WO1995031112A1

WO1995031112A1 - Slow-release non-protein nitrogen source for ruminant feed

Info

Publication number: WO1995031112A1
Application number: PCT/US1995/007044
Authority: WO
Inventors: Wayland Holladay
Original assignee: Magic Makers, Inc.
Priority date: 1994-05-17
Filing date: 1995-05-17
Publication date: 1995-11-23
Also published as: AU2816595A

Abstract

A feed supplement comprising a compound formed by reacting urea and calcium chloride in an aqueous solution provides non-protein nitrogen to ruminants. The supplement provides a slow release of ammonia to enhance utilization and reduce ammonia toxicity.

Description

Slow-Release Non-Protein Nitrogen

Source for Ruminant Feed

BACKGROUND AND SUMMARY OF THE INVENTION

This application claims priority from U.S. application 08/243,281, filed 05/17/94.

The invention relates to feeding beef cattle and other ruminants, and more particularly to non-protein nitrogen feed supplements for ruminants.

Ruminants have evolved to the extent that their ruminal environment fosters a dense population of microorganisms in the forepart of the digestive tract. This allows these animals to obtain energy from the ligno-cellulose complexes that are poorly digested by non-ruminants. In addition, the ruminal microorganisms can utilize NPN compounds (i.e. non-protein nitrogen) to synthesize protein, which can be converted by the host into meat, milk, and fiber for human usage. The non-ruminant, lacking appropriate fermentation capacity, must be provided dietary protein of higher quality (from "Urea and Other Nonprotein Nitrogen Compounds in Animal Nutrition", published by the National Academy of Sciences, 1976). It has been known since 1879 that ruminants could utilize non-protein nitrogen (NPN) and convert it to protein. Recognition of this unique capability opened up possibilities of using non-protein nitrogen sources to provide supplemental protein in ruminant feed rations. Further studies into the mechanisms of NPN usage in the ruminant stomach show that these non- protein nitrogen sources are first hydrolysed to ammonia in the rumen solution, and the ammonia is eventually converted to protein by the action of microbial enzymes. Other microbial enzymes convert available carbohydrates into volatile fatty acids and keto acids. Microbial activity then combines the ammonia and keto acids into amino acids, which in turn are utilized to make microbial protein. When this microbial protein is carried into the abomasum and small intestines, it is broken down to form free amino acids, which can then be utilized by the host animal to form body tissue for growth. Although non-protein nitrogen is, of course, not itself protein, it is referred to in the art as a protein source (because it is eventually converted to protein), and will be referred to in that manner in this application.

Normally, the supply of protein is an expensive portion of the feed cost; a less-expensive substitute is desirable. Beginning about 1945, urea began to be used as a protein source for ruminants. As early as 1951 , it was recognized that mixing urea into molasses was beneficial. In about 1968 it was recognized that it was beneficial to mix urea with starch for feeding.

The urea is in better condition for handling and application to the feed if it is in a liquid solution. Therefore, urea was often dissolved in molasses. There is a necessity to provide a certain minimum amount of carbohydrate with the urea for the urea to be utilized; the molasses serves this function in this type of feed, though other sources of carbohydrates are of course possible.

Kunz, U.S. Patent 2,910,361 discloses a liquid animal feed including urea and molasses. Loomis, U.S Patent 3,248,224 discloses a urea-containing liquid ruminant supplement. Moore, U.S. Patent 3,873,728 discloses mixing urea and calcium carbohydrate in cattle feed. Van Benthem et al., U.S. Patent 5,160,753 discloses the inclusion of calcium chloride in cattle feed.

Normally, ruminant rations include protein, roughage, and carbohydrates. Carbohydrates are normally the feed that provides calories, and one of the most common sources is grain. The cattle are also fed roughage which may widely vary. Besides hay, or straw, or pasturage, or silage, sometimes ground cotton burrs or other sources of roughage are used. The protein is often supplied by cottonseed meal (in addition to the protein found in the grain or hay). In addition to these feeds, the feed for cattle and other ruminants include vitamins, minerals, and similar other supplements.

Ammonia Toxicity

Today, the most common source of non-protein nitrogen in the feeding of ruminants is urea. The main problem which has been encountered in the feeding of urea to ruminants is ammonia toxicity. When the urea is broken down into ammonia in the rumen, the ammonia may be absorbed into the blood stream of the animal. The liver will convert the ammonia into urea, which may be excreted or reabsorbed into the stomach contents. When the rate of ammonia absorption exceeds the capacity of the liver to convert it to urea, ammonia accumulates in the blood and toxicity may occur. If not caught and treated quickly, the resulting toxicity can causes tremors, respiratory difficulties, tetanic spasms and death.

To provide the maximum benefit without risking ammonia toxicity, it has been widely accepted in the industry that urea may be used to replace a maximum of a third of the total protein requirement of an animal. It has also been accepted that the total weight of urea could not exceed 1% of the total dry matter weight of the ration.

Various attempts have been made to find a NPN source which would release ammonia slowly, so that higher concentrations of NPN sources could be utilized. Until recently, any NPN source which seemed to provide some advantage as a nitrogen source also carried a higher price tag in terms of cost vs. nitrogen provided.

Feeding Contexts

The feeding of cattle generally takes place in one of two primary contexts: either in a feedlot, where control over the rations consumed is very high, or in a pasture, where control is much lower.

Feeding in a large feedlot is under largely controlled conditions and feed-lot operators are highly skilled in the formulation of rations for feeding cattle. The normal problem facing the feed-lot operator is to balance the amount of protein, roughage, carbohydrates, minerals and vitamins for feeding the cattle to maximize yield per unit cost. The source and amount of each of these components depends upon many factors which would include the price and the quality of each of the various components. For example, the price and quality of sorghum, corn, wheat, oats, cottonseed meal, hay, corn stalks, cotton burrs, and urea, would all be considered, as would the cost of the purchase of animals at entry into the feedlot and the price of the animals at different weight levels when leaving the feedlot. The feed-lot operators are highly skilled in juggling all these factors to formulate a cost efficient (profit- maximizing) ration for the cattle. It is also recognized that normally, in the feed lot, the food is more concentrated, and therefore in such situations, more urea may be included in the ration. The reason for this appears to be that animals in the feedlot consume higher quality carbohydrate sources than those grazing on pasture and are therefore more able to utilize any ammonia as soon as it is released, rendering them less susceptible to ammonia toxicity. In a typical feedlot scenario, the basic feed may consist of corn, sorghum or other grains, silage or hay (such as alfalfa), and cotton burs, hulls, or other roughage. This will typically contain between 8-9.5% natural protein. For a growing ration in the feedlot, an operator will typically want from 12- 14% protein in the ration; for a fattening ration, the operator will typically want the protein elevated only to 11-12% to allow more carbohydrates in the diet. This means that additional protein of about 3-6% must be added to the feed mix for optimum feeding. Under standard feed procedures previously followed, the operator would typically add as much urea as possible, without risking urea toxicity, then use cottonseed meal or other high-protein sources to round out the protein desired. With a first embodiment of the innovative feed herein disclosed, which is formed from an aqueous solution of urea and calcium chloride, it has been found that all supplemental protein may come from the disclosed feed supplement, without fear of urea toxicity. In a pasture situation, the cattle will be allowed to graze freely for most of their feed intake, but supplemental feeding may take either a liquid or solid form. In a lick feeder, a liquid supplement is available to the animals by licking rotating wheels; an open tub offers open feeding of liquid supplements to the animals as long as the feed lasts. Dry blocks are also used for providing supplemental feeding; these are usually a supplement based on molasses, which is dried after formulation and are simply set out for the cattle to lick. In this situation, one object of the supplemental feed is generally to provide an additional source of carbohydrates, for when grazing, the cattle will typically consume more cellulose, which slows digestion. Grass tends to be fairly low in protein (except in the spring, when protein is higher), so another object is to provide an additional protein source. Molasses or steep water (water in which corn has been soaked, and which contains soluble fractions from the corn) are generally used to provide the carbohydrate component. The disclosed feed supplement can be used to provide the protein source; urea toxicity does not need to be a concern or is greatly reduced.

One problem encountered in a pasture feeding situation is having a feed that is palatable to the animals, so that they get the supplemental feed they need, yet not enticing them to overeat the more expensive supplement when they should be grazing. The molasses, which is often used as a base for liquid or solid supplements, is well liked by the cattle. This may result in over- consumption of the supplement by some animals, leaving little for others in the herd. To cut down on overeating of the supplement, those carrying out the feeding program will sometimes add a restrictor, such as excessive salt, to a supplemental feed mix; while not an ideal additive such a restrictor provides a strong incentive for the animals to limit their intake. By using a second embodiment of the disclosed feed, which uses a different ratio of ureaxalcium, it has been found that not only is a slow-release supplement available, but the supplement itself acts as a restrictor, naturally limiting the intake of the supplement. One example of a typical liquid supplement, using the innovative feed supplement, uses beet molasses 26.42%, cane molasses 30.82% and steep water 25.20%> to provide the carbohydrate, phosphoric acid 1.61% to supply P and to reduce viscosity, the innovative feed derived from a urea and calcium chloride solution 15.66% to provide protein and calcium, trace minerals 0.18%, and Vitamin A 0.11 %.

Thus, the problem faced in the field of ruminant nutrition is to find a source of non-protein nitrogen which: a.) will release ammonia slowly to avoid toxicity and improve nitrogen conversion to microbial protein; b.) will allow a greater percentage of the nitrogen in ruminant feeds to come from NPN sources; c.) is more cost efficient than urea or natural protein; d.) is palatable to the ruminants; e.) is easy to formulate, store and mix into both liquid and dry feeds. In some feeding contexts, such as a lick feeder or dry self-feeders in a pasture, an additional problem can be f.) to restrict the intake per animal of supplemental feeds so that available forage is utilized appropriately. According to the innovative teachings of the present application, these problems are solved by a feed which includes a compound formulated by mixing urea and a solution of calcium chloride. As will be shown, this solution provides a feed supplement that releases ammonia much more slowly than urea alone. It has been found that with this formulation, urea may comprise up to two-thirds of the total protein requirement in a feed mixture, or TWICE the percentage from NPN sources as had been previously possible. Likewise, in this formulation, the total weight of urea (as distinguished from the protein equivalent thereof) can comprise up to about 2% of the total dry matter weight.

Both of the components of this supplement are readily obtainable; they can be processed together and the resulting solution is stable and easily transported and stored. A feedlot study has shown that cattle fed on rations containing one preferred embodiment of this inventive supplement consumed slightly less feed, but maintained the same average growth as animals fed on equivalent rations containing cottonseed meal or urea. The animals fed the innovative supplement also showed an apparent shift toward leaner carcasses, with less waste fat as compared to the animals supplemented with urea. A second preferred embodiment has demonstrated use as a restrictor, to restrict intake of feeds without addition of undesirable components.

Brief Description of the Drawing

The disclosed inventions will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein:

Figure 1 shows a graph of the comparative in vitro digestion rates of cornstarch mixed with two different embodiments of the inventive feed,

(23-0-0-7) and (10-0-0-11), versus urea and cottonseed meal. (The four numbers in the inventive feed refer to N, P, K, and Ca.) Figure 2 shows a bar graph of the dry matter intake of wethers consuming diets containing one of the following as a nitrogen source: cottonseed meal, the inventive feed (23-0-0-7) and (10-0-0-11), or feed grade urea.

Figure 3 shows a bar graph of the dry matter intake of feedlot steer consuming diets containing one of the following as a nitrogen source: cottonseed meal, the inventive feed (23-0-0-7), or feed grade urea.

Figure 4 shows a bar graph of the average daily gain of feedlot steers consuming diets containing one of the following as a nitrogen source: cottonseed meal, the inventive feed (23-0-0-7), or feed grade urea. Figure 5 shows a bar graph of the feed(kg) required to attain 1 kg of gain by steers fed diets containing one of the following as a nitrogen source: cottonseed meal, the inventive feed (23-0-0-7), or feed grade urea. Figure 6 shows a bar graph of the gain(kg) for every 100 pounds of feed ingested by steers fed diets containing one of the following as a nitrogen source: cottonseed meal, the inventive feed (23-0-0-7), or feed grade urea. Detailed Description of the Preferred Embodiments

The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment (by way of example, and not of limitation), in which:

Formulation

In one of the presently preferred embodiments, a stock solution of 38% calcium chloride is mixed with equal parts by weight of dry urea. (Urea as manufactured will generally contain 46% nitrogen, and this has been assumed here.) Other concentrations can be made to satisfy other nutritional needs. The mixture ratio can vary from 1 :0.73 urea to calcium chloride solution, yielding a high NPN, low calcium supplement to a ratio of 1 :4.5 urea to calcium chloride solution to yield a low NPN, high calcium supplement. Because dissolving urea is an endothermic process, heat is added as the ingredients are mixed to attain a temperature of 46-50°F. Once the reaction is complete, the solution is stable and, unlike normal urea solutions, which require high temperatures and special handling to prevent precipitation, can be stored at ambient temperatures as low as -70° F. This supplement will be used to provide the supplemental protein requirements of the cattle or other ruminants being fed.

Analysis

An x-ray diffraction analysis was performed on crystals dried from a sample of the preferred embodiment of the innovative feed supplement. Results indicated that no free urea remained in the sample, indicating that a new compound has been created. A further analysis on the innovative feed was performed at the

Department of Chemistry and Biochemistry at Texas Tech University, with the following results. The liquid sample was evaporated to a white solid by boiling and then drying in a 110°C oven. A microanalysis was ordered. The oxygen content was calculated by difference from 100%. The molecular weight per mole of dissolved particles (total molecules and ions) was measured by vapor pressure osmometry. Finally, solid-state infrared spectra (KBr pellet) were acquired of both the white solid and pure urea as a reference. Relevant details are tabulated below:

Elemental Analysis %Ca %C %H %N %C1 %o experimental finding 8.11 14.54 3.82 26.45 20.96 26.12 calculated for the empirical formula CaC₆H₁₉N_QCl₃0₈ 8.15 14.66 3.89 25.64 21.63 26.03 calculated for the empirical formula CaC₄H₁₆N₈Cl₂0₄ 11.41 13.68 4.59 31.91 20.19 18.22

Molecular Weight A solution prepared by dissolving 2.0284 g of the white solid in 50 ml of distilled water was found to contain 0.562 moles of solute particles per liter by vapor pressure osmometry. On this basis, the average molecular weight per solute particle was calculated to be 722 g/mole. The molecular weight calculated from the experimental best fit empirical formula, CaC₆H₁₉N_oCl3θ₈, is 491.7 g/mole. Dividing this number by the molecular weight per dissolved solute particle gives 6.8±0.4 dissolved particles generated per molecular formula unit, within experimental uncertainty of 7.

Infrared Spectroscopy

The table below shows infrared band positions in cm with proposed vibrational assignments. Key: w=weak, m=medium, s=strong; underlined peaks for the new feed are not found in pure urea or have dramatically changed intensities; a=different bands that overlap into one observed peak.

Assignment Innovative Feed Pure Urea symmetric N-H stretch 3428s^a 3342s asymmetric N-H stretch 3428s^a 3441s carbonyl C=P stretch 1625s^a 1684s

N-H bending vibration 1625s^a 1625s

C-N stretching vibration 1472s 1466s

1402s

1326m other molecular vibrations 1161m 1154m

1067w 1061w

979w 997w

903w

826m

791m 788w

709w 714w

585w

561m 559m

Discussion

Elemental analysis results show that the solid obtained by evaporation of the innovative feed is a mixture of substances which fits the empirical formula CaC₆Hi_QN₉Cl₃0₈ reasonably well. Note that observed percentages for Ca, C, H and O fit the proposed formula extremely well, while small deviations may be noted in the cases of N and Cl. Since pure urea has the formula CH₄N₂0 it is clear that the empirical formula of the innovative feed does not contain a simple integer multiple of urea molecules. This point is underscored by percentages calculated for the literature Ca(urea)₄Cl₂ compound, which differ greatly from the composition of the innovative feed. It can be concluded that the organic content of the innovative feed is similar to that in urea, but components other that urea clearly are present. Several particularly striking points are as follows:

A) The C:N ration of urea is 1 :2, while that in the innovative feed solid is reduced to 1 :1.5 (6:9). This suggests that a partial loss of nitrogen from urea occurs during the preparation of the product. It should also be noted that a small amount of ammonia was liberated from the product in the drying process.

B) The innovative feed contains much more oxygen than the literature CaC₄Hi₆N₈Cl₂0₄ compound. It seems reasonable to conclude that this additional oxygen originates from water used as the solvent. Note that this extra oxygen is not associated with sample wetness, as the solid was dried thoroughly and elemental analysis finds do not show a dramatic increase in hydrogen content.

C) Surprisingly, the Ca:Cl ratio is 1 :3 rather that the 1 :2 ratio expected from the CaCl₂ starting material. This finding clearly points to a modification of the organic content that brings about an increase of +1 unit in electric charge, since calcium exists in nature only as +2 cations.

While it is not clear how this increase occurs, one may conclude that the compound cannot be composed entirely of Ca²⁺ cations, Cl^" anions and neutral urea molecules. It is suspected that urea nitrogen is partially converted to amine functional groups which become protonated to -NH₃ ⁺ charged units.

The known compound Ca(urea)₄Cl₂ ~>Ca + 4 urea + 2 Cl^". In this way, one molecular formula unit would give a total of seven product species in solution. Osmotic pressure measurements indicate that the innovative feed solid also dissociates into seven distinct product particles, even though urea is not the only organic component. Considering the Ca:Cl ration, it is concluded that the dissociation of the innovative feed occurs as follows:

One formula unit of the innovative feed --> Ca²⁺ + 3 Cl^" + 3 organic fragments. While it can be said that the formulas of the three organic fragments add up to C₆H₁₉N₉0₈, there is no evidence at present to specify their exact molecular compositions.

The infrared spectra of the innovative feed and pure urea (H₂NCONH₂) are very revealing, lending further support to the conclusion that the organic content of the product is distinctly different from H₂NCOHN₂. There is very little difference in the N-H and C=0 stretching vibrations, showing that N-H and C=0 bonds are present in both materials. Urea shows only a single C-N stretching vibration at 1466 cm while the innovative feed exhibits a complex series of six peaks (3 major bands) in this region. It appears likely that new types of C-N bonds exist in the product. It is suspected that the condensation of urea molecules occurs to give products in which one or both nitrogen atoms of a particular urea molecule attack the carbonyl carbon atoms of other urea molecules. While the makeup of these condensation products is not certain, the infrared evidence provides strong empirical proof that organic molecules other than urea are present. Note especially the low energy region between 500 and 1000 cm^"1. The innovative feed product shows distinctive new peaks at 826 and 585 cm , a weaker new feature at 903 cm^"1, and a dramatic strengthening of the 791 cm band relative to the analogous 788 cm^"1 feature of pure urea. It is believed that the presence of new organic molecules (possibly an aggregate or oligomer), as demonstrated above, accounts for the slow release feature which is a key attribute of the innovative feed. Experimental Data

To explore the possibilities of using the innovative feed supplement, a research project was carried out at Texas Tech University to explore its suitability. This research was carried out by John L. Cass, as part of his master's thesis, and was under the direction of Dr. C. Reed Richardson, an expert in ruminant nutrition. The thesis is "Urea: Calcium Compounds as a Supplement Source of N and Ca for Ruminants" by John L. Cass, which is hereby incorporated by reference.

In Vitro Studies To begin, a study of the digestibility of the innovative supplement was run, comparing it to the digestibility of urea and cotton-seed meal in an experiment designed to determine ammonia release rate over time. Two formulations of the innovative feed were tested, composed of 23-0-0-7 and 10-0-0-11 N, P, K, and Ca, respectively. In this experiment, in vitro substrates were formulated using ground corn and corn starch. Nitrogen, not supplied by ground corn or corn starch, was supplied by one of the two urea/calcium compounds, feed grade urea, or cottonseed meal. The nitrogen sources were added at levels to achieve 10% and 14%) crude protein fermentation media. One hundred grams of each medium were prepared in which each nitrogen source was weighed and then raised to 25 g with distilled water. This procedure was to ensure similar mixing because of the fact that some nitrogen sources were already in a liquid form. A small stand mixer was used to mix the diets as the liquid was evenly applied by a hand spray bottle. The mixtures were digested by the procedure described by Dinus et al. (1974), and McDougal's buffer, without N, was added to all incubation flasks (Tilley and Terry, 1963). Samples taken during this procedure were analyzed for ammonia content by a colorimetric procedure (Chaney and Marbach, 1962). A Beckman DU-50 Spectrophotometer was used in reading samples in this procedure. Figure 1 shows the results from one of these studies, where 14% cornstarch was the incubation media. Here, the ammonia concentration found in the media is charted for each of the four protein sources over time. It can be clearly seen from this graph that the two innovative feed supplements have a much lower rate of ammonia release than does urea alone. While the different media did not all produce the same results, this figure shows most clearly what is believed to happen in the rumen. Cass concluded that "[w]ith the diets being isonitrogenous, the lower ammonia values show that the urea/calcium products are slower in ammonia release than is urea."

Metabolism Study in Wethers

Once this initial experiment had shown that the two embodiments of the innovative supplement had possibilities as a feed, a metabolism experiment was performed using 12 crossbred wethers to determine the nutritional value of the two formulations of the innovative supplement as compared to cottonseed meal and feed grade urea.

In this experiment, the wethers were placed in complete collection metabolism stalls in an environmentally controlled barn. Four diets were formulated to NRC requirements for growing lambs, and after mixing, the diets were pelleted via a California pellet mill into 7/16 inch pellets. The pelleting was to insure ingestion of the total mixed diet. After the lambs had adjusted to the crates, the urea based diet was fed to all 12 lambs for 28 days before a random assignment to treatments by weight group. After a 14 day adjustment period for the assigned diets, the lambs were placed on a 7 day total collection period of urine and feces. After each 7 day collection period, lambs were randomly switched, as groups, to a different treatment for a 14 day adjustment followed by a 7 day collection period. This pattern continued until each lamb had received every diet resulting in four collection periods. The collection process consisted of total fecal collection, which was weighed, dried in an oven at 65 degrees Celsius, and reweighed to determine dry matter content. After the dried feces were ground through a 1 mm screen in a Wiley mill, a representative sample was taken and stored for subsequent analyses. Diluted HC1 (20%) was added on a daily basis to the urine collection vessels to prevent ammonia nitrogen loss. Ten percent of the total urine volume was kept from each lamb and then subsampled for subsequent analyses. Rejected feed "orts" were removed from the feed bunk on a daily basis. Feed samples as well as "orts" were dried, ground, and sampled for subsequent analyses. All samples collected during this study were analyzed for dry matter, nitrogen content and or protein, and calcium content. Nitrogen was determined by a Kjeldahl procedure and calcium was determined by an atomic absorption machine. Upon completion of the trial the lambs were removed from the crates and an ending weight was taken for each lamb.

It was determined during this test, as is shown in Figure 2, that the 10-0-0-11 formulation of the innovative supplement was causing a markedly decreased intake by the wethers, with a resulting effect on all measurements in the study. It is not known whether this lowered intake has to do with the taste of the feed, or due to other factors caused by the increased calcium intake. The 10-0-0-11 formulation or other analogous concentrations can be useful in feeding programs where feeders desire to limit the feed intake of ruminants on maintenance diets fed in self-feeders or free choice in both dry or liquid feed while adding NPN and calcium.

Feedlot Study

A further study was carried out to evaluate the relative feeding value of the innovative supplement on feedlot performance and carcass grade and yield as compared to feed grade urea and cottonseed meal. Seventy-five steers were divided into 9 pens of approximately 8 animals each. Each pen was assigned to one of three feeding groups: diets were the same for each group except that the supplemental protein source was chosen to be either cottonseed meal, urea or the (23-0-0-7) innovative feed supplement. Steers were weighed at six weigh periods: initial weight, 28, 56, 84, 108, 132 and 147 days. All steers were then killed and weighed at a commercial packing plant at Plainview,

Texas, and carcass data was collected by the meats department staff of Texas

Tech University. Figures 3-6 are taken from this latter study. Figure 3 shows a bar graph of the dry matter intake of feedlot steers consuming diets containing one of the following as a nitrogen source: cottonseed meal, the innovative supplement (23-0-0-7), or feed grade urea.

As can be seen, the dry matter intake for the innovative supplement is slightly reduced, as compared to cottonseed meal or urea. Figure 4 shows the average daily gain of feedlot steers consuming the same diets as above. Here, the innovative supplement showed an average daily gain between that of cottonseed meal and urea.

Figure 5 shows the feed(kg) required to attain 1 kg of gain by steers when fed the test diets. The innovative supplement required the least amount of feed to cause a specified weight gain.

Figure 6 shows the gain efficiency for the selected supplements. The innovative supplement shows the greatest gain efficiency of the supplements tested.

Modifications and Variations As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a tremendous range of applications, and accordingly the scope of patented subject matter is not limited by any of the specific exemplary teachings given.

Although the presently preferred embodiment employs a 1 : 1 weight ratio between dry urea and the 38% calcium chloride solution, less preferably, the ratio can be from about 1 :0.73 to about 1:7.8.

Other concentrations of calcium chloride solution can be utilized, as this was chosen for being an economical, commercially available solution. A commercially available urea liquor can also be used instead of the dry urea, but in this case, it is necessary to utilize dry calcium chloride to obtain the concentrations necessary. At this time, the costs for dry calcium chloride are too high for this to be economically practical. Other formats for presentation of the supplemental feed are possible, such as inclusion in a block supplement utilizing molasses or a similar base.

The formulation of two specific compounds according to the present invention has been described in great detail. However, as will be obvious to those skilled in the art of animal nutrition, the properties of these two specific formulations can be used to predict the properties of intermediate formulations by interpolation. Extrapolation can also be used to predict the properties of still other formulations which follow the innovative teachings disclosed above.

Claims

CLAIMSWhat is claimed is:

1. A feed supplement for ruminants, comprising: a compound formed by reacting urea and calcium chloride in an aqueous solution, wherein said compound provides a slow-release of ammonia in the rumen.

2. The feed supplement of Claim 1, wherein said urea comprises by weight between about 18% and about 58% of said solution.

3. The feed supplement of Claim 1, wherein said calcium chloride is supplied as a 38% aqueous solution.

4. The feed supplement of Claim 1, wherein said solution is heated as said urea and said calcium chloride are combined.

5. The feed supplement of Claim 1, wherein said compound provides up to two thirds of the total protein requirements of the ruminant.

6. A slow-release non-protein nitrogen source for ruminants, comprising: an aqueous solution derived from urea and calcium chloride, formulated to release ammonia in the rumen slower than does urea.

7. The slow-release non-protein nitrogen source of Claim 6, wherein said urea comprises by weight between about 18% and about 58%.

8. The slow-release non-protein nitrogen source of Claim 6, wherein said calcium chloride is supplied as a 38% aqueous solution.

9. The slow-release non-protein nitrogen source of Claim 6, wherein said solution is heated as said urea and said calcium chloride are combined.

10. The slow-release non-protein nitrogen source of Claim 6, wherein said compound provides up to two thirds of the total protein requirements of the ruminant.

11. A feed for ruminants, comprising a high concentrate diet containing a wide range of protein, roughage, carbohydrates, minerals and vitamins; wherein a portion of the protein requirements is supplied by a compound derived from urea and calcium chloride which provides non-protein nitrogen compounds equal to more than 1% of the weight of the feed mixture.

12. The feed for ruminants of Claim 11, wherein urea comprises by weight between about 18% and about 58% of said compound.

13. The feed for ruminants of Claim 11, wherein urea and a 38% solution of calcium chloride are reacted to form said compound.

14. A feed for ruminants, comprising a high roughage diet containing a wide range of protein, roughage, carbohydrates, minerals and vitamins; wherein a portion of the protein requirements is supplied by a compound derived from urea and calcium chloride which provides non-protein nitrogen compounds equal to more than 1% of the weight of the feed mixture.

15. The feed for ruminants of Claim 14, wherein urea comprises by weight between about 18% and about 58% of said compound.

16. The feed for ruminants of Claim 14, wherein urea and a 38% solution of calcium chloride are reacted to form said compound.

17. A feed supplement for ruminants which causes the animals to restrict their intake of said supplement, said supplement comprising a compound derived from an aqueous solution of calcium chloride and urea.

18. The feed supplement of Claim 17, wherein said urea comprises by weight about 18% of said compound.

19. The feed supplement of Claim 17, wherein said calcium chloride is supplied as a 38% aqueous solution.

20. A method of feeding cattle and other ruminants, comprising feeding a supplement which supplies at least a portion of the protein needs of the ruminant with a compound derived from an aqueous solution of calcium chloride and urea, wherein said compound causes the ruminants to restrict their intake of said supplement.

21. The method of feeding ruminants of Claim 20, wherein urea comprises by weight about 18%> of said compound.

22. The method of feeding ruminants of Claim 20, wherein calcium chloride is supplied as a 38% aqueous solution to form said compound.

23. A method of feeding cattle and other ruminants, comprising supplying at least a portion of the protein needs of the ruminant with a compound derived from an aqueous solution of calcium chloride and urea, wherein said compound provides a slow release of ammonia in the rumen.

24. The method of feeding of Claim 23, wherein urea comprises by weight between about 18% and about 58% of said solution.

25. The method of feeding of Claim 23, wherein calcium chloride is supplied as a 38% aqueous solution.