Transcript Rotational grazing for store cattle case study

Rotational grazing for store cattle
case study
Rhidian Jones
Sheep and beef specialist
SAC Consulting
From set stocking to paddocks
Set stocking
Set stocking
Rotational
Paddock
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Grazing system, yield and utilisation
System
Annual
Yield (t
DM/ha)
Utilisation
(%)
Usable
yield
(t DM/ha)
Percentage
increase
Set
stocking
Rotational
8.5
50
4.3
10.2
65
6.6
56%
Paddock
10.2
80
8.2
92%
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Assessing pasture cover
1500 kgDM/ha
4-5 cm
2000 kgDM/ha
6-8 cm
2500 kgDM/ha
8-12 cm
3000 kgDM/ha
>12 cm
4
Rotational grazing of cattle for
cattle
• Objective was to add value to store cattle at grass at South
Mains, Sanquhar- 2009-2012
• Stabiliser bullocks and spare heifers
• Principles of management
– Dry Matter Intake of 2.5% of liveweight
– Pasture cover and grass growth rate measured with rising plate
meter
– Group demand calculated
– Cattle moved when residual height ca1500 kg DM/ha
– Compromise between livestock intake and grass growth
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Basic feed budget
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Size of paddock
1 ha
Pasture cover
2700 kg DM/ha
Desired residual
1500 kg DM/ha
Available DM
1200 x 1 ha = 1200 kg DM
Group size
40 bullocks of 400 kg
Group demand/day
40 x 400 x 2.5% = 400 kg DM/d
= 3 days grazing (1200/400)
Also allow for grass growth with longer grazing periods but
3 days is optimum
• Variables - grass growth, paddock size, grass potential,
cattle getting bigger, fertiliser etc
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6
Typical residual
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Infrastructure
• Permanent electrified wire on top of dykes and fences
• These will last 10-15 years +
• Temporary electric fencing that is hooked onto the
permanent hot wires
• Good layout of fields, i.e. four central fields can be
accessed from different sides to add flexibility
• More water troughs installed in 2010/11 (and 2012) allowing
further subdivision of fields – pipes laid on surface and
disconnected in winter
• Decided on 3 groups of ca 40-45 cattle – nearby handling
facilities not able to cope with more than 50 cattle
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8
9
9
10
10
A
B
C
D
11
11
A
B
C
D
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Results
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2009
– Bullocks averaged 1.08 kg/hd/day
– Mixed groups averaged
0.94 kg/hd/day
– Overall average
1.00 kg/hd/day
2010
– Bullocks averaged 1.10 kg/hd/day
– Heifers averaged 1.00 kg/hd/day
– Overall average
1.07 kg/hd/day
2011
– Bullocks averaged 0.97 kg/hd/day
– Heifers (15) averaged
0.86 kg/hd/day
– Overall average
0.95 kg/hd/day
3 year average
1.01 kg/hd/day
2012
0.92 kg/hd/day
2013
no data but best prices ever!!
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Consistent results
• Compensatory growth effect?
– Ca 0.6 kg/hd/day in winter seems optimum
• Cope with different seasons
– Early & late spring
– Drought and (very) wet conditions
• Flexible
– Take silage/reseed if surplus grass
– Apply fertiliser if deficit forecast
• Quiet cattle
– Get used to moving- only takes 5-10 minutes to shift
• Provides selection data
– Select breeding stock that perform at grass
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Gain at grass against winter lwg
1.60
1.40
Gain at grass
1.20
1.00
weight gain
Linear (weight gain)
0.80
0.60
0.40
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
Winter LWG
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15
Flexibility to take surplus grass as silage
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Quiet cattle
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Why do it?
• Cheapest liveweight gain
– Grazed grass £25 to £50 per tonne of DM
– Need 10-15 kg grass DM/kg gain
– Therefore costs 25p to 75p/kg gained at grass if well
managed, quality is high and unrestricted
• Easy to set up and manage
• Maintains grass quality for longer
• Stock need checking anyway and are easy to
move
• 200 kg at grass is achievable with a 6 ½ month
grazing season and 1 kg/hd/day
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Winter grassland management to get more
early grass in spring
• Set stocking depletes grass reserves
– Productive grasses regrow and get eaten!
– Allows weed grasses to flourish
– Late grass in spring- more concentrates required
• Move sheep around in blocks- 1 day to 1 week
– Allows flexibility
– Remove from wettest fields when conditions unsuitable
– Grass does grow in winter (use a cage and you’ll see)
– PRG given a chance to recover reserves
– Earlier grass in spring- stop feeding concentrates to
sheep sooner and can get cattle out earlier
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Effect of continuous winter grazing on spring
growth
5000
4500
Winter grazing
No winter grazing
4000
kgDM/ha
3500
3000
Reduced feed
requirements
2500
2000
1500
1000
Supplementary
feeding
required
500
0
Spring grazing yield
First cut silage yield
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