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Managing Ewe Nutrition to Drive Lamb Growth Rates
BestWool/BestLamb Conference Bendigo 26 July 2013
Peter Bailey: Project Manager Red Meat Value Chain & Lamb Specialist
Aspirational Targets
• Targeting 400 gLWG / day birth to weaning
• Ewe nutrition & lactation is key
• Maternal Ewes
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lamb weaning weight (> 40kgLW)!!
ewe efficiency (> 80%) ?
ewe kgLW / ha (> 600) ?
lamb CW / ha (> 400) ?
• Merino Ewes
– what are their desired targets?
Benefits of 400 gLWG / day
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Increased lamb vigour and survival
More lambs sold off mum (earlier less days on feed)
Higher dressing out %
Less animal health
Meet (spring) market premium
Improved feed utilisation
Align feed supply and demand profile
Lower (more efficient) cost of production
Free up feed for (more) ewes or other livestock
enterprises
Ewe Condition 3.0 (+ kgLW)
• Why condition score & liveweight?
• CS:
2.5 – 3.5
• LW:
50 – 80kgLW
• Foetus:
0 – 4 lambs
• Changes energy (feed) demand!
Foetus and Mammary development
Ewe Nutrition Mating to Lactation
• Grazing strategies are key
• rotation vs. set stocking
Early – Mid Pregnancy Management
• Time of mob stocking
– allocate ram ratio to ewe mob size
– no physical pressure
• Nutrition
– pasture cover not to drop below 1,200 kgDM pasture cover
– underfeeding in first third of pregnancy reduces cotyledon
numbers – lowers lamb birth weight
– flush with a green pick and rising plane of nutrition
– marginal decrease in CS 3.0 > 2.8 day 40 to 80?
– animal health – vaccinations, drench
Mid-Pregnancy Ewe Shearing?
• An option worth considering?
• Mid winter shearing between day 50 – 100
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pre-scanning
increase birth weights by up to 0.7 kgLW / lamb (up to 1.0 kgLW)
increased vigour, stored energy as fat reserves
Increased lamb survival & decreases lamb mortality by up to 3 %
easier lambing with less wool
• Extra feed required 10 – 15 days
• Positive affect on wool yield and quality
• Must fit your enterprise mix
Mid – Late Pregnancy Management
• Time to change from rotation to set stocking
– set stock 1 week pre-lambing
– lower weaning weight of lamb when ewes set stocked 4 weeks
prior to lambing (c/w 1 week)
• Nutrition
– gradual rising plane of nutrition
– weaning weight increase 2 kg / 100 kgDM pasture cover increase
(target > 1,200 kgDM / ha)
– milk production peak and total
– animal health pre – lamb vaccinations
Understanding Ewe Milk Production
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Understanding Ewe milk production
– rising plane of nutrition from mid pregnancy (post scan) to
lambing
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1.0 – 1.5 – 2.0 x maintenance
ewes lamb at CS 3.0+
enhances lamb energy reserves (fat and glycogen) and vigour
– over lambing pasture cover required > 1,300 kgDM/ha
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minimum allowance offered 6 – 8 kgDM/day
eat 2.5 – 3.5 kgDM/day (3x maintenance)
– health and mineral status
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mastitis, milk fever
Ewe Lactation Curve
Pasture Allowance During Lactation
Ewe Lactation
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Daily milk production peaks at 2 – 3 weeks and produce
– 2.5 kg milk/day (single lamb)
– 3.5 kg milk/day (twin lambs)
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40 – 50 % milk produced in first 4 weeks of lactation
After which it declines by 19.0 – 26.0 g milk/day
By day 100 milk production is down to 0.0 – 0.5 kg
milk/day
– by then the ewe is competing for feed with lambs !
Ewe Lactation
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Ewes with twins produce 30 – 50 % more milk / lactation
than singles
Each twin lamb receives only 60 % as much milk as a
single lamb
Twin lambs forced to eat pasture at an earlier age
Total milk produced is influenced by management
– genetics / breed
– ewe condition / age
– nutrition
Ewe Milk energy Vs lamb Energy
Lamb Nutritional Requirements
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Understanding lamb nutritional requirements for 400 gm /
day growth to weaning. As a guide:
– milk consumed by lambs most important in first 6 weeks
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transition from milk to pasture begins at 3 – 5 weeks of age
– ME requirements
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6 weeks > 20 kgLW requires > 10.0 MJME/day
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8 weeks > 25 kgLW requires > 20.0 MJME/day
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12 weeks > 35 kgLW requires > 28.0 MJME/day
Milk to Pasture Transition: Singles
Milk to Pasture Transition: Twins
Pre – Post Weaning Lamb Growth
• Competition for feed between ewes and lambs begins 30
to 40 days after lambing commenced
• Ewe lactation ends around day 80 – 100!
• Why wean later than day 100 days?
– short of feed – wean earlier < 1,000kgDM/ha ?
– surplus of feed – wean later >1,400kgDM/ha ?
• Compromise lamb growth: 50g – 350g/day!
Summary
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Understand the management requirements of the ewe and lamb
from mating to weaning
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Optimise ewe lactation through genetic selection and culling
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Nutrition, feed quality, match feed supply and demand
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Achieve 400 g/day lamb growth
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Timeframe 100 days
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Improved lamb survival and next years conception