3 - Understand nutritional properties of major arid zone pasture plants

Download the full module

The following information (Tables 4 and 5) on the nutritive value of selected arid zone plants, including perennial shrubs, grasses and forbs, has been collated from a range of sources. However, any analysis of plant nutritive value should be interpreted with caution as the ratings are highly dependent on:

  • when and where the plants were sampled
  • the nature of seasonal conditions prior to and at the time of sampling
  • whether soil particles were present in the samples.

Note: All sampling should focus on leaves and small twigs/branches, as this represents the 'usual' feeding behaviour of cattle.

Table 4: Range of ME (MJ/kg); crude protein (%) and relative mineral content* of preferentially grazed plant species in the arid lands of South Australia (Productive Nutrition Pty Ltd 2009).

Scientific name

Common name

ME (MJ/kg DM)

CP (%)

Mineral levels - high

Mineral levels - low

Acacia victoriae

Prickly acacia

4.6-10.4

10.2-22.7

Ca, Mg, Mo, Fe, Co, Se

P, Na, Cu

Aristida contorta

Kerosine grass

6.7-8.5

5.2-12.2

Fe, Mn, Co, Se, K, Mg

Cu, Na, Se

Astrebla pectinata

Barley Mitchell grass

4.5-11.3

3.3-23.1

Fe, Co, S, Mg. K

Cu, Se

Atriplex vesicaria

Bladder saltbush

6.5-11.2

6.8-21.6

Ca, Mg, Na, S, Mn, Fe, Co, Se

P, Cu, Zn

Chenopodium nitrariaceum

Nitre goosefoot

5.2-11.9

20.1-29.4

Ca, K, Mg, S, Fe, Mn, Se

 

Cullen australasicum

Tall verbine

6.1-14.4

8.1-22.8

Ca, K, Mg, Mo, Zn, Mn, Fe, Co Se

Na

Cullen cinereum

Short verbine

8.7-12.7

14.1-24.1

Ca, K, Mg, Zn, Mo,

Fe, Se

 

Dactyloctenium radulans

Button grass

6.0-10

4.2-22.1

K, Mg, Na, S, Mo, Zn, Mn, Fe, Co

P

Eragrostis australasica

Swamp canegrass

3.4-9.2

3.1-15.2

K. Na, S, Fe

Ca, P, Mg, Zn

Erodium crinitium

Geranium, Storksbill

9.4-10.3

7.9-20.9

Ca, Na, Fe, Co

P, Zn, Se

Iseilema membranaceum

Small Flinders grass

6.8-9.1

3.0-9.2

Fe, Co

Ca, P, Mg, Zn, Mn

Maireana aphylla

Cottonbush

5.7-10.8

6.8-29.5

Ca, K, Mg, Na, Fe, Mn, Co, Se

P, Mo, Zn

Maireana astrotricha

Low bluebush

7.6-10.1

10.4-23

K, Mg, Na, Mn, Fe, P, Cu

P

Salsola kali

Buckbush, Roly-poly

7.9-12.4

8.3-19.2

Mg, Na, Mn, Fe

P, Cu, Se

Scleroleana dicantha

Grey copperburr

4.6-11.2

12.3-30.1

Ca, K, Mg, Na, Mn, Fe, Co,

P, Cu, Se

Trigonella suavissima

Native clover

8.6-12.6

15-29.6

Ca, K, Mg, S, Mn, Fe, Co, Se, Mo

Cu

Zygochloa paradoxa

Sandhill canegrass

3.5-6.9

1.8-10.3

K, Fe, Co, Se

Mg, Na, S, Cu, Zn

Table 5: Range of ME (MJ/kg DM); crude protein (%) and relative mineral content* of preferentially grazed native shrub species in the arid lands of New South Wales

Scientific name

Common name

ME  (MJ/kg DM)

CP (%)

Mineral levels - high

Mineral levels - low

Atriplex leptocarpa

Slender–fruited saltbush

7.4-9.6

24.1-36.2

Ca, Mg, K, Fe, Na, Mn

P

Atriplex lindleyi

Eastern flat-top saltbush

7.5-9.6

14.6-27.7

Mg, K, Na, Mn, Se

 

Atriplex nummularia

Old Man saltbush

8.6-9.2

24.8-29.4

Mg, K, Na, Mn, Zn

P

Atriplex pseudocampanulata

Mealy saltbush

8.6-8.9

27.1-29.4

Mg, K, Na, Mn, Zn

P

Atriplex semibaccata

Creeping saltbush

10.5-10.8

14.3-24.8

Mg, K, Na, Zn

P

Atriplex vesicaria

Bladder saltbush

8.4-8.9

34.2-45.0

K, Na, Zn

P

Chenopodium nitrariaceum

Nitre goosefoot

8.8-10.0

24.1-30.1

Ca, Mg, K, Na, Zn

 

Einadia nutans

Climbing saltbush

9.2-9.7

17.4-26.6

Mg, K, Na

 

Enchylaena tomentosa

Ruby saltbush

5.3-9.4

27.7-28.8

K, Na

P

Maireana aphylla

Cottonbush

5.9-6.0

39.7-60.4

 

P

Maireana brevifolia

Yanga bush

7.5-7.6

21.2-27.3

Na

P

Maireana ciliata

Hairy fissure-weed

8.6

50.6

Na

P

Maireana decalvans

Black cottonbush

8.3

20.3

K, Na

P

Maireana enchylaenoides

Wingless fissure-weed

7.7

56.1

K, Na, Co

P

Maireana pyramidata

Black bluebush

7.2-8.0

19.4-33.3

K, Na

P

Muehlenbeckia florulenta

Lignum

5.8-6.2

34.0-34.2

K, Zn

 

Nitraria billardieri

Dillon bush

9.7-10.7

24.5-25.3

Ca, K, Na, Zn

 

Rhagodia spinescens

Thorny Saltbush

9.1-9.3

25.4-26.1

K, Na, Zn

 

Sclerolaena brachyptera

Short-winged copperburr

6.9-7.5

22.5-33.0

Na

P

Sclerolaena diacantha

Grey copperburr

8.3-8.4

20.7-37.6

K, Na, Zn

P

Sclerostegia tenuis

Slender glasswort

7.3-9.6

20.0-22.2

Mg, Na

P

*Refer to Table 3 in Procedure 2 for abbreviations of minerals

How to conduct your own plant nutrition analysis

1. Determine which plant species to be sampled and tested. Consider the entire range of plants that your cattle utilise in an area by observing them grazing.

2. Determine best time of year to sample (eg at the start and/or at the end of the growing season, in dry and/or wet periods or on a regular schedule such as every 3 months regardless of seasonal conditions).

3. Choose sample locations on property and within paddocks that represent how cattle graze. For example, it is pointless collecting samples from an area that is not grazed, unless you want to understand why the cattle are not grazing there.

4. To collect samples:

  • use clean cutters or your hands to strip the leaves (shrubs) or leaves and soft stems (grasses and forbs) from the plant, taking into account what parts of the plant the cattle graze
  • avoid contaminating with roots and soil
  • put the samples into a zip lock bag and label with the scientific and common name (if you are able find out what this is)
  • record the sample details, including the stage of plant growth, on the Plant Sample Sheet (see Tool 2.02)
  • take a clear photo of the plant including close-ups of its flowers/fruits and/or leaves to compare with reference material if you can't identify the scientific or common name.

5. Send the plant samples to a laboratory for testing (either NSW DPI, Wagga Wagga Feed Quality Laboratory or SGS Feed Testing Laboratory in Toowoomba, Queensland), indicating which tests you want conducted on each sample.

Samples can be analysed using a wet chemistry method for feed value including the following:

  • dry matter content (moisture)
  • metabolisable energy
  • crude protein
  • neutral detergent fibre
  • dry matter and dry organic matter digestibility
  • mineral content including; calcium, phosphorus, potassium, magnesium, sodium, sulphur, boron, copper, molybdenum, zinc, manganese, cobalt and selenium