Nutrient Requirements for Growing Horses

Meeting nutrient needs for:

• Maintenance Growth - muscle, bone

• Stress related factors - weaning, training, environment

Maintaining a steady growth without

causing a growth depression/spurt due to malnutrition

Milk will provide macronutrient needs for foal:

Birth - 2 months old

Milk will provide mineral needs for foal:

Birth - 4 months old

Foal’s digestive tract…when is fiber needed?

• 1-3 months of age, ideal time to supplement a grain mix to the foal’s diet (High CP, lysine, Ca, P)

• High efficiency to utilize grain products at this age

Creep feeding ideal because…

Creep feed helps transition foal into solid feed, helps develop hindgut

ADG: 0-1 months

3.4 lbs/d

• First month has highest gain per day in foal

ADG: 1-2 months

3.0 lbs/d

ADG: 2-3 months

2.6 lbs/d

ADG: 3-4 months

2.3 lbs/d

If no creep feeding…

Nutritionally adequate solid feed is necessary prior to weaning.

If no creep feed is given during the months prior to weaning….

compensatory growth spurt!

If no creep feeding… What can result?

Developmental Orthopedic Disease (DOD)…this is not the only cause of DOD!

Other nutritional factors that may lead to DOD:

Excess energy in the diet

• Sources? CHOs....not protein!

• Imbalance!

• 120% over NRC increases incidence of DOD

Other nutritional factors that may lead to DOD:

Too much fat

• Effect on Ca

• Ideal fat% for diet - 6 to 8%

Other nutritional factors that may lead to DOD:

Mineral imbalance

• Low Cu, High Zn

Growing horse nutrient needs

• Continual need for nutrients to meet growth.

• Nutrients: DE, CP, essential AA, macro/trace minerals for tissue and bone development

Critical growth during first 12 months of age!

• 60% mature weight, 90% of mature height, 95% of bone growth during this time period.

• Earliest maturing tissue - bone

• Last tissue to mature - fat

• How would this affect type of nutrients needed - shifts nutritional priorities from structural minerals and high quality proteins to energy dense diets as the horse matures

ADG: 4-5 months

2.0 lbs/d

ADG: 5-6 months

1.8 lbs/d

ADG: 6-7 months

1.6 lbs/d

ADG: 7-8 months

1.4 lbs/d

ADG: 8-12 months

1.3-1.0 lbs/d

ADG: 12-18 months

0.8 lbs/d

ADG: 18-24 months

0.6 lbs/d

Is excess dietary protein bad???

Balance of DE if there’s an excess of dietary protein, can be used for carbohydrates

Other amino acids that would benefit growing horse?

Arginine & Histidine: support healthy growth and immune function. Arginine can stimulate growth hormone release.

Leucine, Isoleucine, & Valine (BCAAs): essential for muscle metabolism and physical development

Grain needed to meet:

E needs for growth

No restriction on grass forage:

as much as horse can consume (without waste) - DMI will be

appropriate for % of BW

Legume - might need to restrict in weanlings:

Excess protein might cause Ca P loss; growth reduction

Legume: 4-10 months

0.5 lb/100 lb mature BW

Legume: 10-12 months

1 lb/100 lb mature BW

Ab libitum water and TM salt

If necessary supplemented with Cu, Zn and Se