Ewe in pregnancy

• Optimum feeding guidelines for ewes in pregnancy


  Factors affecting these guidelines
• Nutrition


  1. Matching feed supply with feed demand

  2. Pasture supply is very seasonal

  3. Most pasture used for maintenance purposes
• Approximately 60% of what a ewe consumes each year is for maintenance requirements only, with no direct financial return to the farmer
• Maintenance requirements for ewes

  • 50 kg ≈ 0.90 kgDM/d
  • 60 kg ≈ 1.05 kgDM/d
  • 70 kg ≈ 1.20 kgDM/d
• Ewe yearly requirement


  • Maintenance requirements
  • Flushing
  • Pregnancy
  • Lactation requirements
  • Lamb weaned at 25 kg
• Maintenance is 63.5% of total ewe yearly requirement
• Conceptus weight at term

  • Singleton 10 -12kg
  • Twin 16 -18kg
  • Triplet 20 - 22kg
• Early pregnancy nutritional requirements

  • Maintenance level of feeding at least required
  • Extremely low levels of feeding and/or sudden decreases can be associated with embryo loss
  • Slightly higher allowances for poor condition ewes
• Maintenance feeding conditions for a ewe

  • 1 kgDM/d from 1.5 kg DM/d allowance
  • Sward heights of 2 – 4 cm
  • Pasture covers between 800 and 1200 kg DM/ha
• Early pregnancy nutritional requirements

  • Rotational grazing to 800 kgDM/ha, allowance 1.0 to 1.5 kg/d
  • No difference in feed requirements between ewes of different pregnancy-rank
• Mid pregnancy nutritional requirements

  • Determine feed availability for late pregnancy and early lactation
  • Develop plan for feed deficits
  • Organise supplements
• Mid pregnancy nutritional management

  • Offer pregnancy maintenance levels
  • Poor condition multiples slightly above maintenance
  • Ewe losing own body weight/condition
• Mid pregnancy nutritional requirements

  • 1.5 to 1.8 kg DM/ewe/day, 800 kg DM/ha for singletons, 900/1000 kg DM/ha for multiples
  • Use winter crops
• Potential effects of excessive under-nutrition in late pregnancy

  • Increased lamb mortality
  • Sub-optimum colostrum production
  • Delayed milk let down
  • Lower peak milk production
  • Lower total milk yield
  • Low lamb birth weights
  • Poorly developed maternal instinct
  • Increased ewe and lamb losses
  • Increased ewe metabolic disease
  • Lower lamb weaning weights
  • Lower ewe live weights at weaning
• Late pregnancy nutritional requirements

  • Approximately 70% of foetal growth occurs in last 40-50 days
  • Each fetus can gain 100 – 150g/d in very late pregnancy
  • Reducing abdominal space can reduce/limit feed intake
• Hierarchy of demand in last 50 days before lambing


  • Poor condition multiples, lambing first cycle
  • Reminder of first cycle multiples
  • Second cycle multiples
  • Single bearing ewes first cycle
  • Late single bearing ewes
• Late pregnancy nutritional requirements

  • Days 100 to 126: Pasture mass not below 900 kg DM/ha
  • 3 weeks before lambing: 2.0 to 4.0 kg DM/ewe/day, raise post-grazing residuals

  
• Post day 133 of pregnancy


  • Do not graze pasture below 1200 kg DM/ha
  • Multiples allowance of 3 – 4 kg DM/d
  • No advantage grazing above 1800 kg DM/ha

  
• Excessive nutrition in late pregnancy can potentially lead to increased lamb birth weights in singletons and thus dystocia
• Set stocking


  • Graze individual paddocks based on ewe demand (pregnancy rank, body condition)
  • Ideally never below 1200 kg DM/ha in lactation
• Mid pregnancy shearing


  • Increase placental and fetal growth, leading to larger lambs at birth
  • Reduced ewe casting
  • Easier access for lamb to teats
  • Improved wool quality
  • Improved lamb weaning weights
• Conditions for mid pregnancy shearing to work

  • Ewes in appropriate stage of pregnancy
  • Ewes fed at least pregnancy maintenance levels
  • Ewes with BCS of at least 2.5
• Conditions for mid pregnancy shearing to not work

  • Thin ewes
  • Poor feeding levels
  • Less likely to increase singleton birth weight
  • Does not work for hoggets
• Late pregnancy shearing


  • Potential risk of metabolic disorders
  • Can improve lamb survival through ewes feeling the cold at lambing
• Pre-lambing management of ewes


  • Vaccination of ewes at least two weeks pre-lambing
  • Parasite control based on faecal egg count
  • Full belly crutch
  • Clearing environment