AFIA - Laboratory Methods Manual - Australian Fodder Industry ...

Method – 1.1R: How to Take Fodder Samples for Analysis
Version 2
Date 31/08/05
Scope: This procedure is used to obtain fodder samples for analysis; separate methods are used
for hay and silage.
Principle: The accuracy of fodder analysis depends on the sample sent to the laboratory. It is
critical that the sample represents the average composition of the "lot" of fodder sampled; otherwise
the laboratory tests will not be useful.
A "lot" is defined as hay or silage taken from:
- the same species (pure or mixed) and variety;
- the same paddock or pit/bunker; and
- harvested within 48 hours.
Other factors influencing the definition of a "lot" include:
- rain damage;
- weed content;
- soil type;
- treatment after cutting; and
- storage effects.
A "lot" of baled hay or cubes should not exceed 200 tonnes.
Sampling Equipment: Representative hay samples can only be obtained with a probe or core
sampling device. Do not rely on a couple of handfuls or a "flake" from one bale.
• Australian made corers are available from:
KELSPEC SERVICES, PO Box 31, Dunkeld, Victoria 3294 (phone 03 5577 2624);
• Several types are also marketed in the USA.
• A home-made corer can be made from 32mm steel tubing. It should be at least 450mm long
with a slightly scalloped and sharp cutting edge.
• Corers are driven using either a hand brace or by a continuously variable speed, electric drill
(preferred option where practicable). A portable generator is useful and can be justified if
many samples are to be taken. Cordless drills can be used if they meet power (torque)
requirements.
Sample Size Reduction:
The original sample will normally require reducing in size prior to further processing. There are two
ways this can be achieved: By use of a riffle box or by sample coning and quartering. The riffle box
is preferred for certain sample types (e.g. fine chopped maize forage) in that it is faster and yields a
marginally better sub-sample. However, it requires specialist equipment, and for some sample
types, it can be prone to blocking.
Riffle Box: These devices are also known as sample splitters and are available commercially.
The sample is split into two equivalent portions via a series of gates. One half is usually discarded,
and the other retained for analysis, or for further sample reduction
AFIA Laboratory Methods Manual – v7 September 2011 Page 8 of 103