newborn foal born with 17% of its adult BMC 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 calcium supplementation leads to a depression of zinc absorption Very high phosphorus levels will negatively influence calcium absorption Very high phosphorus levels will negatively influence calcium absorption High zinc levels interferes with the uptake of copper High zinc levels interferes with the uptake of copper Low magnesium levels affect calcium absorption 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 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 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 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 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 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 Vitamin D acts by increasing the intestinal absorption of calcium and phosphorus Deficiency of vitamin D will exacerbate an existing imbalance in calcium : 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 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 However bone strength does not only depend on bone mineralisation But also on the quality and quantity But also on the quality and quantity of protein Protein provides the framework base Protein provides the framework base upon which minerals are deposited

What are amino acids? Proteins are comprised of chains of amino acids Proteins are comprised of chains of amino acids 12 amino acids can be synthesised within the horse’s body 12 amino acids can be synthesised within the horse’s body However 10 need to be supplied by the diet However 10 need to be supplied by the diet Essential Amino Acids Essential Amino Acids 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 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 Two groups of weanlings fed different protein supplements The weanlings fed higher-quality protein had more growth of the circumference of their cannon bone The weanlings fed higher-quality protein had more growth of the circumference of their cannon bone Due to greater intake of essential amino acids Due to greater intake of essential amino acids

Broodmares & Protein Maintenance requirements for the first 8 months Maintenance requirements for the first 8 months However the protein requirement increases greatly during the 9 th, 10 th and 11 th month However the protein requirement increases greatly during the 9 th, 10 th and 11 th month The first three months of lactation are equally as important 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 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 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 Weanlings paddock raised & exercised daily vs. box raised Paddock raised weanlings had 33% higher bone densities Paddock raised weanlings had 33% higher bone densities Arab weanlings kept: in stalls 24/day, on pasture 12/day, on pasture 24/day Arab weanlings kept: in stalls 24/day, on pasture 12/day, on pasture 24/day Pasture weanlings had increased bone mineralisation 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 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 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

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