Possible storage losses


Grain weevil

  • It is always necessary to store the feeds and fodders for regular use in an efficient feeding system. Fodders are conserved either as silage or as hay. Concentrate feeds are usually procured in large quantities; stored and used regularly.
  • Farmers may procure a compounded or manufactured feed, or they may procure the feed ingredients separately and mix them just before feeding.
  • The common feed ingredients are grains of cereal crops like sorghum, maize, bajra, etc; edible oil cakes like groundnut oil cake, sesamum oil cake, cotton seed cake, etc; deoiled rice bran, and so on. Most of these ingredients are the produce from fields or agro by -products or agro-industrial by-products.
  • There can be losses in these products either at the field level or during storage. Field losses are seen with the cereal grains during harvesting and post- harvesting operations like threshing, cleaning and drying.
  • Storage losses are more important in case of all the feed ingredients. These losses can be qualitative or quantitative. These losses are brought about by insects, fungi and more importantly rodents i.e. rats. The activity of these biological agents is influenced by the storage environments.
  • Moisture content and temperature are the principal factors in safe storage. The stored grain pests become inactive at low moisture and low temperature conditions.
  • High humidity coupled with high temperature encourages mould formation and provide conditions favourable for rapid growth of insect population.
  • The optimum level of moisture for storing the feed ingredients is less than 10% in India. Temperature below 15ºC retard insect reproduction, while high temperatures (21-43ºC) speedup the life process of all micro - organisms.
  • Insects like beetles, weevils and different larvae feed on stored grains and other ingredients. Grains with higher nutritive value are more susceptible to insect damage. Dead and live insects and their excreta make the commodities unpalatable and unacceptable.
  • The losses due to fungi are mainly due to the development of metabolites like aflotoxin, zearalanone, etc. There may be decay and death of grains because of the fungal attack.
  • Rodents not only consume the feed but also foul it with their excretions. Further they destroy the containers by gnawing holes that result in leakage and wastage of feed ingredients.
  • It is necessary to take all the precautions and control measures as listed below to minimize storage losses:
    • The produce should be thoroughly dried to bring down the moisture content to less than 10%.
    • The feed ingredients are stored in containers such as gunny bags. Polythene bags, metallic bins, etc. which are kept under good hygiene and clean conditions during storage.
    • Stacking is done in such a way as to permit inspection of the bags for storage losses.
    • The produce should be periodically taken out, dried and rebagged to avoid the damage due to insects and fungi.
    • Grains can be mixed with dried neem leaves or ash to prevent insect damage.
    • The storage structures (sheds, buildings, etc.) should be entirely weather proof mainly to prevent leakage of rain water. There should be controlled ventilation to prevent the build up of high temperature and high humidity.
    • Structures are build with provision to make them air tight to enable fumigation when ever necessary. Fumigants are gases which penetrate bulk of grains and kill insects and larvae living within the grain, but fumigation should be done under the strict supervision of experts or trained persons.
    • The dust forms of insecticides such as malathion, lindane can be used to control insect pests.
    • Rodent control is most important during storage and also in the fields. Rodents can be controlled by using rat traps, use of cats and dogs; and use of poisoned baits. In the fields, aluminium phosphide tablets can be used to control rodents by placing them in rat holes and plugging them. During storage bait prepared by using zinc phosphide (0.5%) is more effective. Protecting the grains and other feed ingredients during storage is as essential as producing them in the field.


Last modified: Wednesday, 21 December 2011, 7:09 AM