GB2057873A - Animal feeds - Google Patents

Abstract

A method of promoting growth and improving feed efficiency in animals comprises the oral administration of a feed containing the antibiotic amphomycin.

Description

SPECIFICATION Improvements in animal feeds This invention relates generally to the promotion of growth in economically important animals. More specifically it relates to a method of accelerating the growth rate and simultaneously increasing the feed-utilization efficiency in such animals.

It is well known that the acceleration of growth rates and an increase in the efficiency of feed utilization in economically important animals is an important consideration in agricultural economies. A faster growth rate allows greater use of the facilities employed in raising the animal, thus improving return on investment. An increase in the efficiency of feed utilization results in a lowered cost of production.

In the search for effective growth promoters, it is generally recognised that a relatively small improvement in growth rates and feed efficiency can be advantageous. Thus, for example, in broiler chickens a growth rate acceleration of 3% or more and an increase in feed efficiency of about 2% or more is economically worthwhile, particularly where the active compound is used in relatively small quantities and is favourably priced to the user.

Heretofore a number of compounds have been used as growth promotants for animals, among such compounds are some antibiotics such as penicillin G, bacitracin, chlortetracycline, tylosin, lincomycin and flavomycin. It is known, however, that antibiotics vary in their effectiveness in stimulating growth and increasing feed efficiency and that some are effective for one purpose and ineffective for the other. A compound which gives significant improvement in both the rate of growth and feedconversion efficiency would, therefore, constitute a significant advance in the art.

The antibiotic amphomycin is disclosed and claimed in U.S. Patent No.3,126,317. The production and properties of amphomycin are also described in Antibiotics and Chemotherapy, 3, 1239-1242(1953), Antibiotics Annual 1954-1955, Medical Encyclopedia, Inc., New York, N.Y. at pages 1011-1019 and Antibiotic Medicine and Clinical Therapy, Vol. III No. 2, 142-145 (1956). None of the published literature on amphomycin, however, discloses use ofthis compound as a feed growth additive.

Amphomycin is an acid polypeptide and readily forms salts with pharmaceutically acceptable bases, e.g. the sodium, ammonium, calcium and aluminium salts. By the term "amphomycin" as used herein is meant the free acid or a pharmaceutically acceptable salt thereof.

Accordingly, the present invention provides a method for promoting the growth of and improving the feed conversion efficiency in animals, which comprises the oral administration to the animals of feed containing an effective amount of amphomycin.

Also provided by the present invention is a novel feed composition for animals which comprises a nutritionally balanced feed composition in which there is incorporated therein an amount of amphomycin effective for promoting growth and improving feed conversion efficiency.

The present invention is applicable to all types of non-human animals, but is particularly useful with economically important animals such as chickens, pigs, cattle, turkeys, geese, ducks, horses, goats, rabbits and sheep. Especially important nonruminant animals are chickens and pigs and important ruminant animals include cattle, sheep and goats.

It has been found that daily oral administration of a growth-promoting quantity of amphomycin as a component in the feed consumed by animals significantly accelerates the growth rate of the animals and simultaneously improves the efficiency of feed utilization. In tests in broiler chickens, for example, amphomycin used in concentrations of from about 4 to 12 grams per ton of conventional feed resulted on average in the chickens gaining about 3% more weight and consuming 3% less total feed than comparable chickens fed the same diet without amphomycin. In general concentrations of amphomycin between about 4 and 100 grams per ton of feed have been found to be effective for improving the growth rate and the efficiency of feed utilization in both ruminant and non-ruminantani- mals.

The amphomycin may be added to any nutritionally adequate feed commonly used to feed animals and known to those skilled in the feed art. Such feeds contain grains, fats, minerals, vitamins and the like known constituents in proportions dependent upon the animal to be fed.

Addition of the amphomycin to the feed may be accomplished by known procedures. For example, amphomycin (or a nontoxic salt thereof such as described in U.S. 3,126,317; considered for purposes of the present invention to be equivalent to amphomycin perse) can be incorporated directly into the animal feed in a concentration of from 4-100 grams perton of feed and, by mixing, uniformly distributed throughout. In an alternate and preferred embodiment, the amphomycin can be added to an edible non-toxic diluent, preferably a material having nutritional value, to provide a highly concentrated premix. Using amphomycin concentrate (4 g.

amphomycin/lb.), such a premix may be prepared so as to contain from about 10-30 pounds of amphomycin concentrate per 100 pounds of premix.

A sufficient quantity of the premix is then incorporated in the feed to provide a feed composition containing from 4-100 grams of amphomycin per ton of feed.

The amphomycin-supplemented feed prepared as above when made available to the animal for feeding, ad libitum, results in significantly improved growth rates and feed-utilization efficiency.

In another aspect of the present invention, it has been found that amphomycin when orally administered to ruminant animals having a developed rumen function changes the digestive fermentation of such animals to produce more propionates relative to the production of acetates, thus improving feed utilization efficiency.

It is known that the efficiency of carbohydrate utilization in ruminants is increased by treatments which stimulate the animal's rumen flora to produce propionate compounds rather than acetate compounds (see, for example, U.S. Patent 3,839,557).

Also, the efficiency of carbohydrate use can be effectively monitored by observing the production and concentration of propionate compounds in the rumen. If the animal is making more propionates, it will be found to be using its feed more efficiently.

A standard in vitro method for determining compounds which stimulate propionate production during rumen fermentation is the artificial rumen method described in U.S. Patent 3,794,732. When amphomycin was subjected to this in vitro procedure, it was unexpectedly found to significantly increase the production of propionates in the rumen, thus indicating effectiveness in increasing the efficiency of feed utilization in ruminants. This property in ruminants is presumably in addition to the previously-described feed-utilization efficiency promoting activityofamphomycin in monogastric animals which involves a different mechanism of action.

Amphomycin is typically effective in increasing the efficiency of feed-utilization when administered to ruminants orally as a feed additive in concentrations of from about4to 100 grams per ton of feed.

Appropriate feed compositions containing amphomycin as a feed additive may be prepared as described above.

As indicated in Example 2 below, the in vitro artificial rumen test indicates that amphomycin significantly inhibits methane production as well as increases propionate production. Methane formation is responsible for "bloat" in cattle and also leads to reduced feed efficiency. Also, amphomycin does not significantly inhibit cellulose (cellulose digestion) or affect total calories digested.

The use of amphomycin as a feed additive may be further understood by referring to the examples set forth below, which are provided solely for illustration and are not intended to limit the scope of the invention.

Example I The efficacy of amphomycin in promoting growth and improving the feed efficiency of broiler chicks is illustrated below.

In this example a basal diet was employed containing the following ingredients: 3round yellow corn 544.1 Ibs.

soybean meal (dehulled) 290.4 Ibs.

orn gluten meal (60%) 25.0 Ibs.

ishmeal-herring (65%) 25.0 Ibs.

Vieat & bone meal (47%) 25.0 Ibs.

3calcium phosphate 5.0 Ibs.

limestone 8.0 Ibs.

Trace mineral mix 1.5 Ibs.

Iodized salt 4.0 Ibs.

Premix#1A 5.0 Ibs.

" Premix#2A 5.5 Ibs.

he line chloride (25%) 2.6 Ibs.

vitamin A concentrate 35 grams (30,000 units) Vlethionine 0.4 Ibs.

Fat 53.5 Ibs.

total 995.0 Ibs.

Trace mineral mix contains manganese oxide, ferrous carbonate, potassium iodide, cupric oxide, cobalt sulfate and zinc oxide, all of which are distributed on calcium carbonate.

Bremix#1Aconsists of Vitamin A Conc. 30,000 IUlg 1.47 Ibs.

Vitamin D Conc. 3,000 ICU/g 7.35 Ibs.

Hydrogenated Animal-Vegetable Fat 0.91 Ibs.

Soy meal (dehulled) 90.27 Ibs.

100.00 Ibs.

Premix #2A consists of Riboflavin (20 glIb) 1.50 Ibs.

Ca Pantothenate (32 glIb) 1.56 Ibs.

Niacin 0.44 Ibs.

* Koagulone (16-S) Vitamin K Conc. 1.89 Ibs.

312(60 mgllb) 2.00 Ibs.

Hydrogenated Animal-Vegetable Fat 0.93 Ibs.

g + Soy meal (dehuiled) 91.68 Ibs.

100.00 Ibs.

+ Equivalent to 5.28 g menadionellb.

i f Soy-Fat Mix (92.61 Ibs.) Procedure: Male broiler chickens (Hubbard breeder pullet x White Mountain males) were used as the test animal. They were housed in electrically heated, metal battery brooders equipped with raised wirescreen floors. An attempt was made to raise the level of contamination ofthe unitfora more effective bacteria load as a stress for testing antibiotic. The room and battery units were left unclean from a previous test that terminated before the chicks were started.

Drinking water for the test came from overflow water from a laying cage operation. The water was collected in garbage cans and was allowed to stand overnight to permit particulate matter to settle out.

The birds were vaccinated at 7 days of age for Newcastle, Bronchitis and Marek's. The feed trays were fitted with wire screens riding on top of the feed to minimize feed wastage. Feed and water were fed ad libitum. Four groups often birds each, chosen on the basis of hatching body weight, were fed the experimental diet for a four week test period and four groups were fed the control diet. The groups of birds and diets were placed in the batteries on the basis of position chosen from tables of random numbers.

The birds and the feed were group weighed on a weekly basis. The test was terminated at four weeks of age.

The control diet was prepared as follows: +Premix-69 0.50 Ibs.

Basal diet (as given above) 99.50 Ibs.

Total 100.00 Ibs.

The experimental diet (for amphomycin concentration of 4 grams/ton) was prepared as follows: + +Premix-75 0.50 Ibs.

Basal diet 99.50 Ibs.

Total 100.00 Ibs.

+ Premix-69 consists of: Nutrigard (50% ethoxyquin) 4.99 Ibs.

Fat 0.85 Ibs.

Soy protein 94.16 Ibs.

Total 100.00 lbs.

+ + Premix-75 consists of: Nutrigard (50% ethoxyquin) 4.99 Ibs.

Fat 0.85 Ibs.

Soy protein 84.25 Ibs.

Amphomycin concentrate 9.91 Ibs.

(4 g amphomycin/lb.) Total 100.00 Ibs.

Results: The table below indicates the average four week body weight average percentage change in body weight, average feed efficiency and average percentage change in feed efficiency. As indicated amphomycin art a concentration of 4 grams/ton of feed resulted in a 6.21% increase in body weight and a 4.07% increase in feed efficiency.

Results of Four Week Study Using 4 GramslTon Amphomycin Body Weights Percentage in grams at increase in 4weeks of weight at end age of 4 weeks Amphomycin 817.5 6.21% Exp. Group Control 769.7 - Group Feed efficiency calculated as average feed consumption in grams . average body weight in Improvement in grams * feed efficiency Amphomycin 1.480 4.07% Exp. Group Control 1.553 Group * calculated for both groups at 800 grams body weight from feed efficiency curve. A feed efficiency curve was calculated using the growth and feed con sumption data for each weigh period. The slope of this line represents feed efficiency. Curve followed equation Y=aXb where X=average body weight in grams and Y= average feed consumption in grams.

Example 2 Artificial Rum en Test Amphomycin was evaluated at doses of 0.025, 0.1 and 0.5 mg per incubation (25 ml. inoculum-artifi- cial saliva with cellulose, starch and urea as nutrients) according to the general procedure of Example 5 of U.S. Patent 3,794,732. The results of the test are shown in the following table.

Artificial Rumen Model Test Amphomycin (mg/tube) Control 0.025 a 0.5 Cellulose 68.3#1.4 64.9#2.1 64.0#2.4 57.5#4.0 digested (%) Methane 4.63#0.57 2.88#0.47 2.53#0.20 1.27#0.07 produced Total calories" 1144t15 1108+22 1098+26 1029t43 digested (Calories) Propionateab 50.7#1.0 58.9#0.9 62.1#1.7 67.1#4.7 produced Caloric efficiencyaC 58.2+7.0 62.1 +4,5 68.9t 10.0 65.5+16.8 Urease activityd 100 90 84 60 Results reported as mean # one standard deviation.Controls consist of six observations; all other means consist of three observations.

breported as a percent of total volatile fatty acid calories produced.

CReported as Volatile Fatty Acid Calories Produced Total Calories Digested x 100 d% Of control Analysis In the above test amphomycin can be seen to have significantly increased propionate production and significantly inhibited methane production (responsible for "bloat"). It did not significantly inhibit cellulase or significantly affect total calories digested.

The dose of 0.1 mg. per incubation appears to be the most efficacious; however, bordering doses are acceptable also. As the dose increases, cellulolysis decreases slightly, methane production decreases significantly, propionate production increases significantly and acetate and butyrate production decreases. Higher doses are not detrimental from the standpointofcellulolysis, but depression in acetate and butyrate production results in lowered improvement in caloric efficiency.

From the above test amphomycin is shown to be useful in improving feed efficiency in ruminant animals having a developed rumen function.

Claims (11)

1. A method of promoting the growth of and improving the feed conversion efficiency in nonhuman animals which comprises the oral administration to the animals of feed containing an effective amount of amphomycin.

2. A method as claimed in claim 1 wherein the amphomycin is administered at a concentration of from 4to 100 grams perton of feed.

3. A method as claimed in claim 1 or claim 2 wherein the amphomycin-supplemented feed is administered to chickens.

4. A method as claimed in claim 3 wherein the amphomycin is administered ata concentration of from 4 to 12 grams perton of feed.

5. A method as claimed in claim 1 or claim 2 wherein the amphomycin-supplemented feed is administered to pigs.

6. A method of increasing the efficiency of feed utilization by ruminant animals having a developed rumen function which comprises the oral administration to such animals of feed containing a propionate-increasing amount of amphomycin.

7. A method as claimed in claim 6 wherein the amphomycin is administered at a concentration of from 4to 100 grams per ton of feed.

8. A method as claimed in claim 6 or claim 7 wherein the ruminant animals are cattle, sheep or goats.

9. Afeed for a non-human animal which contains therein a growth promoting and feed conversion efficiency promoting amount of the antibiotic amphomycin.

10. Afeed as claimed in claim 9 substantially as described herein.

11. A method as claimed in claim 1 substantially as hereinbefore described with reference to Example 1 or Example 2.