NZ232513A - Method and apparatus for delivering live anaerobic probiotic bacteria to animals - Google Patents

Description

if- 2325 1 3 Hriottty I , „ . i, 5C \ . _ citcCJ-. ' \-~Z-ZZU* ::::::: | r.t»«S: W'- . , • ;u0u««o. »» -Tjru...^ I P.O. ' No.: Date: NEW ZEALAND PATENTS ACT, 1953 %'»<■ COMPLETE SPECIFICATION METHOD AND APPARATUS FOR ADMINISTERING LIVE BACTERIA /' N, /? "A i \-.-p c/ . — '-o -V ""'EC.,/' ADDITIVES TO LIVESTOCK AND POULTRY \ r\ MICRO CHEMICAL^INC., incorporated in the State of Texas, United States of America, of 311 N. Arthur, Amarillo, Texas 79107., •-S United States of America v'-- hereby declare the invention for which I / we pray that a patent may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement:- (followed by page la) rr 232 5 1 3 1-t- METHOD AND APPARATUS FOR ADMINISTERING LIVE BACTERIA AS FEED ADDITIVES TO LIVESTOCK AND POULTRY 1.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to the administering of live, probiotic anaerobic bacteria to livestock. More particularly, it relates to a method and apparatus for preparing, containing and preserving the 10 viability of an aqueous suspension of said bacteria as a concentrated, homogeneous suspension under controlled-temperature conditions at a feedlot location until time for addition of a diluted portion thereof to animal feed, whereby said bacteria can be regularly 15 administered to large numbers of animals in an efficient manner. 2. General Discussion of the Background chemical additives to cattle and other livestock to 20 supplement feed rations, thereby providing a balanced diet, protecting the animals from disease, and stimulating growth. Such additive supplements, commonly termed microingredients, usually should be administered to each animal on a regular basis in carefully controlled dosages 25 to ensure optimal benefit. Individual dosages are typically small due to the high potency of microingredients. devised for accurately dispensing, at the feedlot, 30 separately stored livestock feed additive chemical concentrates into a volume of fluent carrier material, such as water, for dilution, dispersion, and suspension, and for transporting the resulting slurry into livestock drinking water or feed rations shortly before the time of 35 intended consumption. These methods and apparatuses are disclosed in U.S. Patent Nos. 3,437,075; 3,498,311; 3,670,923; 3,806,001; 3,822,056; and 4,733,971, the disclosures of which are incorporated herein by reference.

It has long been a common practice to administer A number of methods and apparatuses have been - 2 - n -» oi. *■ «8 232 5 1 Additive supplements can also include specific live microorganisms. For example, administration of certain live probiotic bacteria can help restore optimal intestinal flora in animals such as cattle, especially 5 after stressful situations such as transport to a feedlot. Gedek, B., "Probiotics in Animal Feeding--Effects on Performance and Animal Health," Feed Magazine. Nov., 1987. With regular administration, probiotic bacteria also increase nutrient absorption efficiency and help control 10 the proliferation of harmful microorganisms in the animals' digestive tracts that could otherwise cause disease conditions adversely affecting rates of animal development and weight gain. A bacterial species commonly administered to cattle for such purposes is Lactobacillus 15 acidophilus. an anaerobic, lactic acid producer.

Klaenhammer, T. R. (1982) "Microbiological Considerations in Selection and Preparation of Lactobacillus Strains for Use as Dietary Adjuncts," J. Dairy Sci. 65: 1339-1349. An example of such a product is "Cobactin," a lyophilized 20 L. acidophilus formulation from Biotechniques Laboratories, Inc., Redmond, Washington.

Anaerobic bacteria are adversely sensitive to environmental influences such as oxygen, moisture, temperature extremes, and many chemicals. Until recently, 25 the bacteria were mixed with dry, diluting filler material and other additive supplements as a premix. However, animal weight-gain results obtained with such bacteria-containing premixes were inconsistent because large numbers of bacteria died in the premix before 30 addition to feed due to improper formulation, packaging and storage of the premix. At least one manufacturer of bacterial supplements has partially overcome these problems by lyophilizing the bacteria in the absence of chemical microingredients and packaging the dry bacteria 35 in hermetically sealed packets under an inert, arid atmosphere such as dry nitrogen. These advances greatly extend the shelf-life of commercially packaged anaerobic bacterial formulations. However, even properly packaged 232513 anaerobic bacteria become labile due to contact with air and moisture the moment the package is opened. Therefore, ^ such packaging still does not solve the problem of maintaining the bacteria in a live state and delivering 5 them to large numbers of animals in proper dosages after the package is opened. Without some means of extending viability, anaerobic bacteria from an opened package must be properly diluted and presented to the animals within a very short time after opening the package, which is time 10 prohibitive and impractical in large feedlots. Hence, there is still a need for a method and apparatus for * preserving bacteria, after opening the package, in a ready-to-use viable condition at a known concentration that can be delivered at the correct dosages efficiently 15 on a regular basis to large numbers of animals.

There are several known methods used to administer bacteria from a dry concentrate to animals, but the existing methods have significant drawbacks. One known method is to rehydrate the dry bacteria in dilute 20 aqueous suspension and administer the suspension orally via drenching. However, drenching is so cumbersome and time-prohibitive that it is usually only performed during times of critical need, such as immediately after the animals arrive at the feedlot or when an animal is 25 obviously sick.

A second known method is to manually sprinkle dried bacteria onto animal feed in the feed bunks, which is time-prohibitive in large feedlots. Also, to attain more uniform distribution, appreciable predilution of the 30 concentrated bacteria with dry filler material is required, which causes appreciable loss of bacterial viability resulting from contact with concentrated substances. Furthermore, it is practically impossible via this method to ensure that each animal receives a correct 35 and consistent dose when many animals feed from the same bunk.

A third known method is to mix the dry bacteria with feed before distribution to the feed bunks. This 2325 13 method is undesirable because homogeneity of such a mixture is very difficult to attain and because large numbers of bacteria are killed by the time the mixture is presented to the animals.

Accordingly, there remains no known practical method or apparatus for accurately administering regular, small dosages of probiotic bacteria to livestock on a large scale, despite the need for such a method and apparatus.

Heretofore, the aforementioned methods and apparatuses for regularly administering chemical microingredients in small, accurate dosages to livestock on a large scale in a liquid carrier slurry through their feed rations have been thought to be inapplicable to live, 15 anaerobic bacteria of the class described because of the lack of any method or means for storing the bacterial additive in a form that would maintain the viability of the bacteria and yet be usable in such prior methods and apparatuses. More specifically, to be applicable to such 20 prior methods and apparatuses, the live bacteria would need to be stored for prolonged periods of time in dry particulate or liquid form in a known, constant concentration at a feedlot for immediate dispensing by weight or volume, on demand. As a result, despite general 25 knowledge of the benefits of regular administration of probiotics to certain livestock, feedlot operators have not done so because of inadequate methods and lack of a suitable apparatus.

Hence, there is a need for a method and apparatus 30 for: (a) preparing and storing at the feedlot a homogeneous volume of bacterial material, at known concentration and ready for on-demand use, where the bacteria are preserved in a viable state until immediately before presentation to the animals and in a form conducive 35 to accurate dispensing by weight or volume; and (b) feeding the bacteria in a live condition to large numbers of livestock on a regular basis such that each animal receives a correct dosage of live bacteria, preferably 232 5 13 mixed with its feed, and with other microingredients as required.

Accordingly, a primary object of the present invention is to provide a method and apparatus for 5 delivering a known dosage of desired live bacteria mixed with animal feed to large numbers of livestock for ingestion on a regular basis.

Another primary object is to provide a method and apparatus for preserving and storing at a feedlot location 10 a known concentration of a liquid suspension of desired bacteria in live form for prolonged periods in a condition for immediate, on-demand use for administration to animals.

Another primary object is to provide a method and 15 compact apparatus for preparing and storing a concentrated volume of aqueous liquid suspension of live, probiotic bacteria at known concentration at an animal feedlot location, and for preserving said bacteria in a viable condition at a known, stable concentration until time for 20 adding a known mass or volume thereof to animal feed.

Another primary object is to provide a method and apparatus as aforesaid for preparing and storing a concentrated volume of aqueous, liquid suspension of live probiotic bacteria and for preserving said bacteria in a 25 viable condition at a known, stable concentration until time for removing a known mass or volume thereof for further dilution and addition of other microingredients before adding to a known mass or volume of animal feed. Another primary object is to provide a method and 30 apparatus for delivering said concentrated bacterial liquid suspension to a gravimetric or volumetric measuring device to accurately dispense a preselected mass or volume, respectively, of the concentrated bacterial liquid suspension to a known mass or volume of aqueous liquid 35 containing other microingredient additives, which is subsequently added to a known mass of livestock feed ration just before the feed ration is presented to the animals for consumption. / 232513 Another primary object is to provide a method and apparatus for preparing and storing a concentrated volume of aqueous, liquid suspension of live probiotic bacteria and for preserving said bacteria in a viable condition at 5 a known, stable concentration until time for removing a known mass or volume thereof for further dilution and addition of other microingredients before therapeutically administering to animals via other methods such as drenching.

Another primary object is to provide a method and apparatus as aforesaid that adjust the temperature of the concentrated bacterial liquid suspension to within a preselected range for optimal bacterial survival in a viable condition at a known, stable concentration and 15 regulate said temperature within that range uniformly throughout the volume of concentrated bacterial liquid suspension.

Another primary object is to provide a method and apparatus that insulate the concentrated bacterial liquid 20 suspension contained within said apparatus from changes in ambient temperature.

Another primary object is to provide a method and apparatus as aforesaid that keep the concentrated bacterial liquid suspension contained therein uniform with 25 respect to concentration of bacteria. 232 5 I SUMMARY OF THE INVENTION The aforementioned objects are achieved by a storage and preservation method and apparatus for preparing and containing at the feedlot a volume of 5 concentrated bacterial liquid suspension in a known concentration and preserving the suspended live bacteria in a viable state under controlled conditions until time for adding a known mass or volume thereof to animal feed.

The bacteria are typically of a strain conferring a 10 probiotic benefit to the type and breed of livestock that will ingest the bacteria, and are administered in precise live dosages to the livestock for an increased rate of weight gain, enhanced resistance to disease, and other beneficial purposes. The concentrated liquid suspension 15 of bacteria is controllably delivered from the storage apparatus to a gravimetric or volumetric measuring device (such as that disclosed in my U.S. Patent No. 4,733,971) where the suspension is controllably dispensed, metered or weighed, and subsequently delivered at predetermined rates 20 or weights to and mixed homogeneously with a liquid aqueous carrier into which other dry particulate and liquid additive concentrates may also be delivered in predetermined quantities and concentrations. The resulting dilute suspension is then delivered into and 25 mixed with feed ration shortly before presentation to the animals for consumption.

The present invention makes possible for the first time the simultaneous administration of accurate dosages of live bacteria to large numbers of livestock 30 animals on a regular basis for probiotic, therapeutic, or other purposes. Heretofore, there has been no practical method or means to prepare at the feedlot a suspension of live bacteria prior to time of anticipated use and to maintain the viability of the bacteria while in a 3 5 ready-to-use state.

In a preferred embodiment as shown and described, the desired volume of concentrated bacterial liquid suspension is contained in a thermally insulated vessel. / 2325 A gravimetric scale or other weigh means monitors the combined weight of the vessel and its liquid contents, and ensures that the vessel is filled precisely with a preselected mass of aqueous carrier medium. A 5 refrigeration means cools the bacterial liquid suspension to within a desired range, and maintains the temperature thereof within that range. An electronically controlled mixing means agitates the bacterial liquid suspension contained in the vessel to facilitate dispersion of 10 bacteria in the aqueous carrier medium and to maintain temperature uniformity. The apparatus includes an electronically controlled means for recirculating the bacterial liquid suspension to maintain temperature and concentration homogeneity of the concentrated bacterial 15 liquid suspension contained in the vessel and plumbing connected thereto. The vessel is covered to prevent environmental contamination of the contents and to restrict air circulation. The cover has a smaller hinged access door to allow filling of the vessel with aqueous 20 carrier medium and for adding a fresh supply of dry bacteria. Finally, the apparatus also includes a means for controllably dispensing a volume of concentrated bacterial liquid suspension from the vessel to a separate weighing or volumetric measuring means for further 25 controlled dilution of the concentrated bacterial liquid suspension and optional intermixing with other additives in a predetermined formulation before addition of the same to animal feed.

Volumetric or gravimetric dispensing of 30 concentrated bacterial liquid suspension from the vessel to a hopper or slurry mixing vessel in the separate metering or weighing system is controlled by a central processing unit. The central processing unit is also electronically interfaced with the separate weighing 35 system according to U.S. Patent 4,733,971, which is incorporated herein by reference. / \ 2325 BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the present invention will become more apparent from the following detailed description of a presently preferred 5 embodiment, which proceeds with reference to the accompanying drawings wherein: Fig. 1 is a side elevational view diagrammatically depicting the major components of an apparatus in accordance with the present invention. 10 Fig. 2 is a block diagram schematic illustrating use of the present invention together with a separate weighing system (such as disclosed in U.S. Patent No. 4,733,971) that controllably dispenses microingredient additives, both liquid and dry, into a mixing tank filled 15 with a known volume of water, before mixing the resulting slurry with a known amount of animal feed.

Fig. 3 is a block diagram schematic illustrating use of the present invention with a mixing tank filled with a known volume of water, where a known mass or volume 20 of concentrated bacterial liquid suspension is added to a known mass or volume of water before being added to and mixed with animal feed or before being separately administered to animals as a liquid, such as by drenching. 2 5 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is a novel method and apparatus for preparing and storing a concentrated liquid suspension of anaerobic bacteria for use as a probiotic that can be accurately administered in regular, small 30 dosages to livestock on a large scale at a feedlot. In the preferred embodiments, the bacteria are suspended in an aqueous carrier medium having minimal nutrient content to prevent growth or multiplication of the bacteria while still sustaining viability of the organisms. The 35 temperature of the suspension is maintained sufficiently low to inhibit anabolic or catabolic processes that degrade viability (generally, between 36°F to 50°F). The suspension is kept homogeneous with respect to 232 5 13 concentration of bacteria and uniform in temperature. The volume of stored bacterial liquid suspension is kept small to avoid the necessity for large, bulky equipment while containing an adequate supply of ready-to-use bacteria.

For example, a 400-gram packet of dried bacteria, when added to only ten pounds of water, yields a quantity of bacteria in concentrated suspension sufficient to dose 10,000 head of cattle at a single feeding. Also, the apparatus is locatable at a feedlot where feed batches can 10 be formulated and prepared immediately before distribution to the animals. Finally, the apparatus of the present invention is usable in conjunction with existing apparatuses that perform an accurate second dilution step just before adding the bacteria to the feed. For example, 15 in U.S. Patent No. 4,733,971, I describe an apparatus wherewith known masses or volumes of chemical additives in liquid or dry form are suspended in a known mass or volume of carrier liquid such as water before addition to animal feed. Addition of a known mass of concentrated bacterial 2 0 suspension from the apparatus of the present invention to the volume of suspension prepared by the apparatus of my aforesaid patent would achieve sufficient secondary dilution.

General Assembly 25 With reference to the drawings, Fig. 1 illustrates an apparatus shown generally at 10 for preparing, storing, and preserving a volume of known concentration of a concentrated, aqueous suspension of live bacteria to be used as a daily probiotic supplement 30 for livestock. Apparatus 10 comprises a number of major components, including a liquid-holding means or vessel 20 with access means 90; an agitating means including an electrically driven mixer 80, electrically driven pump 40, and electrically actuated valve 30; a temperature control 35 means including a thermostat 70, refrigeration means 50, and insulation means 110; a weighing means 60; a liquid-level detection means 170; and a delivery means including an electrically driven pump 40, electrically / 2325 13 \ actuated valves 3 0 and 12 0, and control means 100.

Control means 100 includes a central processing unit (CPU) 140 and cycle timer 130.

Frame and Subframe 5 Referring further to Figure 1, apparatus 10 comprises basically two frame structures: subframe 150 and frame 160, together with components supported thereby. Subframe 150 is situated beneath frame 160 and supports pump 40 and weighing means 60, the latter comprising 10 generally gravimetric scale 61 which measures the weight of objects resting on its loading pan 62. Frame 160 rests directly on loading pan 62 and supports generally refrigeration means 50, vessel 20, valve 30, exterior side panels 151, top cover 152, access means 90, mixer 80, 15 thermostat 70, liquid-level detection means 170, insulation 110, cycle timer 130, and motor speed controller 84.

Liquid-Holding Vessel and Surrounding Components Vessel 20 is typically cylindrical with its lower 20 end 21 shaped like an inverted cone to facilitate complete draining of liquid contained therein. Vessel 20 is typically constructed of stainless steel. However, it may be made from any other suitable material that does not corrode, contribute toxic substances to contacting aqueous 25 liquids, or deteriorate from prolonged contact with aqueous solutions of the types anticipated during use, and that has acceptable thermal and mechanical characteristics. The volume of vessel 20 is preferably within the range of three to five gallons, but other 30 capacities are also possible and are within the scope of the present invention.

Vessel 20 is mounted vertically inside and at the uppermost portion of frame 160, with the conical portion 21 pointed downward. The apex of conical portion 21 has a 35 round opening 22 to which is connected pipe elbow 23. The upper end of vessel 20 is covered with horizontal panel or cover 152 which has opening 153 externally enclosed by access means 90. Helically wrapped around the exterior of / 232513 \ \ vessel 20 are evaporator coils 51 which comprise part of refrigeration means 50. In the preferred embodiment, the evaporator coils are in intimate contact with the exterior wall of vessel 20, such as by brazing or other suitable 5 process. Insulation means 110, which may be liquid or suitable solid material, surrounds vessel 20 and evaporator coils 51. Exterior side panels 151, attached to appropriate members of frame 160, together with cover 152 and access means 90, complete the encapsulation of 10 vessel 20.

Access means 90 comprises vertical panels 91, hinged lid 93, and handle 92. Hinged lid 93 normally remains in the closed position. Hinged lid 93 may be opened (94) to gain access to the interior of vessel 20 15 for adding a fresh supply of aqueous carrier liquid or of dried bacteria from a commercial packet 95, or for cleaning or inspecting the interior or contents 23 of vessel 20.

Mixer Mixer 80 comprises electrically driven motor 81 mounted vertically atop cover 152, shaft 82 rigidly attached axially to the rotor of motor 81, mixing blade 83 rigidly attached to the distal end of shaft 82, and electronic motor speed control 84 electrically connected 25 via cable 86 to motor 81. Shaft 82 is sufficiently long to ensure that mixing blade 83 is submerged whenever a threshold volume of liquid is contained in vessel 20.

Electronic motor speed controller 84 includes controls 87, 88 and 89 for adjusting various present 30 angular velocities of mixing blade 83, as driven by motor 81, and manual control switch 85 for turning motor 81 on to rotate mixing blade 83 continuously at a particular preset angular velocity, as required. Motor speed controller 84 is also electrically interconnected with 35 refrigeration means 50 (and thermostat means 70) via cable 55. / 2325 1 3 Weigh Means Weighing means 60 is comprised generally of an electronic or mechanical gravimetric scale 61 mounted to the upper surface of subframe 150. (An electronic scale 5 employing an electronic load cell for mass sensing may be less sensitive to environmental interferences such as liquid spills, dust, and mechanical vibration and shock, as well as more reliable, than mechanical beam-type or other scale means. However, either type will suffice.) 10 Weighing means 60 may include a means by which the operator can input various gravimetric data such as "zeroing" the tare weight of that portion of apparatus 10 supported by scale 61, and setpoints corresponding to an "empty" or "full" status of vessel 20. 15 Temperature Control Means The temperature control means is comprised generally of refrigeration means 50, thermostat means 70, and insulating means 110.

Refrigeration means 50 is of conventional design. 20 It is mounted to frame 160, beneath vessel 20.

Refrigeration means 50 consists generally of a compressor 52, condensor 53, receiver tank 54, and other necessary components. It includes evaporator coils 51 wrapped helically around the exterior of vessel 20. Evaporator 25 coils 51 are filled with a suitable refrigerant and are appropriately hydraulically connected to compressor 52, condensor 53, receiver tank 54, and ether components of refrigeration means 50.

Insulation means 110 in the preferred embodiment 30 is comprised of any material suitable for use as a thermal insulator of vessel 20 and its contents 23, such as fibrous or foam material, when appropriately applied circumferentially around vessel 20 and evaporator coils 51.

In a second embodiment (not shown), insulation means 110 comprises a sealed, fluid-filled space between the exterior wall of vessel 20 and a second, wall-forming sheet of similar material conforming to the outside wall <) o «i: -j o > J it) of vessel 20 and enclosing evaporator coils 51. In such a second embodiment, the space between the outside wall of vessel 20 and the inside wall of the conforming sheet is filled with a thermally absorptive liquid material such as 5 propylene glycol. The evaporator coils in this second embodiment may be either in intimate contact with the outside wall of vessel 20 or suspended freely within said fluid-filled space. The outside wall of the conforming sheet may optionally be blanketed with fibrous or foam 10 material as in the preferred embodiment for additional thermal insulation.

Thermostat means 70, mounted to cover 152, comprises a sealed probe 71 which extends vertically downward through an opening in cover 152 into vessel 20 15 such that the distal end of probe 71 is immersed in the liquid contents 23 of vessel 20 at an appropriate depth.

Inside sealed probe 71 is a temperature-sensing element (not shov Electrical switch 73 with appropriate supporting electronic circuitry is electrically connected to 20 temperature-sensing element via cable 75, and to refrigeration means 50 via cable 74. Electrical switch 73 is mounted to frame 160.

Liquid Level Detection Means Liquid level detection means 17 0, mounted to 25 cover 152, comprises a probe 171 extending vertically downward through an opening in cover 152 into vessel 20 such that the distal end of probe 171 is immersed in the liquid contents 23 of vessel 20 at an appropriate depth.

—' Inside probe 171 is any suitable switching device (not shown) that actuates when in contact with a contiguous volume of liquid, such as a conductivity cell, float switch, tilt switch, photo-optical device, or other suitable device that will trigger an electrical signal whenever the volume of liquid 23 in vessel 20 drops below a certain minimum 35 level. Liquid level detection means 170 is electrically connected to alarm 174 via cable 173. Alarm 174 can be audio, visual, or other suitable alarm means, or a '\ ^ ° • combination thereof. * 12FEB1992") ^ 2325 1 Hydraulic Interconnection Apparatus 10 is hydraulically plumbed as follows: Elbow 2 3 is connected to opening 22 on the bottom of vessel 20. The "IN" port 31 of electrically actuated, 5 two-way, normally closed valve 3 0 is connected to the distal opening of elbow 23. (Valve 30 is preferably a solenoid valve, but other types of electrically actuated valves can also be used.) The "OUT" port 32 of valve 30 is connected via flexible hydraulic conduit 33 to the "IN" 10 port 41 of electrically actuated pump 40 mounted to subframe 150. The "OUT" port 42 of pump 40 is connected via flexible hydraulic conduit 43 to the "IN" port 121 of electrically actuated three-way valve 120. (Valve 120 is preferably a solenoid valve, but other types of 15 electrically actuated valves can also be used.) Valve 120 is mounted to a separate weighing or metering system 200 (such as described in my U.S. Patent No. 4,733,971). To the normally closed "OUT" port 123 of valve 120 is attached an outlet nozzle 124 through which a dispensed 20 volume of concentrated bacterial liquid suspension passes prior to further dilution, possible admixture with other microchemical additives, and admixture with animal feed. Flexible hydraulic conduit 125 is connected to normally open bypass port 122 of valve 12 0. The distal end of 25 flexible hydraulic conduit 125 is connected to outlet nozzle 127, which passes vertically through cover 152 at opening 126.

Control Means Cycle timer 130 is any suitable 30 electrically-driven clock or timer-switch mounted to frame 160. It is electrically connected to pump 40 via cable 132, to valve 30 via cable 133, and to electronic motor speed controller 84 via cable 131. Cycle timer 130 comprises a sufficient number and type of relays or 35 similar switching means actuated by an internal programmable clock-timer to turn on and off valve 30, pump 4 0 and motor 81. £325 Central processing unit (CPU) 140 is any suitable programmable microcomputer with keyboard and display, typically mounted separately from apparatus 10. CPU 14 0 is electrically connected to pump 40 via pump driven 5 circuit 142 and cable 141 and to valve 120 via valve drive circuit 144 and cable 143. Pump drive circuit 142 and valve drive circuit 144 are suitable electronic switching devices that, upon receiving a logic signal from CPU 140, deliver sufficient electrical current at proper voltage to 10 operate pump 40 and valve 120, respectively. CPU 140 is typically employed when apparatus 10 is used together with separate weighing and metering means 2 00, such as that in U.S. Patent No. 4,733,971, where CPU 140 is the same device as shown as item 20. When apparatus 10 is used 15 alone, functions performed by CPU 140 can alternatively be performed by a cycle timer or process controller.

However, CPU 140 can also be used in the latter instance for monitoring mass measurements determined by scale 61, allowing the operator to "key in" a desired mass of 20 bacterial liquid suspension to be dispensed from vessel 20 (represented by a loss of mass as measured by scale 61 during dispensation) and allowing CPU 140 to automatically control the actuation of valves and pump until precisely the desired mass is dispensed. 2 5 Operation Vessel 20 contains the volume of concentrated bacterial liquid suspension 23 during preparation and storage thereof. In one embodiment, filling vessel 20 is accomplished by opening hinged door 93 and pouring in the 30 desired mass of aqueous carrier medium, such as water, as measured by gravimetric scale 61. The contents of a commercial package 95 of lyophilized bacteria of the desired strain are added to the liquid in vessel 20.

After filling, hinged door 93 is kept in the closed 35 position. For example, a 400-gram packet of lyophilized bacteria, such as "Cobactin" from Biotechniques Laboratories, Inc., Redmond, Washington, when added to ten 2325 13 gallons of water, yields 10,000 single-animal doses for cattle.

Alternatively, vessel 20 may be controllably filled with aqueous carrier medium such as water through 5 appropriate valves and plumbing connected to a supply of said medium and entering vessel 20 at a convenient location, such as through cover 152 or from the bottom (not shown).

In either embodiment above, gravimetric scale 61 10 informs the operator when vessel 20 has been filled v/ith the correct mass of liquid, such as a fresh supply of aqueous carrier medium before a known mass of bacteria is added thereto. The "tare" weight is the mass of all components of apparatus 10, including "empty" vessel 20, that are mounted to frame 160 which rests on loading pan 62. An "empty" vessel 20 may simply have a subthreshold low volume of liquid remaining in it. The "full" weight is equal to the "tare" weight plus the desired mass of liquid contained in vessel 20 and plumbing connected 2 0 thereto.

Refrigeration means 50 chills the liquid contents of vessel 2 0 to a temperature preselected by the operator and sensed by thermostat 70 (generally between 36 and 50°F). Thermostat 70 provides the electrical thermal 25 feedback signal via switch 73 and other appropriate electronic circuitry to refrigeration means 50, energizing compressor 52 whenever the temperature of the liquid contained in vessel 20 rises above an operator-preset upper temperature limit, and de-energizing compressor 52 3 0 whenever said temperature drops below an operator-preset lower temperature limit. Operator-setting of upper and lower temperature limits may be accomplished via manually adjusting thermostat setpoints at switch 73.

Mixer 80 periodically agitates the concentrated 35 bacterial liquid suspension during storage in vessel 20 to ensure temperature uniformity thereof and to ensure bacterial concentration uniformity. Mixer 80 is also run whenever a fresh batch of concentrated bacterial 232 5 13 suspension is being prepared and whenever a portion of the contained volume of concentration bacterial liquid suspension is being dispensed from vessel 20.

The angular velocity of the rotor of mixer motor 5 81 is governed by motor speed controller 84. Motor 81 runs at a fast speed, as manually preset by control 87, whenever the operator is adding dried bacteria 95 to the liquid contained in vessel 20, to facilitate dispersion. (The operator turns manual control switch 85 on to 10 activate the fast mixing speed. Switch 85 is kept in the off position during all other times.) Motor 81 periodically runs at a medium speed as manually preset by control 88, during storage of concentrated bacterial liquid suspension in vessel 20, to ensure temperature and 15 bacterial concentration uniformity throughout the volume of liquid. A typical period is one minute running every fifteen minutes, as triggered by cycle timer 130 electrically connected to motor speed controller 84 via cable 131. Motor 81 also runs at a medium speed whenever 20 liquid is being dispensed from vessel 20. Motor 81 runs at a slow speed, as manually preset by control 89, whenever refrigeration means 50 is running, to prevent localized freezing of the concentrated bacterial liquid suspension against the walls of vessel 20. 25 Valves 30 and 120 and pump 40, in combination, drain vessel 20 and recirculate the concentrated bacterial liquid suspension 23 to ensure uniformity of temperature a concentration thereof. Valve 30 and pump 40 are energized simultaneously, allowing flow of liquid from vessel means 30 20 through flexible hydraulic conduits 33 and 43. When valve 30 and pump 40 are energized, but valve 120 is de-energized, liquid from vessel 20 is pumped from opening 22 through valve 30, conduit 33, pump 40, conduit 43, valve 120 to bypass port 122, through flexible hydraulic 35 conduit 125, and exiting outlet nozzle 127 back into vessel 20, thereby effecting recirculation of the liquid contents of vessel 20. / 23£ 5 13 When valves 30 and 120 and pump 40 are simultaneously energized, liquid from vessel 20 is pumped from opening 22, through valve 30, conduit 33, pump 40, conduit 43, valve 120 to "OUT" port 123, and exiting 5 nozzle 124, thereby effecting dispensation of concentrated bacterial liquid suspension from vessel 20. Because valve 120 is utilized for both dispensing and recirculation functions, as described above, recirculation and dispensation cannot occur simultaneously.

Switched electrical power from cycle timer 130 simultaneously energizes pump 4 0 and valve 3 0 for recirculating the contents of vessel 20. The operator presets the durations of energization and non-energization on cycle timer 130, such as a one-minute energization 15 every fifteen minutes.

Simultaneous energization of valves 30 and 120, and of pump 40, for dispensing a portion of the concentrated bacterial liquid suspension from vessel 20 is effected by an electrical signal from CPU 140. If the 20 present apparatus is used in conjunction with a separate weighing and/or metering system 200 (as in U.S. Patent 4,733,971), CPU 140 is also electrically interfaced with the scale means 217 (Fig. 1), and possibly other components of system 200, to achieve an integrated system 25 for feed formulation, preparation and delivery.

Alternatively, if the apparatus of the present invention is used alone, simultaneous energization of valves 30 and 120 and pump 40 may be effected by a simpler process controller than a microprocessor, such as a relay or 30 analogous switching device.

Fig. 2 Embodiment In one embodiment, as shown partially in Fig. 1 and schematically in Fig. 2, concentrated bacterial liquid suspension 23 from apparatus 10 exits nozzle 124 upon 35 simultaneous energization of pump 40 and valves 30 and 120 into a weighing or volumetric metering hopper 207 of separate weighing system 200. Hopper 207 is typically partitioned into separate chambers, one for each of the 23251 other microingredients controllably dispensed therein from microingredient containers 201, 202 and 203 through valves 204, 205 and 206, respectively. Alternatively, multiple hoppers can be used. Hopper 207 can either be rotatably 5 tipped to empty its contents (not shown), or the contents can be dumped through a bottom door or drained through valves 208 (one valve 208 for each chamber of hopper 207). Hopper 207 empties into mix tank 211 which has been prefilled with a known volume or mass of carrier water 10 through valve 216, thereby creating a dilute microingredient suspension of known concentration. The dilute suspension is agitated with mixer 215 to achieve a uniform mixture, then drained using pump 212 into feed truck 213 which has been prefilled with a known mass or 15 volume of animal feed from bin 209 through valve 210. As the dilute microingredient suspension is added to the feed in truck 213, the feed is tumbled or otherwise agitated to ensure uniform distribution of suspension throughout the feed. Afterward, the feed is delivered to feed bunks 214 2 0 for presentation to the animals.

In the Fig. 2 embodiment, the concentrated liquid suspension of live bacteria simply becomes one of several microingredients available for formulation with other microingredients, upon demand, and selected by a feed 25 truck operator through a remote control terminal (not shown) of CPU 140, adjacent to feed truck 213. That is, the system of Fig. 2 operates essentially as described in U.S. Patent No. 4,733,971.

Fig. 3 Embodiment 30 In a second embodiment, as shown schematically in Fig. 3, concentrated bacterial liquid suspension 23 from apparatus 10, on demand, exits nozzle 124 directly into mix tank 211 prefilled with a known volume or mass of water through valve 216. In this second embodiment, no 35 separate weighing or volumetric metering system is used. Instead, gravimetric scale 61 is used to monitor the dispensation of liquid from vessel 20 (as net weight loss). The addition of a known mass of concentrated / 2325 \ bacterial suspension 23 to a known mass or volume of water in mix tank 211 creates a dilute suspension of bacteria at a known, proper dilution. The dilute suspension is agitated with mixer 215 to achieve a uniform mixture, then 5 drained using pump 212 into feed truck 213 which has been prefilled with a known mass or volume of animal feed from bin 209 through valve 210. As the dilute bacterial suspension is added to the feed in truck 213, the feed is tumbled or otherwise agitated to ensure uniform 10 distribution of suspension throughout the feed.

Afterward, the feed is delivered to feed bunks 214 for presentation to the animals.

The second embodiment shown in Fig. 3 can also be used to prepare a dilute bacterial suspension for purposes 15 other than adding to animal feed. For example, the dilute suspension in mix tank 211 can be conducted to a drenching apparatus for direct oral administration of therapeutic dosages to animals.

In either of the above first and second 20 embodiments, the entire process, from dispensing concentrated bacterial liquid suspension from apparatus 10 to presentation to the animals for consumption, need consume only a few minutes, which is a sufficiently short amount of time that no significant bacterial death occurs. 25 The concentration and volume of dilute bacterial suspension contained in mix tank 211 can be carefully tailored to ensure that the entire amount of feed to which the dilute bacterial suspension is added is uniformly coated with bacteria without wasting excess liquid. 30 Further, the concentration of bacteria in the dilute suspension contained in mix tank 211 can be carefully tailored to such variables as the total mass or volume of feed, average feed granule size, particle density, and surface area, and amount of feed normally consumed by each 35 animal at a single feeding, to optimize the bacterial dosage each animal receives at a feeding.

Both the system of Fig. 2 and that of Fig. 3 are capable of delivering small, accurate dosages of live 111 5 1 bacteria in liquid suspension on a regular basis and on demand to large numbers of livestock, such as cattle in commercial feedlots, when the concentrated suspension is first diluted with an aqueous liquid carrier and then 5 intermixed with the animals' feed rations.

Having illustrated and described the principles of the invention in a principal and several alternative embodiments, it should be apparent to those skilled in the art that the invention can be modified in arrangement and 10 detail without departing from such principles. I claim all modifications coming within the spirit and scope of the following claims. >-». ' ) • J ^ t. y

Claims (83)

WHAT WE CLAIM IS:

1. A method of delivering temperature-sensitive probiotic anaerobic live bacteria into animals for treatment comprising: 5 depositing the live bacteria in a carrier liquid, the liquid being in a temperature range that will maintain the bacteria alive without substantially promoting bacteria growth or multiplication, maintaining the liquid in said temperature range 10 and suspending the bacteria in the liquid, while maintaining the bacteria in suspension in the liquid and maintaining the liquid in said temperature range, delivering the liquid with the live bacteria in suspension therein in a measured amount to the animals for 15 consumption.

2. The method of claim 1 wherein the live bacteria are a lactic acid-producing bacterial species.

3. The method of claim 1 wherein the temperature of the suspension is maintained in a range 20 from substantially 32°F to substantially 50°F.

4. The method of claim 1 including preventing the suspension from freezing by at least intermittently agitating it.

5. The method of claim 1 wherein the bacteria 25 deposited into the liquid carrier are transferred from a substantially oxygen-free environment.

6. The method of claim 1 wherein the measured amount of the suspension is deposited in a feed ration for the animals just before the feed ration is presented to 3 0 the animals for consumption.

7. The method of claim 1 wherein the measured amount of the suspension is delivered with a predetermined amount of feed ration to the animals.

8. The method of claim 1 wherein the measured 35 amount of the suspension is diluted in a known volume of liquid carrier before delivery of the suspension to the animals.

9. The method of claim 8 wherein the liquid carrier is mixed with a feed ration for the animals.

10. The method of claim 7 including intermixing the measured amount of the suspension with the predetermined amount of the feed ration to disperse the suspension throughout the feed ration.

11. The method of claim 7 wherein the measured amount is obtained by weighing.

12. The method of claim 7 wherein the measured amount is obtained by metering on a volumetric basis.

13. The method of claim 7 wherein the measured amount is obtained by a combination of weighing and volumetric metering.

14. The method of claim 1 wherein the bacteria deposited into the liquid are lyophilized and in a dry particulate medium.

15. The method of claim 1 including intermittently cooling the liquid to maintain the desired temperature range.

16. The method of claim 1 wherein a measured amount of bacteria is deposited and suspended in a known amount of liquid to create a liquid bacterial suspension of predetermined concentration, and establishing and maintaining a substantially uniform dispersion of the bacteria in the liquid suspension by at least intermittently agitating.

17. The method of claim 3 including: depositing the bacteria into the liquid carrier from a substantially oxygen-free environment, and agitating the suspension at least intermittently to prevent it from freezing while cooling the suspension and to maintain a substantially uniform dispersion of bacteria within the suspension, and delivering a measured amount of the suspension with a predetermined quantity of feed ration to the animals for consumption.

18. A method of enhancing weight gain in \, ^livestock and poultry comprising feeding an animal a - 25 <•) J. i j measured quantity of a liquid suspension containing a predetermined concentration of live lactic acid-producing bacteria wherein the temperature of the suspension is controlled while maintaining the bacteria in a substantially uniform dispersion within the suspension until a short time before delivering the suspenion to the animal, and then by diluting the suspension in a known quantity of carrier liquid and delivering the diluted suspension to the animal.

19. The method of claim 18 including maintaining the suspension at a temperature of substantially 50°F or below and preventing the suspension from freezing before feeding.

20. The method of claim 18 wherein the feeding 10 is accomplished by mixing the diluted suspension into an animal feed ration.

21. The method of claim 18 wherein the feeding is accomplished by applying the diluted suspension to an animal feed ration at an animal feed station. 15

22. The method of claim 18 wherein the feeding is accomplished by drenching the animal with the diluted suspension.

23. A method of improving the absorption of nutrients in the intestines of animals comprising 2 0 dispersing a predetermined amount of live anaerobic probiotic bacteria in a known quantity of liquid to form a liquid bacterial suspension of known concentration, controlling the temperature of the suspension within a temperature range that inhibits growth and multiplication 25 of the live bacteria, while preventing the suspension from freezing, maintaining a substantially uniform dispersion of the bacteria within the suspension, and administering the suspension on demand and in measured amounts to the animals. 30

24. The method of claim 23 wherein the suspension is diluted in a liquid carrier before being administered to the animals.

25. The method of claim 23 wherein the bacterial • " species is a lactic acid-producing type. 35

26. An apparatus for preserving and delivering 12FFk live anaerobic probiotic bacteria for use in livestock feeding applications, the apparatus comprising: / - 26 - \ \ liquid holding means for holding a supply of carrier liquid and dry particulate live bacteria-containing medium in the carrier liquid, temperature control means for controlling and 5 maintaining the temperature of the carrier liquid in the holding means within a predetermined temperature range, suspension means for creating a substantially uniform dispersion of the bacteria medium in the liquid carrier to provide a liquid bacterial suspension, 10 and delivery means for delivering amounts of the liquid suspension to a point of use.

27. The apparatus of claim 26 wherein the point of use is a dispensing means for dispensing measured amounts of microingredients into a livestock feed ration. 15

28. The apparatus of claim 27 wherein the dispensing means includes means for determining the measured amounts by weight.

29. The apparatus of claim 27 wherein the dispensing means includes means for determining the 2 0 measured amounts by volume.

30. The apparatus of claim 26 wherein the suspension means includes agitating means for agitating the carrier liquid.

31. The apparatus of claim 30 wherein the 25 agitating means includes a mixing means in the liquid holding means.

32. The apparatus of claim 30 wherein the agitating means includes pumping means comprising a portion of said delivery means. 30 33. The apparatus of claim 26 wherein the delivery means includes pumping means for pumping the liquid suspension from the liquid holding means and valving means selectively operable in a first position to deliver a portion of the liquid suspension from the pumping means 35 to the point of use and selectively operable in a second position to recirculate the liquid suspension from the ^ pumping means back to the liquid holding means. 12 FEB 1992

X \ - 27 -

34. The apparatus of claim 33 wherein the delivery means includes second valving means for controlling the flow of the liquid suspension from an outlet of the liquid holding means to the pumping means. 5

35. The apparatus of claim 26 wherein the temperature control means includes insulating means in surrounding relationship to said liquid holding means.

36. The apparatus of claim 26 wherein the temperature control means includes cooling means for 10 cooling the temperature of the liquid suspension in the liquid holding means.

37. The apparatus of claim 36 wherein the cooling means comprises refrigeration means.

38. The apparatus of claim 3 6 wherein the 15 temperature control means includes thermostatic means operable with said cooling means for controlling the temperature of the liquid suspension.

39. The apparatus of claim 26 wherein the liquid holding means is a liquid holding tank for retaining the 20 liquid suspension, the tank having a closed top cover and a closeable infeed opening for delivering dry bacteria into the holding tank.

40. The apparatus according to claim 39 wherein the holding tank has a liquid outlet opening and valving 25 means for controlling the flow of liquid from the outlet opening.

41. The apparatus of claim 40 wherein the suspension means comprises a mixing means within the tank.

42. The apparatus of claim 41 wherein the 3 0 temperature control means includes thermostatic means within the tank.

43. The apparatus of claim 2 6 wherein the delivery means includes means for delivering measured amounts of the liquid suspension to the point of use. 35 44. The apparatus of claim 43 wherein the . delivery means includes liquid conduit connecting an <4 x\\ outlet of the liquid holding means to a liquid inlet of / the liquid holding means for enabling recirculation of a 171 /

A o r 12 FEB1992 ■'/ v\ - 28 - ^' / i t) , i V f 12 FEB S-?-' liquid suspension from the outlet to the inlet, pumping means in the liquid conduit for effecting the recirculation, and valving means in the conduit means operable in a first position for delivering liquid 5 suspension to the point of use and operable in a second position for recirculating the liquid suspension from the outlet through the pumping means to the liquid inlet of the holding means.

45. The apparatus of claim 44 including control 10 means for controlling the recirculation and delivery of the suspension including means for controlling the amount of suspension delivered to the point of use.

46. The apparatus of claim 45 wherein the temperature control means includes cooling means operable 15 intermittently for reducing the temperature of the liquid suspension within the liquid holding means to maintain the temperature of the suspension within the temperature range, and control means for operating the suspension means during recirculation of the liquid suspension and 20 for operating the suspension means intermittently during operation of the cooling means.

47. The apparatus of claim 46 wherein the control means controls the operation of the cooling means and the recirculation means such that recirculation does 25 not occur during a cooling cycle.

48. The apparatus of claim 45 wherein the control means includes timing means for controlling the duration of a recirculation cycle of the suspension.

49. The apparatus of claim 48 wherein the 30 control means includes means for operating the suspension means intermittently during a recirculation cycle.

50. The apparatus of claim 26 wherein said delivery means comprises: dispensing means for dispensing the suspension, 35 receiving tank for receiving a liquid carrier, the suspension dispersed by the dispensing means, and optionally other microingredient feed additives, • - <;, - 29 - mixing means in the receiving tank for forming a liquid slurry of the liquid carrier, suspension and other microingredients therein, slurry delivery means for transporting the slurry 5 from the receiving tank means into a feed ration, and measuring means operable with the dispensing means for dispensing a measured amount of the suspension for deposit in the receiving tank.

51. The apparatus of claim 50 wherein the 10 measuring means comprises means for weighing the amount of suspension dispensed and discontinuing operation of the suspension means when a predetermined weight of suspension is dispensed.

52. The apparatus of claim 51 wherein the means 15 for weighing includes a scale hopper into which the suspension is dispensed, the scale hopper including means for discharging the predetermined weight of the suspension into the receiving tank.

53. The apparatus of claim 26 wherein the 20 delivery means includes means for diluting measured amounts of the liquid suspension in a liquid carrier before delivering the suspension to the point of use.

54. The apparatus of claim 53 wherein the delivery means includes measuring means for measuring the 25 amount of liquid suspension delivered to the dilution means.

55. a method of delivering temperature-sensitive probiotic bacteria in a live condition into non-human animals as a means of increasing nutrient absorption efficiency and controlling the 5 proliferation of harmful microorganisms in the digestive tracts of such animals, such method comprising: depositing the bacteria in an aqueous liquid, suspending the bacteria in the liquid to form a concentrated aqueous suspension of the bacteria, . 10 controlling the temperature of the concentrated suspension to maintain said temperature within a range V £ that will maintain the bacteria in a viable condition v 12 FEB 1992° ' without promoting bacteria growth or multiplication, 6 O // - 30 - while providing a substantially uniform 15 suspension of the bacteria therein, delivering on demand at least a portion of the concentrated suspension into an aqueous carrier liquid to form a dilute suspension of the bacteria, delivering the dilute suspension into a feed 20 ration for the animals, dispersing the dilute suspension in the feed ration, and delivering the feed ration containing the dispersed dilute suspension therein to the animals for consumption.

56. A method according to claim 55 wherein the 25 bacteria are deposited in the aqueous liquid from an arid and substantially oxygen-free storage environment.

57. The method of claim 56 wherein the bacteria in the storage environment are lyophilized.

58. The method of claim 55 wherein the bacteria 30 are of the species Lactobacillus acidophilus.

59. A method according to claim 55 wherein the temperature of the concentrated aqueous suspension is controlled by at least intermittently refrigerating the suspension. 35

60. The method of claim 59 including the step of at least intermittently agitating the suspension when refrigerating the suspension to prevent the suspension from freezing.

61. The method of claim 55 wherein the aqueous liquid is agitated while depositing the bacteria therein.

62. The method of claim 55 wherein a known amount of bacteria is deposited in a known amount of 5 aqueous liquid to form a concentrated aqueous suspension of bacteria having a known concentration.

63. The method of claim 55 wherein a measured amount of the concentrated aqueous suspension of bacteria is delivered to a known amount of aqueous carrier liquid ^LQ and the resulting dilute aqueous suspension of bacteria is °^delivered to a known amount of the animals' feed. *A\ \ fms - 31 -

64. The method of claim 63 wherein the measured amount is obtained by weighing.

65. The method of claim 55 wherein the steps of 15 delivering the concentrated aqueous suspension of bacteria to the aqueous carrier liquid, delivering the resulting dilute aqueous suspension of the bacteria to the animals' feed ration, and dispersing the dilute suspension in the feed ration are performed just before the feed ration is 2 0 presented to the animals.

66. The method of claim 55 wherein the dilute aqueous suspension of bacteria is substantially uniformly dispersed throughout the feed ration before the feed is presented to the animals for consumption. 25

67. The method of claim 55 wherein probiotic bacteria are added to the animals' feed just before each feeding of the animals.

68. A method of dosing a population of animals en masse with live probiotic bacteria as a means of 30 enhancing the rate of weight gain of the population, such method comprising: depositing a known amount of the bacteria in a measured amount of aqueous liquid, suspending the bacteria in the liquid to form a 35 concentrated aqueous suspension of the bacteria having a known concentration, controlling the temperature of the concentrated aqueous suspension within a non-freezing temperature range that inhibits growth and multiplication of the bacteria without killing the bacteria, while providing a substantially uniform suspension of the bacteria therein, delivering on demand a 5 known amount of the concentrated suspension into an aqueous carrier liquid to form a dilute aqueous suspension of the bacteria having a known concentration, mixing the dilute suspension with a known amount of animal feed before presentation of the feed to the 10 animals for ingestion. - £ u 1 12FEBD9;: - 32 fJ> O (.), J i

69. The method of claim 68 wherein probiotic bacteria are added to the feed ration of the population of animals with a frequency suitable for achieving the desired rate of weight gain of the population. 15

70. The method of claim 69 wherein the population of animals is dosed with bacteria at each feeding of the population.

71. The method of claim 68 wherein the aqueous carrier liquid also contains other microingredient feed 2 0 additives.

72. The method of claim 68 wherein the bacteria are of the species Lactobacillus acidophilus.

73. A method of maintaining probiotic bacteria at an animal feedlot in a ready-to-administer condition 25 for administration en masse to a large population of animals at the feedlot, the method comprising: depositing the bacteria in dry form in an aqueous liquid, suspending the bacteria in the liquid to form a 3 0 concentrated aqueous suspension of the bacteria, controlling the temperature of the concentrated suspension within a non-freezing temperature range that inhibits growth and multiplication of the bacteria in the liquid without killing the bacteria. 3 5

74. The method of claim 73 wherein the bacteria deposited in the aqueous liquid are lyophilized.

75. The method of claim 73 wherein a known amount of dried bacteria is deposited and suspended in a known amount of aqueous liquid, thereby forming a suspension of the bacteria having a known concentration.

76. The method of claim 73 wherein the temperature of the suspension is controlled by at least 5 intermittently refrigerating the suspension.

77. The method of claim 76 including the step of agitating the suspension when refrigerating the suspension to prevent freezing the suspension. v, ^ & N r o ^ V ^ == 4^ C'> \ 12 FFR1QQ? ^7 - 33 - 9 O <"; r- - •- ' J i) i ,)

78. A method as defined in claim 1 of delivering temperature-sensitive probiotic anaerobic live bacteria into animals for treatment substantially as herein described with reference to any example thereof and with or without reference to the accompanying drawings.

79. A method as defined in claim 23 of improving the absorption of nutrients in the intestines of animals substantially as herein described with reference to any example thereof and with or without reference to the accompanying drawings.

80. An apparatus as defined in claim 26 for preserving and delivering live anaerobic probiotic bacteria for use in livestock feeding applications substantially as herein described with reference to any example thereof and with or without reference to the accompanying drawings.

81. A method as defined in claim 55 of delivering temperature-sensitive probiotic bacteria in a live condition into non-human animals ■ as a means of increasing nutrient absorption efficiency and controlling the proliferation of harmful microorganisms in the digestive tracts of such animals substantially as herein described with reference to any example thereof and with or without reference to the accompanying drawings.

82. A method as defined in claim 68 of dosing a population of animals en masse with live probiotic bacteria as a means of enhancing the rate of weight gain of the population substantially as herein described with reference to any example thereof and with or without reference to the accompanying drawings.

83. A method as defined in claim 73 of maintaining probiotic bacteria at an animal feedlot in a ready-to-administer condition for administration en masse to a large population of animals at the feedlot substantially as herein described with reference to any example thereof and with or without reference to the accompanying drawings. r. fr,y.! ^7ifr. • V li+fi/Thc-i- authorised Agent j. f-MfiK & 90N r L-" V i«2 p E n r ^s. r. | 8/992 ^7