Patent Description:
In the animal industry it is common to find pelleted feed. Pelletization is a transformation of powder feed into small granules having all the required nutrients for an animal. Typically, production from the raw materials through pelletization accounts for <NUM> - <NUM>% of the cost of making animal feeds. Finding a procedure or modification to decrease the cost of production without reducing feed quality has been one of the most important inquiries in the animal industry. Several studies indicate that pelleting improves feed conversion by as much as <NUM>%. This improvement in performance is attributed to decreases in feed wastage, ingredient segregation, and energy expenditures while eating (<NPL>.

Durable pellets reduce waste, reduce segregation, improve palatability and allow larger meals to be eaten in less time. Chicks given mash spent <NUM>% of a <NUM> hour day eating vs. <NUM>% for pellet-fed chicks (<NPL>). The process of pelletization requires a conditioning step, which involves steam to gelatinize the starch in the diet and to produce better binding, thereby increasing the durability of the pellets. Starch gelatinization is the process in which water in the form of steam is diffused into the starch granule, causing swelling (<NPL>). As the gelatinized starch cools it forms a gel, which acts as an adhesive, causing particle binding (<NPL>). The addition of high amounts of moisture also lowers the onset temperature required for starch gelatinization to occur. Gelatinized starch has generally been thought to improve enzymatic access to glucosidic linkages and consequently improve digestibility (<NPL>).

Feed pellets are damaged during loading, unloading, storage, conveying and transferring to feeders. The handling and transport of the feed often results in increased fines and broken pellets and, in extreme cases, reduces the total percentage of pellets that reach the feeders. It is thought that for every <NUM>% increase in fines, there is a loss of one point of feed conversion, which then requires more feed eaten to produce the same amount of meat. The most common measurements used to assess pellet quality are the pellet durability index (PDI) and the modified pellet durability index (MPDI). PDI is determined by the percentage of intact or partial pellets remaining after they have been in a tumbling-spinning box for <NUM> minutes. The MPDI is similar to PDI but five <NUM>-mm hex nuts are added to the pre-tumbled pellets to simulate handling and transportation of feed. According to the present invention, percent fines is improved at least <NUM>% compared to a control sample treated with water, preferably at least <NUM>% or <NUM>%.

During conditioning, steam adds up to <NUM>% moisture to feed. Each percent of moisture added to the feed through steam raises the mash temperature about <NUM>, which improves the conditioning process by optimizing pellet mill operation and pellet durability (<NPL>) but this moisture is lost when the pellet is cooled down.

Several studies have shown that the addition of water on top of the moisture added during the conditioning process can improve pelletization (<NPL>; <NPL>). Motitz et al and Hott et al reported an increase in PDI and a decrease in energy usage by the addition of <NUM> to <NUM>% moisture to a corn-soybean based diet at the mixer (<NPL>;.

Moisture addition at the mixer was shown to increase pellet quality and decrease pellet mill energy consumption. Moisture addition was also found to reduce the temperature difference (ΔT) between the conditioned mash and the hot pellets, which indicates a decrease in die wear.

Moisture added cold to feed in a mixer becomes bound in the various heat-related reactions, such as starch gelatinization resulting in an increased PDI. Also this moisture is not as easily removed from pellets as moisture added in conditioning. However, the extra moisture is able to migrate to the pellet surface, which can result in a significant molding hazard. The use of a surfactant in moisture additives facilitates the absorption of water into the mash feed, thereby reducing the molding hazard.

Moisture addition raises a couple of concerns, which are the relation between high moisture and mold growth, and nutrition dilution (<NPL>). Examples of fungi commonly found in stored grains are from the Aspergillus, Penicillium, and Fusarium genera, e.g. A. parasiticus, F. tricinctum and P. citrinum, (<NPL>). Mold spore growth and germination often elicit feed spoilage and the production of mycotoxins, both of which are detrimental to poultry production. found that the process of pelleting conventional poultry diets reduces mold counts, while the addition of a mold inhibitor further reduces these counts (<NPL>).

Commercial mold inhibitors are composed of one or more organic acids. These are primarily propionic, benzoic, butyric, acetic, and formic acid. Organic acids have been a major additive for reducing the incidence of food borne infections. The mechanism by which small chain fatty acids exert antimicrobial activity is that undissociated (RCOOH = non-ionized) acids are lipid-permeable and so can cross the microbial cell wall, then dissociate in the more alkaline interior of the microorganism (RCOOH-> RCOO- + H+) making the cytoplasm unstable for survival. This release of hydrogen ion disrupts cytoplasmic function and inhibits growth (<NPL>). The use of organic acids, especially formic and propionic is well documented in the art.

The application of propionic acid and other organic acids as feed preservatives has been well documented (<NPL>). Propionic acid is a more potent mold inhibitor than acetic, valeric, butyric, lactic or benzoic acid. Propionic acid has an effective dose between <NUM> and <NUM> wt. % contrary to the other organic acids that require more than <NUM> wt. Preservation of high moisture corn was obtained when treated with <NUM>% of a mixture containing <NUM> wt. % propionic acid and <NUM> wt. % acetic acid. This product was fed to weanling pigs without causing any detrimental effect on performance. The addition of <NUM>, <NUM>, <NUM>, <NUM> and <NUM> wt. % acetic acid to water did not affect performance or intestinal microbial counts in broiler chickens (<NPL>).

Several patents disclose the use of organic acids as antimicrobials but do not suggest any other benefits. <CIT> teaches an antimicrobial acidic formulation based on an organic acid and a surfactant for the treatment of food and food contact surfaces. This composition is stabilized with propylene glycol, an antifoaming agent and a salt. The acids used include acetic acid but not butyric acid. It also includes an alkyl sulfate surfactant but not an ethoxylated castor oil. <CIT> discloses a mold inhibitor comprising a mixture of two buffered organic acids, a surfactant and an essential oil, together being less corrosive than a single, unbuffered organic acid. <CIT> discloses a method for inhibiting the growth of pathogens in pelleted feed that increases the efficiency of the pelleting process without introducing bad odors owning to the presence of the ammonium salt of butyric acid.

Feed and feed ingredients are vectors of pathogenic bacteria in animals which can carry over to humans. Food borne illness problems due to Campylobacter spp. , Shigella spp. , Listeria monocytogenes, Yersenia enterolitica, Salmonella spp. coli infections are prevalent in many countries. CDC statistics suggest that <NUM> million people become sick each year due to consumption of undercooked meat, eggs, shellfish, unpasteurized dairy products and unwashed vegetables. Food-producing animals are the major reservoir of non-typhi serotypes of Salmonella enterica, which cause an estimated <NUM> million illnesses, <NUM>,<NUM> hospitalizations and <NUM> deaths each year in the United States. Salmonella, a facultative intracellular pathogen, is capable of infesting humans and animals resulting in infection. After ingestion, Salmonella can inhabit and penetrate the intestine causing a systemic infection (<NPL>). The majority of the salmonellosis present in humans has been traced to the consumption of eggs (<NPL>). Factors present in eggs help maintain lower Salmonella levels in freshly laid eggs (<NUM>% incidence) even though eggs from the oviduct of the same hen show higher Salmonella levels (<NUM>% incidence); these factors may include antibodies, antibacterial enzymes and iron-sequestering and bacterial protease-inhibiting proteins in yolk and albumen (<NPL>). Pelletization at high temperature and high-pressure conditions reduces the number not only of Salmonella but also other bacteria. The problem with pelletization is that there is no protection against microbial recontamination of feed before animal consumption, e.g. at bagging, transport, feeders.

Many products have been developed for the preservation of water and feed for animal uses. Examples of water additives are ammonium quaternary products, chlorite-based products, chlorination, chlorine dioxide and acid compounds (acetic, sorbic, ascorbic, citric, and formic acid). Methods for preservation of feed include heat treatment, organic acids, formaldehyde, essential oils and irradiation. The elimination of Salmonella with organic acids requires high levels of treatment, which implies high cost to the animal industry. Formaldehyde is thought to be a cancer-causing chemical, even though a link has not been demonstrated. Irradiation of feed is not cost-effective and not consumer-friendly. Sodium percarbonate is a powerful oxidizer that is used as an antimicrobial in feed at a level of <NUM>-<NUM>% of the diet.

Organic acids have been a major additive to reduce the incidence of food borne infections. The use of small-, medium- and long-chain fatty acids, e.g. formic, propionic, butyric, lactic, citric, malic, and others, are well known.

Ethoxylated castor oil emulsifier is produced by the reaction of castor oil with ethylene oxide. Ethoxylated castor oil emulsifiers are of various chain lengths, depending on the quantity of ethylene oxide used during synthesis. The molar ratio can vary from <NUM> molecule of castor oil to <NUM> - <NUM> molecules of ethylene oxide, producing an ethoxylated castor oil emulsifier named PEG-x (polyethylene glycol) castor oil emulsifier, where x is the number of ethylene oxide moieties (<NPL>). These emulsifiers have been widely used to solubilize water-insoluble drugs for human and animal treatments. They are nonvolatile, stable compounds, which do not hydrolyze or deteriorate on storage. Castor oil is obtained from the seeds of Ricinus communis and consists primarily of the triglycerides of ricinoleic, isoricinoleic, stearic and dihydroxystearic acids. Castor oil is <NUM>% ricinoleic acid (<NUM>-Hydroxyoleic acid), a nontoxic, biodegradable and renewable resource.

Several PCT applications have been filed on uses for ethoxylated castor oil surfactant. <CIT> relates to a surfactant-water emulsion added to animal feed before, or after, heat treatment. The emulsion helps maintain or reduce water lost during heat treatment. The emulsion consists of <NUM> to <NUM> parts water and <NUM> to <NUM> parts surfactant. <CIT> teaches the surfactant can facilitate dispersion of molasses. <CIT> discloses the use of ethoxylated castor oil in animal feed to improve the nutrient value of feed. <CIT> adds ethoxylated castor oil to conventional dry animal feed to improve the availability of nutritious substances, increase animal growth and decrease mortality. These four patents mention the addition of ethoxylated castor oil surfactant, preferably as an emulsion, to improve digestibility of hydrophobic substances in animal feeds but do not show how best to use them in the production process to decrease energy consumption and to prevent mold and bacterial growth in feed.

<CIT> discloses a solution to be sprayed on cereal meals for use in fodder, said solution comprising ethoxylated castor oil, propylene glycol and propionic acid. The solution is sprayed on the meals essentially to reduce their dusting capacity.

The invention relates to a stock solution and to a method for making pelleted animal feed and is set out in the appended set of claims.

An object of the invention is to provide a chemical composition that improves the pelleting process, including where an extrusion process is employed, of animal feed and that has anti-microbial activity.

Another object is to provide a method for making pelleted animal feed, comprising:.

Also described herein is a pelleted animal feed made by a process comprising: preparing a composition containing.

Benefits of the invention include:
Percent fines is improved at least <NUM>% compared to a control sample treated with water, preferably at least <NUM>% or <NUM>%.

Energy consumption is improved at least <NUM>% compared to a control sample treated with water, preferably at least <NUM>% or <NUM>%.

Pellet moisture is improved at least <NUM>% compared to a control sample treated with water, preferably at least <NUM>% or <NUM>%.

The treated feed has a bacterial load which is less than <NUM>,<NUM> cfu/g, preferably less than <NUM>,<NUM> cfu/g.

The treated feed has a mold load which is less than <NUM>,<NUM> cfu/g, preferably less than <NUM>,<NUM> cfu/g.

"Weight percent" of a component is based on the total weight of the formulation or composition in which the component is included.

"Organic acid" includes formic, acetic, propionic, butyric and other C<NUM> to C<NUM> fatty acids, or mono-, di-, or triglycerides of C<NUM> to C<NUM> organic fatty acids.

"Antimicrobial terpene" can include allyl disulfide, citral, pinene, nerol, geraniol, carvacrol, eugenol, carvone, anethole, camphor, menthol, limonene, farnesol, carotene, thymol, bomeol, myrcene, terpenene, linalool, or mixtures thereof. More specifically, the terpenes may comprise allyl disulfide, thymol, citral, eugenol, limonene, carvacrol, and carvone, or mixtures thereof. The terpene component may include other terpenes with anti-microbial properties.

The term "effective amount" of a compound means an amount capable of performing the function or having the property for which the effective amount is expressed, such as a non-toxic but sufficient amount to provide the desired level of pelletizing, milling or anti-microbial benefits. Thus an effective amount may be determined by one of ordinary skill in the art using only routine experimentation.

When pelletizing feed, steam is injected into the mash then the mass is pelleted. In extruded feed, steam is injected into the mash under pressure then the mass is pelleted. Extruded feed is less dense than mash feed.

Formulations vary not only in the concentrations of the major components, e.g., the organic acids, but also in the type of terpenes, surfactant(s) and water concentration. This invention can be modified by adding or deleting the terpene, type of organic acid, and type of surfactant.

The terms "synergistic effect" or "synergy" mean improved palletizing or preservative effects when the ingredients are added as a mixture compared to the individual components.

In general, the stock solution of the invention has a composition that contains:.

The composition of the present invention may also contain an effective amount of organic acids having <NUM> to <NUM> carbons.

The antimicrobial terpenes, plant extracts or essential oils containing terpenes can be used in the compositions of this invention as well as the more purified terpenes. Terpenes are readily available commercially or can be produced by methods known in the art, such as solvent extraction or steam extraction/distillation or chemical synthesis.

The surfactant is non-ionic including ethoxylated castor oil surfactants with <NUM> to <NUM> ethylene molecules distributed normally around a mean of <NUM> to <NUM>.

The composition of the stock solution contains <NUM> - <NUM> wt. % organic acids; exemplary acids include <NUM> to <NUM>% by weight acetic acid, <NUM> to <NUM>% by weight propionic acid, and <NUM> to <NUM>% by weight butyric acid. The composition comprises up to <NUM>% by weight antimicrobial terpenes or essential oils, and <NUM> to <NUM>% by weight surfactant. The stock composition may comprise <NUM> to <NUM>% water.

The stock composition of components a), b) and c) is diluted with water to form a heat-treating composition which is a <NUM> to <NUM> wt. % aqueous mixture, preferably a <NUM> to <NUM> wt. This aqueous mixture is applied to the non-pelleted feed in amounts of <NUM> to <NUM> wt. % based on the total feed, preferably <NUM> to <NUM> wt%.

The acids of component a) may be buffered or unbuffered. The buffer may be calcium hydroxide, ammonium hydroxide or sodium hydroxide.

The heat-treating composition may be applied to the animal feed in an amount of <NUM> to <NUM> wt. % based on the weight of the starting animal feed, preferably <NUM> to <NUM> wt.

In general, component a) is <NUM> - <NUM> wt. %, component b) is <NUM> - <NUM> wt. %, component c) is preferably about <NUM> - <NUM> wt%, based on the weight of said composition.

Component b) may contain a second surfactant that is a non-ionic surfactant. When a second surfactant is present it is preferably a non-ionic surfactant selected from polysorbates and polyoxyethylenes.

Component c) preferably contains terpenes selected from the group consisting of allyl disulfide, thymol, citral, eugenol, carvacrol, limonene or carvone, or mixtures thereof.

The present invention is effective against fungi. Examples of these infective agents are Aspergillus fumigatus, Rhizoctonia solani, Penicillum spp. and others.

The present invention is effective against bacteria. Examples of these infective agents include E. coli, Salmonella spp. , Clostridia spp. , Campylobacter spp. , Shigella spp. , Brachyspira spp. , Listeria spp. , Arcobacter spp. , and others.

The method of the present invention maintains moisture level in the pelletized feed higher than in an untreated feed or conventional pelletizing methods.

The aqueous mixture of the present invention is applied to the raw material before entering the mixer. The aqueous mixture may be applied to the unmixed raw materials in the mixer or applied during the mixing of the raw ingredients and may be applied during the wet mixing cycle.

The mixture of the present invention is applied by a spray nozzle.

The aqueous mixture is applied so as to provide a uniform and homogeneous distribution of the mixture throughout the feed.

Various patents and publications are referenced throughout this specification.

The surface tensions of various organic acids and different formulations of the present invention were determined. Solutions were diluted to <NUM>% in water and tested using a Fisher Surface Tensiomat Model <NUM>. It was observed that formulation <NUM> with unbuffered acids and polysorbate-<NUM> resulted in lowered surface tension as shown in Table <NUM>.

Polysorbate-<NUM> is allowed only for use in milk replacers and not for feed application. In the European Union ethoxylated castor oil surfactant is allowed for use in all animals. In order to determine a suitable surfactant to replace polysorbate-<NUM>, the surface tensions of different PEG ethoxylated castor oil surfactants were tested in <NUM>% solutions.

The two best formulations from Example <NUM> were prepared using polysorbate-<NUM> or castor oil PEG-<NUM>. The surface tension of <NUM>% solutions of each formulation in water was determined.

Different formulations of the present invention were developed and tested for their effectiveness against mold growth in a mold plug study. Chemicals were added to potato dextrose agar (half-strength) in individual agar plates and allowed to solidify for <NUM> hours. <NUM> or <NUM> diameter agar plugs were aseptically obtained from <NUM>-day cultures of A. parasiticus, F. tricinctum or P. citrinum and placed on the center of petri plates containing agar with and without chemical addition. Plates were incubated at <NUM> and growth areas of the cultures were measured daily for up to <NUM> days. Formulations used are shown in Table <NUM>. Mold growth results are shown in <FIG>.

The objective of this study was to determine the efficacy of the present invention in decreasing the growth of Salmonella. The study consisted of the following treatments: Control, <NUM> % Formaldehyde (F) at <NUM>%, <NUM>%, <NUM>%, <NUM>% concentrations and the present invention (T) at <NUM>%, <NUM>%, <NUM>%, and <NUM>% concentrations. The test products were added to sterile deionized water to provide appropriate solutions. <NUM> ul of a nutrient broth containing a culture of Salmonella typhimurium (ATTC <NUM>) was added to each dilution tube. After addition, tubes were vortexed and allowed to stand at room temperature. At <NUM> and <NUM> hours after addition of the inoculum, <NUM> ul of the solution was plated on Standard Methods Agar (triplicate). Plates were incubated at <NUM>± <NUM> for <NUM> hrs prior to enumeration. The present invention at a concentration of <NUM>% was as effective in reducing Salmonella growth as the same concentration of Formaldehyde. The results are shown in <FIG> and <FIG>.

Study <NUM>: A study was conducted in a commercial-scale feed mill. The aim of the study was to show improvements in conditioning, energy reduction, mill throughput, reduction in shrinkage, quality improvements and to illustrate cost savings. The trial was conducted using a new pelleting machine. The diet used was # <NUM> Duck Feed. The treatment solution was sprayed into a six-ton single shaft ribbon mixer and was applied through <NUM> atomizing nozzles. The level of inclusion in the treated feed was <NUM> wt. % application of a <NUM> wt. % solution of the present invention in water.

Study <NUM>: A second study was conducted in a commercial-scale feed mill. The aim was to show improvements in conditioning, energy reduction, mill throughput, reduction in shrinkage, quality improvements and to illustrate cost savings. Two types of pig feed were used for the study. The level of inclusion in the treated feed was <NUM> wt. % of a <NUM>% solution of the present invention in water. One percent water was added to the control group.

Study <NUM>: A third study was conducted in a commercial-scale feed mill. The aim was to show improvements in conditioning, energy reduction, mill throughput, reduction in shrinkage, quality improvements and cost savings. A <NUM> Sa Broiler Grower diet was used. The level of inclusion in the treated feed was <NUM> wt. % of a <NUM>% solution of the present invention in water. One percent water was added to the control group.

Study <NUM>: Trials were run at a pilot feed plant. The aim of these trials was to assess the moisture retention of the invention compared to water and simultaneously compare milling parameters such as conditioning temperatures (°C), energy consumption (kWh/ton) and pellet quality (expressed as a % fines). Three different types of feed were used, broiler, pig and dairy diets. To the control diets, <NUM> wt. % water was added at the conditioner, and for the treated feed <NUM> wt. % of a <NUM> wt. % solution of the present invention in water was added at the mixer. All parameters measured were improved by the use of the invention as shown in tables <NUM>-<NUM>.

A palatability study was conducted to test for the effect of feeding diets untreated or treated with the present invention on palatability of feed. Two hundred male broiler chickens were weighed in groups and allotted to <NUM> treatments. Each treatment consisted of <NUM> repetitions of <NUM> chicks each. The treatments are described in the following table:.

The diets consisted of commercial corn-soybean diets prepared as suggested above and fed for <NUM> days. Control diet was fed to all chickens for the first week. Chickens were weighed at <NUM> week of age and sorted by weight into respective treatments. The feed was tested for the presence of organic acids and for the suggested dose of heat-treating solution.

Starting at the second week of age, chickens were offered untreated and treated feed at the same time. Two feeders, one at each side of each cage, were marked based on treatment. Initial feed weight was taken as well as daily weights. The feeders were switched daily. This study determined any difference in feed intake when comparing treated and untreated feed.

Pen chick weights were measured weekly for three weeks. Feed conversion and feed intake was calculated for the same time periods as the body weights.

Palatability was assessed as Intake Ratio (IR): <MAT> whereas A= test feed, C= control feed.

There were no differences in body weight gain or weekly feed intake. During the pretreatment period (first week of age) feed intake and body weight gain were similar for all treatments. At the start of the second week, chickens preferred to eat the treated feed independent of the treatment level and this was observed during the third week of age also. Based on the Intake Ratio (IR), chickens preferred the treated feed.

Claim 1:
A stock solution comprising:
(a) <NUM> - <NUM> wt%. of an organic acid selected from the group consisting of acetic, propionic, butyric and mixtures thereof,
(b) <NUM> - <NUM> wt.% of ethoxylated castor oil surfactant having an HLB from <NUM> to <NUM> and a molar ratio of <NUM> molecule of castor oil to <NUM> - <NUM> molecules of ethylene oxide, wherein the ethoxylated castor oil surfactant has <NUM> to <NUM> ethylene oxide molecules distributed normally around a mean of <NUM> to <NUM>,
(c) antimicrobial terpenes or essential oils, wherein the antimicrobial terpenes or essential oils are present in an amount of up to <NUM> % by weight.