Presented by Jane Wamatu, ICARDA, at the EIAR-DBARC-ICARDA-ILRI (LIVES)-FAO Training Workshop on Reproduction in Sheep and Goat, Debre Berhan, Ethiopia, 13-15 October 2014

1. Sheep Nutrition for Reproduction
Part I: Nutrition as a Major Environmental Factor Affecting
the Reproductive Axis
Jane Wamatu
EIAR-DBARC-ICARDA-ILRI (LIVES)-FAO Training on Reproduction in
Sheep and Goat, Debre Berhan, Ethiopia, 13-15 October 2014
J. Wamatu

2. Outline
 Factors that influence feeding of an ewe
 Feeding regimes/stages
 Typical nutritional disorders

3. Ewe Nutritional Needs are not Static
 The objective of feeding the ewe is to produce lambs,
whether these are for breeding, for fattening or for
slaughter
 Feeding an ewe depends on many factors
o Age
o Weight
o Body condition
o Stage and level of production
o Environmental factors and level of exercise

4. Ewe Nutritional Needs are not Static
 The standard of nutrition for ewes can be classified
into 3 main stages:
o Pre-breeding to breeding
o Early gestation to mid gestation
o Late gestation and early lactation

5. Pre-Breeding → Breeding
The level of nutrition in the weeks before mating and during the
mating period is important in determining the number of lambs
conceived
Aim
 Replenish body reserves lost after last pregnancy
 Minimize number of ewes which fail to show
oestrus
 To ensure that a sufficient number of eggs are
shed at ovulation and subsequently fertilized
 To maximize number of fertilized eggs which
are implanted and develop into viable embryos and foetuses

6. Pre-Breeding → Breeding
How to achieve the aim
 Ewes are in appropriate body condition
at the beginning of the mating period
 The good body condition is maintained
for the first weeks of pregnancy when
risk of embryonic mortality is greatest
 Body condition scoring: Score 0
(emaciated) to Score 5 (very fat)

7. Pre-Breeding → Breeding
How to achieve the aim
 The better the body condition at mating, the higher is the ovulation
rate and the higher is the lambing percentage
 The number of eggs shed by ewes with a particular condition score
at mating depends largely on the breed
 Ewe lambs should be atleast 60 % of their expected mature
liveweight
 Ewes that are already in good body condition (3.5) do not generally
respond to flushing (current nutrition).
NB: In some breeds, ovulation does not respond to body condition

8. Pre-Breeding → Breeding
 The length of time required to prepare ewes for mating depends on
their initial condition and the quality of feed available (4 - >6 weeks)
 Attention should be paid to energy and protein intake
 Suggested quantities of energy are generally related to maintenance
of liveweight and specific rates of liveweight gain, rather than to
changes in condition score
 Approx. 1kg change in weight is equal to approx. 0.1 units in body
condition

9. Pre-Breeding → Breeding
Summary
 Ewes should be in proper body condition
by mating time – BCS 3.5
 Lean ewes should be managed
separately for at least 6 weeks to ensure
uniformity of flock condition at mating
 Loss of weight or condition should be
avoided during the mating period

10. Early → mid-gestation
Nutrition during pregnancy determines
the number of lambs subsequently born
alive with a birth weight which will
ensure that they survive and are capable
of growing well
 Placental development occurs first 30 to 90
days of pregnancy
 Placental size or weight affects nutrient
transfer between the ewe and her fetuses

11. Early → mid-gestation
 Underdeveloped placentas result in low birth weights,
regardless of late gestation nutrition.
 21 days of severe underfeeding or 80 days of moderate
underfeeding can affect placental development.
Do not overfeed or underfeed; aim for a body condition
score of 3 to 3.5
Nutrient requirements are only slightly above maintenance

12. Early → mid-gestation
 15-30% of eggs shed at ovulation fail to result in the birth
of the lamb
 The main reason is failure of embryos to implant in the first
month after mating
 Severe undernourishment or high levels of post-mating
nutrition may result in impaired embryo survival
Ewes should maintain a constant weight during the month
following mating
Avoid abrupt change in the level of nutrition

13. Early → mid-gestation
 It is important to maintain their weights over this period.
Prevent losses exceeding the equivalent of 0.75 units in
condition score.
 Protein requirements for growth are low, but should not fall
below 10g CP per MJ of ME to ensure
 Only small losses inbody condition should be allowed during
this period
 Even short periods of severe undernutrition must be
avoided

14. Late gestation → early lactation
Nutrition after lambing has a major
effect on milk production and hence
on lamb growth rate
 Proper feeding and management during
late gestation are crucial to a successful
lambing
 During the last 4 to 6 weeks of
gestation, 70 percent of fetal growth is
occurring

15. Late gestation → early lactation
 The mammary system is developing.
 High output of protein in milk and colostrum production
 Additional undegraded dietary protein is required
 Protein sources relatively resistant to degradation in the rumen
are recommended
 The recommended rate of inclusion is influenced by their
degradability, potential production (milk) of the ewe and her ME
intake

16. Late gestation → early lactation
 High output of protein in milk (colostrum production
 The ewe’s rumen capacity is decreasing.
 Nutrient requirement increase rapidly towards the end of
pregnancy and nutrient supply must be increased
 Lean ewes should be given preferential feeding
 For economy of feed use, ewes should be grouped according to
nutrient requirement e.g lambing date and age

17. Nutritional disorders
Hypomagnesaemia
 This refers to magnesium deficiency
 Occurs in the first 4-6 weeks of lactation at the peak of milk
production when there is a large demand of the very limited
reserves of magnesium in the body
 First sign of an outbreak is a dead ewe which appeared normal
only a few hours earlier
 An adequate intake of magnesium is ensured by including 6g of
magnesium oxide evenly distributed in the daily ration of
concentrate offered in early lactation

18. Nutritional disorders
Hypocalcaemia
 Also referred to as lambing sickness
 Occurs just before, during or just after lambing
 Ewes show uncoordinated movements, muscular tremors and
rapid breathing
 Ewes fall with the head and hind legs extended, rapidly develop
paralysis and go into a coma
 Treatment with calcium borogluconate solution generally results
in a rapid recovery

19. Nutritional disorders
Muscular dystrophy
 Also known as white muscle disease
 Arises from deficiency in Vitamin E/selenium in the diet
 Symptoms are stiffness in young, rapidly growing lambs around
3-4 weeks
 Symptoms can also occur immediately after weaning at 4-6
weeks of age
 Main factors influencing amounts of vitamin E/selenium occurring
naturally in feeds are the type of soil on which the crop is grown,
weather conditions during growing season and storage (high
moisture storage leads to deterioration in their vitamin E status)

20. Nutritional disorders
Hypomagnesaemia
 First 4-6 weeks of lactation at the
peak of milk production
Hypocalcaemia
 Lambing sickness
 Uncoordinated movements
Muscular dystrophy
 White muscle disease
 Deficiency in Vitamin E/seleniun
 Stiffness in young, rapidly growing
lambs around 3-4 weeks.