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18 Cards in this Set
- Front
- Back
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Best time of year for lambing/joining
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-time of lambing decided by joining time
-joining time (i.e. 5 months prior to lambing) must consider: pasture growth pattern pasture composition aim of enterprise flock structure stocking rate breeding season time of shearing marketing plans cost of supplementary feeds other farm activities e.g seeding, harvesting |
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Ideal conditions of ewe flocks at joining
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-good nutrition in the 6 months prior to joining
-BCS 3-3.5 |
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Nutritional Management of pregnant ewes:
1. 1-3 mo 2. 4-5mo |
1. feed requirements similar to non-pregnant (dry) ewes; maintain BW; avoid sudden changes in availability or feed type (e.g. 300g/hd/day oats OR 200g/hd/day lupins)
2. feed requirements increase greatly -single foetus=2X requirements -twins=2.5X -triplets=3X (e.g 450g/hd/day oats OR 300g/hd/day lupins) |
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Consequences of underfeeding pregnant ewes
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1. preg tox
2. hypocalcaemia 3. small lambs 4. poor colostrum and milk production 5. adverse effects on subsequent reproductive performance (e.g. non-cycling) 6. Decreased return from wool |
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Consequences of overfeeding pregnant ewes
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1. preg tox
2. excessive foetal growth>dystocia 3. small birth-weight lambs |
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Pregnancy toxaemia
-predisposing factors |
-bad weather
-sudden change in diet -cessation of supplementary feeding -yarding, trucking, driving -disease (affecting ability to graze e.g. Footrot, foot abscess) |
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Pregnancy toxaemia
-Aetiology and pathogenesis |
-metabolic disease associated w/ inadequte food intake
-hyperketonaemia and usually hypoglycaemia -Dx on history and clinical findings |
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Pregnancy toxaemia
-Hx |
-last 6 weeks of pregnancy
-death of pregnant ewes, blind ewes, sick ewes (often Autumn lambing ewes) -thin, pregnant ewes due to lamb in 6 weeks |
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Pregnancy toxaemia
-CS |
-ewes separate from mob
-thin, poor body condition (BCS 1-2) -may appear blind (no fear of man or dog) -stop eating and refuse food -wool break -drowsy/nervous signs -recumbency in 3-4 days |
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Pregnancy toxaemia
-Clin path findings |
(blood and urine)
-hypoglycaemia -hyperketonemia (elevated plasma B-OH butyrate) -ketonuria (pathogneumonic) -elevation of plasma cortisol |
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Pregnancy toxaemia
-Necropsy findings |
FETUS: dead/decomposed (more commonly twin/triplet foeti)
LIVER: enlarged pale to yellow, fatty, friable (fatty degeneration) FAECES: firm, dry ADRENALS: enlarged GIT SAND KIDNEYS: cerebral and renal lesions (renal failureand terminal uraemia) EYE FLUID OR CSF: elevatted ketone |
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Preg Tox:
DDx |
1. Hypocalcaemia**
2. Other causes of blindness (CCN< pink eye, FSE) 3. Other causes of nervous signs (enterotoxaemia, hypoMg, listeriosis, CCN, Scrapie) |
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Pregnancy toxaemia
-Tx |
correct management issues
1. Ewes able to walk: -put on better pasture/give supplementary feed 2. Unable to stand: -U/S to determine if lamb alive or dead (if dead, prognosis is poor) Triage: correct fluid, e/lyte, acid-base imbalance Options: 1. Caesarian section 2. Induction of parturition 3. Glycerol or propylene glycol + other trial Tx 3. Rucumbent/comatose -euthanise |
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Hypocalcaemia
-Epidemiology |
-last month of pregnancy +/- early lactation
-young sheep grazed on green oats -cereal grain only diets -crutching/shearing (stress) -transport -oxalate containing plants |
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Hypocalcaemia
-CS |
-stiff, staggery gait
-muscle tremor -weakness, drowsy appearance -increased RR -increased HR -normal or lowered temp -abscence of rumen movements +/- bloat |
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Hypocalcaemia
-Tx |
-calcium borogluconate 20-30g by slow IV
-move affected mob to a new paddock -prevent preg tox: feed |
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Termination of pregnancy in the ewe
1. What drugs? 2. When do you admin? |
1. Prostaglandins:
ram in w/ ewes: <1 week: 5 days after removal of ram 1-2 weeks: 4 weeks after removal of ram 2-4 weeks: 7 days, then 21 days after removal of ram Unknown: immediately (Cloprostenol PGF2a analogue) 2. Corticosteroids (dexamethasone) -140 days of pregnancy - |
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Mastitis
-Dx -Tx protocol |
Dx:
-hungry/starving lamb w/ mother -ewe which refuses suckling -lame ewe -recumbent ewe -udder missing -wool break Dx procedure: 1. milk culture 2. milk SCC Tx: cull after lambs weaned |
