Grain Storage without Drying
Drought across Europe and a stronger Euro caused 2003 wheat
to rise to £80 per ton ex combine for clean dry samples - some £15+/t above 2002
Grain for conventional storage over 6 months should be Max 16%
moisture - preferably 14.5% and kept cool - below 15 and preferably 10C. At 18%
moisture store for a maximum 6 months and keep cool with low
volume ventilation fans. Linseed should be below 10% moisture
- preferably 7%.
There are EC laws governing the max permissible levels of fungal toxins =
mycotoxins eg Aflatoxin and Ochretoxin in milk. Poor storage
encourages the development of storage aflatoxins. Expensive additives or
inoculants used at inappropriate moisture or storage environments place the cows
liver and several bulk tanks worth of milk at risk.
Crimping by roller is simple, for all cereals - but
generally not pulses. Acids or inoculants work to a degree, but the cost
is expensive - up to £23 per ton of Dry Matter. Feedout rates must be very fast
in summer - preferably one foot per day. Recent developments with whole grain
treatment with Urea, Innoculant (Biograin), and the Forage processor mill
for ground grain (not Corn Cracker) offer realistic alternatives. The
lowest cost least technically demanding is Urea treatment and is a direct
replacement for Caustic Treated Grain. With a good water supply 25 tons per
hour can be processed for storage up to a year under plastic with
minimal vermin damage at £1t/ processing and £3 materials costs.
|For dairy cows & beef the product can be fed whole BUT
must be wetted to reach as close to 30% moisture at treatment if dry, and
further wetted up to 2 days at Feedout. This is best achieved with a Diet Feeder
borrowed pre clamping. At Feedout the grain can be soaked via bucket
or Diet Feeder.|
|To ensure maximum crop yield, harvest when the grain
is mature in the region of 25-35% DM - harvesting at higher moistures in a
green straw crop will result in significant yield loss. |
|Add 25kg of Urea per ton of wheat (3%of Dry Matter for
wheat but 4% DM for Barley) at 30-35% DM - but see treatment
table Most use fertiliser UREA -
but for absolute safety - feed grade is advised.|
|Leave 6-8 weeks before feeding for the ammonia to preserve
with the wheat to form true protein.|
|Protein levels will be lower than those described below due
to some escape of ammonia gas.|
|DO NOT ROLL OR CRIMP THE SAMPLE at any time during the
treatment and clamping process |
|DO NOT UREA TREAT SAMPLES BELOW 25% MOISTURE WITHOUT
|DO NOT FEED UREA TREATED GRAINS ALONG WITH OTHER UREA
TREATED FEEDS EG WHOLE CROP OR MOLASSES BASED UREA LIQUIDS in quantity|
|SEE OPTIONS FOR
MOULDS CAN |
|See U.Wisconsin evaluation of
Q. Why are pests becoming more important in relation to
A. Firstly, the market now demands complete freedom from any
pests and, with low grain prices, standard terms are strictly enforced.
Secondly, many stores have been registered under the Assured Combinable Crops
Scheme and will be subject to inspection to meet the scheme's objectives. And
thirdly, the majority of pests but especially mites and rodents are
significantly more difficult to control using the pesticides that we have
successfully used over many years.
Q. Why are these pests becoming more difficult to control?
A. There is increasing resistance in many beetle and mite
populations to the organophosphate pesticides currently approved for admixture
with grain (Figure 1). Most of these have been on the scene for some 30 years.
Levels of resistance, particularly in storage mites, have risen to such levels
that control of established pests is not possible, even with a very effectively
applied treatment. Finally, while some rodent populations can survive after
eating large quantities of anticoagulant bait, there is also strong evidence
that behavioural resistance in some populations is contributing to control
Q. Why are mites seen as so important now?
A. Storage mites are strongly allergenic and there is
currently great concern about food intolerances and allergic reactions. While a
study of cereal-based foodstuffs purchased from retail outlets showed mites were
present in 1 in 5 products sampled, the general infestation level was very low
(at 1 mite per 20g of sample - or the equivalent of 75 in a household bag of
flour). However, some samples contained very large mite numbers - in one sample
of cereal Rusk baby food, nearly 400 mites per 20g were present.
Q. Is there any evidence that they can cause harm?
A. Mite allergens have been linked to the steady rise in
asthmatic problems in this country, which have to date remain unexplained.
Killing mites present in a foodstuff is not the answer, as mites constitute an
allergenic challenge even when dead. Mites have probably always been present in
foodstuffs, but it is possible that other environmental factors are predisposing
people to react to storage mites in their diet. Finally, early results from a
clinical trial show that more atopic individuals in the Manchester area reacted
to storage mite allergens than to house dust mite allergens - and we are all
aware of the media attention that house dust mites attract.
Q. What can be done to prevent problems with insect and mite
pests in stored grain?
A. The best - cheapest and most effective - answer is to cool
and dry the grain to prevent pests developing Insects do not generally breed
below 15°C and mites will not survive cereal moisture contents of 14.5% or
lower (7% mc on oilseed). Ensure that grain is dried and cooled as quickly as
possible to these levels. However, the cooler the grain becomes, the less the
risk of any pest problems developing (remember there is a 15°C maximum for
grain going into intervention). For longer-term storage in this country, 5°C
should be the target by the year-end. With the right equipment, this is a very
cheap strategy costing only around 10 pence per tonne of grain for the energy
required (or 5 pence per tonne if you have access to low tariff electricity and
can blow at night) (Figure 4). A differential thermostat ensures the most
efficient use of electricity