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Urea treatment of wheat Straw
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Page 1: Urea Treatment of Wheat Straw

Urea treatment of wheat Straw

Page 2: Urea Treatment of Wheat Straw

Wheat Straw as animal feed

poor quality dry roughagegiven to the cattle (ruminants) as fillers

because straw hardly has any feeding value

highly deficient in minerals, vitamins, proteins

DCP=0.0; TDN=48.3

Page 3: Urea Treatment of Wheat Straw

Digestive utilisation of straw Straw has Parietal carbohydrates in

their cell wall The microbes in the rumen colonise

the ingested feed particles The cellulolytic strains partially

degrade (or hydrolyse) the cellulose and the hemicelluloses through using the enzyme, cellulase

Page 4: Urea Treatment of Wheat Straw

The degradation of the cell walls requires the microbes to attach themselves to the feed particles so that the enzymes can penetrate inside the fibrous structures, hence the need for the microflora which secretes these enzymes.

But wheat straw shows a high proportion of lignified walls, incrusted with lignin in a very complex manner

Page 5: Urea Treatment of Wheat Straw

the lignified walls resist for a long time the microbial degradation and the peristatic mastication (of rumination) and they are thus only digested slowly.

Page 6: Urea Treatment of Wheat Straw

Conditions for good digestive utilisation In order for the cellulolytic fermentation

process to be correctly carried out, the microorganisms in the rumen must be able to find• the nutritive elements which they need for

self development and to enable them to degrade (through cellulolysis) the polysaccharides of the cell walls of the wheat straw

Page 7: Urea Treatment of Wheat Straw

the physical and chemical conditions for maintenance of good cellulolysis.

Page 8: Urea Treatment of Wheat Straw

Importance of wheat straw

fibrous in nature Generally low in digestibility produce laxative effect after absorbing

more water from intestine.  cheap and readily available source of

energy to the animal body

Page 9: Urea Treatment of Wheat Straw

Need for urea treatment of straw

To increase nutritive value (protein source as in rumen microorganism convert nitrogen into protein) of wheat straw

To increase digestibility of

wheat straw

Page 10: Urea Treatment of Wheat Straw

Urea treatment: principle CO (NH2)2 + H2O -------> 2 NH3 +

CO2 urease

urea +water ammonia+carbonic gas Once hydrolysis is completed one molecule of urea(i.e. 60 g) generates two

molecules of ammonia (i.e. 34 g). 5 kg of urea thus allows production of 2.83 kg

of ammonia.

Page 11: Urea Treatment of Wheat Straw

Urea treatment : process Three ways of urea treatment

– Treating small quantities within walled enclosures

– Treatment of large amounts of forage in stacks or heaps

– the use of urine

Page 12: Urea Treatment of Wheat Straw

Convential method of urea treatment Weigh the urea about 4% of straw. Prepare the urea solution (30-50%) Sprinkle the urea solution on wheat

straw Press the straw and seal in the plastic

bag or silo or pit or trench

Page 13: Urea Treatment of Wheat Straw

Procedure(new method)

 Weigh the required amount of urea (4% of straw)

 Mix it with double the amount of farm manure (as urease source)

 30% moisture by adding water  Putting this mixture in a bag, piling the

straw on the bag, again moistening the straw with water (50% of straw)

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Incubating this material for a month under the cover of plastic sheet or mud plaster.

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Difference from conventional method

Three steps are eliminated preparation of urea solution sprinkling of solution on straw  pressing the straw during treatment

process

Result in labour saving upto 55%

However, efficiency is 30% less than the conventional urea treatment method

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Preparation of urea treated straw

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Urea treatment : Advantages It acts in just the same way on the

vegetal matter as if anhydrous ammonia is used:– dissolving the parietal carbohydrates

(mainly the hemicelluloses)

– swelling the vegetal matter in an aqueous environment, so easing access by the rumen's cellulolytic microorganisms

Page 18: Urea Treatment of Wheat Straw

– reducing the physical strength of the cells, so easing mastication by the animal and digestion by the microbes,

– enriching the forage in nitrogen, as is also the case if anhydrous ammonia is used.

Page 19: Urea Treatment of Wheat Straw

Key success factors for urea treatment Practical conditions affecting successful

treatment include the:– presence of urease– application rate of urea– moisture content– ambient temperature – the length of the treatment period– the degree of hermetic sealing achieved

during the treatment– the quality of the wheat straw to be treated

Page 20: Urea Treatment of Wheat Straw

THANKS