Comparing Feeding Supplements with Grazing Off

The economic advantage of grazing for 10 weeks off-farm is compared to buying in supplements. The calculations are specific for four situations:

  • maintaining a 55 kg breeding ewe;
  • growing a 35 kg ewe hogget at 100g per day;
  • maintaining a 450 kg beef cow; or
  • growing a 300 kg replacement beef heifer at 2 kg per week.

In a drought situation it is not possible to feed usual stock numbers at maintenance levels. This means that if no action is taken stock will lose weight. If it is possible to feed say, 80 percent of stock at maintenance levels on existing pasture covers, then farmers need to decide what to do for the other 20 percent of stock – the options are to sell them, to send them off for grazing or to fully feed supplements. In most cases selling will be the best option. However, this paper compares the options of feeding supplements vs grazing off if the farmer wishes to retain those stock.

Supplementary Feed Costs

  • Hay costs $7 per 25 kg bale
    85% DM; 7.85 MJME/kgDM
    167 MJME/bale (4.19 cents per MJME)
  • Barley costs $400 per tonne landed on the farm
    86% DM; 13.1 MJME/kgDM
    11266 MJME/tonne (3.55 cents per MJME)
(Note: DM = drymatter; MJME = megajoules of metabolisable energy)

Maintaining Ewes

Key assumptions for holding a 55 kg ewe at maintenance:

  • Requires 11.1 MJME for maintenance per day
  • Fifty percent of the animal’s maintenance feed requirement is coming from either feed
  • 5.55 MJME hay costs 23c/day
  • 5.55 MJME barley costs 20c/day

This relates to real weights of:

  • 0.83 kg hay (30 ewes per bale);
  • 0.5 kg barley per ewe per day.

The combined feed cost is $0.43 per ewe per day (barley $0.20, hay $0.23).
The cost per ewe for 10 weeks' hay and barley feeding is 70 days x $0.43 or $30.10.

Growing Hoggets

Key assumptions for growing a 35 kg hogget at 100g per day:

  • Requires 13.6 MJME per day
  • Of the diet, 50% is from hay and 50% from barley
  • 6.8 MJME hay equals 1.02kg which costs 28 cents per day
  • 6.8 MJME barley equals 0.6kg which costs 24 cents per day

The combined feed cost is $0.52 per hogget per day (barley $0.24, hay $0.28 per day)
The cost per hogget for 10 weeks' feeding is (70 days x $0.52 per day) or $36.40

Summary of Costs for Supplementary Feeding Sheep

Hay and barley Maintaining
ewes		 Growing
hoggets
Cost per day 43 cents 52 cents
Cost for 10 weeks $31.10 $36.40

Grazing Off

Grazing off comprises three main costs:

  • The transport cost in getting the sheep to and from grazing
  • The grazing charge per week
  • The number of weeks the sheep are away

The underlying assumption is that the sheep will come home heavier than they went away.

Table 1 sets out the cost per day in association with the transport cost for grazing sheep; that is, both the grazing and the transport cost have been added together to establish the feed cost per day per ewe.
A 10 weeks' off-farm period is used.

Ewe Grazing

If full supplementary feeding at home costs 43 cents per ewe per day, paying $6 transport costs and up to $2.20 a week grazing fee (a total cost of 40 cents per ewe per day) is a cheaper option.

Hogget Grazing

The same exercise can be used with 35 kg hoggets gaining 100 grams per day. Full supplementary feeding costs $0.52 per day. Reference to Table 1 suggests that full supplementary feeding at home is an expensive option even at $2.40/week grazing fee and $10.00 transport (a total cost of 49c per ewe per day).

Grazing Risks

Although grazing off may be the cheaper option, things can go wrong. Risks include:

  • Stock losses
  • Stock losing weight
  • Cost to future production from weight loss

Therefore, you need to remember that the comparisons above assume that you are maintaining ewes or growing hoggets as outlined. If this is not achieved on the grazing option, then the relative cost of grazing increases.

Table 1: Total cost (cents) per day per sheep including grazing fees and return transport

Grazing cost
per week		 Grazing cost
per day ($)		 $4.00 $5.00 $6.00 $7.00 $8.00 $9.00 $10.00
$2.40 0.343 0.40 0.41 0.43 0.44 0.46 0.47 0.49
$2.20 0.314 0.37 0.39 0.40 0.41 0.43 0.44 0.46
$2.00 0.286 0.34 0.36 0.37 0.39 0.40 0.41 0.43
$1.80 0.257 0.31 0.33 0.34 0.36 0.37 0.39 0.40
$1.60 0.229 0.29 0.30 0.31 0.33 0.34 0.36 0.37
$1.40 0.200 0.26 0.27 0.29 0.30 0.31 0.33 0.34
$1.20 0.171 0.23 0.24 0.26 0.27 0.29 0.30 0.31
$0.80 0.114 0.17 0.19 0.20 0.21 0.23 0.24 0.26

Maintaining Beef Cows

Key assumptions for holding a 450 kg cow at just above maintenance (50 grams per day gain):

  • Feed demand 60 MJME/day
  • Hay costs $7 per 25 kg bale and barley costs $400 per tonne landed on the farm (as above)
  • Half of the cow's maintenance feed requirement is coming from barley; 50% ration from hay
  • 30 MJME hay @ 4.19c/MJME, which costs $1.26 per day
    This equates to 4.5 kg hay (5.5 cows per bale per day)
  • 30 MJME barley @ 3.55c/MJME, which costs $1.07 per day
    This equates to 2.66kg barley

The combined cost is $2.33per cow per day.
The total cost of fully feeding supplements for 10 weeks is $163.10 (or $16.31 per week).

Growing Beef Heifers

Key assumptions for growing a 300 kg replacement beef heifer 300 grams per day (2 kg per week):

  • Requires 55 MJME per day
  • Hay cost as above that is $7 per bale. Barley costs $400 per tonne landed on the farm
  • Of the diet, 50% is from hay and 50% from barley
  • 27 MJME hay @ 4.19c/MJME; costs $1.13 per heifer per day. This equates to 4.05 kg hay per day
  • 27 MJME barley @ 3.55c/MJME, cost $0.96 per day. This equates to 2.4 kg barley

The combined cost is $2.09 per heifer per day.
Total cost for hay and barley feeding for 10 weeks is 70 days at $2.09 or $146.30.
($14.63 per week).

Summary of Costs for Supplementary Feeding Cattle

Hay and barley Maintaining
cows		 Growing beef
heifers
Cost per day $2.33 $2.09
Cost for 10 weeks $163.10 $146.30

Off-farm Cattle Grazing vs At-home Supplementary Hay and Barley Feeding

Fully feeding hay and barley is expensive and it is generally much more profitable to graze off farm, even if seemingly high transport costs are involved (for example, for a cow $12 per head per week and $40 transport, a cost of $2.29 per day; for a heifer $11 per week and $35 transport cost, a cost of $2.07 per day).

Table 2: Total cost per day per cattle beast including grazing fee and return transport

Grazing cost
per week		 Grazing cost
per day (cents)		 $15.00 $20.00 $25.00 $30.00 $35.00 $40.00
$15.00 2.143 2.36 2.43 2.50 2.57 2.64 2.71
$14.00 2.000 2.21 2.29 2.36 2.43 2.50 2.57
$13.00 1.857 2.07 2.14 2.21 2.29 2.36 2.43
$12.00 1.714 1.93 2.00 2.07 2.14 2.21 2.29
$11.00 1.571 1.79 1.86 1.93 2.00 2.07 2.14
$10.00 1.429 1.64 1.71 1.79 1.86 1.93 2.00
$9.00 1.286 1.50 1.57 1.64 1.71 1.79 1.86
$8.00 1.143 1.36 1.43 1.50 1.57 1.64 1.71
$7.00 1.000 1.21 1.29 1.36 1.43 1.50 1.57
$6.00 0.857 1.07 1.14 1.21 1.29 1.36 1.43
$5.00 0.714 0.93 1.00 1.07 1.14 1.21 1.29
$4.00 0.571 0.79 0.86 0.93 1.00 1.07 1.14
$3.00 0.429 0.64 0.71 0.79 0.86 0.93 1.00
$2.00 0.286 0.50 0.57 0.64 0.71 0.79 0.86
$1.00 0.143 0.36 0.43 0.50 0.57 0.64 0.71

Summary

Off-farm grazing is a very viable option when the animal's feed requirement must come from grain and hay. The actual cost of transport is a very insignificant part of the total cost. The two key factors are the time grazed off-farm, to avoid using supplements that are more expensive, and grazing cost per week.

In some situations where a low transport cost is involved, off-farm grazing for even four weeks can be much cheaper than full supplementary feeding at home.

The calculations do not take into account the daily cost in machinery, time or labour in feeding out. This chore is another good reason for grazing off if satisfactory grazing is available.

Previous PageTable Of ContentsNext Page

Contact for Enquiries

Manager
North Island Regions
Sector Performance Policy
MAF Policy
Hamilton
NEW ZEALAND

Phone: +64 7 957 8313
Contact this person

 
Print this page Print this page




Biosecurity New Zealand Web Site