Stocking Rates/Grazing Systems

Question 1

4 main grazing principles:

Answer 1

1. which animals (livestock species, age, etc.)
2. how many (i.e. stocking rate)
3. when to graze/how long to graze
4. where do animals graze (distribution)

Question 2

carrying capacity is…

Answer 2

number of animals that a piece of land can support on a long term basis w/out damage to the ecosystem

NOT equal to stocking rate

Question 3

stocking rate is…

Answer 3

number of animals a lang manager places of a piece of land for a specified period

*must balance forage supply and demand

*carrying capacity does not change but stocking rate does

Question 4

AU is…

Answer 4

Animal Units
1 AU = 1000 lbs of grazing animals (ruminants)

Question 5

AUE is…

Answer 5

Animal Unit Equivalent
conversion factor reflecting the number of AU in a given animal

Cow = 1
sheep = .2
rabbit = .02

Question 6

AUM is…

Answer 6

Animal Unit Month

amount of forage an AU will eat in a month

Question 6

calculate AUM for hindgut fermentor

Answer 6

1000lbs x 3% = 30 lbs/day x 30 days = 900 lbs

Question 7

calculate AUM for ruminant

Answer 7

1000lbs x 2.5% = 25 lbs/day x 30 days = 750lbs

Question 8

4 steps for the Forage-Demand Method

Answer 8

1. calculate USABLE forage
2. adjust for accessibility (water sources, terrain)
3. calculate forage demand of animals
4. calculate stocking rate

Question 9

How to calculate USABLE forage

Answer 9

1. determine biomass supply
   weight biomass/acre x area
2. factor in proper use
   total biomass/acre x proper use % x area

ex: you manage a 1200 acre ranch, avg production is 500lbs/acre. Ranchh is in sagebrush steppe plant community and has PUF 30%.

1200 x 500 = 600,000
600,000 x .30 = 180,000

in AUM’s: 180,000 / 750 or 900

Question 10

Proper Use Factor

Answer 10

helps calculate/adjust stocking rate by considering ecological processed/what the land can sustainably support without damage long term.

Sagebrush grassland: 30-40%
Shortgrass Prarie: 40-50%
Coniferous Forest: 30-40%
Oak Woodlands: 30-40%

Question 11

Adjusting for Accessibility: Water

Answer 11

0-1 miles from H20, no reduction
1-2 miles from H20, 50 % reduction
> 2 miles from H20, 100% reduction, ungrazable

Question 12

Adjusting for Accessibility: Slope

Answer 12

0-10% no reduction
11-30%, 30% reduction
31-60%: 60% reduction
>60%: ungrazable

Question 13

Calculating Forage Demand

Answer 13

weight of animal x daily intake x number of days grazing

Ex: on avg cows in herd weight 1000 lbs and graze on the ranch for 3 months. How much forage would each cow consume?

1000 x 2.5% = 25 lbs/day x 90 days = 2, 250 lbs/cow/season

in AUMs 2250/750 or 900 =

Question 14

Calculating stocking rate

Answer 14

usable supply/demand =

Question 15

Proper stocking rates impact….

Answer 15

rangeland health
production/economic gains

Be flexible (no more than 60% of herd breeding stock) and constant (size could be sustained with 25% decrease in precip)

Question 16

True/False: Does Heavy use equal overgrazing

Answer 16

False.

Heavy use is during a specific season such that increased levels of utilization are observable. Overgrazing is repeated heavy grazing yielding damage to plant communities.

Question 17

Does overstocking always lead to overgrazing?

Answer 17

No. ex: targeted grazing

Question 18

Overresting is…

Answer 18

excessive resting (no grazing) periods that result in damage to plant community (in systems that have been historically grazed).

Question 19

3 principles of grazing mgmt are…

Answer 19

1. know/communicate your objectives (informative indicator changes to be measured)
2. balance supply/demand via stocking rate
3. manage livestock placement/distribution/timing

Question 20

Grazing Methods/Systems boild down to…

Answer 20

avoid grazing during sensitive times
provide effective rest

Question 21

Grazing system/method defn

Answer 21

planned effort to leave some areas unused for at least part of the year

Question 22

grazing period defn

Answer 22

season (timed event) and # of days when pasture is grazed

Question 23

deferment

Answer 23

period of non grazing until key forage set seed

Question 24

Rest

Answer 24

period of non grazing for full year

Question 25

What do grazing systems accomplish?

Answer 25

1. maintain/improve veg
2. uniform use grazing units
3. stabalizing forage supply
4. enhance forage quality
5. improve ecological processes

Question 26

5 basic grazing methods:

Answer 26

1. continuous grazing - graze whole area whole season (pro: simple, con: excessive use)
2. deferred rotation - do not graze at least 1 pasture until after seed set, rotate pastures deferred (pro: working with life cycle, con: less animal choice)
3. rest rotation - same as deferred rotation but for full year (pro: range cond improves, con: dorment stems mixed with green, lower quality)
4. short duration - high intensity, low frequency, each pasture grazed short time on a rotating schedule, no rest or deferment. each grazed 2x year. climate dependent (bad in deserts) (pro: stocking rate higher, con: plant health decreases)
5. Seasonal suitability - moving livestock to different areas (up in elevation) depending on growth/pattern vegetation. “following the green” (pro: green forage all year, con: high mgmt)