Using 2nd generation annual, hardseeded pasture legumes to ‘meat’ lamb production targets in southern Australian mixed farming zone

Lucy Watt1,2

1School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga2Graham Centre for Agricultural Innovation, Wagga Wagga

T: (02) 69332012, M: 0447088195, E: luwatt@csu.edu.au

Overview

Most commonly used species• Subterranean clover (Trifolium subterranean L.)• Medic spp. (Medicago spp.)

Annual regenerating pasture legumes in southern Australian mixed farming (wheat-sheep) zones

• Lucerne (Medicago sativa L.) – perennial legume

Climatic, edaphic and biological constraints

Overview

1. Arrowleaf clover (Trifolium vesiculosum Savi)

2. Biserrula (Biserrula pelcinus L.)

3. Bladder clover (Trifolium spumosum L.)

4. Gland clover (Trifolium glandiferum Boiss)

5. French serradella (Ornithopus sativus Brot)

2nd generation alternative, self-regenerating annual pasture legumes

1 2 3 4 5

Wide spread adaptation to Australian mixed farming systems with multi-purpose roles

(ruminant production and provision of N in mixed farming systems)

Overview

2nd generation alternative, self-regenerating annual pasture legumes

• Deep rooting systems

o Ability to remain green and productive in very dry conditions

0 0.5 1 1.5 2 2.5

Arrowleaf

F. serradella

Biserrula

Sub clover

Rooting depth (m)

Source: Adapted from Carr et al. 1999

Overview

2nd generation alternative, self-regenerating annual pasture legumes

• High herbage production (kg DM/ha)

0

500

1000

1500

2000

2500

3000

Subterranean clover cv.Seaton Park

French serradella cv.Margurita

Biserrula cv. Casbah

He

rbag

e P

rod

uct

ion

(kg

DM

/ha)

Source: Adapted from Hackney et al. 2013

Overview

2nd generation alternative, self-regenerating annual pasture legumes

• High/comparable nutritive values to traditional spp.o Ability to maintain nutritional value later into the season

0

10

20

30

40

50

60

70

80

90

14/1

0/2

01

1

28/1

0/2

01

1

11/1

1/20

11

25/1

1/2

01

1

9/12

/201

1

23/1

2/2

01

1

6/01

/201

2

20/0

1/2

01

2

Dig

esti

bili

ty (

DO

MD

%)

0

5

10

15

20

25

30

14/1

0/2

011

28/1

0/2

011

11/1

1/2

011

25/1

1/2

011

9/12

/201

1

23/1

2/2

011

6/01

/201

2

20/0

1/2

012

Cru

de

pro

tein

(%

)

Biserrula

Sub clover

Source: Adapted from Hackney et al. 2012

0

2

4

6

8

10

12

14

16

14

/10

/20

11

28

/10

/20

11

11

/11

/20

11

25

/11

/20

11

9/1

2/2

011

23

/12

/20

11

6/0

1/2

012

20

/01

/20

12

Met

abo

lisab

le e

ner

gy (

MJ/

kg D

M)

Biserrula

Sub clover

Overview

2nd generation alternative, self-regenerating annual pasture legumes

• High/comparable nutritive values to traditional spp.o Ability to maintain nutritional value later into the season

Source: Adapted from Hackney et al. 2012

Overview

• A wide range of agronomic studies undertaken in various regions throughout Australia (e.g. Hackney et al. 2012; 2015)– Increased adoption of these species in the 400-650 mm mixed farming zone,

principally for use in cropping rotations

• In more recent years, livestock producers have begun to introduce these species into their pasture mixes as forages for grazing livestock

2nd generation hard-seeded, self-regenerating annual pasture legumes

• The expected impact on livestock production, both as grazed and conserved forages is largely unknown

?

Utilising second generation legumes as conserved forages

Why is it important?

• Utilisation of pasture growth in spring rarely exceeds 30% in this region (Kaiser et al., 2006)

• Feed gaps are common in the summer, autumn and often winter

• Conservation of excess spring growth would provide an alternative to:

1. Purchasing supplementary feed 2. Untimely sale of livestock

$$$X

Merino lambs (9-10 months)

Hay Diets (sourced from Riverina)

• Arrowleaf clover (cv. Cefalu) late vegetative (80 cm tall)• Bladder clover (cv. Bartolo) 40% flowering (40 cm tall)• Subterranean clover (cv. Mt Barker) not assessed

Measurements• Liveweight gain (g/head/day)• Dry matter intake • Organic matter digestibility

Utilising second generation legumes as conserved forages

0

50

100

150

200

250

300

Arrowleaf Bladder Sub

Live

we

igh

t ch

ange

(g/

he

ad/d

)Utilising second generation legumes as conserved forages

ab

a

b

249 g/d

204 g/d182 g/d

CP (%)

ME (MJ/kg DM)

In vivo OMD (%)

DMI (kg/d)

LWG (g/d)

Arrowleaf Cl. 15.8 9.8 67.6 1.34 204ab

Bladder Cl. 20.4 10.3 72.9 1.50 249a

Sub Cl. 15.6 9.0 65.3 1.31 182b

Utilising second generation legumes as conserved forages

Table 1. Average crude protein (CP), metabolisable energy (ME), in vivo organic

matter digestibility (OMD) and lamb DMI and LWG of the arrowleaf clover, bladder

clover and subterranean clover hays.

Exploring alternative options for grazable pastures – which legume performs best?

September – November 2015

Merino and XB Lambs

Pastures • Arrowleaf clover (cv. Arrotas)• Bladder clover (cv. Bartolo)• Biserrula (cv. Casbah) • Lucerne (cv. Sardi) • Lucerne/phalaris (cv. Advanced AT)

Stocked according to the carrying capacity of the pasture • Seed set • Pasture production (biomass)

Exploring alternative options for grazable pastures – which legume performs best?

Table 2. Average carrying capacity of the legume and legume-grass pastures throughout the

2015 grazing trial.

Carrying capacity (sheep/ha)

Arrowleaf 21.5

Biserrula 16.2

Bladder 15.1

Lucerne 27.1

Lucerne-phalaris 31.8

NB. The carrying capacity set was based on feed availability and stage of growth in the annual

pasture legumes to manage for seed set and subsequent year regeneration

020406080

100120140160180200

Arr

ow

leaf

Bis

err

ula

Bla

dd

er

Luce

rne

Luce

rne

/ph

alar

isLive

we

igh

t ch

ange

(g

/he

ad/d

)

Spring 2015 (Sept-Nov)

Exploring alternative options for grazable pastures – which legume performs best?

Exploring alternative options for grazable pastures – which legume performs best?

$/ha *

Arrowleaf clover 475.34

Biserrula 295.29

Bladder clover 307.21

Lucerne 414.30

Lucerne-phalaris 366.49

What is the value in $/ha?

*2.80/kg used to calculate value of liveweight gain

• Equivalent or greater potential than traditional pasture

species

• High liveweight gains Lambs of Merino and XB breeds

• High nutritive value

• High spring pasture productivity

Conclusions

Thank you to Meat and Livestock Australia and

Australian Wool Innovation for funding this research