1. Principles of veld management

2. Carrying Capacity
potential of an area to support livestock through grazing and/or browsing and/or fodder production over an extended number of years without deterioration to the overall ecosystem.
Assumption: Livestock daily DM intake equivalent (Demand) to % bodyweight.
To balance supply and demand correction for:
Grazing (Harvest) efficiency
Forage loss (fouling, trampling etc)
Soil water holding capacity e.g clay versus sands
Run-off and woody cover

3. Two major carrying capacity determination approaches
Feed resources based
Use by livestock pre-conditioned by proper use factors geared to prevent over exploitation and safeguard rangeland productivity
Use empirical and or simulation models
Uses rainfall records- 1mm produce 0.3kg DM???? Studies done in Matopos
Uses livestock intake requirements
Proper use % of available biomass

4. Two major carrying capacity determination approaches
Animal oriented approach
Permissible amount of feed intake as in feed resource based approach but need to consider herbage quality and nutrient output thus lower estimates than plant based approach

5. Problems with carrying capacity estimates
Scale or area of assessment
Stock mobility
Communal resources
Several niches
May include land units Kilometres apart
Difficult to quantify
Preference between animals species differ and assessing the fraction of edible feed becomes complicated (Especially with browse)- multi species systems
Variability
Time and space
Climatic
Production objectives/sytems
Livestock mix

6. Factors to consider in CC estimation
Topography
Water distribution
Wildlife influence
Season
Grazing management practice
Non livestock demands

7. Carrying capacity concept
General definition must encompass :
elements of animal production goal,
acceptable resource condition and
time
Optimum density (or carrying capacity)= carrying capacity in livestock oriented range management Economic carrying capacity.
Subsistence density (Carrying capacity) = Population size at which an equilibrium between food demand and Supply is reached without external influence.
Synonmous of carrying capacity= environmental carrying capacity, ecological carrying capacity, maximum carrying capacity, potential carrying capacity.
Economic or optimum carrying capacity-equilibrium held in place by human intervation.

8. Carrying capacity concept
There are numerous managed equilibria depending on: production goals
All are lower than subsistence
In practise carrying capacity means different things to different people depending on production objectives.
Carrying capacity has been applied to cattle mostly-graminoid herbage preferred by cattle have become the norm for assessment- hhrebs, dwarf shrubs and other woodies are classified as undesirable.

9. Carrying capacity concept
In Sub-Saharan Africa
Range production more a function of climate than stocking rate
Climate and SR effects interacts and exert episodic rather than continuous impacts
Livestock populations are more likely to be depressed by drought than overgrazing
In the recovery wet years after a drought a, usually the regenerative capacity of the herds is often too low to keep with recovery of forage production

10. The use of carrying capacity concept
Planning purpose
Calculation of average productivity with respect to feed resources and expected livestock output
Need to recognise spatio-temporal flu actions

11. Principles of range management
Manipulation of vegetation and foraging animals to accomplish animal production objectives and rangeland sustainability
Successful range management are based on the following principles:
Control of animal numbers
Spatial distribution of animals- (1) and (2) Stocking rate related
Rest
Period of use
Top hamper control

12. Range management Control of animal numbers
Perhaps most important factor in grazing management
Done through the use of stocking rates
Stocking rates- the must be based on the productivity of the area, animal needs and management objectives. Amount of land which the manager allocates to each livestock unit over the entire graze able period of the year (ha/Lu or Lu/ha). Function of the operator.
Stocking rate must be based on the productivity of the area, animal needs and management objectives.

13. Two terms describing productivity of an area
Grazing capacity—the area (in ha) of a particular type of vegetation required to support one livestock unit for the entire period that the land is grazed, without deterioration of the veld
Carrying capacity
STOCKING RATES affects:
Forage production
Individual animal performance
Animal production per unit area
Economic returns
Ecosystem sustainability

14. Stocking effects on forage production
Generally, as stocking rate increase, the quantity of the forage available declines because:
An a short term basis, the rate of forage depletion exceeds the rate of forage accumulation
On a long term basis, the interaction of biotic and abiotic factors on plant growth
Heavy stocking rates- reduction in build up of carbohydrate reserves
Quality of forage may be increased in the short term by high SR due to removal of low quality forage
Long term changes in species composition under SR RESULTS IN LOW QUALITY FORAGE
SR effects are also manifested by three stocking rate related factors namely- Stocking density, stocking intensity and stocking pressure.

15. Stocking effects on forage production
Stocking Density-
relationship between the number of livestock units and areas of land at any given instant in time.
I f an operator divides 100 ha of pasture, veld etc into four paddocks, each of 25 ha and places 50 LU of cattle on the area and practice rotational grazing, the stocking rate would be 0.5 LU/ha (50÷100), whilst the stocking density of the paddock being grazed would be 2LU/ha (50÷25).
Stocking pressure-The mass of available forage the operator has allowed per livestock for a relatively short period of time.
Stocking Intensity-
An expression reflecting simultaneously both the degree of stock concentration (stock density) and length of grazing period.
found by multiplying the stocking density by the period of grazing to give the number of LU day/ha.
expression of the degree of utilization of an area, and generally only has a meaning in relation to relatively short grazing periods. (often expressed in cattle days per ha (CDH)).
Forage availibility- The mass of available forage per hectare at any instant in time

16. Grazing systems
A grazing system is a specialized management which defines periods of grazing and no grazing for two or more paddocks or management units
The objectives of utilizing grazing systems are:
Improve range condition
Achieve spatial distribution of animals through paddock size and shape
Promote uniform forage utilization by reducing selective grazing
Increases animal performance
Increase flexibility of range management
Improve forage quality and quantity

17. Grazing systems The choice of a grazing system is affected by:
Climate, topography, type of vegetation, type of live stock, water availability and management capacity

18. Grazing systems Continuous grazing-
Management in which animals are kept in a single enclosure for the entire grazeable period of each year.
The number of animals in the enclosure may be varied according to the grazing, but at least some animals are present at all times during the grazeable period;
Deferred grazing/Rotational resting-
management which requires the grazing allocated to a group or groups of animals for the entire grazeable period, to be subdivided into at least one enclosure more than the number of herds
involves the successive resting of the enclosure from grazing for specific purposes such as seeding and translocation aimed at restoration of vigour and productivity, rather than merely to allow regrowth of vegetative material for grazing

19. Grazing systems Rotational grazing-
management which requires the grazing allocated to a group or groups of animals for the entire grazeable period, to be subdivided into at least one enclosure more than the number of herds in a rotation,
so that at any time the animals are concentrated on as small part of the grazing available to them as paddocking permits and involves the succcesuve grazing of the enclosures in a rotation.
Rotational resting and grazing-
Management which incorporates both concepts of above types of grazing management.
See Tainton, beef production management

20. Calculations
A farmer from the Middleveld asks for help. He tells you he has one herd of 375 steers weighing 360 kg each in 1200 ha divided into six camps. Each camp has 54t of forage dry matter. After inspecting his veld with him you decide that he should be using a mid- season grazing cycle of 54 days, and estimates his current grazing capacity as 1LU:4ha (where, in this case, 1LU is the same as 450kg). He now wants to know:
Stocking rate
Current carrying capacity
Stocking density
Grazing period
Rest period
Stocking intensity
Stocking pressure

21. Calculation Forage availability Stocking intensity in the early season
Give appropriate units for each answer
ANSWERS
Stocking rate= 375×360 × = 0.25 LU/ha or 1 LU:4 ha
(6× 200)
ii) Current carrying capacity
= 6×200×1= 300LU 4
iii) Stocking density
= 375 × 360 × 1 = 1.5LU/ha or 1LU:0.67 ha

22. Grazing period
= 54 =9 days 6
v) Rest period
=54 × 5 = 45 days (54-9=45 days)
vi) Stocking intensity (=stocking density × grazing period)
= 1.5 × 9= 13.5 LU.days/ha

23. Stocking pressure 54 × 450 × 1 = 0.18 t DM/LU 360 375
viii)Forage availibility
= 54 = 0.27t DM/ha
200
ix) Stocking intensity in the early season
=1.5 × 5 = 7.5 LU.days/ha Note the shorter grazing period

24. Assignment
You visit a successful rancher in Kadoma (Natural Region 111, in the higher rainfall area part of the middle veld) and find in one area of his ranch he has 500 steers of 300kg mean body mass rotating through six paddocks. Each paddock is 250 ha in size with, in mid- summer s a standing herbage of 54 toonnes of dry matter before grazing. The current grazing capacity is 1LU:4 ha. The farmer is uses a grazing cycle of 54 days in mid-summer, and imposes the same stocking intensity on each of the paddocks at any particular time of the year.
Calculate the following for the ranch, giving appropriate units:

25. Current carrying capacity
Stocking rate
Stocking density
Grazing period
Rest period
Mid –summer stocking intensity
Forage availability in mid-summer
Stocking pressure in mid summer
The appropriate stocking intensity in early summer

26. The grazing cycle in early summer
The rest period in early summer
The grazing period in early summer (12)
(b) Discuss what options the farmer has for increasing his overall carrying capacity of that section (8)