Wheat Straw Treatment | An Article | By Husnain Zahid

Wheat Straw Treatment

HUSSNAIN ZAHID

AHSAN SALEEM

WASEEM HASHIM

KBCMA COLLEGE OF VETERINARY AND ANIMAL SCIENCES (UVAS SUB-CAMPUS),

NAROWAL 

Introduction:

          Straw is most abundant of all agricultural resides. It is composed of cellulose and hemi-cellulose. These are bound to lignin and resistant to microbial attack. It is used for burning, making paper as poor quality roughage which is given to cattle, buffalo (Ruminants). It is deficient in nutrification and has ability to digest slowly in ruminants. It is alternative source of nutrition for live-stock animals but wheat straw alone does not give proper nutrition to animals which they require. That’s why wheat-straw is treated with urea.

Method:

          Nutritional value of wheat-straw (which is low protein and low digestible roughage) can be improved through physical or chemical methods. Efficacy of treating straw with urea for improving its nutritive value is considered equivalent to aqueous ammonia. However, adoption rate of urea-treatment by farmers is low. So, there is need to simplify urea-treatment methods.

            The new method involves weighing required amount of urea (4% of straw) mixing it with double the amount of farm manure (as a urease source) giving 30% moisture in a bag, pilling the straw on the bag, again moistening the straw with water (50%) of straw and incubating this material for one month under the cover of plastic sheet or mud-plaster can save labour by 55%.

Method of Spraying:

            For spraying of urea solution over a layer of 100kg straw or whatever quantity that is chosen, gardeners’ sprinkler can be used to achieve uniformity in solution coming in contact with straw. For chopped wheat straw, some hand mixing after the spray of urea solution is desirable.

Compactness of Stack:

⮚      If 1 layer of 100kg has been treated, an additional layer of 100kg is placed on top and sprayed with urea. A compact stack has two advantages.

⮚      Firstly, effectiveness of ammoniation process is better

⮚      Secondly, there are less chances of mould growth which leads to spoilage of the straw. Better the compaction and airtightness of attack better will be quality of treated straw.

Storage Method:

            Covering of the stack is important, though particularly the larger and more densely packed stacks could be open i.e. covered with only a layer of untreated straw. Sealing can be done with polythene, coconut or banana leaves or empty urea-bags stitched together.

Wheat Straw Treatment

            When small heaps are treated it becomes important to have stack adequately sealed.

Effect of Treatment on Straw Quality:

            Urea treatment improves straw quality in terms of digestibility and intake treated straw positively affects animal production and health.

Nutritive Value:

Treated straw increases the crude-protein content in order of 4 to 5 percentage units due to addition of ammonia. The higher intake and digestibility is due to increased rate and extent of cell wall degradation.

Effects of Treatment on Straw

Straw Type	US/TS	DMI	DDMI	DOMI	DMD	OMD	IVOMD
Wheat	US	63-64	35-38	0.86	39-40	40-41	44-47
	TS	71-84	50-76	1.36	42-50	43-53	51-83

 

Animal Health:

          Generally, it can be said that by replacing a large amount of Untreated Straw (US) by Treated Straw (TS) in the ration:

⮚      Butterfat increases to some decimal points.

⮚      Milk yield increases of 0-1.5 liters, but 0.5-1 liter appears to be a reasonable range depending on other feeds fed stage of lactation and body weight of animal.

⮚      Animals of 100-150kg body weight will lose 50-100g/day if fed on only US, whereas they will gain 50-100g/day when fed on TS alone.

⮚      In some cases, by feeding animals on TS dung gets slightly stickier.

⮚      Urea toxicity due to feeding of treated straw (TS) is unlikely or even impossible because straw and urea are well mixed and intake of straw is slow.

⮚      Fungal growth in straw can produce mycotoxins which cause abortion or other ill effects but ammonia produced from urea while treating straw is efficient to inactivate the mycotoxins.

⮚      Vitamin A deficiency in treated straw and untreated straw can cause fertility problems in cow, but this can be prevented by including some green fodder in ration.

⮚      Skin becomes shiny when animals are fed upon TS.

 

 

Limitations of Wheat Straw Treatment:

⮚    When straw availability is low/limited some formers get discouraged because stack of straw gets exhausted quickly.

⮚    A farmer who uses urea on credit or other limited resources prefer to use urea on cash crop rather than treatment of straw, where returns are low.

⮚    For large dairy farmers, straw availability and labour may be problem.

Conclusion:

⮚      Urea treatment improves nutritive value of straw in terms of total content, energy digestibility and intake.

⮚      Crude protein content increases.

⮚      The effectiveness of treatment depends upon:

a)      Type of Straw

b)      Concentration of Urea

c)      Moisture Level

d)      Method of Spraying

e)      Method of Storage

Technology can be adopted where:

⮚      Grasses or other green fodder are not available.

⮚      Straw is cheap and readily available.

Wheat Straw Treatment