Equine Nutrition 2: Feeding Guidelines

• Equine Nutrition 2 covers guidelines for determining horse feeding based on needs and feasibility, and establishing the appropriate amount to be fed.

Horse's Requirements

• Determining a horse's nutritional requirements involves considering its life stage, categorized as young/growing, adult, athletic, aged/geriatric, or lactating.
• Determining a horse's weight can be done through a scale, weight tape, or calculations based on measurements.
• The weight calculation formula uses heartgirth and body length measurements.
• Multiply heartgirth by itself to get Y, then multiply Y by the length (total). Then divide the total by 330.
• A weight tape measures girth circumference and provides an estimated body weight in pounds.
• Nutrient Requirements of Horses (NRC) tables help determine horse requirements. Grains are less variable than forages.

Feed Options

• Forage options include pasture, hay, silage, and haylage.
• Concentrate options include grain, textured feeds, and pelleted or extruded feeds.

Calculating Feed Amount

• Consider NRC requirements when calculating feed amounts for horses.
• Feed tags offer info on nutrients provided in feed.
• Follow manufacturer recommendations.
• Estimate DE based on crude fiber, if the label has no DE. Crude fiber is inversely related to DE.
• It is possible to adjust the feed for fat. For each 1% over 5% fat, add 0.02 Mcal/lb DE.
• For hay analysis, 10-12% crude protein is adequate for most horses. Estimate DMI (dry matter intake) to about 2-2.5% of BW.

Adjustments to Feed

• Evaluate a horse's body condition by looking at tailhead, along the spine, crest, withers, barrel/ribs, and behind the elbow.

Special Needs

• Special needs to consider when feeding horses includes obesity, arthritis, insulin dysregulation, and developmental orthopedic disease (DOD).

Maintenance

• Maintenance nutritional needs for a 500 kg adult includes 16.7 Mcal DE, 8.5% CP, 20 g Ca, and 14 g P.
• Provide hay at ~2% of body weight, potentially decreasing to 1.5% with supplementation.
• Provide free-choice, clean water.
• Provide 8 kg (17.6 lbs) of quality roughage (DM), as well as TM salt.

Work/Exercise

• Exercising horses may need an increased DE requirement. Also, the horse can need more Ca, P, K (may double), and up to 4x more Na.
• Protein should be proportional to DE, and vitamin intake should increase variably.
• Horses in light work need a 25% increase in DE requirement, those in moderate work need a 50% increase, and those in heavy work need a 100% increase.
• Provide light-work horses with 0.5-1.5 lbs/24 h of grain versus 2-3 lbs/24 h for moderate-work horses and > 4 lbs/24 h for heavy-work horses. All should have access to 15 – 17.5 lb hay / 1000 lb BW.
• A 500 kg heavy-work horse may need 26.6 Mcal DE, 862 g CP, 40 g Ca, and 29 g P along with concentrate. Free choice, clean water, and trace minerals should be supplemented.

Reproduction (Stallions)

• Stallions in breeding season have ~20% greater nutritional needs than stallions in the off season. Those off season have a ~10% increase.

Reproduction (Pregnancy)

• During early pregnancy, maintenance of 4 months occurs. Sometimes the owner may overfeed the mare.
• By the 11th month of pregnancy, increase CP/DE by 30% and Ca/P by 80%.

Late Pregnancy Feeding Sample Rations With An 1,100 lb Horse:

• Grass hay: 16.5-19.25 lbs, and 2.75-5.5 lbs concentrate, as well as free choice of TM salt and mineral mix,
• With legume hay: 19.25-22 lbs. Free choice TM salt and mineral mix, can have no concentrate.

Reproduction (Lactation)

• Nutritional requirements are greatest for mares in the first two months of lactation.
• These can include ~2x > DE, ~2.5x > CP (~14-15%), and ~2.5x > Ca & P.
• DMI needed: 3% BW, VDMI: 2-2.5% BW. Owners tend to underfeed.
• In that case, must supplement with concentrate and minerals.
• Be sure to stop concentrate at Weaning. Separate foal from the mare. Decrease roughage to maintenance amount, and don't forget about the foal.

Mares In Lactation Sample Rations With An 1,100 lb Horse:

• Grass hay: 16.5 - 22 lbs. Free choice 1.5-2.0 lbs. With 5.5-11 lbs, concentrate (greater than 16% CP).
• Legume hay: 27.5-33 lbs. Free choice 2.5-3.0 lbs with concentrate, may or may not be needed.

Growing Horses

• Provide nursing foals with creep feed by wk 1. GIT isn't mature for capacity fermentation, need to provide additional energy and protein in an easily digestible form.
• Provide creep feed by 2-3 weeks of age at 1 lb per month to increase with weaning.
• These can be in commercial, local mill, or homemade form. Should consist of 14% CP, 0.8% Ca, 0.5% P, and 50 ppm Cu (can decrees to 25 ppm at weaning).
• Weanlings (6 mo., 500 kg mature weight., ADG 0.72 kg), should have monthly check ups, to assess nutrient requirements.
• Some requirements include 15.5 Mcal DE, 676 g (~14-16% CP), 29.1g Lysine and ~38.6 Ca, and ~21.5 g
• For Est. feed intake for growing horses (500 kg mature weight.) At age 4 months, to have a req. At 13.3 (Mcal). Hay at 0-2.0 kg and creep/grain (kg) at 2-4.
• Feed for a weanling includes free choice of water and roughage, plus 0.5 lb / monthly age/d(max. 7-9lb) of concentrate. Local mill should involve nutritionist.
• Most yearlings attain 90% of height, 70% of weight by 1 yr. The DMI needed is 2.5% BW in hay with VDMI: 1.5 – 2% so must utilize concentrate.

Yearling Notes Depending on Age:

• At 12 mo.: provide 18.8 Energy (Mcal); 3-5 Hay kg; 2-4 Grain, kg
• At 18 mo.: provide 19.2 Energy (Mcal) Initiate training; and increase DE and CP accordingly. 4-6 Hay, kg; 2-4 Grain, kg
• At 19 mo.: provide 19 Energy (Mcal); 6-7 Hay, kg; 1-2 Grain, kg. Feed for maitenance.

Older Horses

• Older horses have decreased digestion due to poor teeth and GI motility/enzyme action.
• These can require health & metabolic concerns such as; Pituitary pars intermedia dysfunction (PPID) and laminitis plus Decreased immunity or degenerative joint disease.
• Offer high quality hay that is easier to digest with more leaves, and less stems
• Don't offer to lush of feed due to possible colic issues or laminitis.
• If Losing weight , add gain with caution to laminitis plus add fat such as corn or soy oil. Can supplement of offer Complete feeds for their dental health. Also check for medical problems.