Forest and Horse Health Relationships: Introduction to Horse Paddock Grazing Systems by Dr. Bridgett McIntosh

1. INTRO TO HORSE PADDOCK GRAZING SYSTEMS:
FORAGE & HORSE HEALTH
RELATIONSHIPS
DR. BRIDGETT MCINTOSH
DEPARTMENT OF ANIMAL SCIENCE
M.A.R.E. CENTER
MIDDLEBURG, VA
GREENING
YOUR
HORSE
PADDOCK
SYSTEM
John Marshall
Soil & Water
Conservation
District
Piedmont
Environmental
Council

2. Forage is foundation of
equine diet
Horses need 1.5% to
3% of their body
weight in forage each
day:
17 to 33 lb/day for
the average horse
Graze 14-18 hrs/day
Move 10 miles/day
WHY IS PASTURE IMPORTANT?

4. Slide Design, K.Treiber

5. PASTURE GRASS ALONE EXCEEDS MOST
NUTRIENT REQUIREMENTS
Light Exercise (assuming intake at 2% BW)
126%
211%
174%
272%
183%
550%
204%
71% 99%
215%
835%
68%
489%
417%
138%
0%
100%
200%
300%
400%
500%
600%
700%
800%
900%

6. BENEFITS OF PASTURE
Provides optimal nutrition
Reduces colic and digestive
disorders
Reduces gastric ulcers
Reduces respiratory disease
Increases bone mineral content
in young growing horses
Promotes normal healthy
behavior
Reduces development of vices

7. Overstocking
Overgrazing
Manure management
Mud management
MANAGEMENT PROBLEMS

8. PROBLEM GRAZERS
Selective grazers= uneven grazing
Biting top grazers = leaf removal
Large & heavy = soil compaction & trampling
Manure distribution = uneven grazing &
parasites

9. Healthy Horses
+
Healthy
Environment?
HEALTHY
PASTURE
S
HOW DO
WE
ENSURE

10. KEYS TO A HEALTHY PASTURE
 What is purpose of pasture?
 Exercise
 Nutrition
 Both?
 Size of usable acreage
 Stocking rate
 Pasture species selection
 Proper planting
 Soil testing
 Grazing management
OR
Turnout for exercise?
Nutrition?

11. • Depends on characteristics of your pasture
• Maintain at least 70% vegetative cover
regardless of time of year
• 2 acres per horse
STOCKING RATES

12. HOW MUCH PASTURE?
Turnout Time (d) Acres
< 3 h 0.5
3-8 h 1
8-12 h 1.5
24 h 2 +
Stocking rates can be
increased with elevated
levels of management:
Mowing
Rotational grazing
Irrigating
Fertilizing
Overseeding

13.  Several species make good horse pastures
 Cool Season
 Tall Fescue*
 Orchardgrass
 Kentucky Bluegrass
 Timothy
 Warm Season
 Bermudagrass
 Crabgrass
 Legumes
 Clover
 Alfalfa
FORAGE SPECIES SELECTION
* Ky 31 Tall fescue is toxic to broodmares but perfectly safe for all other classes of horses

14. COOL SEASON VS WARM SEASON GRASSES

15. PLANTING GUIDELINES
Cool Season Forages
Fall is best
August-September
Spring
Frost seed January-March
Drill February to April 1
Warm Season Forages
Late spring/early summer (May)
Do not graze too soon!

16. PLANTING RECOMMENDATIONS

17. RENOVATE OR START OVER?
Continue current management if:
75% or more desirable plants
Improve Management or overseed:
40-75% desirable plants left
Start over if:
Less than 40% desirable plants

18. Soil tests indicate soil pH and fertility
Lime (to adjust pH)
Nitrogen (N)
phosphorous (P)
Potassium (K)
Other nutrients, Ca, Zn, Cu, Mg, etc.
Soil tests should be performed on each
pasture or field every 2 to 3 yrs.
Apply N fertilizer when plant growing
ie. at “green-up”
SOIL TESTING FOR HEALTHY PASTURES

19. Soil samples are collected
by walking in a zig-zag
pattern and collecting
samples to a depth of 3-6”
from at least 20 locations.
3-6”
HOW TO COLLECT SOIL SAMPLES

20. SUBMITTING SOIL SAMPLES
 Mix samples thoroughly and submit
a single composite sample (about 1
cup) for pastures 10 acres or less.
 Larger pastures require a greater
number of samples.
 Label sample box so that the test
results can be easily identified.
 Fill out information sheet
 Soil sample boxes and supplies can
be obtained from your county
extension office
 What kind of soil do you have?
 http://websoilsurvey.nrcs.usda.gov/app/Ho
mePage.htm

21. HORSES SPOT GRAZE FAVORITE
AREAS AND SELECTIVELY GRAZE
FAVORITE SPECIES, AND ARE
CAPABLE OF ELIMINATING
PLANTS IF PASTURES ARE NOT
MANAGED.

22. GRAZING MANAGEMENT
 Pastures are made up of individual
plants
 Understanding how plants grow can
help us understand how to manage
the pasture
 The best weed control is a healthy
stand of forage

23. HOW GRASS GROWS
• Main growing point at base
produces leaves
• Growing points throughout stem and
at base of leaf blade
• Vegetative vs. reproductive growth
• Photosynthesis
• Regularly removing first new leaves
in the spring will weaken the plant
root, and eventually it will die
Missouri State University

24. Adapted from NRCS, Bozeman, MT
TAKE
HALF /
LEAVE
HALF
SERIOUS
DAMAGE TO
THE ROOT
SYSTEM OF
THE PLANT
CAN OCCUR IF
AS LITTLE AS
10 PERCENT
ADDITIONAL
PLANT LEAF
VOLUME IS
REMOVED

25. KEEP PLANTS GROWING FAST
Individual
pasture-plant
growth
Plant height (inches)
0 2 4 86 10 123
Fastest
growth
Slow growth zone!!!!!

26.  Key point: REST the pastures
 Graze for a short time then allow forage to
regrow
 Need to rotate between several fields
 Ideally, first field is ready to be grazed
when horses are done on last field
 How many fields? How long between
rotation? Depends!
Size of fields
Stocking density
Available forage
ROTATIONAL GRAZING FOR
OPTIMAL PASTURE PRODUCTION

27. ROTATIONAL GRAZING
EXAMPLE LAYOUT

28.  Temporary electric fencing works great!
 One-strand if separating paddocks only
 Avoid metal t-posts
INTERNAL PADDOCK FENCING

29. REST & RECOVER
Remove at
3-4”
Graze at
6 - 12”
(cool season
grasses)

30. Adapted from NRCS, Bozeman, MT
CONSIDER THE SPECIES

31. Cool season Grasses
Time of Year Recovery Time
First rotation (late
Mach/April)
14-16 days
Fast Growth (May-
June and Fall)
20-30 days
Summer/Winter 30 to 40 days
Warm Season Grasses
GRAZING GUIDELINES
Time of Year Recovery Time
Early fast growth 14-21 days
Normal growth
conditions
21-28 days
Slower growth 35 to 45 days
• Recovery time will depend on how short the forage was
grazed, growing conditions, soil fertility etc.
• Separate paddocks by cool season and warm season if
possible.

32. For the Plants &
Environment
Increased forage
production
Plants remain young &
vegetative
Uniform grazing
Erosion reduced
NPS pollution reduced
For the Horse
Improved nutrition
Exercise & grazing reduce
risk for colic, bad
behavior
Grazing increases mineral
bone density in young
horses
Decreases mud and
erosion
Improve skin and hoof
condition
BENEFITS OF ROTATIONAL GRAZING

33.  Pastures provide
optimal nutrition
for most horses
BUT…
 Sometimes
healthy pasture
not healthy for all
horses!
 Metabolic
Syndrome
 Obesity
 Insulin resistance
 Laminitis/Founder
HEALTH CONSIDERATIONS FOR GRAZING
0 2 4 6 8 10 12 14 16 18 20 22 24
0
2
4
6
8
10
12
14
16
18
20
FF
Pasture
SS
Time, hr
Insulin,mIU/L
Staniar et al, 2004

34. 0
10
20
30
40
50
60
70
80
90
100
110
120
NSC
Insulin-Grazing
Insulin-Control
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
0600 2400 1800
2130
Last blood sample
0930
First blood sample
INSULIN
DAY 1-2
NSC
DAY 1-2
0600
TIME
2400 1800
First pasture sample Last pasture sample
24001200 1800 0600 1200 1200 1800 0600 1200 2400 0600
Insulin,mIU/L
ForageNSC,%DM
Hay
PASTURE NSC (SUGAR)
EFFECT ON GRAZING HORSES
McIntosh et al, 2005

35. EFFECTS OF GRAZING MANAGEMENT ON
PLANT CARBOHYDRATES
cont
rot
0
2
4
6
8
%DM
sugar
SH
O
R
T
TA
LL
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
WSC%,DM
7.7
7.1
*
McIntosh et al., 2013 & 2014

36. BODY CONDITION SCORING
(BCS)
Score of overall
body fatness
< 4
underweight
4 ≤ BCS < 7 moderate
7 ≤ BCS < 8 overweight
BCS ≥ 8 obese
Henneke et al., 1983

37. CRESTY NECK SCORE (CNS)
SCALE 0 TO 5
0 1 2
3 4 5
Carter, 2009

38. GRAZING
MUZZLES
DRY LOTS
Reduce
NSC
intake
Allow for
exercise
Turnout
in early
am

39. RECOMMENDED
CONSERVATION PRACTICES
Rotational Grazing
Heavy Use Areas or Dry lots
Mud Management & fat horses
Manure Management & Composting

40.  Mud Management
 High stocking rates
 Wet conditions
 Drought or slow forage
growth
 Restrict grazing
 Disease avoidance
 Weight loss
 300 ft2 per horse
HEAVY USE AREAS OR DRY LOTS

41. MANURE MANAGEMENT
 Horses produces 30-50 lbs manure per day
 10 tons or 12 cubic yards per year
 9.1 tons of manure per year containing
 11 lb N, 2 lb P, 8 lb K
 Parasites transmitted through manure
 Pastures source of greatest risk of
infection
 Composting kills weed seeds &
parasites
 Dragging???
 Can spread parasites

42. COMPOSTING MANURE
 1 Horse produces .81 ft3 manure or 1.6-2.4 ft3
with bedding
 2 Horses for 4 months:
 Two 12 x 12 x 5 ft bins
 12 horses for 2 months:
 Three 20 x 20 x 5 ft bins
 Turn every 2-3 weeks (oxygen)
 Temp should reach 130-160F
 Complete after 1-4 months
 No odor, moist but not wet
 Analyze for nutrient content
 Apply to land according to soil test
 READ HERBICIDE LABELS IF USED

43. MANAGEMENT SOLUTIONS FOR
HEALTHY HORSES & ENVIRONMENT
 Three to five grazing seasons
required for measurable change
 Set realistic goals for acreage
available
 Higher level of management
may be needed to meet goals
 Develop management protocols
to be efficient
 Nutritionally & economically &
environmentally

44. Conservation BMP Model Farm
Turfgrasses for heavy use areas and
diet paddocks
Horse genetics & disease
Mixed species grazing
Native warm season grasses
Wankopin nature trail
Facebook.com/marecenter
NEW AND EXCITING PROJECTS AT THE MARE CENTER

45. THANK YOU
Middleburg Agricultural Research and Extension Center (MARE Center)
Dr. Bridgett McIntosh
bmcintosh@vt.edu
540.687.3521 ext
22
http://www.arec.vaes.vt.edu/middleburg/