GB1562805A

GB1562805A - Feeding of ruminants

Info

Publication number: GB1562805A
Application number: GB37625/76A
Authority: GB
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1975-09-11
Filing date: 1976-09-10
Publication date: 1980-03-19
Also published as: PL110326B1; ATA675276A; BE846142A; SE423858B; AU1758276A; JPS5238377A; DK409576A; NL7609884A; DD128412A5; MX4365E; HU182652B; NO763122L; NO143831B; BR7606005A; SU695525A3; DE2540509C2; PT65570B; IT1075029B; BG27535A3; DK147961C

Abstract

The feed additive to promote nutrient conversion and growth in ruminants and animal species with a similar physiology of the digestive system contains salinomycin, its physiologically acceptable salts and/or esters and carrier material. The feed additive can be given together with the feed or before or after feeding.

Description

(54) IMPROVEMENTS IN AND RELATING TO THE FEEDING OF RUMINANTS (71) We, HOECHST AKTIENGESELLSCHAFT, a body corporate organised according to the laws of the Federal Republic of Germany, of 6230 Frankfurt/Main 80, Postfach 8003 20, Federal Republic of Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to agents for the improvement of the nutrient efficiency and the growth of ruminants and animal species having a similar digestive pattern.

The use of antibiotics as feed additives in animal nutrition has already been proposed.

The common antibiotics, for example Bacitracin, Oleandomycin and Virginiamycin are mainly used for animals having a single gastric cavity; they do not have any specific effect on the rumen digestion in ruminants. We have found that the agents of the invention, which contain Salinomycin, have a special effect on the animal species digesting cellulose, due to the fact that they show a specific positive influence on the microflora necessary for this kind of digestion.

The invention provides a process for improving the nutrient efficiency and the growth of a ruminant or rabbit which comprises administering into the digestive system of the animal, preferably orally, Salinomycin or a physiologically tolerable salt or a physiologically tolerable ester thereof. A mixture of Salinomycin, and/or a salt and/or an ester thereof may be used.

The invention also provides a preparation for improving the nutrient efficiency for the growth of a ruminant or rabbit which comprises in the range of from 0.5 to 5% by weight of Salinomycin and/or a physiologically tolerable salt and/or a physiologically tolerable ester thereof, in admixture or conjunction with a suitable carrier, preferably in the form of a feedstuff, preferably fodder (i.e. for cattle).

As stated above the process and preparation of the invention are to be applied to ruminants, for example beef cattle, heifers, dairy cows and sheep, and to rabbits; the latter animals having a similar digestive pattern to ruminants, i.e. they are animals which can digest crude fibres or cellulose.

Suitable animals to which the process of the invention may be applied are, for example, those in which the administration of Salinomycin or a physiologically tolerable derivative thereof causes an increase in the proportion of propionic acid at the expense of acetic acid and/or butyric acid in the digestive system.

Salinomycin, its salts and esters have been described, for example, in British Patent Specification No. 1 378413 and in German Offenlegungsschrift No.

2 353 998. In these places, its use as anticoccidiosis agent has also been mentioned.

Suitable physiologically tolerable salts and esters to be used according to the invention instead of, or together with, Salinomycin, are, for example, ammonium salts, alkali metal salts, especially sodium or potassium salts, alkaline earth metal salts, especially magnesium or calcium salts, and alkyl esters, especially those derived from alcohols having from 1 to 8, preferably from 1 to 4, carbon atoms, and the benzyl ester.

It has been found that an agent, especially a feedstuff, which contains Salinomycin, effects an improved nutrient efficiency as well as an accelerated growth m ruminants. An improved nutrient efficiency means that a given weight increase is produced by a reduced feedstuff supply. It has also been found that in the rumen of ruminants the ratio of acetic acid: propionic acid: butyric acid is influenced by the administration of a preparation of the invention, especially in the form of a feedstuff, in such a manner that the proportion of propionic acid - which is most useful for energy metabolism -- is increased at the expense of acetic acid and butyric acid, due to which process a considerably improved nutrient efficiency is obtained.It is of particular importance that this effect also occurs during the feeding of NPN compounds (non-protein nitrogen) common for the nutrition of ruminants, for example, urea, biuret and diammonium phosphate as nitrogen source for the supply of protein.

Preferably the Salinomycin or salt or ester thereof is administered at intervals for a long period of time i.e. during a growth and/or a fattening period, especially the final fattening period-up to the time of slaughter, for example. Administration to a healthy animal is especially preferred.

Instead of being administered in the form of pure Salinomycin, the active substance may be given as a dried mycelium or raw product.

Salinomycin is preferably administered immediately before, during or immediately after feeding. Thus a preferred method of administering the active substance is in many cases its addition to the feedstuff in the form of a concentrate.

Preferably the feedstuff comprises cellulose and/or crude fibres.

A concentrate (premix) of this kind may be prepared, for example, by mixing the active substance or the mycelium containing the same or the raw product with a physiologically tolerable solid or liquid carrier. Suitable solid carriers are, for example, by-products of cereals, for example wheat flour of inferior quality, wheat bran or de-oiled rice bran, and also corn meal, soy meal, bolus alba or calcium carbonate. As liquid carriers, there may be used physiological salt solutions, distilled water and physiologically tolerable organic solvents. It is also possible to add suitable additives, for example, emulsifying agents, dispersing agents, wetting agents or gelatinising agents.These concentrates suitably contain, for example, in the range of from 0.5 to 5% by weight of the active substance, however, the concentration of this substance may also be considerably higher or lower, depending on the purpose of application.

For administering the active substances together with a feedstuff, a premix is suitably mixed with the feedstuff, for example by stirring, shaking or grinding. The use of a powdery concentrate has proved to be particularly useful for being mixed with feedstuffs, particularly fodder.

It is possible to add the substances used according to the invention to supplementary feedstuffs or to the entire feedstuff, or only to part of the daily feed ratlon.

The feed to which the active substance is added in accordance with the invention may be one of the feedstuffs commonly used in the nutrition of ruminants, for example cereals, for example barley, oats, corn and alfalfa (lucerne), hay, or mixed feedstuffs, e.g. fodder, containing the above ingredients. It is also possible to use a protein concentrate, which is common as feed, or mixtures or mineral substances, salt in block form or feed blocks, or liquid feed. Thus, the supplementary feed for cattle may contain, for example, as the main ingredients, dry chips, corn meal, coarse soybean meal, molasses and bran of peeled oats, and furthermore a mixture of mineral substances, wheat bran and urea, or a salt in block form for sheep may consist, for example, of bone meal and sodium chloride.

Another method of administering the active substance as such or in the form of, for example, a concentrate or a suspendable powder, is to add it to the drinking water or to another drink, for example milk.

A substance of the invention may also be administered orally to the animals before, during or after feeding, for example in the form of a solid or liquid preparation, for example a tablet, a capsule, granules, a bolus, a juice or syrup, or in the form of a concentrate mentioned above, preferably in unit dosage form. In this way the mixing with the feedstuff - which is important according to the invention -- is effected immediately after the application in the stomach, thus producing the effect of a considerably improved nutrient efficiency and increased growth.

Tablets, capsules, boli, pills, granules and other preparations for oral administration containing the active substance, may also contain suitable auxiliary agents and additives which are generally used in pharmaceutical technology. The active substances may be mixed, for example, with powdery diluents; for example, microcrystalline cellulose, sugar or starch may be used for filling up the volume of a capsule. Tablets may be prepared in known manner, containing, for example, cellulose, lactose, sodium chloride, starch, surface-active agents, for example sodium lauryl sulphate, binding agents, for example gelatin, starch, dextrin and cellulose derivatives. Pharmaceutically suitable auxiliaries for the preparation of liquid formulations are, for example, vegetable oils, collidone, cellulose derivatives, inter alia auxiliary dispersing agents or emulsifying agents and water.

An aqueous suspension of Salinomycin may for example contain, beside Salinomycin, raw product or ground mycelium, carboxymethyl cellulose, collidone 25, Aerosil (Aerosil is a trade mark), appropriate buffer substances, and water.

However, the most convenient method of administering the active substance according to the invention, is feeding the substance directly together with the feedstuffs.

The amount of active substance to be used according to the invention may vary, depending on the type of feeding. Typically, it may be in the range of from 0.5 to 500 mg/kg of feed, i.e. corresponding to a dosage df from 0.02 to 5.0 mg of Salinomycin per kg of body weight per day. It is advantageous to choose a content of Salinomycin in the fodder which corresponds to a dosage of from 0.1 to 1.0 mg/kg of body weight per day. However, it is possible to exceed the abovementioned limits considerably in appropriate cases. If the active substances is administered to the animal directly in the form of an oral preparation, the dosage is suitably within the above-mentioned limits per kg of body weight per day. Thus, for example, those preparations which are administered directly to fully-grown cattle suitable contain from about 10 to 500 mg of Salinomycin.Preparations which are to be administered to smaller ruminants, for example sheep or goats, suitably contain a correspondingly reduced amount of active ingredient.

The following Examples illustrate the invention. The percentage quoted in the Examples are all percentages by weight.

EXAMPLE 1.

A feeding test using Salinomycin was carried out on 12 fattening bulls that were kept with individual feeding and self-watering facilities and were bound to a barn. Six animals formed the Salinomycin test group, and the other six animals formed the untreated control group. The average weight of the animals was approximately 350 kg at the beginning of the test. The test period was 8 weeks with individual weighing at 2 week intervals. The feed consisted of a protein concentrate.

and corn silage which was given to the animals in an increasing amount (from 2 to 4 kg of protein concentrate per animal per day and from 16 to 20 kg of corn silage per animal per day) according to their nutrient demand. The composition of the protein concentrate was as follows: Barley 26% Oats 20% Corn 45% Carbonate of feed lime 2% Hostaphos (Na-Mg-Ca-phosphate) 4% Urea 2% Sodium bicarbonate 1% 100% Starch equivalents: 657 st.e.

Digestible protein 11.1% The Salinomycin dosage was chosen in such a way that 100 mg of the antibiotic agent per animal per day were ingested, together with the protein concentrate (in the form of a meal), in the form of a 2% concentrate with corn meal.

Results: Table 1 shows the weight gain in both the test and control groups, and also the additional weight gain obtained as a result of the administration of Salinomycin: TABLE 1

Average weight Average weight Additional weight Test gain in the gain in the gain in the period in control group test group test group weeks in kg in kg in % 2 14.8 21.3 +43.9% 4 35.3 39. 0 +10.5% 6 54.8 62.2 +13.5% 8 61.5 68.7 +11.1% Table 2 shows the nutrient efficiency in both the test and control groups, and also Table 2 shows the improvement given as a result of the administration of Salinomycin:: TABLE 2

Average Average Improvement efficiency efficiency resulting from the Test number+ in number+ in administration of period the control the test Salinomycin ia weeks group group in % 2 .3264 1865 +42.9% 4 2843 2295 +19.3% 6 2777 2249 +19.1% 8 3307 | 2777 +16.0% +.tfficiency number = starch equivalents per kg of weight gain.

Tables 3 and 4 show how the content of low molecular weight fatty acids in the rumen juice has changed within the "Salinomycin group", compared with the control group, at the end of a test period of 8 weeks. In order to determine the values given in Tables 3 and 4, samples were taken by means of a stomach tube and were subjected to gas chromatography.

TABLE 3

Average amount of the fatty acids present in 100 ml of given juice after a test period of 8 weeks in mg Type of fatty acid Control group Test group C2 190.73 135.65 C3 53.90 80.75 C4 1 41.92 19.72 TABLE 4

Proportion of the individual fatty acids in the rumen juice in NO after a test period of 8 weeks Type of fatty acid Control group Test group -C2 66.56 57,45 C3 18.80 34.20 C4 14.92 8.35 100% 100% Tables 3 and 4 show that the proportion of propionic acid (C3) which is valuable for the energy metabolism was considerably increased at the expense of acetic acid (C2) and butyric acid (C4), which changes result in a far better nutrient efficiency.

EXAMPLE 2.

A feeding test using Salinomycin was carried out on 22 fattening bulls, with 11 animals forming the control group and the other 11 animals forming the test group.

The animals were kept bound to a barn with individual feeding and self-watering facilities. Their average weight at the beginning of the test was 400 kg. The test period was 6 weeks and included individual weighing at 2 week intervals. The feed consisted of a protein concentrate and corn silage which was given to the animals in an increasing amount (from 2 to 4 kg of protein concentrate per animal per day and from 16 to 20 kg of corn silage per animal per day) according to their nutrient demand. The composition of the protein concentrate was as follows: Oats 40% Corn 24% Urea 2% Sodium bicarbonate 1% Lucerne green meal (alfalfa meal) 15% Dry Chips 15% Mixture of mineral substances (Phosca Bully) 3% 100% Starch equivalents 586 st.e.

Digestible protein 12.4% The Salinomycin dosage in the test group was 100 mg per animal per day, the antibiotic agent being administered, together with the protein concentrate, in the form of a 2% concentrate with corn meal.

Results: Table 5 shows the weight gain in the test and control groups, as well as the additional weight gain obtained as a result of the administration of Salinomycin.

TABLE 5

Average weight Average weight Additional weight @@ Test gain in the gain in the gain in the period control group test group test group in weeks in kg in kg in % 2 17.3 23.6 +36.4 4 32.1 35.2 + 9.7 6 49.8 53.6 + 7.6 Table 6 shows the nutrient efficiency in the test and control groups, as well as the improvement given as a result of the administration of Salinomycin:: TABLE 6

Average Average Improvement @@@ @@ efficiency efficiency resulting from the Test number in number in administration of period the control the test Salinomycin in weeks group group in % 2 3217 2363 +26.5 4 3477 3176 + 8.7 6 3387 3113 + 8.0 Tables 7 and 8 show how the content of low molecular weight fatty acids in the rumen juice changed within the "Salinomycin group", compared with the control group, after a test period of 6 weeks. The values given were determined by the same method refered to in Example 1.

TABLE 7

,Average amount of the fatty acids present in 100 ml of rumen juice after a test period of 6 weeks in mg Type of fatty acid Control group Test group C2 278.80 205.92 C3 78.16 95.55 C4 55.90 | 26.07 TABLE 8

Proportion of the individual fatty acids in the rumen juice in % after a test period of 6 weeks Type of fatty acid Control group Test group C2 67.53 62.87 C3 18.93 29.17 C4 13.54 7.96 100% 100% The increase of propionic acid led to the same conclusions as those already mentioned in Example 1.

EXAMPLE 3.

A feeding test using Salinomycin was carried out on 25 fattening bulls (Holstein Friesians) bound to a barn with individual feeding and self-watering facilities; the average weight at the beginning of the test was approximately 260 kg; the test period was 20 weeks and included an individual weighing every four weeks.

The feed consisted of a protein concentrate and corn silage which was given to the animals in an increasing amount (from 2 to 4 kg of protein concentrate per animal per day and from 16 to 20 kg of corn silage per animal per day) according to their nutrient demand. The composition of the protein concentrate was as follows: Barley 26% Oats 20% Corn 45% Carbonate of feed lime 2% Hostaphos (Na-Mg-Ca-phosphate) 4% Urea 2% Sodium bicarbonate 1% 100% Starch equivalents 657 st.e.

Digestible protein 11.1% The animals were distributed into the following groups: Group I: 5 Animals without treatment (control) Group II: 6 Animals treated with 100 mg of Monensin per animal per day Group III: 7 Animals treated with 50 mg of Salinomycin per animal per day Group IV: 7 Animals treated with 100 mg of Salinomycin per animal per day The antibiotics were administered to test groups II, III and IV in daily doses together with the protein concentrate (in the form of a meal).

Results: The following Table shows the average weight gain and nutrient efficiency in the control group and the 3 test groups at each weighing during the test period of from 4 to 20 weeks. In addition to the absolute values the relative values have been indicated for the test groups, as compared with the untreated control group, in per cent.

In the weight development, an additional weight gain of + 10% and + 17.8% was obtained as a result of the administration of Salinomycin of 50 mg and/pr 100 mg per animal per day respectively after a test period of 20 weeks whereas 100 mg of Monensin per animal per day only resulted in an additional weight gain of + 0.2%.

The nutrient efficiency was improved by the two Salinomycin dosages by + 9.0% and + 15.5% respectively, whereas the improvement for 100 mg of Monensin per animal per day was + 5.4%.

Control Monensin Salinomycin Salinomycin n = 5 100 mg/an.a.d. 50 mg/an.a.d. 100 mg/an.a.d. Initial n = 6 n = 7 n = 7 weight Initial wt. Initial wt. Initial wt. 258.8 kg 261.2 kg 260.7 kg 260.7 kg Test period abs. abs. rel. abs. rel. abs. rel. in weeks (kg) (kg) (%) (kg) (%) (kg) (%) Average 4 29.0 34.0 117.2 33.9 116.9 35.9 123.8 weight gain per 8 64.2 63.8 99.4 72.6 113.1 74.3 115.7 animal 12 96.4 96.5 100.1 106.2 110.2 112.6 116.8 16 130.2 126.0 96.8 144.9 111.3 150.6 115.7 20 164.6 165.0 100.2 181.0+++ 110.0 193.9+++ 117.8 Average 4 3305 2807 84.9 2855 86.4 2647 80.1 nutrient efficiency 8 3259 3145 96.5 2900 89.0 2793 85.7 st.e./kg of wt. 12 3462 3246 93.8 3145 90.8 2929 84.6 gain 16 3509 3412 97.2 3152 89.8 3005 85.6 20 3558 3366 94.6 3237+++ 91.0 3005+++ 84.5

+++Significance: 99.9% probability.

EXAMPLE 4.

A feeding test using Salinomycin was carried out on 26 fattening bulls (red and white Holstein Friesians) kept bound to a barn with individual feeding and selfwatering facilities; the average weight at the beginning of the test was about 225 kg; the test period was 20 weeks and included an individual weighing every 4 weeks.

The feed consisted of a protein concentrate and corn silage which was given to the animals in an increasing amount (from 2 to 4. kg of protein concentrate per animal per day and from 1-6 to 20 kg of corn silage per animal per day) according to their nutrient demand. The composition of the protein concentrate was as follows: Barley 26% Oats 20% Corn 45% Carbonate of feed lime 2% Hostaphos (Na-Mg-Ca-phosphate) 4% Urea 2% Sodium bicarbonate 1% 100% Starch equivalents 657 st.e.

Digestible protein: 11.1% The animals were distributed into the following groups: Group I: 6 Animals without treatment (control) Group II: 6 Animals treated with 100 mg of Monensin per animal per day Group III: 7 Animals treated with 50 mg of Salinomycin per animal per day Group IV: 7 Animals treated with 100 mg of Salinomycin per animal per day The antibiotics were administered to the test groups II, III and IV in daily doses together with the protein concentrate (in the form of a meal).

Results: The following Table shows the average weight gain and nutrient efficiency in the control group and the 3 test groups at each weighing during the test period of from 4 to 20 weeks.

In addition to the absolute values the relative values are shown for the test groups, as compared with the untreated control group, in per cent.

In the weight development, an additional weight gain of + 17.5% and 21.7% was obtained as a result of the administration of Salinomycin of 50 mg and/or 100 mg per animal per day respectively after a test period of 20 weeks whereas 100 mg of Monensin per animal per day only resulted in an additional weight gain to + 2.4%.

The nutrient efficiency was improved by the two Salinomycin dosages by + 12.5% and + 15.4% respectively, whereas 100 mg of Monensin per animal per day did not result in any improvement.

Control Monensin Salinomycin Salinomycin n= 5 100 mg/an.a.d. 50 mg/an.a.d. 100 mg/an.a.d. Initial n = 6 n = 7 n = 7 weight Initial wt. Initial wt. Initial wt. 225.0 kg 223.8 kg 223.6 kg 224.3 kg Test period . abs. abs. rel. abs. rel. abs. rel. in weeks (kg) (kg) (%) (kg) (%) (kg) (%) Average 4 27.5 26.4 96.0 30.4 110.6 33.5 121.8 weight gain per 8 54.7 53.2 97.3 62.0 113.4 62.7 114.6 12 83.5 86.4 103.5 98.0 117.4 101.0 121.0 16 117.3 122.5 104.4 142.1 121.1 147.6 125.8 20 157.5 161.2 102.4 185.0+++ 117.5 191.7+++ 121.7 Average 4 2987 3014 100.9 2640 88.4 2318 77.6 nutrient efficiency 8 3089 3114 100.8 2693 87.2 2638 85.4 st.e./kg of wt. 12 3238 3134 96.8 2780 85.9 2691 83.1 gain 16 3228 3166 98.1 2739 84.6 2634 81.6 20 3179 3175 99.9 2781+++ 87.5 2691+++ 84.6

+++Significance: 99.9% probability EXAMPLE 5.

Supplementary feed (for beef cattle) Dry chips 30% Corn meal 15% Coarse soybean meal 15% Molasses 15% Bran of peeled oats 15% Wheat bran 2.5% Urea 1.5% Mixture of mineral substances 5.0% Salinomycin-mycelium premix (with 2.5 mg/g) 1.0% 100% Thus, 1 kg of supplementary feed contained 25 mg of Salinomycin, Grazing cattle were given from 2 to 4 kg of supplementary feed per day, i.e. from 50 to 100 mg of Salinomycin.

EXAMPLE 6.

Salt in block form (for sheep) Bone meal 6 kg Sodium chloride 3 kg Salinomycin-mycelium as 1% premix 1 keg 10kg 10 Grams of salt in block form contained 10 mg of Salinornycin, i.e. a daily dose for a sheep.

EXAMPLE 7.

Bolus (for cattle) Microcrystalline cellulose 8000 mg Corn starch 1200 mg Methylhydroxyethylcellulose 900 mg Magnesium stearate 300 mg Colloidal silicic acid (Aerosil - a trade mark) 400 mg Na-amylopectine-glycolate 1000 mg 50% Salinomycin raw product 200 mg 12000 mg l Bolus of 12 g contained 100 g of Salinomycin, i.e. the daily dose for cattle.

EXAMPLE 8.

Tablet (for sheep) Microcrystalline cellulose 900 mg Corn starch 200 mg Carboxymethylcellulose 150 mg Magnesium stearate 50 mg Talcum 50 mg Aerosil (a trade mark) 350 mg Na-amylopectine-glycolate 180 mg NaCl l00 mg 50% Salinomycin raw product 20 mg 2000 mg l Bolus of 2.0 g contained 10 mg of Sälinomycin; i;e.the daily aose for a sheep.

WHAT WE CLAIM IS: 1. A process for improving the nutrient efficiency and the growth of a ruminant or rabbit which comprises administering into the digestive system of the animal Saliniomycin and/or a physiologically tolerable salt and/dr a physiologically tolerable ester thereof.

2. A process as claimed in claim 1, wherein the Salinomycin or salt or ester thereof is in the form of a mycelium or a raw product.

3. A process as claimed in either claim 1 or claim 2, wherein an ammonium salt, an alkali metal salt or an alkaline earth metal salt of Salinomycin is administered.

4. A process as claimed in either claim l or claim 2, wherein an alkyl ester of Salinomycin is administered.

5. A process as claimed in claim 4, wherein the alkyl ester is derived from an alcohol having from l to 8 carbon atoms.

6. A process as claimed in claim 5, wherein the alkyl ester is derived from an alcohol having from 1 to 4 carbon atoms.

7. A process as claimed in either claim 1 or claim 2, wherein the benzyl ester of Salinomycin is used.

8. A process as claimed in any one of claims 1 to 7, wherein the Salinomycin or salt or ester thereof is administered at intervals during a period of growth and/or fattening.

9. A process as claimed in any one of claims 1 to 8, wherein the Salinomycin or salt or ester thereof is administered to a healthy animal.

10. A process as claimed in any one of claims 1 to 9, wherein the Salinomycin or salt or ester thereof is administered immediately before, during, or immediately after feeding.

11. A process as claimed in any one of claims 1 to 10, wherein the Salinomycin or salt or ester thereof is administered in admixture or conjunction with a feedstuff or drink or a supplementary feed.

12. A process as claimed in any one of claims 1 to 10, wherein the Salinomycin or salt or ester thereof is admixed with a suitable physiologically tolerable carrier to form a premix which is administered as such to the animal or is admixed with a feedstuff or a drink or a supplementary feed which is subsequently administered to the animal.

13. A process as claimed in claim 12, wherein the carrier is wheat flour, wheat bran, de-oiled rice bran, corn meal, soy meal, bolus alba, calcium carbamate, a physiological salt solution, water or a physiologically tolerable organic solvent.

14. A process as claimed in either claim 12 or claim 13, wherein the repmix

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

EXAMPLE 8.

Tablet (for sheep) Microcrystalline cellulose 900 mg Corn starch 200 mg Carboxymethylcellulose 150 mg Magnesium stearate 50 mg Talcum 50 mg Aerosil (a trade mark) 350 mg Na-amylopectine-glycolate 180 mg NaCl l00 mg 50% Salinomycin raw product 20 mg

2000 mg l Bolus of 2.0 g contained 10 mg of Sälinomycin; i;e.the daily aose for a sheep.

WHAT WE CLAIM IS: 1. A process for improving the nutrient efficiency and the growth of a ruminant or rabbit which comprises administering into the digestive system of the animal Saliniomycin and/or a physiologically tolerable salt and/dr a physiologically tolerable ester thereof.
2. A process as claimed in claim 1, wherein the Salinomycin or salt or ester thereof is in the form of a mycelium or a raw product.
3. A process as claimed in either claim 1 or claim 2, wherein an ammonium salt, an alkali metal salt or an alkaline earth metal salt of Salinomycin is administered.
4. A process as claimed in either claim l or claim 2, wherein an alkyl ester of Salinomycin is administered.
5. A process as claimed in claim 4, wherein the alkyl ester is derived from an alcohol having from l to 8 carbon atoms.
6. A process as claimed in claim 5, wherein the alkyl ester is derived from an alcohol having from 1 to 4 carbon atoms.
7. A process as claimed in either claim 1 or claim 2, wherein the benzyl ester of Salinomycin is used.
8. A process as claimed in any one of claims 1 to 7, wherein the Salinomycin or salt or ester thereof is administered at intervals during a period of growth and/or fattening.
9. A process as claimed in any one of claims 1 to 8, wherein the Salinomycin or salt or ester thereof is administered to a healthy animal.
10. A process as claimed in any one of claims 1 to 9, wherein the Salinomycin or salt or ester thereof is administered immediately before, during, or immediately after feeding.
11. A process as claimed in any one of claims 1 to 10, wherein the Salinomycin or salt or ester thereof is administered in admixture or conjunction with a feedstuff or drink or a supplementary feed.
12. A process as claimed in any one of claims 1 to 10, wherein the Salinomycin or salt or ester thereof is admixed with a suitable physiologically tolerable carrier to form a premix which is administered as such to the animal or is admixed with a feedstuff or a drink or a supplementary feed which is subsequently administered to the animal.
13. A process as claimed in claim 12, wherein the carrier is wheat flour, wheat bran, de-oiled rice bran, corn meal, soy meal, bolus alba, calcium carbamate, a physiological salt solution, water or a physiologically tolerable organic solvent.
14. A process as claimed in either claim 12 or claim 13, wherein the repmix

also contained one or more additives selected from emufsifying agents, dispersing agents, wetting agents and gelatinizing agents.
15. A process as claimed in any one of claims 12 to 14, wherein the premix contains in the range of from 0.5 to 5% by weight of Salinomycin or a salt or ester thereof.
16. A process as claimed in any one of claims 12 to 15, wherein the premix is in the form of a powder.
17. A process as claimed in any one of claims 11 to 16, wherein the Salinomycin or salt or ester thereof is administered in admixture or conjunction with a feed stuff or drink or a supplementary feed which is a cereal, a protein concentrate, a mineral substance, a liquid feed, a non-protein nitrogen feedstuff, drinking water or milk.
18. A process as claimed in any one of claims 11 to 14, wherein the Salinomycin or salt or ester thereof is administered in admixture or conjunction with a feedstuff which is common for the nutrition of ruminants or rabbits.
19. A process as claimed in any one of claims 11 to 16, wherein the Salinomycin or salt or ester thereof is administered in admixture or conjunction with a feedstuff which comprises cellulose and/or crude fibres.
20. A process as claimed in claim 12, wherein the premix is in the form of a tablet, a bolus, capsule, granule, a juice or a syrup.
21. A process as claimed in either claim 12 or claim 20, wherein the premix is in unit dosage form.
22. A process as claimed in any one of claims 1 to 21, wherein the dajly dose of Salinomycin or salt or ester thereof is in the range of from 0.02 to 5 mg/kg body weight.
23. A process as claimed in claim 22, wherein the daily dose of Salinomycin or salt or ester thereof is in the range of from 0.1 to 1.0 mg/kg body weight.
24. A preparation for improving the nutrient efficiency and the growth of a ruminant or rabbit which comprises in the range of from 0.5 to 5% by weight of Salinomycin and/or a physiologically tolerable salt and/or a physiologically.

tolerable ester thereof, in admixture or conjunction with a suitable carrier.
25. A preparation as claimed in claim 24, wherein the carrier is a feedstuff, drink or supplementary feed.
26. A preparation as claimed in claim 25, substantially as described in any one of Examples 1, 2 and 5 to 8 herein.
27. A process as claimed in claim 1, carried out substantially as described in any one of Examples 1 to 5 herein.
28. A process as claimed in claim 1, wherein there is administered a preparation as described in any one of Examples 5 to 8 herein.
29. A process for the preparation of a preparation as claimed in claim 24, which comprises combining in the range of from 0.5 to 5% by weight of Salinomycin and/or a salt and/or an ester thereof with a liquid or solid carrier or feedstuff.