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Sep 05, 2022 229 likes •421 views

Using 2 nd generation annual, hardseeded pasture legumes to meat lamb production targets in southern Australian mixed farming zone Lucy Watt 1,2 1 School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga 2 Graham

SLIDE 1

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 Wagga 2Graham Centre for Agricultural Innovation, Wagga Wagga

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

SLIDE 2

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

SLIDE 3

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)

SLIDE 4

Overview

2nd generation alternative, self-regenerating annual pasture legumes

Deep rooting systems
Ability to remain green and productive in very dry conditions

0.5 1 1.5 2 2.5 Arrowleaf

F. serradella

Biserrula Sub clover Rooting depth (m)

Source: Adapted from Carr et al. 1999

SLIDE 5

Overview

2nd generation alternative, self-regenerating annual pasture legumes

High herbage production (kg DM/ha)

500 1000 1500 2000 2500 3000 Subterranean clover cv. Seaton Park French serradella cv. Margurita Biserrula cv. Casbah Herbage Production (kg DM/ha)

Source: Adapted from Hackney et al. 2013

SLIDE 6

Overview

2nd generation alternative, self-regenerating annual pasture legumes

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

10 20 30 40 50 60 70 80 90

14/10/2011 28/10/2011 11/11/2011 25/11/2011 9/12/2011 23/12/2011 6/01/2012 20/01/2012

Digestibility (DOMD %)

5 10 15 20 25 30 14/10/2011 28/10/2011 11/11/2011 25/11/2011 9/12/2011 23/12/2011 6/01/2012 20/01/2012

Crude protein (%)

Biserrula Sub clover

Source: Adapted from Hackney et al. 2012

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2 4 6 8 10 12 14 16 14/10/2011 28/10/2011 11/11/2011 25/11/2011 9/12/2011 23/12/2011 6/01/2012 20/01/2012 Metabolisable energy (MJ/kg DM)

Biserrula Sub clover

Overview

2nd generation alternative, self-regenerating annual pasture legumes

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

Source: Adapted from Hackney et al. 2012

SLIDE 8

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

?

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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

SLIDE 10

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

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50 100 150 200 250 300 Arrowleaf Bladder Sub Liveweight change (g/head/d)

Utilising second generation legumes as conserved forages

ab a b

249 g/d 204 g/d 182 g/d

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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.

SLIDE 13

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)

SLIDE 14

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

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20 40 60 80 100 120 140 160 180 200 Arrowleaf Biserrula Bladder Lucerne Lucerne/phalaris Liveweight change (g/head/d)

Spring 2015 (Sept-Nov)

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

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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

SLIDE 17

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

SLIDE 18

Thank you to Meat and Livestock Australia and Australian Wool Innovation for funding this research