Sheep nutrition

Question 1

Ewe production cycle

Answer 1

Tupping, early pregnancy, mid pregnancy, late pregnancy, lambing, lactation, weaning, flushing

Question 2

When does implantation occur

Answer 2

Early pregnancy

Question 3

Where do you examine for BCS

Answer 3

backbone and loin area, behind the last rib (spinous processes)

Question 4

Order of BCS going up in terms of where they are kept

Answer 4

Hill ewe, upland ewe, lowland ewe

Question 5

What is flushing

Answer 5

Increasing the plane of nutrition before tupping

Question 6

Ovulation rates in relation to weight

Answer 6

thin ewes ovulate less - less lambs
fat ewes ovulate more but have higher rates of embryonic deaths

Question 7

When does implantation occur

Answer 7

3-4 weeks of gestation

Question 8

When does placental development occur?

Answer 8

From 30 days after conception - complete by 3 mo

Question 9

Foetal growth percentages

Answer 9

90% in last third, 60% in the last month

Question 10

Risks of underfeeding during late gestation

Answer 10

• Low lamb birth weight and survival
• Reduced udder weight and mammary development
• Weakened ewe/lamb bond
• Pregnancy toxaemia
• Ewe slow to lactate and poor supply of colostrum
• Reduced lamb growth
• Reduced lactation yield by 7-35%

Question 11

Risks of overfeeding during late gestation

Answer 11

• Oversized lamb and dystocia
• Prolapsed vagina
• Weak ewe/lamb bond
• Pregnancy toxaemia
• Lambing difficulties and delayed lactation
• Reduced lamb vigour
• Potential for high BCS to impact future performance

Question 12

When does development of ewe udder occur

Answer 12

Primarily in last third of pregnancy, last 5% in first month of lactation

Question 13

Main risk factors for mastitis

Answer 13

Poor milk production and cross suckling

Question 14

DMI percentages for different stages (Dry ewe, late pregnancy, lactation)

Answer 14

Dry ewe- 1.5% BW
Late pregnancy - 2.0-2.5% BW
Lactation - 3.0-3.5% BW

Question 15

Feed space needed for ewes

Answer 15

Large ewes: concentrates - 50cm, restricted forage - 25cm, ad lib forage/TMR - 15cm
Small ewes: concentrates - 45cm, restricted forage - 20cm, ad lib forage/TMR 15cm

Question 16

How much colostrum do lambs need

Answer 16

50ml/kg within 6 hrs

Question 17

when does peak milk yield occur in ewes?

Answer 17

2-4 weeks after lambing

Question 18

what weight should lambs have ideally exceeded by weaning

Answer 18

25kg

Question 19

Average weight of a twin lamb at birth

Answer 19

4kg

Question 20

target BCS for rams at tupping

Answer 20

3.5

Question 21

Hypocalcaemia

Answer 21

largely triggered by stress, looks almost identical to pregnancy toxaemia

Question 22

Hypomagnesaemia

Answer 22

can happen in late gestation and early lactation ewes. Often first indication is finding a dead sheep. Tetanic spasms, seizures.

Question 23

Cobalt deficiency

Answer 23

Causes: progressive debility, poor growth rate, poor wool quality and growth, inanition, and anaemia. Adult sheep less affected but can have effect on fertility.

Diagnosis: blood sampling or liver biopsy

Treatment: Vit B12 injection or oral

Question 24

Copper deficiency

Answer 24

Molybdenum is an antagonist so high molybdenum can lock up copper in the soil.
Clinical disease may not occur until liver stores are very low.
Presents with poor wool growth and structure (steely wool syndrome). More dramatic form is swayback (paresis/paralysis, ataxia)

Question 25

Copper toxicity

Answer 25

Stored in the liver until critical level is reached and leads to a haemolytic crisis. Few clinical signs in build u-p but when crisis reached death is rapid

Question 26

Selenium/Vit E deficiency

Answer 26

Stiff lamb disease/white muscle disease