Sheep 1 Flashcards
What is an EBV
Estimated breeding vale - the difference (+ or -) between an individual animal and the herd/breed benchmark. Have to half the EBV to predict the outcome (as only recieve half the genes).
Recorded traits e.g. scan weight at 21 weeks of +6 = offspring should be 3kg heavier at 21 weeks.
Give 7 key performance indicators for sheep flocks
1) Scanning %
2) Lambing % - born alive, alive after 1 week, weaned, REARED/number of ewes put to tup.
3) Ewe mortality (1-3%)
4) Culling rate for ewes/ replacement rate (20%)
5) Ewe: Tup ratio 40:1
6) Lamb mortality:
- scanning to birth (6%)
- Birth to turn out (6%)
- Turn out to sale (2%)
- Overall birth to sale (8%)
7) Lamb growth rates - 0.25kg/day.
What problems are caused by nutrition around lambing time?
1) Metabolic disease:
- Pregnancy toxaemia/twin lamb
- Hypocalcaemia
- Hypomagnesaemia
2) Ewe
- Mastitis
- Dystocia (over feeding)
3) Lamb mortality/morbidity
- low lamb birth weight
- Poor colostrum
- Milk production.
what BCS would you want a lowland sheep to be at WEANING
2-2.5
BCS for a lowland TUPPING
3.5 (or 3-3.5)
BCS for a lowland LAMBING`
3
What is the general principle for feeding ewes pre-tupping?
flushing
what is flushing?
increasing feeding to ewes before mating and increasing BCS by 0.5 to improve the number of eggs produced.
- usually managed by grass. may require supplementary concentrates.
What is important in feeding early to mid pregnancy?
Early pregnancy embryo implants + early development. Dont do any sudden changes.
Winter.
Mid pregnancy - placenta develops maintain BCS or lose 0.5 units.
If underfed - small placenta - low lamb birth weights.
Mammary development.
Why is the last 90 days to lambing the most crucial time for nutrition?
70% of fetal growth occurs in the last 6 weeks of gestation.
The mammary system is developing. The ewe’s rumen capacity is decreasing.
What are the aims of feeding in late pregnancy?
To support fetal growth
To support mammary development….
