Monoesters, inner complex salts or monoester salts of hexahydro-beta-acid and application thereof as animal feed additives

Abstract

Disclosed are monoesters, inner complex salts or monoester salts of hexahydro--acid, and application thereof as animal feed additives. The compounds as shown in formula (I), (II) and (III) show low toxicity or non-toxicity to animals, and have higher stability and better growth promotion effects than those disclosed in other patents, which make them more suitable to be applied as growth promoters used in feed and have a very good application prospect in cultivation industry.

Claims

1. Inner complex salts of hexahydro--acid, having a structural formula as shown in formula (I): ##STR00008## wherein R.sub.1 is isopropyl, isobutyl or sec-butyl; and wherein M is a divalent metal ion of copper, zinc, manganese, cobalt, iron, calcium or magnesium.

2. Acetate ester salts of hexahydro--acid, having a structural formula as shown in formula (II): ##STR00009## wherein R.sub.1 is isopropyl, isobutyl or sec-butyl; and wherein M is a divalent metal ion of copper, zinc, manganese, cobalt, iron, calcium or magnesium.

3. Monoesters of hexahydro--acid, having a structural formula as shown in formula (III): ##STR00010## wherein R.sub.1 is isopropyl, isobutyl or sec-butyl; wherein R.sub.2 is (CH.sub.2).sub.nCH.sub.3, and wherein n=0 to 16.

4. An animal growth-promoting feed additive composition, comprising: the inner complex salts of hexahydro--acid according to claim 1.

5. An animal growth-promoting feed additive composition, comprising: the acetate ester salts of hexahydro--acid according to claim 2.

6. An animal growth-promoting feed additive composition, comprising: the monoesters of hexahydro--acid according to claim 3.

7. A method of feeding an animal, comprising: administering a feed comprising an animal growth-promoting feed additive comprising the inner complex salts of hexahydro--acid according to claim 1 to an animal.

8. The method of claim 7, wherein the animal is a pig, chicken, duck, goose, beef cattle, dairy cattle, sheep, fish, shrimp, fox, marten or raccoon dog.

9. The method of claim 7, wherein the inner complex salts of hexahydro--acid are provided at an additive dosage of 0.1 to 200 ppm.

10. A method of feeding an animal, comprising: administering a feed comprising an animal growth-promoting feed additive comprising the acetate ester salts of hexahydro--acid according to claim 2 to an animal.

11. The method of claim 10, wherein the animal is a pig, chicken, duck, goose, beef cattle, dairy cattle, sheep, fish, shrimp, fox, marten or raccoon dog.

12. The method of claim 10, wherein the acetate ester salts of hexahydro--acid are provided at an additive dosage of 0.1 to 200 ppm.

13. A method of feeding an animal, comprising: administering a feed comprising an animal growth-promoting feed additive comprising the monoesters of hexahydro--acid according to claim 3 to an animal.

14. The method of claim 12, wherein the animal is a pig, chicken, duck, goose, beef cattle, dairy cattle, sheep, fish, shrimp, fox, marten or raccoon dog.

15. The method of claim 12, wherein the monoesters of hexahydro--acid are provided at an additive dosage of 0.1 to 200 ppm.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

(1) The present invention is described in further detail with reference to embodiments which shall not be regarded as limits to the present invention.

Embodiment 1

Extraction of -acid

(2) 1 kg of hop extracts, 1 L of absolute ethanol, and 90 g of potassium hydroxide (which was dissolved in 100 ml of water) were added into a 5 L vessel, and stirred at room temperature to give a uniform mixture. The mixture was added with 3 L of tap water with stirring, stirred for one hour, let stand for 30 minutes, and filtrated to remove grease and insolubles. The filtrate was collected, and the layers were separated. CO.sub.2 gas was passed through the water phase to give a great amount of precipitate. Then the water phase was added with 1.2 L of aqueous solution of 10% potassium hydroxide, followed by addition of 200 mL of n-hexane, and the layers were separated. The organic phase and the oil layer were removed. The water phase was collected, adjusted with aqueous solution of 20% phosphate acid, and extracted with 1 L of n-hexane. The resulting organic phase was concentrated in vacuum to give about 400 g of crude product of -acid (the content was about 90%).

(3) ##STR00004##

(4) To a hydrogenation reactor was added about 360 g of the crude product of -acid, followed by 95% ethanol to afford a total volume of 2.5 L, and eventually 36 g of 10% palladium on carbon. Agitation began and the reactor were purged with nitrogen for three times and then with hydrogen for three times. Then the reaction was continued for 1215 hours at room temperature under a pressure of 0.60.7 MPa. After the reaction was complete, the resulting solution was filtrated to remove the palladium on carbon. The filtrate was concentrated in vacuum to remove of the solvent, added with 3.5 L tap water with stirring, stirred for about 12 hours, and then subjected to suction filtration. The solids were collected as hexahydro--acid, about 340 g after being dried over night at 50 C.

Embodiment 3

Synthesis of Inner Complex Salts of Hexahydro--acid

(5) Synthesis of salt derivatives of the hexahydro--acid is as shown below, wherein the first step is the formation of potassium salt by the reaction between hydroxyl group and potassium hydroxide, followed by the formation of corresponding salt by replacing the potassium with other metal.

(6) ##STR00005##

Process

Embodiment 3.1

Preparation of Copper Salt of Hexahydro--acid (IST_011_011)

(7) 5.0 g of hexahydro--acid was dissolved in 15 ml of 95% ethanol. 2.1 g of potassium hydroxide was dissolved in 32 ml of water. The potassium hydroxide solution was added dropwise into the hexahydro--acid solution, and the resulting mixture was stirred to give potassium salt. Then 5.0 g of copper chloride dihydrate was dissolved in 30 ml of water, and the resulting solution was added dropwise into the potassium salt solution. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water, and dried to give 5.4 g of dark blue solids (copper salt of hexahydro--acid), the yield of which is about 93%.

Embodiment 3.2

Preparation of Magnesium Salt of Hexahydro--acid (IST_011_012)

(8) 5.0 g of hexahydro--acid was dissolved in 15 ml of ethanol. 1.8 g of potassium hydroxide was dissolved in 20 ml of water. The potassium hydroxide solution was added into the hexahydro--acid solution, and the resulting mixture was stirred for 1 hour. 2.9 g of magnesium chloride hexahydrate (1 eq) was dissolved in 20 ml of water, and the resulting solution was added dropwise into the potassium salt solution. Then the resulting mixture was stirred for 1 hour to give white solids and then filtrated. The filter cake was washed with water, and dried to give 5.0 g of white solids (magnesium salt of hexahydro--acid), the yield of which is about 97% (FIG. 1).

Embodiment 3.3

Preparation of Calcium Salt of Hexahydro--acid (IST_011_013)

(9) 5.0 g of hexahydro--acid was dissolved in 15 ml of 95% ethanol. 1.9 g of potassium hydroxide was dissolved in 32 ml of water. The potassium hydroxide solution was added dropwise into the hexahydro--acid solution, and the resulting mixture was stirred to give potassium salt. 3.4 g of calcium chloride was dissolved in 20 ml of water, and the resulting solution was added dropwise into the potassium salt solution. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water and dried to give 4.4 g of yellowish solids (calcium salt of hexahydro--acid), the yield of which is about 80% (FIG. 2).

Embodiment 3.4

Preparation of Zinc Salt of Hexahydro--acid (IST_011_014)

(10) 6.0 g of hexahydro--acid was dissolved in 15 ml of 95% ethanol, followed by addition of 1.8 g of potassium hydroxide, and then stirred to give salt. The resulting solution was added with 3.0 g of zinc chloride and stirred for 1 hour, then added dropwise with 20 ml of water and stirred for 1 hour, and added with 60 ml of water and stirred for 2 hours. Then the solution was filtrated, the filter cake was washed with water, and dried to give 6.8 g of yellowish solids (zinc salt of hexahydro--acid), the yield of which is about 99% (FIG. 3).

Embodiment 3.5

Preparation of Manganese Salt of Hexahydro--acid (IST_011_015)

(11) 5.0 g of hexahydro--acid was dissolved in 15 ml of 95% ethanol. 2.0 g of potassium hydroxide was dissolved in 32 ml of water. The potassium hydroxide solution was added dropwise into the hexahydro--acid solution, and the resulting mixture was stirred to give potassium salt. 4.3 g of manganese chloride was dissolved in 50 ml of water, and the resulting solution was added dropwise into the potassium salt solution. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water, and dried to give 5.6 g of yellow solids (manganese salt of hexahydro--acid), the yield of which is about 98% (FIG. 4).

Embodiment 3.6

Preparation of Cobalt Salt of Hexahydro--acid (IST_011_016)

(12) 5.0 g of hexahydro--acid was dissolved in 15 ml of 95% ethanol. 2.0 g of potassium hydroxide was dissolved in 32 ml of water. The potassium hydroxide solution was added dropwise into the hexahydro--acid solution, and the resulting mixture was stirred to give potassium salt. 7.0 g of cobalt chloride hexahydrate was dissolved in 50 ml of water, and the resulting solution was added dropwise into the potassium salt solution. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water, and dried to give 5.3 g of yellowish solids (cobalt salt of hexahydro--acid), the yield of which is about 93% (FIG. 5).

Embodiment 3.7

Preparation of Ferrous Salt of Hexahydro--acid (IST_011_017)

(13) 6.1 g of hexahydro--acid was dissolved in 24 ml of 95% ethanol, followed by addition of 2.0 g of potassium hydroxide, and then stirred to give salt. The resulting solution was added with 4.6 g of ferrous sulfate heptahydrate and stirred for 1 hour, then added dropwise with 20 ml of water and stirred for 1 hour, and added with 60 ml of water and stirred for 2 hours. Then the solution was filtrated, the filter cake was washed with water, and dried to give 6.1 g of brown solids (ferrous salt of hexahydro--acid), the yield of which is about 88% (FIG. 6).

Embodiment 4

Synthesis of Acetate Ester Salt Derivatives of Hexahydro--acid

(14) Synthesis of acetate ester salt derivatives of hexahydro--acid is as shown below, wherein the first step is the formation of potassium salts by the reaction between hydroxyl group and potassium hydroxide, followed by the formation of corresponding salt by replacing the potassium with other metal.

(15) ##STR00006##

Process

Embodiment 4.1

Preparation of Copper Salt of Acetate Ester of Hexahydro--acid (IST_011_004)

(16) 5 g of acetate ester of hexahydro--acid was dissolved in 40 ml of 95% ethanol. The resulting solution was cooled to 0 C. with stirring, and then added with 95 ml of aqueous solution of 1% potassium hydroxide dropwise within about 20 minutes. 2.0 g of copper chloride dihydrate was dissolved in 20 ml of water, and the resulting solution was added dropwise into the potassium solution. Then the resulting mixture was stifled for 1 hour and filtrated. The filter cake was washed with water, and dried to give 4.5 g of dark green solids (copper salt of acetate ester of hexahydro--acid), the yield of which is about 83% (FIG. 7).

Embodiment 4.2

Preparation of Magnesium Salt of Acetate Ester of Hexahydro--acid (IST_011_005)

(17) 5.3 g of acetate ester of hexahydro--acid was dissolved in 40 ml of 95% ethanol. The resulting solution was cooled to 0 C. with stirring, and then added with 100 ml of aqueous solution of 1% potassium hydroxide dropwise within about 0.5 h. 0.98 g of magnesium sulfate was dissolved in 10 ml of water, and the resulting solution was added dropwise into the potassium solution. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water, and dried to give 4.8 g of yellowish solids (magnesium salt of acetate ester of hexahydro--acid), the yield of which is about 87% (FIG. 8).

Embodiment 4.3

Preparation of Calcium Salt of Acetate Ester of Hexahydro--acid (IST_011_006)

(18) 5.3 g of acetate ester of hexahydro--acid was dissolved in 40 ml of 95% ethanol. The resulting solution was cooled to 0 C. with stirring, and then added with 100 ml of aqueous solution of 1% potassium hydroxide dropwise within about 0.5 h. 1.0 g of calcium chloride was dissolved in 10 ml of water, and the resulting solution was added into the potassium solution. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water, and dried to give 2.5 g of yellowish solids (calcium salt of acetate ester of hexahydro--acid), the yield of which is about 46% (FIG. 9).

Embodiment 4.4

Preparation of Zinc Salt of Acetate Ester of Hexahydro--acid (IST_011_007)

(19) 0.5 g of acetate ester of hexahydro--acid was dissolved in 40 ml of 95% ethanol. The resulting solution was added with 95 ml of aqueous solution of 1% potassium hydroxide dropwise within about 20 minutes. 0.9 g of zinc chloride was dissolved in 20 ml of water, and the resulting solution was added into the potassium solution. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water, and dried to give 2.5 g of yellowish solids (zinc salt of acetate ester of hexahydro--acid), the yield of which is about 46% (FIG. 10).

Embodiment 4.5

Preparation of Cobalt Salt of Acetate Ester of Hexahydro--acid (IST_011_009)

(20) 10.4 g of acetate ester of hexahydro--acid was dissolved in 80 ml of 95% ethanol. The resulting solution was cooled to 0 C., and added with 200 ml of aqueous solution of 1% potassium hydroxide dropwise within about 0.5 h, followed by the addition of 4.5 g of cobalt chloride hexahydrate. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water, and dried to give 8.0 g of brown solids (cobalt salt of acetate ester of hexahydro--acid), the yield of which is about 73% (FIG. 11).

Embodiment 4.6

Preparation of Manganese Salt of Acetate Ester of Hexahydro--acid (IST_011_008)

(21) 10.5 g of acetate ester of hexahydro--acid was dissolved in 80 ml of 95% ethanol. The resulting solution was cooled to 5 C., and added with 200 ml of aqueous solution of 1% potassium hydroxide dropwise within about 20 minutes. 1.9 g of manganese chloride was dissolved in 30 ml of water, and the resulting solution was added dropwise into the potassium solution. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water, and dried to give of dark brown solids (manganese salt of acetate ester of hexahydro--acid), the yield of which is about 72%.

Embodiment 4.7

Preparation of Ferrous Salt of Acetate Ester of Hexahydro--acid (IST_011_010)

(22) 10.5 g of acetate ester of hexahydro--acid was dissolved in 80 ml of 95% ethanol. The resulting solution was cooled to 5 C., and added with 200 ml of aqueous solution of 1% potassium hydroxide dropwise within about 20 minutes. 5.0 g of FeSO.sub.4.7H.sub.2O was dissolved in 30 ml of water, and the resulting solution was added dropwise into the potassium solution. Then the resulting mixture was stirred for 1 hour and filtrated. The filter cake was washed with water, and dried to give 5.0 g of red-brown solids (manganese salt of acetate ester of hexahydro--acid), the yield of which is about 45% (FIG. 12).

Embodiment 5

Synthesis of Monoesters of Hexahydro--acid (IST_011)

(23) Various monoester derivatives of hexahydro--acid were formed by the reaction between hexahydro--acid and acyl chloride with triethylamine as alkali and dichloride methane as solvent. Following is a schematic of the preparation of the target ester derivatives. Water should be prevented from involving in the preparation.

(24) ##STR00007##

Embodiment 5.1

Preparation of Mono Acetate Ester of Hexahydro--acid (IST_011_001)

(25) 20 g of hexahydro--acid (with a molecular weight of 420) was dissolved in 200 ml of dichloride methane, followed by the addition of 4.8 g of triethylamine (with a molecular weight of 101.19). The resulting mixture was cooled to 50 C. with stilling. 3.9 g of acetyl chloride (with a molecular weight of 78.5) was dissolved in 20 ml of dichloride methane, and the resulting solution was added dropwise into the hexahydro--acid solution within 0.5 h. Then the reaction was continued for 1 hour, monitored by HPLC. The mixture was then let stand until room temperature, added with 40 ml of pure water, stirred, and the layers were separated. The organic phase was washed with 100 ml of water for three times, dried over anhydrous sodium sulfate, and subjected to decompression to remove the solvent and give 22.6 g of oily product (mono acetate ester of hexahydro--acid), the yield of which is 104% (FIG. 13).

Embodiment 5.2

Preparation of Mono Decanoate Ester of Hexahydro--acid (IST_011_002)

(26) 20.4 g of hexahydro--acid (with a molecular weight of 420) was dissolved in 100 ml of dichloride methane, followed by the addition of 4.8 g of triethylamine with a molecular weight of 101.19). The resulting mixture was cooled to 50 C. with stirring. 9.8 g of decanoly chloride (molecular weight: 190.71, d: 0.92) was dissolved in 50 ml of dichloride methane, and the resulting solution was added dropwise into the hexahydro--acid solution within 0.5 h. Then the reaction was continued for 1 hour, monitored by TLC. The mixture was then let stand until room temperature, added with 40 ml of pure water, stirred, and the layers were separated. The organic phase was washed with 50 ml of water for three times, dried over anhydrous sodium sulfate, decolored on silica gel, and the solvent was removed to give 27.5 g of oily product (mono decanoate ester of hexahydro--acid), the yield of which is 102% (FIG. 14).

Embodiment 5.3

Preparation of Mono Stearate Ester of Hexahydro--acid (IST_011_003)

(27) 10.0 g of hexahydro--acid (with a molecular weight of 420) was dissolved in 40 ml of dichloride methane, followed by the addition of stearoyl chloride (with a molecular weight of 302.9). The resulting mixture was cooled to 0 C. 2.4 g of triethylamine (with a molecular weight of 101.19) was dissolved in 6 ml of dichloride methane, and the resulting solution was added dropwise into the hexahydro--acid solution within 0.5 h. The reaction was continued for 2 hours, monitored by TLC. The mixture was then let stand until room temperature, and added with 50 ml of pure water. No distinct liquid-separation was observed. Then the mixture was added with 5 g of sodium chloride and stirred, the layers were separated. The organic phase was dried over anhydrous sodium sulfate, and then the solvent was removed, to give 16.9 g of oily product (mono stearate ester of hexahydro--acid), the yield of which is 103% (FIG. 15).

Embodiment 5.4

Preparation of Butyrate Ester Hexahydro--acid (IST_011_018)

(28) 5.0 g of hexahydro--acid (with a molecular weight of 420) was dissolved in 40 ml of dichloride methane, followed by the addition of 1.8 g of butyryl chloride (with a molecular weight of 106.6). The resulting mixture was cooled to 0 C. 3 ml of triethylamine with a molecular weight of 101.19) was dissolved in 6 ml of dichloride methane, and the resulting solution was added dropwise into the hexahydro--acid solution within 0.5 h. Then the reaction was continued for 2 hours, monitored by TLC. The mixture was then let stand until room temperature, added with 50 ml of pure water, stirred, and the layers were separated. The organic phase was dried over anhydrous sodium sulfate, and the solvent was removed. Then a column chromatography was performed to give 2.4 g of oily product (butyrate ester of hexahydro--acid), the yield of which is 40% (FIG. 16).

Embodiment 5.5

Preparation of Caprylate Ester of Hexahydro--acid (IST_011_019)

(29) 5.0 g of hexahydro--acid (with a molecular weight of 420) was dissolved in 40 ml of dichloride methane, followed by the addition of 2.9 g of caprylyl chloride (with a molecular weight of 162.6). The resulting mixture was cooled to 0 C. 3 ml of triethylamine (with a molecular weight of 101.19) was dissolved in 6 ml of dichloride methane, and the resulting solution was added dropwise into the hexahydro--acid solution within 0.5 h. Then the reaction was continued for 2 hours, monitored by TLC. The mixture was then let stand until room temperature, added with 50 ml of pure water, stirred, and the layers were separated. The organic phase was dried over anhydrous sodium sulfate, and the solvent was removed. Then a column chromatography was performed to give 3 g of oily product (caprylate ester of hexahydro--acid), the yield of which is 46% (FIG. 17).

Embodiment 5.6

Preparation of Laurate Ester of Hexahydro--acid (IST_011_020)

(30) 5.0 g of hexahydro--acid (with a molecular weight of 420) was dissolved in 40 ml of dichloride methane, followed by the addition of 4.2 ml of lauroyl chloride (with a molecular weight of 218.8). The resulting mixture was cooled to 0 C. 3 ml of triethylamine (with a molecular weight of 101.19) was dissolved in 6 ml of dichloride methane, and the resulting solution was added dropwise into the hexahydro--acid solution within 0.5 h. Then the reaction was continued for 2 hours, monitored by TLC. The mixture was then let stand until room temperature, added with 50 ml of pure water, stirred, and the layers were separated. The organic phase was dried over anhydrous sodium sulfate, and the solvent was removed. Then a column chromatography was performed to give 4 g of oily product (laurate ester of hexahydro--acid), the yield of which is 53% (FIG. 18).

Embodiment 5.7

Preparation of Cetylate Ester of Hexahydro--acid (IST_011_021)

(31) 5.0 g of hexahydro--acid (with a molecular weight of 420) was dissolved in 40 ml of dichloride methane, followed by the addition of 5.5ml of palmitic chloride (with a molecular weight of 274.9). The resulting mixture was cooled to 0 C. 3 ml of triethylamine (with a molecular weight of 101.19) was dissolved in 6 ml of dichloride methane, and the resulting solution was added dropwise into the hexahydro--acid solution within 0.5 h. Then the reaction was continued for 2 hours, monitored by TLC. The mixture was then let stand until room temperature, added with 50 ml of pure water, stirred, and the layers were separated. The organic phase was dried over anhydrous sodium sulfate, and the solvent was removed. Then a column chromatography was performed to give 3.5 g of oily product (cetylate ester of hexahydro--acid), the yield of which is 44% (FIG. 19).

Embodiment 6

Thermo Stability Test of Esters and/or Salts of Hexahydro--acid

(32) The esters and/or salts of hexahydro--acid prepared in the above embodiments were mixed with corncob powder to obtain premixes with a mass fraction of 2%. Samples (the premixes) were placed in crucibles, and then placed in oven at 100 C. for different durations. Then 1.0 g of each of the samples (three duplicate samples from each sample) and 50 ml of ethanol were added into a conical flask, followed by the addition of 100 L of concentrated hydrochloric acid. The mixture was then subjected to sonication for 5 minutes, and then filtrated. The filtrate was transferred into a 50 ml volumetric flask, topped up to the final volume with ethanol, and then filtered with a 0.45 m microporous membrane and subjected to HPLC analysis.

(33) Results of the stability test were as shown in table 1. Results showed that the thermal stability of each of the esters and/or salts of hexahydro--acid was enhanced.

(34) TABLE-US-00001 TABLE 1 Change of the main component of the esters and/or salts of hexahydro--acid after being heated at 100 C. for different durations Content when Content when being being Initial heated at heated at content 100 C. for 100 C. for Compound (%) 20 h (%) 44 h (%) Hexahydro--acid 2.0 0.06 0 Mono acetate ester of 2.0 1.52 1.11 hexahydro--acid Mono decanoate ester of 2.0 1.93 1.82 hexahydro--acid Copper salt of acetate ester 2.0 1.50 1.28 of hexahydro--acid Magnesium salt of acetate 2.0 1.42 0.7 ester of hexahydro--acid Calcium salt of acetate ester 2.0 1.21 0.31 of hexahydro--acid Zinc salt of acetate ester of 2.0 1.64 0.70 hexahydro--acid Manganese salt of acetate 2.0 0 0 ester of hexahydro--acid Cobalt salt of acetate ester 2.0 0.17 0.12 of hexahydro--acid Ferrous salt of acetate ester 7.0 1.69 1.63 of hexahydro--acid Magnesium salt of 2.0 1.49 0.91 hexahydro--acid Calcium salt of 7.0 0.35 0.09 hexahydro--acid Zinc salt of 2.0 0.95 0.52 hexahydro--acid Ferrous salt of 2.0 0.14 0.05 hexahydro--acid Butyrate ester of 2.0 1.74 0.69 hexahydro--acid Caprylate ester of 2.0 2.0 1.51 hexahydro--acid Laurate ester of 2.0 2.0 1.96 hexahydro--acid Cetylate ester of 2.0 1.98 1.93 hexahydro--acid

Embodiment 7

Application Effect in Broiler Feed

(35) 500 1-day-aged, healthy, fast-grown yellow feather broilers (female) in the same growing state and similar in weight were randomly divided into five groups according to table 2, 100 broilers in each group. Broilers of each group were fed with different dosages of mono decanoate ester of hexahydro--acid or hexahydro--acid.

(36) The broilers were kept in cages and fed with food and water ad libitum during a 30 days test period, wherein weight gain and feed conversion efficiency of the broilers fed with mono decanoate ester of hexahydro--acid had been significantly improved, and improvement of the productivity of the broilers fed with mono decanoate ester of hexahydro--acid was more significant than that of the broilers fed with hexahydro--acid in the same dosage (table 3).

(37) TABLE-US-00002 TABLE 2 Grouping of tested animals, and dosage of additives Quantity of Group the broilers Additive Dosage Administration 1 100 2 100 Hexahydro--acid 2 ppm Mixed with feed 3 100 Mono decanoate ester of 2 ppm Mixed with hexahydro--acid feed 4 100 Hexahydro--acid 20 ppm Mixed with feed 5 100 Mono decanoate ester of 20 ppm Mixed with hexahydro--acid feed : control blank, wherein neither mono decanoate ester of hexahydro--acid nor hexahydro--acid was added

(38) TABLE-US-00003 TABLE 3 Application effect of mono decanoate ester of hexahydro--acid and hexahydro--acid in broiler feed Initial Average Con- Average Feed weight Survival weight sumption daily weight conversion Group (g) rate (%) gain (g) (kg) gain (g) efficiency 1 39.0 100 738 154.64 24.6 2.09 2 39.0 100 745 147.76 24.83 1.983 3 39.3 100 768 147.94 25.6 1.926 4 39.2 100 758 149.18 25.26 1.968 5 39.5 100 797 146.42 26.57 1.837

Embodiment 8

Application Effect in Pig Feed

(39) 120 67-day-aged, Duroc-Yorkshire-Landrace crossbred lean pigs similar in weight were randomly divided into six groups, 20 pigs in each group. Pigs in each group were fed with mono cetylate ester of hexahydro--acid with the types and the dosages listed in table 4. The pigs were fed with food and water ad libitum for 14 days, wherein weight gain and feed conversion efficiency of the pigs fed with mono cetylate ester of hexahydro--acid had been significantly improved. Grouping and results of the trial were as shown in table 4 and table 5.

(40) TABLE-US-00004 TABLE 4 Grouping of the animals, and dosages of additives Quantity of Group the pigs Additive Dosage (mg/kg) Administration 1 20 2 20 3 20 Cetylate ester of 5 Mixed with hexahydro--acid feed 4 20 Cetylate ester of 25 Mixed with hexahydro--acid feed 5 20 Cetylate ester of 5 Mixed with hexahydro--acid feed 6 20 Cetylate ester of 25 Mixed with hexahydro--acid feed

(41) TABLE-US-00005 TABLE 5 Application effect of cetylate ester of hexahydro--acid in pig feed Average Average Average daily Consump- Feed initial weight gain weight gain tion conversion Group weight (kg) (kg) (kg/day) (kg) efficiency 1 17.01 5.875 0.419 271.3 2.309 2 16.87 5.685 0.406 257.9 2.269 3 17.53 7.18 0.512 298.4 2.078 4 17.74 7.985 0.570 272.5 1.706 5 17.02 7.11 0.508 277.2 1.949 6 17.81 8.12 0.580 274.5 1.690