AU4833790A

AU4833790A - Improvements relating to manufacture of rice straw silage

Info

Publication number: AU4833790A
Application number: AU48337/90A
Authority: AU
Inventors: Kenneth Donald Williamson
Original assignee: EIGHTH MILIEU NOMINEES Pty Ltd
Current assignee: EIGHTH MILIEU NOMINEES PTY Ltd
Priority date: 1988-12-29
Filing date: 1989-12-29
Publication date: 1990-08-01

Description

IMPROVEMENTS RELATING TO MANUFACTURE OF RICE STRAW SILAGE

The present invention relates to a method of production of rice straw silage.

Despite the fact that rice straw is an excellent _c source of roughage protein and starch it is rarely used as animal food for the reason that treatment to break down cellulose/silica scales in the straw is relatively difficult and expensive. Furthermore, it is necessary to preserve the fodder and this can only be achieved as is presently known ₁₀ to applicant by the addition of anhydrous ammonia.

Accordingly, large quantities of dried rice straw, particularly in Asian countries, has only limited use as bedding or as a roughage supplement which has little or no goodness. _lς It is known that the cellulose/silica scales may be broken down by treatment by ammonia gas so that protein starch is released and nitrogen is absorbed to improve the digestability of the food by animals. Unfortunately anhydrous ammonia is relatively expensive and therefore ₀ economic treatment is difficult. Presently rice straw is allowed to dry and is harvested into small round bales for storage. The bales would conventionally have a diameter in the range of 800 ma down to 400 mm.

Australian Patent Specification No. 66487/81 and _ς 490,664 disclose the formation of a preserved biomass by the addition of additives such as urea and the like. Specification No. 490,664 also discloses the step of ensilage of the mixture. Other examples of urea additive work is disclosed in U.S. Patent Specification Nos. _fJ 3,063,839, 3,180,735 and 3,585,043.

Japanese Specification No. 84/053806 relates to fibrous feedstuff production using vegetable fibre, taw lees and other nutrients mixed together in an air-tight package to form a paste. _ς The present invention has as its major objective the provision of a process for treatment of rice straw which increases the protein starch content and digestability of the straw in a relatively cheap, simple and effective manner thereby making the straw a viable animal food. In one aspect of the invention there is provided.- ' the step of adding urea preferably in particulate granule form, to moist rice straw windrows, harvesting the straw and urea mixture together into a bale, packaging the bale in tightly wrapped plastic film to substantially hermetically seal the straw and urea mixture to the surrounding atmosphere to allow chemical reaction within the sealed package, to thereby increase protein/starch content for use as an animal food of improved digestability and goodness.

Conveniently the urea includes 46% nitrogen by weight and is added in the range of 2 to 6% by weight of the straw, the resulting mixture of urea and moist rice straw in a sealed environment reacting to form ammonia gas.

Conveniently the straw is cut and harvested whilst still retaining a relatively high moisture content of up to at least 30% with a minimum of 20% moisture.

In use the urea would be added to the windrow just prior to bailing of the straw in a round baler so that the mixture of urea and rice silage would be formed in the baler chamber. Immediately after forming of the bale and discharge from the baler chamber the bale would be wrapped by a simple inexpensive wrapping machine that will eliminate air entering the bale thus causing silage to form and allowing ammonia gases formed in the moist mix to penetrate the straw. Alternatively, the urea may be added directly into the bale forming chamber during the formation of the bale. Alternatively, other enzymes may be used as an additive with or as an alternative to the urea.

With the urea and straw totally enclosed in the wrapped bale, the formation of ammonia will preserve the fodder and increase its digestability; solubiliεation of hemicellulose will occur. Further, the ammonia kills seeds and insects that may be in the harvested material.

It has been found that the minimum of 2% urea will preserve the rice straw but will only result in a minimum increase in digestability. By increasing the levels of urea will increase digestability thus having the duel result of preserving the crop by preventing mould and increasing digestability by causing swelling and rupture of the hemicellulose lignan bonds. In a practical arrangement of the invention it has been found that a feed ingredient applicator innoculating the windrows with urea may be used and in one good example the so-called GANDY (Trade Mark) feed ingredient applicator 5 has been found to provide excellent results.

After formation of the small round bale the bale must be wrapped by self-sealing plastic film or sheeting entirely enclosing the bale to hermetically seal the bale from the outside atmosphere, a machine suitable for this ■in purpose is marketed under the SILAWRAP Trade Mark. The self-sealing plastic film should be adhesive at least on one side to provide improved sealing as it is wrapped around a formed bale.

In another aspect of the invention there is ₅ provided a method of making rice silage, comprising the step of adding urea or other enzymes prior to or during the baling of rice straw, such as by adding granulate urea or enzymes to the rice straw during formation of a bale in a bale forming chamber, packaging the bale in a tightly _Q wrapped plastic to substantially hermetically seal the baled mixture of rice straw and additive to the surrounding atmosphere to prevent ingress of air, thereby allowing chemical reaction within the sealed package and to increase the protein/starch content in the treated rice straw for use ₅ as an animal food of improved digestability and goodness. It will be appreciated that the present invention provides a simple and effective method of improving preservation and digestability of rice straw whereby it may be possible for a commercially viable rice straw treatment _Q process to be achieved.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS;

1. A method of forming rice straw silage comprising the steps of mixing urea with freshly harvested moist rice straw, harvesting the straw and urea mixture together into a bale, packaging the bale in tightly wrapped plastic film to substantially hermetically seal the straw and additive mixture to the surrounding atmosphere to allow chemical reaction within the sealed package, and thereby increase protein/starch content for use as an animal food of improved digestability and goodness.

2. A method of making rice silage comprising the step of adding urea or other enzymes prior to or during the baling of rice straw into a compacted package, packaging the bale package in a tightly wrapped plastic to substantially hermetically seal the baled mixture of rice straw and additive to the surrounding atmosphere thereby preventing ingress of air, allowing a chemical reaction within the sealed package which increases the protein/starch content in the rice straw for use as an animal food of improved digestability and goodness.

3. A method as claimed in Claim 1 or Claim 2, wherein the urea includes approximately 46% nitrogen by weight and is added in the range of 2 to 6% by weight of the rice straw.

4. A method as claimed in Claims 1 to 3, wherein the straw is cut and harvested whilst still retaining a relatively high moisture content of up to at least 30% moisture.

5. A machine for performing the method as claimed in any one of Claims 1 to 4, comprising a bale forming chamber for forming a bale of rice straw, injection means for injecting a nitrogen rich composition such as urea into said rice straw prior to or during collection into the bale forming chamber of the rice straw.

6. A machine as claimed in Claim 5, further comprising wrapping means for tightly wrapping plastic film around a formed bale to hermetically seal the baled mixture.