IES65610B2 - A pig feed production process - Google Patents

Abstract

Barley and wheat are stored in bulk storage silos (4,5) and are drawn as required into a hammermill (6) having a fine mesh to produce a very fine powder output, in turn delivered to batch supply containers (10, 11). Various other solids are received in a pre-milled condition and are also stored in various containers (12, 13, 14). Water is heated to 70{C. Citric acid production yeast by-product is pumped into a storage tank 31 where it is continuously agitated. Meat and bone meal stick water having an oil content of less than 3% is stored and heated with a continuous agitation in a tank 32. Glass-lined tanks (31, 32) are used for yeast and stick water storage and agitation. The liquid raw material delivery order to a mixing tank (17, 18) is stick water, yeast by-product and water. This provides an homogenous mix in which the oil in the stick water is dispersed and the various contents are thoroughly mixed before addition of the solids. Both input and output of the raw materials and feed respectively is controlled by use of load cells on the mixing tanks. This helps to provide for re-circulation of the output feed to detect leaks and for control of delay times between different raw material delivery stages.

Description

A Pia Feed Production Process The invention relates to a process for the production of pig feed.

Heretofore, many different feed compositions have been used for pigs and these generally fall into two basic categories, namely dry feed and wet feed. Dry feed generally comprises grain and additional dry components such as soya meal and meat meal, etc. Various minerals and vitamins are generally included also to help provide a high nutritional value to maximise pig growth.

Wet feed may be produced as described in PCT Patent Specification No. WO 82\03159 in which the feed is referred to as a protein soup mainly based on such materials as blood, slaughterhouse waste, partially digested intestine content from slaughterhouses, industrial protein waste, fish pulp, whey, yeast cream, skim milk, etc. In general, a characteristic of wet feed is that it is difficult to control the nutritional content because of the nature of the raw materials used. Another aspect is that physical handling is difficult - both during production and in distribution in a pig farm. This is because of the tacky nature of the feed. This has led to development of sophisticated sampling and control systems such as those described in PCT Patent Specification Nos. WO 89\11089 and WO 89\11090. For example, in WO 89\11089 an automatic sampling arrangement is described in which use is made of a single sampler which stretches all over the width of the receiving weigher so that it can receive from a number of different outlets. As described in WO 89\11O9O samples are automatically transferred to an analysing station through a pneumatic conveyor system.

S6561Ο Accordingly, the invention is directed towards providing a process for production of feed having a high nutritional value for rapid pig growth which is consistent from batch to batch, and which is simple to handle during production and distribution. Another object is that the process be inexpensive to carry out.

According to the invention, there is provided a pig feed production process comprising the steps ofs10 milling grain which is transferred from bulk storage, and transferring the milled grain to a batch supply container; heating water to a temperature in the range 65°C to 75°C in a batch supply tank; heating fat and bone meal stick water having an oil content of less than 3% and a solids content of in excess of 4% to a temperature in the range of 65°C to 75°C and continuously agitating the stick water; storing a citric acid production yeast by-product having a solids content in the range of 18-20% and continuously agitating the yeast by-product; storing minerals and vitamins in containers for batch supply; delivering the following liquid raw materials to a mixing tank while maintaining continuous agitation: heated stick water to a batch weight proportion of 16% to 18%; yeast by-product to a batch weight proportion of 15% to 17%; and heated water to a batch proportion of 44% to 55%; subsequently delivering the following solid raw materials to the mixing tank while maintaining continuous agitation: grain to a batch weight proportion of 15% to 19%; and minerals and vitamins to a batch weight proportion of 1% to 2%; a controller continuously monitoring raw material inputs to the mixing tank by receiving signals from mixing tank load cells, directing a delay of 40-60 seconds between delivery stages, and directing the following final mixing and feed delivery operations: agitating of all batch raw materials for 8 to 12 minutes after delivery of the last raw material; and pumping the feed to outlet containers whereby the discharge quantity is continuously monitored by reading mixing tank load cell output signals.

In one embodiment, the stick water and yeast batch supply tanks are glass-lined and have side-mounted impellers operated for continuous agitation during the process.

Preferably, the stick water has an oil weight percentage of approximately 2% and a solids weight percentage of approximately 5%.

In one embodiment, the sequence for delivery of the liquid raw materials is first stick water, second yeast byproduct and third water.

Preferably, the following solid raw materials are delivered to the mixing tank after delivery of the liquid raw materials: tallow, meat and bone meal, molasses and soya, each to a batch weight proportion of in the range 1-2%.

In another embodiment, the controller directs holding of a residue from a previous batch of a similar type in the mixing tank and pre-heating of this residue before the raw materials are delivered to the mixing tank.

In a further embodiment, the controller directs recirculation of the mix feed through an output circuit while continuously monitoring weight of the mixing tank to detect any leaks.

Preferably, the mixing tank has a plurality of verticallymounted Impellers for agitation during the mixing and delivery production stages.

In one embodiment, the grain is milled in a hammermill having a screen opening size in the range of 3-4mm. In this latter embodiment, the grain preferably includes barley and wheat, the barley being supplied at a batch weight proportion in the range of 12-14% and the wheat being supplied at a batch weight proportion in the range of 3-5%.

The invention also provides pig feed whenever produced by a process as described above.

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:Fig. 1 is a schematic representation of a pig feed production apparatus for carrying out a process of the invention; and Fig. 2 is a flow chart illustrating the process.

Referring to Fig. 1, there is illustrated a system 1 for the production of a wet pig feed. The system 1 comprises a wheat and barley inlet hopper 2 from which an auger 3 rises for delivery of barley to a bulk storage barley silo 4 and a bulk storage wheat silo 5. The silos 4 and 5 are used for storage of very large quantities of barley and wheat to provide a continuous source of these raw materials for up to a year after harvest. Augers extending from the bottom of the silos 4 and 5 feed barley and wheat to a hammermill 6. The hammermill 6 has a screen size of 3.5 mm and a radial inlet for use in both directions of rotation of the hammers. This provides uniform wear of the screens and the hammers and efficient milling. It has been found that such a hammermill is suitable for milling of both barley and wheat to a very fine consistency so that it may be suspended in a highliquid content wet feed for easy distribution through pipework, pumps, valves, etc.

An auger first above at ground level delivers milled barley and wheat through an inlet hopper 8 for addition of solid raw materials such as meal and soya. An overhead conveyor 9 extends from the hopper 8 for delivery of the various solid raw materials to batch supply containers including a barley container 10, a wheat container 11, a meal container 12 and a soya meal container 13. The system 1 also comprises a number of small hoppers 14 for the reception of low-volume solid raw materials such as minerals and vitamins. Augers 15 connect both the hoppers 14 and the containers 10 to 13 to a top manifold 16 for a pair of mixing tanks 17 and 18. For any one batch of pig feed, one of the mixing tanks 17 or 18 is used, valves (not shown) in the top manifold 16 controlling the feed direction. The system 1 also comprises a tank 19 for tallow and a tank 20 for cane molasses. These are also connected to the top manifold 16.

Water for a production batch is stored in a tank 30 which has heating elements. The water in the tank 30 is agitated by a side-mounted impeller rotating about a substantially horizontal axis. The system 1 also comprises a yeast tank 31 which is glass-lined and which also has a side-mounted impeller. However, there is no heating arrangement in the tank 31. Finally, there is a tank 32 for stick water. This tank is glass-lined, has a side-mounted impeller for agitation and also includes heating elements and associated control circuits. Pumps and pump lines 33 connect outlet ducts of the tanks 30, 31 and 32 to inlets of the mixing tanks 17 and 18.

For delivery of produced pig feed, the system 1 comprises feed supply lines 50 and 51 associated with the mixing tanks 17 and 18 respectively. These have valves 52 and 53, respectively. The feed supply lines 50 and 51 are connected to a pig feed circuit 54 which has a primary pipeline in a closed loop configuration and is connected to a large number of individual outlets for pig pens. The circuit 54 is connected to return pipelines 55 for recirculation of feed back to the mixing tanks 17 and 18. The system 1 comprises a computer controller which is connected to load cells at the bases of the mixing tanks 17 and 18 and to the various augers, pumps and valves throughout the system 1. The load cells can detect weight in the mixing tank to an accuracy of 1kg in 10 tonnes. Operation of the controller in conjunction with these load cells is important, as described below.

Referring now to Fig. 2, a production process of the invention which utilises the system 1 is now described. This process is indicated generally by the numeral 17 and comprises steps 71 to 91 inclusive. In step 71 wheat and barley are stored in bulk in the silos 5 and 4 respectively. There is sufficient in these silos for up to one year's production after harvest time and accordingly there is effectively a continuous supply. When a batch of feed is to be produced a quantity is drawn from the wheat silo 5, this quantity being in the range of 3-5% of the total batch weight. This is milled in the hammermill 6 which, as described above, has 3.5mm screen openings to produce a very fine powder which may be suspended in liguid having a consistency of approximately that of water. Likewise, a quantity of barley is drawn from the silo 4, the quantity being in the range of 12-14% of the batch weight. This is also milled in the hammermill 6. The milled wheat and barley are (separately) transferred on the conveyor 7 to the relevant batch supply containers 10 and 11. Further, in step 74 meal and soya are added at a hopper 8, each being at a weight of in the range of 1-2% of the batch weight. Again, these are transferred to the relevant batch supply containers 12 and 13. Other minor raw materials include tallow, which is stored in a container 19 and cane molasses (75-80% solids) in a container 20. Minerals and vitamins and fish meal are added to the various hoppers 14. The step 73 of Fig. 2 includes the batch feed storage of the mill fishmeal soya, meat and bone meal, minerals, vitamins, tallow and cane molasses.

In step 75, water is delivered to the tank 30 to a quantity in the range of 44-50% of the total batch weight. This water is heater to a temperature in the range of 6575°C and preferably 70°C. The side-mounted impeller is operated for continuous agitation. The raw material which is delivered to the tank 31 is a yeast composition having a yeast solids content of 18-20%, the balance being water. This raw material is a by-product of a citric acid production process and is extremely inexpensive to purchase and Indeed some manufacturers pay for it to be removed from their premises. This raw material is pumped into the tank 31 to a quantity in the range of 15-17% of the batch weight. Because the tank 31 is glass-lined and there is agitation by virtue of a side-mounted impeller, very little of the yeast adheres to the sides of the tank and it has a uniform consistency.

The raw material which is added to the tank 32 is stick water from a meat and bone meal production process. An important aspect of the stick water is that it has an oil content of lower than 3% and indeed in this embodiment it is only 2%. The solids content (generally meat and bone meal) is approximately 5% and preferably over 4%. The remaining portion is water. This raw material is also extremely inexpensive to supply and again many meal producers pay for it to be taken from their premises. This is because it is a necessary by-product of bone and meat meal production and is very difficult to dispose of.

Some manufacturers evaporate it off to recover the 5% solids, however, this is an expensive process.

An important aspect of the invention is the fact that a wet pig feed is produced which includes yeast and stick water to a total batch proportion of approximately 34%. This provides a very high nutritional value for the feed and is also extremely useful in repetitive production of feed having a uniform consistency both in terms of physical and nutritional content. The high liquid content of these raw materials help to ensure that the produced feed is easy to handle as it may be pumped through a feeding system in a pig farm.

The fact that the tank 32 is glass-lined and has a sidemounted impeller helps to ensure that the stick water has a uniform consistency and that very little adheres to the side parts of the tank. In particular, for stick water the side impeller is important to prevent oil separating and there is at all times an homogenous mix.

Storage and agitation of the yeast is indicated by the numeral 76. The yeast is not heated and remains at ambient temperature. Heating and agitation of the stick water is indicated by the numeral 77. The stick water is brought to a temperature of 70°C and is generally at a temperature in the range of 65-75°C.

The controller of the system 1 operates using as a primary input the weight of the particular mixing tank 17 or 18 which is being used. Input and output quantities are controlled centrally using this parameter and accordingly, to ensure fault-tolerance, there is redundancy in the load cells used. Because the particular mixing tank directly supplies a pig feed circuit 54, it will retain a residue of 150kg of the previous batch, provided it is of the same type. This is to ensure that the supply lines of the circuit 54 do not become empty. This feature would also apply generally in output distribution of produced pig feed. In step 78 the residue is agitated and pre-heated in the mixing tank.

In step 79 the stick water is delivered to the mixing tank. As stated above, this is in the range of 16-18% of the total batch weight. This weight is monitored by the load cells under the particular mixing tank. Because the input quantity may be controlled in this way, it is envisaged that the tanks 30, 31 and 32 may be arranged to hold much more than which is required for an individual batch, the input quantity to the mixing tank 17 or 18 being controlled by the controller in response to the load cells. While the raw materials are being delivered to the mixing tank, the controller directs operation of impellers within . the mixing tank to maintain the content continuously agitated. The mixing tank has three impellers mounted about a central vertical shaft. The controller directs a delay of 30 to 60 seconds and preferably 40 seconds between delivery of each raw material, during which period the existing contents are comprehensively agitated for thorough mixing.

In step 81 the yeast is added to a batch proportion by weight of in the range of 15-17%. This brings down the temperature of the mix because the yeast has not been preheated. However, in step 82 the heated water is delivered to a batch proportion by weight quantity of in the range 44-50%. This helps in the thorough mixing of the liquid ingredients and brings the temperature back up to close to 70°C.

It has been found that by adding the liquid raw materials in this order, they are mixed together very well and the oil content of the stick water is particularly well dispersed. Further by delaying delivery of the solid raw materials until the three liquids have been delivered, mixing can take place very comprehensively. As indicated generally by the step 83 the solids are delivered in sequence, again with 40-second delays between different delivery stages. The delivery order is as followssRaw Material Batch Proportion by Weight Cane Molasses 1-2% Tallow 1-2% Minerals and Vitamins 1-2% Barley 12-14% Wheat 3-5% Meat and Bone Meal 1-2% Soya 1-2% The particular quantities used within these ranges depend on the type of feed required for the particular pig development stage.

An important aspect of the process is that all of the solids which are added have a very fine consistency. The barley and wheat are milled in the hammermill 6 and the other solids are bought pre-milled whereby the particle sizes are such that the raw material may be suspended in a liquid mix with a reasonable degree of agitation. As each raw material is added in turn, the load cells of the particular mixing tank are used to monitor the exact quantity to a 1kg accuracy.

As indicated by the step 84, when all of the raw materials have been added there is agitation in the mixing tank for approximately 10 minutes to ensure that the mix is consistent. In step 85 the feed is delivered by the pumps and 53 and the feed supply lines 50 and 51 to the feed circuit 54. This initial pumping action is carried out with all of the outlets of the feed circuit 54 closed by the central controller. Furthermore, the feed is recirculated back to the mixing tank in the lines 55 and there is continuous monitoring of the mixing tank weight. This is an extremely simple way of ensuring that there are no leaks in the feed circuit or in any of the output lines of the mixing tank. If there are any leaks, these are repaired as indicated by the step 87, before continuing. In step 88 the controller directs pumping to a first feed station of the circuit 54 and again, the quantity delivered is controlled according to the weight of the mixing tank. When the correct quantity has been delivered as indicated by the step 89 the controller directs opening of the second feed station and pumps the feed to it as indicated by the step 90. These steps are then repeated for each successive feed station during which there is monitoring of weight in the mixing tank and the necessary control of the valves as indicated by the step 91.

It will be appreciated that delivery of the produced feed is extremely simple because it may be all controlled directly from the mixing tank and this is in turn made possible by the fact that the feed has a very high liquid consistency and comprises fine solid particles whereby it may be easily pumped In circuits at a high flow rate and using relatively simple liquid pumping and distribution systems.

In general, it will be appreciated that the invention provides for production of a pig feed which has consistent nutritional and physical characteristics from one batch to the next by virtue of the fact that stick water and a citric acid yeast by-product are used and by virtue of the milling of the solid raw materials such as wheat and barley. It has been found that by combining such a yeast composition with stick water and the other raw materials a very high pig growth rate has been achieved. Another very important aspect is the fact that the feed may be very inexpensively produced as the yeast and stick water raw materials cost nothing and indeed manufacturers pay to have them removed. In this way, a very valuable raw material which is easily handled obtained at little or no cost. These raw materials contribute towards the thorough admixture of the solid raw materials for ease of handling and distribution and for consistency in the feed from one batch to the next. Further, it has been found that by controlling inputs and outputs and mixing in the manner described by use of load cell primary inputs, overall control is very easily achieved in a simple manner.

The invention is not limited to the embodiments hereinbefore described, but may be varied in construction and detail.

Claims (5)

1. A pig feed production process comprising the steps of:milling grain which is transferred from bulk storage, and transferring the milled grain to a batch supply container; heating water to a temperature in the range 65°C to 75°C in a batch supply tank; heating fat and bone meal stick water having an oil content of less than 3% and a solids content of in excess of 4% to a temperature in the range of 65°C to 75°C and continuously agitating the stick water; storing a citric acid production yeast by-product having a solids content in the range of 18-20% and continuously agitating the yeast by-product; storing minerals and vitamins in containers for batch supply; delivering the following liquid raw materials to a mixing tank while maintaining continuous agitation: heated stick water to a batch weight proportion of 16% to 18%; yeast by-product to a batch weight proportion of 15% to 17%; and heated water to a batch proportion of 44% to 55%; subsequently delivering the following solid raw materials to the mixing tank while maintaining 5 continuous agitation: grain to a batch weight proportion of 15% to 19%; and minerals and vitamins to a batch weight proportion of 1% to 2%; 10 a controller continuously monitoring raw material inputs to the mixing tank by receiving signals from mixing tank load cells, directing a delay of 40-60 seconds between delivery stages, and directing the following final mixing and feed 15 delivery operations: agitating of all batch raw materials for 8 to 12 minutes after delivery of the last raw material; and pumping the feed to outlet containers whereby 20 the discharge quantity is continuously monitored by reading mixing tank load cell output signals.

2. A production process as claimed in claim 1, wherein the stick water and yeast batch supply 25 tanks are glass-lined and have side-mounted impellers operated for continuous agitation during the process.

3. A production process as claimed in claims 1 or 2, wherein the stick water has an oil weight percentage of approximately 2% and a solids weight percentage of approximately 5%. 5

4. . A production process substantially as hereinbefore described, with reference to any illustrations and accompanying drawings.

5. Pig feed whenever produced by a process as claimed in any preceding claim.