Tool 11.7

Module Index

Module 1 - planning

Module 2 - wool

Module 3 - meat

Module 4 - people

Module 5 - NRM

Module 6 - soil

Module 7 - pasture

Module 8 - grazing

Module 9 - genetics

Module 10 - more lambs

Module 11 - sheep health

Module 12 - pastoral production

Hot Topics

MODULE 11: Healthy and Contented Sheep

Index

Common trace element deficiencies include copper, selenium and cobalt. The table below summarises the important information for the management and prevention of trace element deficiencies.

Conditions where trace element deficiencies occur

Trace element	Conditions that suit deficiency
Copper	Known deficient regions such as coastal sandy soils, granite soils, peat swamps, exacerbated by excess molybdenum or lime application. Deficiency typically occurs after an extended period of green feed with copper more available in dry feed. Growing and breeding stock most at risk.
Selenium	Known deficient regions, such as coastal sandy soils, acidic soils, sedimentary and granite soils, usually in high rainfall regions exacerbated by high superphosphate application and clover dominance. Typically deficiencies are greatest when feed is lush. Young growing stock most at risk.
Cobalt	Known 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. Young growing stock most at risk.

* Krasnozem: red, deep, well-structured acid soil with a relatively high clay content that gradually increases with depth

Maps of trace element and mineral deficiencies for southern Australia

These maps highlight the main regions where trace element deficiencies occur but do not cover all the areas with trace element deficiencies.

Figure 1. Areas where livestock may be at risk of selenium deficiency or toxicity

Risk of Selenium Deficiency
Source: G.J. Judson and D.J. Reuter (1999). Soil Analysis: An Interpretation Manual. Edited by K.I. Peverill, L.A. Sparrow and D.J. Reuter. Pp.325–329. (CSIRO Publishing: Melbourne)”

Figure 2. Areas where livestock may be at risk of cobalt deficiency

Source: K.I. Peverill and G.J. Judson (1999). Soil Analysis: An Interpretation Manual. Edited by K.I. Peverill, L.A. Sparrow and D.J. Reuter. Pp.325–329. (CSIRO Publishing: Melbourne.)“

Management to prevent deficiency

Trace element	Management
Copper	Copper capsules to provide longer-term (12 months) prevention. Top dress pasture periodically (usually 5–7 years) if copper in herbage low – generally most cost-effective. When applying molybdenum to pasture, add copper if copper marginal in herbage. Discuss dosage and options with your veterinarian and agronomist.
Selenium	Oral selenium drench (sodium selenite/sodium selenate) at 0.1 mg Se/kg body weight for immediate treatment of animals, giving 6–8 weeks protection. Many drenches now have selenium added but drenching frequency is a limitation. Will not protect for severe deficiency. Selenium pellets or injection for longer-term protection. Top dress pasture (depends on cost/benefit). Usually too expensive, except in high stocking rate situations. Discuss dosage and options with your veterinarian and agronomist.
Cobalt	Vitamin B12 injection (8–12 weeks prevention) or cobalt pellets for longerterm prevention. Top dress pasture (variable response). Discuss dosage and options with your veterinarian and agronomist.