When Conditioning, It Isn’t Just About Cardio and Muscle; Consider Bone Density Too

Bone remodeling occurs constantly throughout a horse’s lifetime and is essential to the maintenance of proper growth, soundness and longevity. Remodeling is most active in young, growing horses, but horses of all ages experience it to some degree. There are two reasons for remodeling: firstly, it allows bones to adjust to the physical stress new activities put on the skeleton. Secondly, it replaces bone that has been damaged by injuries, and it repairs microscopic bone damage caused by recurring microtraumas.

Research has revealed that one of the keys to healthy bone formation is exercise. Exercise stresses the bone and stimulates bone remodeling. When horses are kept in stalls due to injury, relocation, or a demanding training and competition schedule, stress on the bones is insufficient to maintain optimal bone turnover and bone density is quickly lost.

Many riders forget that a horse’s skeleton is constantly changing in response to his environment and job. As workloads increase or type of work changes, bone density increases to support the additional stress on the skeleton. When exercise is decreased, bone density decreases. Horses confined to a stall may have significant losses in bone density, which leaves them at greater risk for injury or fracture when they return to work.

Consider these familiar-sounding scenarios: a young Thoroughbred is put into training for the first time, a middle-aged event horse is coming back after an injury, a pleasure horse gets a new job as a hunter. In each case it takes months for a horse’s bones to adapt to a new job or level of work. Typically cardiac and muscle conditioning occurs faster than bone adaptation, especially in horses that have been fit in the past. When conditioning, training or rehab programs are rushed, injuries occur. Establishing a slow, steady conditioning program and providing adequate levels of minerals are imperative to reduce the risk of buck shins, splints, fractures and other bone-related injuries.

Nutrients are critical to bone development.

Proper nutrition is important to optimal bone health. For example, calcium makes up 35% of bone, and microminerals such as zinc and copper play an important role as cofactors in bone development. When choosing a bone supplement look for one that includes a well-balanced blend of nutrients. Chelated minerals are digested more efficiently than plain minerals. Chelation, the bonding of minerals to amino acids, protects minerals as they travel through the digestive tract and enhances absorption. Some marine sources of calcium and trace minerals have a unique cellular structure, which makes them more digestible than commonly used ground limestone.

Ingredients to look for in bone supplement:

Macrominerals:

Calcium*

*The ratio of calcium (Ca) to phosphorus (P) is critical. The total diet should contain a Ca:P ratio of 2:1 to ensure optimal calcium absorption and utilization. Ratios of less than 1:1 can cause serious bone abnormalities.

Microminerals:

Magnesium

Zinc

Copper

Manganese

Vitamins:

Vitamin D

A well-balanced bone supplement is beneficial when:

• Mature horses are starting a new job
• Young horses first go into training
• Horses return to training after a layoff
• Horses are recovering from a skeletal injury
• Horses are on restricted diets for other medical reasons
• Older horses have a demanding competition schedule
• Horses are laid up due to illness or injury (supplement during the layoff period to protect bone density)

Overfeeding minerals or feeding them in the incorrect ratios can cause as much harm as underfeeding. Feed all supplements according to recommendations. Do not offer multiple mineral supplements unless directed by your veterinarian. If you are feeding the recommended amount of a fortified concentrate (grain or pellet), check with your veterinarian before offering additional mineral supplements.