This article will help you to identify and manage the following nutritional disorders that can occur in goats.
- Bloat
- Grain poisoning
- Copper deficiency
- Selenium deficiency
- Cobalt deficiency
- Iodine deficiency
- Thiamine (vitamin B1) deficiency
This summary provides details of the prevailing conditions under which each problem is likely to occur, explains how to diagnose the problem and lists preventative management strategies.
Bloat
Conditions when likely to occur:
Consumption of large amounts of lush, green, leguminous feed or lucerne hay.
Diagnosis:
- Clinical signs: gases form in the rumen causing distension on the left upper side. Death can occur quickly as pressure builds on the diaphragm causing failure of heart and lungs.
- Pasture assessment: at-risk pastures are those with a high proportion of legume, lush and in vegetative growth.
Treatment:
Cooking oil or a bloat oil product can be administered to break up the gaseous foam in the rumen.
Preventative management strategies:
- Avoid grazing high-risk pasture.
- Provide access to roughage in the form of hay or dry pasture.
- For producers adopting intensive rotational grazing, slow the rotation so that goats are grazing more mature pasture. This may reduce risk but will not eliminate it.
- In intensive grazing or strip grazing situations, daily spraying of bloat oil on high-risk pastures prior to grazing may be cost-effective. This strategy will not be cost-effective or practical in many situations. Bloat oil in water troughs may be considered if water availability is controlled. Bloat blocks are less reliable.
- During periods of lush pasture growth maintain regular routine and intake of food and water.
Grain poisoning
Conditions when likely to occur:
- Ingestion of large quantities of grain in a short period of time, resulting in an excessive build-up of lactic acid in the rumen.
- Changing from one type of grain to another too quickly.
- Rapid increase in the level of grain feeding.
Diagnosis:
Kicking at the belly, obvious pain and discomfort, grinding of teeth, standing dejectedly, not moving, sometimes bloated and scouring.
Preventative management strategies:
- Change the diet slowly; any change in feed type or amount of ration should be gradual.
- Provide fibre in the diet.
- Use a buffer in the ration.
Copper deficiency
Conditions when likely to occur:
- Copper deficient regions such as coastal sandy soils, granite soils and peat swamps; exacerbated by excess molybdenum or lime application.
- Deficiency typically occurs after an extended period of green feed.Copper is more available in dry feed.
- Growing stock and breeding stock are more susceptible to copper deficiency than other stock classes.
Diagnosis:
- Biopsy: Liver copper levels are very low, eg 2.6-17.2mg/kg, normal levels are greater than 40mg/kg.
- Blood samples should be taken from healthy goats and compared with those from affected goats. Normal serum or plasma copper levels are 500-1100mcg/litre.
- Soil: copper levels in the soil are poorly correlated with animal status, so do not use soil test to assess animal copper status. Soil copper level of 5ppm is adequate, but 4ppm molybdenum reduces available copper by 50%. Sulphur levels of 2g/kg or above also reduce copper availability.
- Abattoir: collection of liver samples if field biopsy not possible.
- Clinical signs: rough dull coat, poor growth, scouring, anaemia and poor reproductive ability.
- Kids may have an erratic swaying gait (swayback), usually weak and in poor condition. This is followed by paralysis.
- Confirmation of copper deficiency should be through blood sampling a proportion of the herd. Having done this, the most appropriate level of copper supplement can be determined.
Preventative management strategies:
- Treat stock with a copper injection prior to the high risk periods of winter and spring. Alternatively, copper capsules can be used to provide longer-term (12 months) prevention.
- If copper levels in the herbage are low, top dress pasture periodically with copper (usually 5–7 years).
- When applying molybdenum to a pasture, also add copper, if copper levels are marginal in the herbage.
- Discuss dosage and management options with your veterinarian and agronomist. Be aware that toxicity can be induced by overdosing with copper supplements.
Selenium deficiency
Conditions when likely to occur:
- Selenium-deficient regions, such a coastal sandy soils, New South Wales tablelands, acidic soils, sedimentary and granite soils, usually in high rainfall regions, exacerbated by high superphosphate application and clover dominance. Refer to the article Trace Element deficiencies, Australia for more detail on selenium deficient regions.
- Typically deficiencies are greatest when feed is lush.
- Young growing stock are most at risk.
Diagnosis:
- Blood biochemistry: precise information on goats is not available. New Zealand work suggests that goats have a higher requirement for vitamin E than sheep and this may also be true for selenium.
- Clinical signs: stiff-legged gait, arched back and death.
Preventative management strategies:
- Both selenium and vitamin E are necessary.
- Selenium can be administered as oral doses, injection or slow-release pellets lodged in the rumen.
- Selenium is potentially an extremely toxic substance and must be administered with care. Note that selenium supplements are commonly found in clostridial vaccines and anthelmintic drenches, so take care not to oversupply.
- Selenium should be administered to does prior to joining and again one month before kidding.
- Treat kids at marking. Repeat dose for kids at weaning, with further doses at 3, 6, 9 and 12 weeks up to joining.
- Slow selenium pellets or long-acting injections can be used for longer-term protection.
- Top-dress pasture – the decision to topdress should be made on the basis of cost/benefit analysis. It is usually too expensive to treat pastures, except in high stocking rate situations. Selchip™ at 300gms/ha is a cost effective product.
- Vitamin E is administered by injection. It can also be mixed with a grain ration and fed immediately.
- Discuss dosage and management options with your veterinarian and agronomist.
Cobalt deficiency
Conditions when likely to occur:
- Cobalt deficient regions such as coastal calcareous sands, high-rainfall granite soils and krasnozem soils, exacerbated by liming and high superphosphate application, especially in lush seasons. Refer to Trace Element deficiencies, Australia for more information.
- It has not been diagnosed in goats.
Diagnosis:
- Blood biochemistry: vitamin B12 deficient plasma, with levels less than 0.2mcg/ml indicate deficiency. A normal liver contains 0.32- 2.0mcg/gram of cobalt.
- Pasture cobalt levels can be assessed, but are rarely tested. Levels below 0.8 parts per million indicate deficiency.
- Clinical signs: ill-thrift, weepy eyes, severe wasting and eventually death.
- Clinical response to deficiency treatment can be tested by comparing a treated mob with control (untreated) mob. Treatment group would receive either a vitamin B12 injection or cobalt pellets.
Preventative management strategies:
- Vitamin B12 injection will provide prevention for about 8–12 weeks. Slow release cobalt pellets can be used for longer term prevention.
- Top-dressing pastures with cobalt gives variable responses. Cobalt levels in pasture can be tested – below 0.8 parts per million indicates a deficiency.
- Discuss dosage and management options with your veterinarian and agronomist.
Iodine deficiency
Conditions when likely to occur:
- Iodine deficiency occurs especially in mountainous areas such as on the Great Dividing Range in Victoria and coastal New South Wales.
- Iodine levels tend to be low in lush clover-dominant pastures with a history of high superphosphate application.
Diagnosis:
Clinical signs: thyroid gland swells producing a goitre; this is only a problem in new born kids. Adults appear to tolerate seasonal deficits.
Preventative management strategies:
- Drenching is recommended. Avoid feeding iodine as a lick as it is important to accurately control intake by the doe.
- Pregnant does grazing in high rainfall areas should receive a drench of iodine once or, in some cases, twice during the last two months of their pregnancy.
- Feed seaweed.
Thiamine (vitamin B1) deficiency
Conditions when likely to occur:
- Goats eating plants that are rich in the enzyme “thiaminase”, such as bracken fern, mulga fern, rock fern and nardoo.
- After a dry period, the plants listed above will get away more quickly than other pasture species. Stock eating the fresh growth of these plants are at risk.
- Feeding large quantity of molasses, or a sudden increase in concentrates.
- Sudden changes of diet may predispose to thiamine deficiency, especially in young stock.
Diagnosis:
Clinical signs include:
- stargazing – head up and tilted back,
- disorientation and aimless wandering,
- apparent blindness, oscillating eyes, may appear cross-eyed,
- lying down, head thrown back and stiff legs, convulsions and coma.
Preventative management strategies:
- Graze goats on fern-free paddocks until there is sufficient pasture or other grazing opportunities.
- Make available alternative feed ie good-quality hay so that stock are less likely to eat fern.
- Reduce the amount of fern on the property.
