Term
| opportunities for improved animal health |
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Definition
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The lambing percentage.
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Lambgrowth.
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Ectoparasitism.
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Illthriftinewes.
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Lameness.
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Lambdeaths.
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Specificdiseaseproblems.
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Term
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Definition
| an opportunity for continuing involvement with flock health planning |
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Term
| why worry about poor lamb growth rates? |
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Definition
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Replacement of headage payments by the single farm payment
– profitability now related to conversion of forage to meat.
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The feed conversion efficiency of ill thrifty lambs can be half that of thriving lambs.
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The longer lambs are kept on a farm, the more they are predisposed to compounding effects of other diseases.
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Term
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Definition
Few UK sheep farmers routinely weigh their finishing lambs.
Ill thrift problems are often only identified when lambs fail to reach slaughter weights as expected - economic loss has already been incurred.
Importance of monitoring to identify production limiting disease in finishing lambs before significant economic loss occurs.
Need for a sound diagnostic approach.
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Term
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Definition
- assume trace element deficiency and supplement with copper, cobalt and selenium
- adopt a rational approach to the diagnosis and management of the problem ( flock health planning)
- – Are these animals
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– Identify the constraints by rationally investigating any animal health problem.
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– Ensure that the most appropriate remedies are used efficiently, based on assessment of the individual circumstances.
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– Evaluate the response and cost benefits.
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– Monitor to ensure satisfactory productivity.
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Term
| Important trace element deficiencies in farmed ruminant livestock |
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Definition
Cobalt
– ill thrift in ruminant lambs.
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Term
| Common causes of ill thrift in growing lambs are well defined as: |
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Definition
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poor nutrition
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perinatal management and disease
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parasitic gastroenteritis
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cobalt deficiency
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selenium deficiency
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liver fluke
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other specific infectious and management problems –
respiratory disease
lameness
sheep scab
(coccidiosis)
border disease
Brassica poisoning
tick borne fever
etc.
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Term
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Definition
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Farming system and feed management throughout the year.
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Times of lambing and weaning.
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Lambing percentage and spread.
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Worming regime and anthelmintics used.
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Previous trace element problems and supplements used.
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Observations of scouring, coughing, lameness or skin disease.
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Weather conditions
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Term
| Clinical exam- the whole farm and environment |
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Definition
- pasture and feed availability over the whole farm
- variation in size and weight within the group
- body condition scores across the group
- lameness, coughing, scouring, ocular disease and pruritus
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Term
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Definition
Faeces
– worm egg counts.
– (coccidia oocyst counts).
– (identification of fluke eggs).
• Serum
– vitamin B12.
– (selenium).
• Blood
– GSHPx.
– (selenium).
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Term
| Gross postmortem exam and sample collection |
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Definition
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Fresh liver for trace element assay.
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Examine liver for evidence of fluke.
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Check the abomasum for evidence of heavy parasite burdens.
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Check for respiratory disease and other post mortem signs.
- dont be sidetracked by incidental findings
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Term
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Definition
- cause of ill thrift in weaned, growing lambs.
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Term
| cobalt deficiency clinical signs |
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Definition
ill thrift, open fleeces hollow sublumbar fossae, low grade conjuctivitis and anemia
- empty, pot bellied, depressed
- Fatty infiltration of the liver (ovine white liver disease) has been associated with low vitamin B12 status of lambs.
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Term
| Animal requirements for cobalt |
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Definition
cobalt required for the manufacture of vit B12 which is required in the liver for utilisation of rumen-derived propionic acid in energy production.
- VIT B 12 also required for metabolism of certain S-amino acids which are necessary for optimum growth and wool production
- sheep have a higher requirement for cobalt than cattle and deer
- Vitamin B12 readily crosses the placenta and is stored in the foetal liver. Concentrations in milk and colostrum are also high. Pasture cobalt concentrations vary throughout the year, and are generally lowest during spring and highest during the winter. Consequently, clinical signs are most commonly reported in weaned lambs during the summer and in the newborn lambs of deficient dams during the spring.
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Term
| Diagnosis of cobalt deficiency |
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Definition
• Soil
– soils derived from acid igneous rock are low in cobalt.
– Mn, Fe & Ni in the soil interfere with plant cobalt uptake. – soil pH >6.3 can affect cobalt availability.
– soil compaction can reduce pasture uptake of cobalt.
– drainage can reduce pasture cobalt uptake.
• Pasture
– plant species differ in ability to accumulate cobalt. – confused by soil contamination of samples.
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Term
| Diagnosis of cobalt deficiency 2 |
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Definition
- PM ID of fatty liver changes associated with ill thrift may support a diagnosis of cobalt deficiency
- perform a dose response trial
- SerumvitaminB12 concentrations
– immediate dietary intake
• diagnosis of deficiency.
– large individual variation unless animals are severely deficient.
– affected by:
• change of pasture.
• concurrent liver disease.
• yarding.
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Term
| Vitamin B 12 reference values |
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Definition
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Based on numerous controlled supplementation trials.
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An indication of the probability of a weight gain response at a particular concentration of vitamin B12.
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Based on the mean of 10 serum or 3 liver samples (outliers removed).
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Diagnosis of deficiency – use lower ‘normal’ value.
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Prediction of sufficiency – interpret in the lower end of the ‘normal’ range.
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Different reference ranges for ewes and lambs.
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Term
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Definition
Short term Co supplementation
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– oral drenching with cobalt sulphate.
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– foliar liquid application of cobalt sulphate.
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– vitamin B12 injections.
• Long term Co supplementation
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– intraruminalcobaltbullets.
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– pasture top-dressing with cobalt sulphate.
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– free access mineral supplements?
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Term
| Ovine white liver disease ( OWLD) and hepatic encephalopathy |
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Definition
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lack of menace.
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– sudden onset depression.
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– progression to stupor.
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– fine muscle fasciculations.
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– ataxia.
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– head pressing.
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– 8 died.
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– noresponsetovitaminB1injections.
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– raisedGGT,GLDH&ASTingroup.
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– liver vitamin B12 <0.1 μg/kg.
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– fatty livers on postmortem.
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