Pasture-based nutrition considerations for horses

Dr. Gary Heusner

Extension Bulletin 1224 Forage Systems for Horses in Georgia

1. http://commodities.caes.uga.edu/fieldcrops/forages

2. Forage Extension Publications

Master Equine Management Training

Master Equine Management Training

Master Equine Management Training

Master Equine Management Training

12 hrs in 12 hrs in daylightdaylight

12 hrs at 12 hrs at nightnight

24 hrs in 24 hrs in pasturepasture

Time grazingTime grazing 10.810.8 9.29.2 17.217.2

Percent of Percent of avail timeavail time

89.789.7 76.476.4 71.671.6

Horse Diet Basics

1. Water intake2. Maximize forage intake3. Minimize concentrate consumption4. Balance the ration in the following order (a)energy (b) protein (c) minerals (d) vitamins5. Monitor body weight & body condition score

Horse diet basics (cont)

6. Change feedstuffs gradually (7-14 days)7. Calcium to phosphorus should be between

3:1 to 1:18. Supplement minerals & vitamins9. Feed each horse as an individual

ENERGY

• Carbohydrates CHO• Fats CHO• Calories• Digestible energy• Megacalories per day

• i.e. 1100 pound horse requires 16.4 mcals/day

• digestible energy ratios key to proper diet formulation

Energy intake

• Determining adequacy?• Weight• body condition scoring• general health• behavior• how much in feed?

Body Condition Score

Minimum Body Condition Score

• 5 MODERATE• Back level. Ribs cannot be visually

distinguished but can be easily felt. Fat around tail head beginning to feel spongy. Withers appear rounded over spinous processes . Shoulders and neck blend smoothly into body.

BC 4.5

BC 5.5

Master Equine Management Training

Things to Consider When Choosing a “Base” Horse Forage

• Perennials should form foundation of grazing system– Dependable!– Persistent– Productive– Dependable

• Think about climate and timing of production

Horses grazing tall fescue/bermudagrass near Athens GA

Cautions (forages to avoid)

• High endophyte fescue Broodmares, young growing horses• Sudangrass & Sorghum X Sudan hybrids and

Johnsongrass cystitis, prussic acid• Annual clovers will not eat

Warm Season Perennials

• All base forages should be perennials!

• Warm season plants produce in summer monthsLate April – first frost

• Very drought tolerant and most are grazing and treading tolerant

• Bahiagrass and Bermudagrass

Hybrid Bermudagrass

• Must be established vegetatively

1.Slow2. Expensive3. Small acreage

contracting difficult

• Benefits1. Higher yields2. Good quality3. Possible hay production varieties = Coastal,

Russell, Tifton 85

Seeded Bermudagrass• Common bermudagrass can be a good choice for pastures!

– Dense sod– Good quality – Yields approximately 60-70% of hybrids

• Cheyenne– Excellent alternative to common and hybrids– Yields approach Coastal– Weed problems at establishment– ~$80 per acre seed cost

• Giant – Does not survive more than one or two years!!!

• Currently looking at several alternatives for Georgia

Cool Season Perennial Grasses

• Tall fescue is most persistent and productive species for this area

• Orchardgrass will persist in this area for 2 years under grazing– Less productive in fall than

tall fescue• Timothy and KY Bluegrass

are NOT an option

Tall fescue

Signs of Fescue Toxicosis in the Horse

• fertilityfertility

• Pre-mature placental separationsPre-mature placental separations

• Prolonged pregnancy (avg. 27 days past)Prolonged pregnancy (avg. 27 days past)

• Foaling difficulty (dystocia)Foaling difficulty (dystocia)

• placental retentionplacental retention

• Agalactia or low milk productionAgalactia or low milk production

• Low IgG levels in colostrumLow IgG levels in colostrum

Warm Season Annuals

• Crabgrass is probably best warm season annual pasture for horses– Can be used in combination

with tall fescue• Millets can be grazed with

horses but are difficult to manage

• Sorghums should be avoided due to urinary cystitis problems (johnsongrass, sorghum-sudan, sudangrass) Crabgrass

Cool Season Annual Grasses• Best utilized as a

complimentary species• Perform well in dormant

bermudagrass pastures– Wheat– Oats– Annual ryegrass

• Broadcasting 20-25 lbs/ac of annual ryegrass on closely grazed bermudagrass is economical and effective

• Do not overseed annual grasses into tall fescue

Annual ryegrass + white cloversod seeded in dormant bermudagrass

Forage IntakeCLASS OF HORSE DAILY FEED INTAKE

(% OF BODY WEIGHT)RELATIVE FORAGE QUALITY (RFQ)

Maintenance 1.5-2.0% 75 or greater

Gestating mare 1.5-2.0% 80 or greater

Lactation 2.0-3.0% 90 or greater

Growing (weanlings) 2.25- 3.25% 100 or greater

Work (performing) 1.75- 3.25% 100 or greater

Stallions (non breeding) 1.5-2.0% 75 or greater

Stallions breeding 1.75-2.5% 80 or greater

Lbs of grain/100 lbs Body Weight

Total Air Dry Feed Consumption % of Body Weight*

Type of Work Rate of Growth Physiological Function

0.0-0.5 1.5-2.0 None Maintenance First 2/3 of gestation

0.25-0.75 1.8-2.2 Lighta Slow Last 1/3 of gestation

0.75-1.25 2.0-2.3 Moderateb Medium Lactating mare, Stallion

in service

1.25-1.50 2.0-2.5 Heavyc Fast Lactating mare in drylot

1.5-1.75 2.5-3.25 Very heavyd __ __*On an AS FED BASIS approximately 90% dry matteraLight work defined as 1 to 3 hours per week average heart rate 80 bpmbModerate work defined as 3 to 5 hours per week average heart rate 90 bpmcHeavy work defined as 4 to 5 hours per week average heart rate 110 bpmdVery Heavy work various; ranges from 1 hour per week speed work to 6-12 hours per week slow work, heart rate 110 – 150 bpm

INTAKE OF GRAIN ACCORDING TO TYPE OF WORK OR PHYSIOLOGICAL FUNCTION

Summary

• Horses were designed to be grazers.• Properly managed pastures provide the ideal

source of nutrients.• Pastures provide for exercise and better

health conditions.• Manage pastures as in a “growing and

harvesting” mode.