IE44638B1 - Improved lipid containing feed supplement - Google Patents

Description

In one aspect this invention relates to a feed supplement for animals. In another aspect this invention relates to a process for producing a feed supplement which has a high lipid content but which is easy to produce, handle and store. In still another aspect, this invention relates to a feed supplement which contains a high quantity of lipid but which can be fed to ruminants in higher amounts than conventionally available lipid supplements.

One object of modern livestock feeding techniques is to increase the amount of lipids ingested by the animals. Meat, meat by-products, and milk all contain large amounts of fat and therefore increased lipid intake causes a proportional increase in production of these products. Currently, most of the lipid materials used to supplement stock and pet feed s are incorporated in a liquid form. Hot liquid lipids are sprayed on the other nutritional ingredients and allowed to coalesce for feeding. This method requires that the user install holding tanks, pumps and pipe work, and when the lipid materials are solid at ambient temperatures, heating equipment is required to fluidize the lipid so that it may be sprayed over the feed. Furthermore, feed treated in this manner cannot be stored for any appreciable amount of time because of its tendency to turn rancid, to become contaminated, and to attract insects.

Ruminants, such as cattle and sheep, present a special problem with regard to lipid supplemented feeds. The complex digestive system of the ruminant is a multigastric system v/ith a first stomach called a rumen wherein bacteria known as micro1-16 3 8 - 3 flora are present. The fermentation produced by ths presence of these microrlora in the rumen is an important part of the digestive process. High fat diets have been found to inhibit this rumen fermentation resulting in severe imbalance of gastric processes. As a result, feeding high concentrations of lipids resulted in a loss of appetite and in some cases causes the animals to become infirm.

Thus, high lipid containing feed supplements presently suffer from several disadvantages. Among these is the expanse and inconvenience that a user must incur if he wishes to produce his own high lipid feed supplement. Furthermore, lipid supplements now conventionally available and commonly used cannot be conveniently stored, handled or kept free from contamination. Additionally, when the feed supplement is to be fed to ruminants there is the added disadvantage that presently available supplements can only be used at levels of approximately 2 to 6 percent of the total feed because of the special gastric problems of ruminants discussed above.

According to the present invention there is provided a process for producing a lipid containing feed supplement comprising: a) forming an aqueous solution of protein? (b) admixing a lipid material with said aqueous solution to form an emulsion? (c) contacting the emulsion so formed with effective amount of a pH adjusting agent selected from the group consisting of physiologically acceptable acids and salts of polyvalent metals to cause gelatinization of said proteinaceous solution in the absence of added heat; and ,j 4 6 3 8 - 4 (d) drying the resulting emulsion to form a powder.

The improved lipid containing feed supplement according to the invention is relatively easy to handle and store and which contains lipid in a structure that will substantially retard oxidation and rancidity thereof. The feed supplement produced by previous lipid additions to the animals ration.

Lowering the pH of the emulsion to preferably approximately 6.0 or lower insures fche formation of a gel which lends itself to drying by common types of drying equipment such as various types of agricultural dryers, for example. The dried product is particulate which can be easily stored in bags, bins or stockpiles. The particulate feed supplement produced by this precess can contribute as much as about 15% of the total diet of a ruminant as lipid without any of the ill effects heretofore associated with high lipid diets. Certain types of medicants and vitamins may be added to the feed supplement during its production to enhance its dietary properties as required.

For example, the proteinaceous solution can be prepared in a stainless steel vertical tank fitted with a heavy duty stirrer. An amount of water preferably equal to about 60 to 70 weight percent of the final gelatinized emulsion is deposited in the tank and a proteinaceous material is admixed therein until thoroughly wetted. The proteinaceous material can, for example, be added in an amount approximately equal to 5 to 40% of the weight of the solution. It can be either of animal origin, for example, blood,casein, or vegetable origin such as, oilseed protein, e.g., soy beans or soy meal. Mixtures of the two or more types of protein sources may also be used. Once the proteinaceous material is thoroughly wetted an amount of solubilization agent sufficient to insure complete solution may be added to the mixing tank. Suitable solubilization agents include caustic materials 4 6 3 8 such as sodium hydroxide, calcium hydroxide and potassium hydroxide. In addition, it has been found that calcium oxide, sodium chloride, and calcium chloride are effective, However, the hydroxides are preferred and of these sodium hydroxide is the most preferred. The proteinaceous material will dissolve into aqueous solution in the presence of these solubilization agents without the addition of heat to the system. If the water is warmer, the solubilization will merely occur at a faster rate. The temperature of the protein solution must be at least at the melting point of the lipid when the lipid material is solid at ambient temperatures.

When a lipid material (melted if necessary) is added to this proteinaceous solution and stirred thoroughly, an oil-inwater emulsion is formed, the lipid material being the dispersed phase and consisting of globules generally in the range of from 1/2 micron to 50 microns in size and predominantly in the range of 1/2 to 10 microns. The proteinaceous solution forms the continuous phase of the emulsion. Any kind of lipid material may be used such as vegetable oils, fish oils, or animal fats for example.

If animal fat is used, it is melted by heating to a temperature in the range of from 40 to 50°C so that it turns liquid and may be easily dispersed within the preheated proteinaceous solution by mixing. In addition, any dietary lipid containing polyunsaturated fats may be used. The lipid can comprise from about 6 to about 25% by weight of the emulsion. The preparation of the emulsion should not take place at a temperature which will render the protein insoluble in the water. A suitable emulsion forming temperature for most protein is a temperature no higher than 55°C.

The emulsion described above this consists of finely divided particles of lipids suspended in a proteinaceous solution. 4 638 It has been found that by lowering the pH of this emulsion to an acid pH of 6.0 or below a gel can be produced. It is believed that the proteinaceous solution is gelatinized and thereby encapsulates the dispersed phase of the emulsion v/hich consists of finely divided particles of lipid. The degree of gelatinization which occurs can be controlled according to the amount by which the pH of the emulsion is lowered. As noted above, it has been found for example, that when the pH of the emulsion is lowered to an acrd pH value, of approximately 6.0 or below a gel will result. If the pH of the emulsion is not lowered to this value, a slack gel results which cannot be effectively dried by conventional agricultural drying equipment. It has been established that when the pH of the emulsion is lowered to a value of from 3.5 to 5.0 a firm gel results which can be dried using such conventional drying equipment.

As mentioned above, any physiologically acceptable acid could be used as a pH adjusting agent. Acids such as nitric acid, for example, which should not be used in the preparation of animal feed. Some examples of acceptable acids are phosphoric acid, hydrochloric acid, sulfuric acid, lactic acid, ligno sulphuric acid, and acetic acid. The preferred pH adjusting agent is 75 to S5% concentrated phosphoric acid. Alternatively, as mentioned above, pH adjusting agents such as salts of polyvalent metals, such as aluminum in the form of aluminum sulfate for instance, can also be employed. The amount of pH adjusting agent which is necessary to form the desired gel will vary according to the type of lipid material used. Generally, the higher the free fatty acid content of the lipid employed the more pH adjusting agent must be used to obtain the desired pH value. ' The gel which is obtained from contacting the above 4 6 3 3 described emulsion with a pH adjusting agent when utilizing proteins other than blood will contain from about 60 to 70 per cent of water (most of the water .initially present). With blood, some syneresis does occur to yield a free aqueous phase. However, in either case, the consistency of the gel is generally such that it will not adhere to a metallic substrate or container and therefore it is suitable for passing into common types of agricultural dryers. Prior to drying, the removal of free water by centrifuging, pressing and the like is desirable. Conventional types of agricultural dryers include rotary drum dryers, turn dryers, and flash or fluid bed dryers. The above described gel can be dried using any of these drying techniques. The moisture content of the gel is reduced by drying to not more than 14% by weight of the gel. If the dried feed supplement contains more than 12% by weight of water there will be a tendency to mold. Therefore, the gel is preferably dried until it contains 10 to 12% by weignt . ,-. o of water. Dryer temperatures xn ths range or trom 650 to 700 F. with outlet temperatures of from about 175 to 190OF are adequate to accomplish this result. Particle size of the feed supplement upon drying will be related to the amount of agitation which occurs during the drying of the gel. In a rotary drum dryer, for example, some attrition takes place within the rotating drum. Generally, the final particulate product has a range of particle sizes from very fine powder (-325 mesh—U.S. Std.) to up to about 10 mesh (U.S. Std.).

The powdered feed supplement can generally contain from 20 to 60% lipids by weight. Absorbent materials such as silicate, bentonite, alfalfa meal, oats, bran, and baggasse can be added if desired. When such absorbents are present the protein content of the feed supplement should be from 5 to 35% by weight thereof. In addition, various medicaments such as common types of anti,j 4.6 3 θ - 8 biotics and lipid soluble vitamins stay be added to the lipid before the emulsion is formed.

The high lipid feed supplement formed by the above described process can be used as a feed supplement for various types of animals including dogs, eats, and it may even be used as a form of fish food. For example, conventional dry food for dogs and cats comprises extruded kibbles, and there is a limitation on the maximum quantity of fat which can be processed through an extruder. Since it is often desirable to have a high .quotient of energy from fats or oils than can be processed through an extruder it is thus necessary for the manufacture of such dry foods to spray additional fats and oils onto the formed kibble. This application of additional fat or oil is often limited by the fact that tha fats and oils so sprayed onto the kibble will go into phase and migrate to the container wall which makes the product undesirable to some consumers. Other deleterious effects such as rancidity, odors are also inherent because of the accessibility of the oils to oxygen. In some formulations of canned pet foods, the addition of concentrated energy in the form of fats and oils is desirable, but again, there is commonly a limitation on the amount of such fats and oils which can be added insofar as fats and oils will again migrate, go into phase and rise to the top of the container which is objectionable to the manufactuer and customer for the reasons stated above. The microencapsulated fats and oils of the subject invention substantially prevent the above-mentioned deleterious features and allow greater quantities of fats and oils to be incorporated into both dry and canned pet food.

Furthermore, it should be noted that tallow fed to fish may result in liver abnormalities, however, fish oil incorporated as the lipid material of the feed supplement of the present - 9 invention may be employed effectively, The feed supplement of the present invention has a surprising advantage however, when used as a supplement for ruminant feeds. Normally, ruminants cannot bs fed a diet which contains more than 2 to S% fat content. Feeds containing greater fat contents apparently inhibit rumen function which seriously impairs the complex digestive system of ruminants. The novel feed supplement of the present invention has been used to increase the fat content of ruminant feedstuffs up to 12% without any deleterious effects which commonly accompany such a high fat diet. It is believed that these surprising results are obtained because the lipid content of the feed supplement is entrapped or encapsulated within the proteinaceous material of the feed supplement and therefore does not go into phase or form a layer of lipid and thus does not rise to the top of the rumen fluid but rather is passed on through the rumen to the abomasum and the small intestine. Thus, the majority of the lipid contained in the feed supplement is not released within the rumen and consequently the fermentation process carried on by the micro-flora of the rumen is not disturbed. Thus, by employing the process of the present invention a high lipid feed supplement with improved handling characteristics is produced which has the unexpected capability of allowing the fat content of a ruminant's diet to be increased to about 15% for example depending on the balance of the ruminant's ration.

The invention can be more easily understood from a study of the following examples which are included for illustration purposes only and are not intended to limit the scope of the invention. 4 6 3® -10 EXAMPLE- 1 A high lipid content feed supplement was produced according to the subject invention in the following manner. A 200 gallon stainless steel vertical tank fitted with a heavy duty stirrer with a shaft speed of approximately 34 rpm was filled with 450 pounds of water at approximately 65°C. With the heavy duty stirrer activated, ICO pounds or soy meal and 35 pounds of sunflower meal were mixed into the water until thoroughly Wetted.

A solubilisation agent, in the form of 5-1/2 pounds or caustic soda dissolved in 20 pounds of water, was added to the slurry and mixing, continued for approximately 10 minutes. Then, 90 pounds of tallow at 45°C·.was added and mixed for another 5 minutes. The mixture was then pumped to a 200 gallon stainless steel vertical holding tank fitted with a cone bottom fitted '5 with an outlet of about 2 inches in diameter. Prom the holding tank the mixture was pumped to a stone mill (Model 830 obtained from Moorehouse Industries, Fullerton, California) with the mill gap set at 0.008 inches. The discharge of the stone mill was ' . T . into a mixer and, when about half of the above mix has been dis20 charged into the mixer, 20 pounds of 75% phosphoric acid was added to the mixer with stirring. Stirring continued until a firm gel was formed. The gel'was then transferred to an agricultural dryer. (Heil Model S75—22B) which operated at an outlet temperature of between 180 and 190°F. The product was dried until its moisture content xvas approximately 10 to 14 percent. A small amount (approximately 2.5 pounds) of an absorbent in the form of calcium silicate (Miorocel E sold by Johns Manville) was added to the final product to improve the flow characteristics.

The product obtained from the dryer was a dark brown, odor30 -less powder. Particle size varied from very fine to aggregate particles about 1/4 inch in diameter. The resultant product was 'J d 8 3 8 - 11 easy to handle and could be placed in paper sacks without any apparent migration or leaching out of the lipid materials. The product contained approximately 33 percent by weight lipids and was suitable for mixing with common types of feed mixes.

EXAMPLE 2 A feed supplement prepared according to the procedures outlined in Example 1 was tested for its effect on the fat content in cows milk. Three feed mixes were prepared for use in the test, ώ first mix being the baseline mix containing none of the feed supplement of the present invention. The other two test mixes contain 10 percent and 20 percent by weight, respectively, cf a feed supplement prepared according to the procedures of Example 1, Table 1 indicates the make up of each of the three mixes.

Baseline Mix Barley—16 lbs. Alfalfa hay—24 lbs.

TABLE 1 Test Mix //1'—10% Barley—12 lbs.

Alfalfa hay 24 lbs.

Feed Supplement— lbs.

Test Mix # 2—20% Barley—8 lbs. Alfalfa hay—24 lbs Feed Supplement— lbs · Each of the three mixes was fed to the same cow under substantially the same conditions. The cow was fad each of the mixes separately for a period of 6 days each. Each day the total milk output of the cow was measured and the milk analyzed for fat content. The result of these procedures is tabulated in Table 2.

TABLE 2 Feed Daily Avg. Total lbs. Milk Daily Avg. Total lbs. Fat Baseline 51.2 1.74 Test Mix # 1 49.5 2.02 Test Mix ff Ϊ 50.3 2.14 As is shown by Table 2, the output of milk by the cow was only slightly affected by the addition of feed supplements while the fat content produced increased remarkably. For instance, when Mix ^1 containing 10% of the feed supplement of the subject invention was fed to the cow the fat content of the milk increased by 20% over the fat content found in milk produced while the cow was on the baseline feed. Mixture //2, containing 20% feed supplement, resulted in a 25% increase of fat content in the milk.

EXAMPLE 3 The procedure Of Example 2 -were followed with the exception that feed supplement content was raised to 30% by weight. Table shows the content of the test mix and baseline feeds and Table shows the results obtained: Baseline Mix TABLE 3 Test Mix # 3—30% Barley*-24 lbs. Barley—12 lbs.

Alfalfa hay—24 lbs. Alfalfa hay—24 lbs.

Feed Supplement—12 lbs .

Feed Baseline Text Mix#2 TABLE 4 Daily Avg. Total lbs. Milk 48.7 47.1 Daily Avg. Total lbs. Fat 1.640 2.078 As can be seen from Table 4 the use of Test Mix //2 which contained 30% by weight feed supplement resulted in a surprising increase of approximately 31% in the fat content of the milk produced.

Claims (19)

1. CLAIMS :1. A process for producing a lipid containing feed supplement comprising: a) forming an aqueous solution of protein; b) admixing a lipid material with said aqueous solution to form an emulsion; (c) contacting the emulsion so formed with effective amount of a pH adjusting agent selected from the group consisting of physiologically acceptable acids and salts of polyvalent metals to cause gelatinization of said proteinaceous solution in the absence cf added heat; and d) drying the resulting emulsion to form a powder.

2. A process according to claim 1, wherein said aqueous solution is prepared by admixing a proteinaceous material with an aqueous solution which contains an efr'active amount of a solubjllzation agent.

3. A process according to claim 2, wherein said solubilization agent is selected from sodium hydroxide, calcium hydroxide, calcium oxide, sodium chloride, and calcium chloride.

4. A process according to claim 1, 2, or 3, wherein said aqueous solution contains about 5 to about 40% by weight of said proteinaceous material.

5. A process according to any preceding claim, wherein said emulsion formed from said lipid and said aqueous solution contains from about 6 to about 25% by weight of lipid.

6. A process according to any preceding claim, wherein said admixing of said lipid material with said proteinaceous solution to form an emulsion is performed at a temperature at least above the melting point of/ the lipid. 4 4 6 3 8 - 14

7. A process according to any preceding claim, wherein the acid pH of the gelatinized emulsion is less than 6.0.

8. A process according to claim 7, wherein the acid pH of the gelatinized emulsion is from 3.5 to 5.0.

9. A process according to any preceding claim, wherein said drying lowers the moisture content of said high lipid feed supplement to less than 14 percent by weight.

10. A process according to claim 9 wherein said drying lowers the moisture content to a range of from 10 to 12% by weight. - ’

11. A process according to any preceding claim, wherein said pK adjusting agent is an acid selected from phosphoric acid, lactic acid, acetic acid, sulfuric acid and ligno sulfonic acid.

12. A process according to claim 11, wherein said pH adjusting agent is phosphoric acid.

13. A process according to any preceding claim, wherein the lipid content of the resulting particulate supplement is from 20 to 60 percent by weight, of the powder.

14. A process according to any preceding claim which further comprises separating excess water from the resultant, gel before drying said gel.

15. A precess according to any preceding claim, wherein said aqueous solution comprises blood.

16. A process according to any preceding claim, wherein said emulsion is prepared at a temperature no higher than 55°C.

17. A process according to any preceding claim, wherein said resultant feed supplement has a lipid content of from 20 to 60 percent by weight thereof.

18. A process for producing s lipid containing feed supplement substantially as hereinbefore described in any of tne Examples.

19. A lipid containing feed supplement whenever made by 5 the process of any preceding claim.