Post-weaning

• Benefits to fast lamb growth rates post-weaning

  • Heavier lambs give more options (e.g. breeding as ewe hogget, holding at later date when feed is short)
  • Less feed consumed
  • Less exposure to potential ill health issues
  • Less animal health remedies required
  • Less labour required
  • Higher lifetime performance and sale value
  • Less greenhouse gas produced
• Estimated daily feed requirements of weaned lambs and hoggets

  • Liveweight (kg)
  • Rate of gain (g/day)
  • Feed requirement (MJ/day)
• Most farmers will tell you their lambs grow at 200 g/d, but this is not true
• The average lamb growth rate in NZ of weaned lambs is actually around 80 to 100 g/d
• Growing from 25 to 35kg


  1. 50 g/d => 200 days

  2. 100 g/d => 100 days

  3. 200 g/d => 50 days
• Feed requirement per day

  • 50 g/d = 0.83 kg DM
  • 100 g/d = 1.0 kg DM
  • 200 g/d = 1.4 kg DM
• Total feed requirement (approximate)

  • 50 g/d = 166 kg DM
  • 100 g/d = 100 kg DM
  • 200 g/d = 70 kg DM
• Why fast lamb growth rates are best from a nutritional perspective


  • Less total feed consumed to reach target weight
  • Less feed used for maintenance
• Feed conversion efficiency for different lamb growth rates between weaning at 24 kg and a target live weight of 34 kg


  1. Liveweight (kg)

  2. Lamb growth rate (g/day) from 24-34kg

  3. Feed requirement (kg DM/day)

  4. Days to target weight (34kg)

  5. Feed consumed (kg DM)

  6. Conversion efficiency % (kg DM/LW gain x 100)
• Lamb liveweight change in response to pasture allowance and post-grazing mass

  Hogget liveweight change in response to pasture allowance and post-grazing mass
• Effect of management on live weight gain
• Lamb growth from weaning to 10 months of age


  • Weaning generally occurs at 10 to 16 weeks of age
  • Live weight gains of at least 100 to 130 grams per day are required
  • In summer, lambs / hoggets should be a priority class of stock
  • Regular weighing allows farmers to monitor progress
• Nutritional management of the weaned lamb

  • On a ryegrass white clover mix lambs should be allowed to pick
  • Allowances of 3 - 4 kg DM/day, and post grazing masses of 1200 kg DM/ha
• Lambs seem to do better when set stocked
• Herbage intakes will also affect wool growth and quality
• Parasite control and minerals should be monitored
• Grass quality and quantity is often decreased in late summer / autumn (autumn ill thrift)
• Crops can be used to increase (maintain) lamb growth rates (e.g. Clovers, Rape, Lucerne, Chicory, Pasja)
• Why are growth rates often higher on crops than on ryegrass?

  • Ryegrass and white clover production is often decreased in dry conditions
  • In autumn ryegrass looses quality
  • Endophytes in ryegrass in autumn negatively affect growth of lambs
  • Facial eczema is not an issue on crops
  • Crop management and structure mean lambs are less exposed to internal parasites
• Comparative feeding values for liveweight gain of different pasture species

  • White clover (Huia)
  • Lotus paniculatus (Maku)
  • Lucerne (Wairau)
  • Red clover (Pawera)
  • Italian ryegrass (Paroa)
  • Short rotation ryegrass (Manawa)
  • Perennial ryegrass (Ariki)
  • Perennial ryegrass (Ruanui)
  • Timothy
  • Browntop
• Pasture allowance (kg DM/lamb/day), live weight gain (g/day) on different pasture types
• Lamb growth pattern


  • Feedstuff
  • DM/kg of total
  • ME/kg DM
  • Crude Protein
• Traditional non bred ewe lamb/hogget growth (10 - 18 months)


  • Non pregnant hoggets should still be achieving growth rates of 50 - 75g/day during the winter
  • Allowances should be 1.2 to 1.5 kg DM/d with post grazing masses of 700 -1000 kg DM/ha
  • Hoggets should be either run on a separate block or in front of mature ewes in the rotation
  • Should be set stocked in spring to achieve growth rates of 200 g/day
  • Ideally pasture masses should not go below 1200 kg DM/ha
• Setting targets and weighing regularly allows a farmer to determine how his / her hoggets are performing and to take early action if required (i.e. she should be 60kg at 18 months)
• Health – minerals and parasites need to be monitored