Sheep nutrition Flashcards
Ewe production cycle
Tupping, early pregnancy, mid pregnancy, late pregnancy, lambing, lactation, weaning, flushing
When does implantation occur
Early pregnancy
Where do you examine for BCS
backbone and loin area, behind the last rib (spinous processes)
Order of BCS going up in terms of where they are kept
Hill ewe, upland ewe, lowland ewe
What is flushing
Increasing the plane of nutrition before tupping
Ovulation rates in relation to weight
thin ewes ovulate less - less lambs
fat ewes ovulate more but have higher rates of embryonic deaths
When does implantation occur
3-4 weeks of gestation
When does placental development occur?
From 30 days after conception - complete by 3 mo
Foetal growth percentages
90% in last third, 60% in the last month
Risks of underfeeding during late gestation
- 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%
Risks of overfeeding during late gestation
- 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
When does development of ewe udder occur
Primarily in last third of pregnancy, last 5% in first month of lactation
Main risk factors for mastitis
Poor milk production and cross suckling
DMI percentages for different stages (Dry ewe, late pregnancy, lactation)
Dry ewe- 1.5% BW
Late pregnancy - 2.0-2.5% BW
Lactation - 3.0-3.5% BW
Feed space needed for ewes
Large ewes: concentrates - 50cm, restricted forage - 25cm, ad lib forage/TMR - 15cm
Small ewes: concentrates - 45cm, restricted forage - 20cm, ad lib forage/TMR 15cm
How much colostrum do lambs need
50ml/kg within 6 hrs
when does peak milk yield occur in ewes?
2-4 weeks after lambing
what weight should lambs have ideally exceeded by weaning
25kg
Average weight of a twin lamb at birth
4kg
target BCS for rams at tupping
3.5
Hypocalcaemia
largely triggered by stress, looks almost identical to pregnancy toxaemia
Hypomagnesaemia
can happen in late gestation and early lactation ewes. Often first indication is finding a dead sheep. Tetanic spasms, seizures.
Cobalt deficiency
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
Copper deficiency
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)
Copper toxicity
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
Selenium/Vit E deficiency
Stiff lamb disease/white muscle disease
