There are many in the livestock industry that claim that dung analysis is the most accurate method to determine animal mineral deficiencies. It is certainly more immediate compared to hair analysis which typically records the mineral status of an animal from a few months previous. Blood analysis can be helpful, but tends to be difficult and costly to obtain. It is also important to remember that blood only transports minerals, so does not necessarily reflect the actual tissue mineral status - ie the working end of the animal (N.B. hair is a form of body tissue). 

Soil analyses are probably the least reliable option as minerals that appear to be present in soil are often 'locked-up' and not available to plants. For example you may have plenty of magnesium showing up in a soil test, but little in the plant, and therefore very little in the animal. Leaf tests may give bit more of a reliable clue (though are often limited to testing only a single plant species at a time), but there is nothing like getting it from the so-called 'horses mouth' - the animal itself. The following instructions for dung analysis for cattle have been extracted from the Queensland's DPI&F website:

Determining cattle nutrient status
I. Collecting and preparing faecal samples

Désirée Jackson and Peter Martin, Department of Primary Industries and Fisheries

Introduction

The nutrient status of a ruminant, or the assessment of the quality of its diet, can be determined by the analysis of freshly excreted faecal samples from a group of animals running together in a paddock.

Faecal nutrient analysis can be carried out for ruminants that are grazing pasture for those nutrients that are not being fed as supplements.

Where stock have access to browse or numerous pasture species, it is difficult to know which pasture or browse species, which plant parts and what proportion of each species to collect, in order to get a good representation of an animal's diet. In such cases, faecal sampling is a more accurate technique to pasture sampling. A faecal sample is the culmination of the animal's total diet.

Sampling prerequisites

1. A bulk sample is required from at least 10 animals; 20 animals is better. All 20 samples are placed into one container and mixed thoroughly.
2. All stock which are sampled should be of the same age, weight/condition, class (male or female), and stage of production (empty and dry, empty and lactating, or pregnant and lactating).
3. Best results will be obtained from samples taken directly from the rectum or from freshly voided dung (less than 10 minutes old). Samples taken from cowpats up to 12 hours old may still provide useful results but these results will not be as reliable as those from fresh dung. If dung beetles have been in the cowpats, do not sample from these pats.
4. Keep the bulk dung samples as cool as possible until you reach home or they will ferment. The sample can be frozen after collection, particularly if it will be stored or in transit from a remote area for an extended time.
5. Ensure a clean plastic glove or spoon and a clean container are used for sampling. Be careful that any containers used do not contain dishwashing detergent residues because they can contain phosphorus.

IMPORTANT

Once stock are being fed supplements, only those nutrients which are not being fed to stock can be analysed. If urea, sulphate of ammonia, vegetable protein meal or blocks containing nitrogen are being fed, then the faecal sample can not be analysed for nitrogen. If phosphorus supplements, vegetable protein meal, or blocks containing phosphorus are being fed, then the faecal sample can not be analysed for phosphorus.

The results of an analysis for one paddock or class of stock, are not necessarily representative of another paddock.

Sampling procedures

1. With a gloved hand or a clean spoon, take 100 to 200 grams from 10 to 20 animals or cowpats, mix in a plastic bag and send about 0.5 to 1 kg for analysis.
2. If animals can be run up a race, collecting samples from the rectum is the most ideal. Alternatively, collect samples from freshly voided dung in the yards or from the paddock. If any older cowpats are available, remove the top layer and take samples from the "fresh" dung underneath.
3. Once enough individual samples have been collected, mix thoroughly and with a gloved hand, transfer 0.5 to 1 kg to a suitable jar. Close the jar tightly.
4. Label the jars clearly with simple identification which you will be able to recognise when results of analysis are returned, for example, "Paddock 1 - heifers".
5. Keep the dung samples as cool as possible until you reach home.

Freezing the sample

1. If freezing the sample, store in the freezer for at least 12 hours.
2. Frozen samples should be dispatched for analysis by overnight freight. They should not be sent by post.

(IMPORTANT: Although faecal samples taken for nutrient analysis can be stored in the freezer, faecal samples taken for EPG (worm egg) counts, must not be stored in the freezer.)

Drying the sample

An alternative to refrigeration and freezing the sample is to dry it. Dry dung can be sent by post provided it is well-packed and sealed.

1. Spread dung thinly over aluminium foil and leave in the sun.
2. When the dung is dry, peel it off the foil into a jar or clip-seal plastic bag.

Getting the sample analysed

1. Pack the frozen sample in an esky with an ice brick and seal the esky lid well with tape.
2. Ensure a separate page with details of the sample is included. Details which are required include:

• property owner
• property address
• phone and/or fax number
• date of sampling
• class of stock
• stage of production (dry/lactating, pregnant/empty)
• current supplements being fed
• which analyses you would like done: nitrogen and/or phosphorus

The sample must be sent by overnight freight to:

Health and Nutrition Biochemistry Laboratory
Animal Research Institute
Fairfield Road,
YEERONGPILLY QLD 4105

Contact your beef extension officer or Mr Peter Martin, DPI&F on +61 7 3362 9509 for costs for the various analyses.

If you would like to have your results interpreted (status of your pasture and whether supplementation is required), please contact your local beef extension officer.

Further information

• Contact your local beef extension officer in DPI&F
• Contact DPI&F on telephone 13 25 23 (Queensland residents) 8am to 6pm weekdays. Non Queensland residents phone +61 7 3404 6999; Email

Unfortunately Queensland DPI&F no longer do the actual dung tests, but I have been directed to Ecowise in Brisbane and Canberra. I do not know more than this so it is probably worth contacting them and making some inquiries.