Making More from Sheep Australian Wool Innovation Limited Meat & Livestock Australia
MODULE 8: Turn Pasture into Product
Tool 8.4
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There are some simple, short-term feed budgets you can calculate manually, without the need for a computer. Some examples are given below.

To fill in the budget template, you will need to:

  • Measure the pasture mass (kg green DM/ha) in the paddock you have allocated to the stock to get your starting point (tool 8.6)
  • Estimate pasture quality (tool 8.6 or tool 7.6 in Grow More Pasture)
  • Determine the estimated intake of livestock from the table below
  • Look up typical pasture growth rates for your pasture type and soil fertility (see tool 8.2)
  • Define the minimum target pasture mass (kg green DM/ha) for the class of stock (see procedure 8.2 or the MLA Pasture ruler).

To convert pasture mass to Feed on Offer (FOO), add 300kg/ha..

Q1: How many lactating ewes with twins can I put in a 40ha paddock for a 42 day lambing, while ensuring the minimum to meet stock requirements is maintained?

Pasture available
Present pasture mass (tool 8.6):
1,700 kg green DM/ha
Less required minimum pasture mass (kg green DM/ha)*:
1,500 kg green DM/ha
Available pasture:
200kg green DM/ha
Plus pasture growth (42 days lambing x 40 kg green DM/ha/day):
1,680kg green DM/ha
Total Available Pasture:
1,880kg green DM/ha

Livestock Requirements
Ewe intake 2.9 kg green DM/head/day x 42 days**+ spoilage of 15%
140kg green DM/head
Less required minimum pasture mass*:
Total available pasture
 
1,880
= 13.4 ewes/ha

Livestock requirements
 
140
 
Stocking rate 13.4 ewes/ha x 40ha = approximately 536 ewes for the paddock

* The minimum pasture mass is 1,500kg green DM/ha to ensure that nutrient needs of these lactating ewes with twins are met (see procedure 8.2).
** Intake estimate from the table (downloaded here (75 KB)) (pasture digestibility 70%).

Q2: How long will a 16ha paddock last stocked with 400 pregnant ewes ensuring pasture is kept above a minimum level to meet livestock requirements?

Pasture available
Present pasture mass:
1,000 kg green DM/ha
Less required minimum pasture mass:
700 kg green DM/ha
Available pasture:
300kg green DM/ha
Daily growth rate of pasture*:
27kg DM/ha/day
Total Available Pasture:

Stocking density (400 ewes divided by 16ha):
25 ewes/ha
Livestock requirements**
(1.2 kg green DM/head/day x 25 ewes/ha + spoilage of 15%):
35kg DM/ha/day

Results

These calculations indicate a net pasture loss of 8kg green DM/ha/day (ewes are consuming 35kg green DM/ha/day which is 8kg greater than the pasture growth rate of 27kg green DM/ha/day).

Therefore, available pasture is declining at the rate of 8kg DM/ha/day.

How long will the paddock last (300kg DM/ha divided by 8kg green DM/ha/day)? About 38 days

When calculating short term (1-5 days) feed budgets, except in spring, pasture growth may be ignored.
* From tool 8.2
** Intake estimate from the table (downloaded here (75KB)) (pasture digestibility 70%)

Stocking rate calculator

A stocking rate calculator can be downloaded from http://www.mla.com.au/News-and-resources/Tools-and-calculators/Stocking-rate-calculator using the search function. This calculator automates the process shown below.

Q3: Will I have enough pasture for my 50kg early pregnant Merino ewes to meet their nutritional requirements over 3 months given I have an average of 500 kg DM/ha (green) in my 40ha paddock now?

3 month feed budget

To fill in the budget template below, you will need to:

  • Estimate pasture mass (kg green DM/ha) in the paddocks you have allocated to the stock to get your starting point
  • Look up typical pasture growth rates for your pasture type and soil fertility (see tool 8.2)
  • Estimate pasture quality (see tool 7.6 in Grow More Pasture)
  • Look up the minimum pasture mass required (kg DM/ha) for the class of stock to meet their requirements (see tool 8.5)
  • Determine the estimated intake of livestock for each month from the table (downloaded here (75KB))
  • Look up the target condition/fat score for the class of stock in question (see tool 3.3 in Market Focused Lamb and Sheepmeat Production and tool 10.1 in Wean More Lambs)
  • Account for a spoilage factor due to trampling, dung and urine. A figure of 15% is used here.

Step 1: Calculate available pasture as per step 1 above

Present pasture mass: 500 kg green DM/ha (A)  
Less required minimum pasture mass: 500 kg green DM/ha (B)  
Available pasture (A-B) 0 kg green DM/ha (C)  
       
Plus growth for the period      
Growth rate per day* x number of days      
June: 17 kg DM/ha/day x 30 days 510 kg green DM/ha +    
July: 16 kg DM/ha/day x 31 days 496 kg green DM/ha +    
August: 26 kg DM/ha/day x 31 days 806 kg green DM/ha =    
Growth for the period 1,812 kg green DM/ha (G)  
Total available pasture for 92 days (C+G) 1,812 kg green DM/ha (H)  
       
Step 2 Livestock requirements (from the table downloaded here (75 KB))      
(Intake per day + 15% spoilage) x No. of days      
(0.9kg** + 0.3kg spoilage) x 92 days 110 kg green DM/head (I)  
Stock density that will achieve desired outcome (H ÷ I) 17 head/ha (J)  
       
Step 3: Number of stock in the paddock to achieve desired outcome      
J x paddock area (ha)      
17head/ha x 40 ha 680 ewes in the paddock.    

 

In the above example 680 ewes in the 40 ha paddock would ensure that pasture requirements for the early pregnant ewes are always met during pregnancy.

* From Tool 8.2
** Intake estimate from the table (downloaded here (75 KB)) (pasture digestibility 70%)