STOCKING RATESTOCKING RATE

DefinitionDefinition

The number or biomass of animals stocked in a unit of land

Stocking rate unitsStocking rate units

• 5 cattle/ha• 5 KK cattle/ha• 5 sheep/ha• 5 animal units/ha (1

a.u. = one 2-year old cattle)

• 1000 kg biomass/ha

Importance of stocking rateImportance of stocking rate

• Understocked (stocking rate too low)– The feed supply is not

used to capacity– Pastures become

mature and uneven– The farmer does not

get maximum returns

Overstocked (stocking rate too high)Overstocked (stocking rate too high)

– Animals get inadequate feed

– Pastures get too short and overgrazed

– The farmer does not get maximum returns

Optimum Stocking RateOptimum Stocking Rate

The stocking rate which will give maximum animal production while sustaining pasture growth

Factors determining optimum Factors determining optimum stocking ratestocking rate

• Type of pasture

• Fertilizer input

• Type of animals

• Climate

• Availability of supplementary feed

Response of animals to stocking Response of animals to stocking raterate

• Production per animal– Declines with increasing stocking rate– The decline is linear

• Production per hectare– Increases with increasing s.r. up to a

maximum then declines– The response is quadratic

Stocking RateCattle/ha

LWG kg/animal LWG kg/ha

1 300 300

2 250 500

3 200 600

4 150 600

5 100 500

6 50 300

7 0 0

Stocking Rate and Animal Production

0

100

200

300400

500

600

700

1 2 3 4 5 6 7

Stocking Rate cattle/ha

kg

Stocking Rate

LWG kg/an

LWG kg/ha

Ya= a -bX

Yh = aX – bX2

Optimum stocking rateOptimum stocking rate

Y= a – bX

Where Y=LWG per head

X=stocking rate

Optimum stocking rate = a/2b

Y=a-bXY=a-bX

• a = intercept• the maximum output per animal• Reflects the quality of pasture• High quality pastures have high value of a• b = slope• The decline in animal output with increase in

stocking rate• Reflects quantity of pasture• Productive pastures have low value of b

Animal Type

Pasture Type

Stocking rate animal/ha

Expected LWG/day

Beef Cattle

Grass + 300 kg N/ha

4-5 (crossbred) 400-450 g

6-7 (KK) 300-350 g

Grass + legume

2-3 (crossbred) 300-350 g

3-4 (KK) 300-350 g

Optimum Stocking Rates for Beef Cattle

Animal Type

Pasture Type Stocking rate animal/ha

Expected milk kg/d

Dairy cattle

Grass 0 N 1 (S/F) 6-7

Grass + legumes

2 (S/F) 12-13

Grass + N 2-4 (S/F) 7-10

Optimum Stocking Rate Dairy Cattle

S/F = Sahiwal Friesian cross

Animal Type

Pasture Type Stocking rate animal/ha

Expected LWG/d

Goats & Sheep

Grass unfertilized

10 30-80 g

Fertilized grass 30-40 30-80

Optimum Stocking Rates for Goats and Sheep

Grass Species Stocking Rate animals/ha

N fertilizer rate kg N/ha

LWG g/day LWG kg/ha yr-1

Brachiaria decumbens

8 150 286 835

300 353 1031

Digitaria setivalva

6 150 276 604

300 341 747

Panicum maximum

6 150 335 734

300 403 883

Effects of stocking rate, N fertilizer and grass species on animal production

Species Stocking Rate animals/ha

DM Yield of pasture kg/ha

% of sown grass

% weeds % bare spaces

Guinea 6 2552 85.5 7.2 7.3

8 1276 30.2 53.7 16.6

10 986 10.3 74.5 15.2

Signal 6 3044 94.0 0.5 5.5

8 2171 81.2 9.3 9.5

10 1513 38.0 46.4 15.6

Effects of stocking rate on yield and composition of grass pasture

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