ANTIBIOTIC FEED COMPOSITIONS AND METHOD OF ENHANCING FEED EFFICIENCY AND PROMOTING GROWTH IN MONOGASTIC ANIMALS

Abstract: Methods and compositions utilizing virginiamycin and a glycopeptide antibiotic derivative which enhance feed efficiency and promote growth of monogastic animals, particularly broilers. The preferred compounds to be used as active ingredients are virginiamycin and ardacin.

Description: ANTIBIOTIC FEED COMPOSITIONS AND METHOD OF ENHANCING FEED EFFICIENCY AND PROMOTING GROWTH IN MONOGASTIC ANIMALS Field of the Invention The present invention relates to Antibiotic Animal Feed Compositions which are useful to enhance feed efficiency and promote growth. In particular this invention relates to a combination of antibiotics in animal feed which provides an improvement in growth and feed utilization efficiency which is greater than can be achieved when either antibiotic is fed alone. The added response of the combination is novel and unexpected since each of the antibiotics have similar antimicrobial spectra. Background of the Invention It is known that certain additives to the diet of healthy animals enhance the feed efficiency and promote growth of the animals. For example, ardacin, also known as the AAD ' 216 complex, is fully described in U.S. Patent 4,548,974. The patent discloses that the complex exhibits both antibiotic and growth promoting activity. Antibiotic compositions for animal feeding which contain virginiamycin are disclosed in U.S. Patent 3,627,885. However, although ardacin and virginiamycin are known individually for their growth promoting activity, when added to animal feed, the combination of these antibiotics in animal feed, advantageously chicken feed, have unexpectedly provided an improvement in growth and feed efficiency which is greater than can be achieved when either of the antibiotics are fed alone. This novel discovery is particularly outstanding when feeding growing broilers as will be illustrated hereafter. Description of the Invention The animal feed compositions of this invention will contain the combination of ardacin and virginiamycin in an amount of from about 2.5 ppm to about 30 ppm of animal feed. Preferably, the ratio of virginiamycin to the glycopeptide antibiotic derivative will be 1:1. These feed compositions are administered orally to growing meat producing animals such as ruminants, swine and advantageously chickens-. For commercial use, the active ingredients may be used as premix formulations in which the active ingredients are distributed uniformly throughout a standard animal feed carrier. The premix or concentrate is then mixed with either a normal or a special fattening diet of the animal as desired. Examples of such carriers are soybean meal, ' corn oil ground corn, barley, wheat, mineral mixtures such as vermiculites, diotomaceous earth, corn gluten meal, corn distillers solubles or soy flour. The premix may be in a liquid or solid form. The concentration of the combination of active ingredients in the premix may be from about 5% to about 75% by weight or a concentration of 100-2000 times greater than that in the complete feed composition. The premix is then uniformly mixed with the whole ration which is fed to the target animal. Such premix compositions are included in the term feed compositions as employed herein. The supplemental animal feeds themselves may also contain cellulosic roughage such as cellulose, hay,, straw, corn stalks, cotton seed hulls, oats, barley and cereal beans; natural oils such as animal fats, fish oils, and whole oil; vegetable oils such as soybean oil, olive, oil, sunflower oil, peanut oil, and cottonseed oil; antioxidants, minerals, vitamins, antibiotics, anthelmintics and other appropriate medicaments. The diets employed in this invention were prepared from a standard formula characteristic of poultry diets used by the broiler industry. The formulas meet the criteria set forth by the National Research Council. The feed efficiency and growth promotant studies were determined in broilers employing the following formulas and procedure. FEED FORMULAS INGREDIENT STARTER GROWER FINISHER Yellow com (ground) Soybean oil meal ( ehulled, 48%) Valley Blend (51%) Oil (poultry fat) Deflourinated Phosphate 18 L-Lysine 78.4% Limestone- (ground) Salt Methionine Choline 70 Vitamin premix Trace mineral premix A premix of the active ingredients in ground corn meal was added to, and uniformly mixed with the above feed formulas. The final mixture resulted in the treatment as outlined in Table I. Crumbled feeds were fed from day 0 to day 21, i.e., starter to grower and pelleted feeds were fed from day 22 to day 49. Experimental Procedure Day-old, broiler chickens (Peterson x Arbor Acres) were assigned to pens in blocks. Seventy-two birds, 36 males and 36 females, were placed in each of 72 floor pens. All pens were provided their respective medicated feed and water ad libitum. The six treatments were randomly assigned to pens within each of the 12 blocks in the following manner: Table I Blocks 1 2 3 4 5 6 7 8 9 10 11 12 Control 2 7 14 19 30 33 38 .47 54 60 62 72 VM 10 ppm 6 - 8 17 24 26 35 42 45 52 56 63 70 ARD 5 ppm 5 12 15 22 27 36 37 48 53 59 64 67 ARD 2.5 ppm + VM 2.5 ppm 4 11 18 21 29 34 40 46 51 58 66 69 ARD 2.5 ppm + VM 5 ppm . 1 9 16 20 25 31 41 44 49 57 65 71 ARD 1.25 ppm + VM lOppm 3 10 13 23 28 32 39 43 50 55 61 68 Virginiamycin and ardacin were fed until the final weigh day with Maduramicin added as a coccidiostat until Day 45. The birds were weighed by pen and sex at change from starter to grower (Day 21) and at end of study (Day 47) . Feed consumption was measured during starter, grower and finisher periods. Mortality was recorded daily along with, weights of dead birds. Any bird that died or was culled during the first seven days of the trial was replaced with a bird of the same sex from a holding pen of the same shipment. The weights of the dead birds were used to calculate feed efficiency. Following are the results obtained. Table π Dav 21 Day 7 Av Av Body Body Treatment n_ Wt .lbs. FCR* Mortality Wt . FCR Mortality Control 12 1.32 1.56 1.9 4.59 2.15 7.8 VM 10 ppm 12 1.39 1.49 2.2 4.76 2.16 8.9 ARD 5 ppm 12 1.46 1.50 1.9 4.77 2.13 7.3 ARD 1.25 ppm + VM 10 ppm 12 1.51**c 1.42**c 2.4 4.86 2.08*a 7.8 ARD 2.5 ppm + VM 2.5 ppm 12 1.47** 1.47 2.0 4.88+ 2.05**b 10.2a ARD 2.5 ppm + VM 5 ppm 12 1.50**b 1.45+b 1.9 4.84 2.07**b 10.5b Statistical significance of ardacin + VM combinations to VM 10 p (two-tailed t-test) denoted: +P<0.10; *P<0.05; *.*P<0.01. Statistical significance of ardacin + VM combinations to ardacin 5 ppm (two-tailed t-test) denoted: a P<0.10; t) P<0.05; C P<0.01. * Feed Conversion Ratio - Amount of feed required to gain one pound. The deaths that are disclosed in Table II were not treatment related but were from causes common to the poultry industry. There were no unusual deaths observed in this trial. The above results set forth in Table II clearly demonstrated that after both days 21 and 47 the average body weight of broilers fed any of the three ardacin/virginiamycin combinations were significantly heavier than broilers fed these compounds alone. Further, the feed conversion of broilers treated with the ardacin/virginiamycin combinations was also significantly better than that noted for broilers fed the compounds alone. The method of this invention comprises allowing monogastric animals such as poultry or swine, to feed ad- libitum on the supplemented rations or to be fed under pen conditions on a regular schedule. The supplemental feed rations are presented to the animals by methods known to the art. Ad libitum feeding in the pen is most convenient to increase the growth of the animal and feed efficiency of the operation. The animals are fed an effective but nontoxic quantity of the active ingredients sufficient to produce growth and increase feed efficiency.

Claims: What is Claimed is: 1. The method of enhancing feed efficiency and promoting the growth of animals compromising orally administering to said animal an effective but nontoxic quantity of a combination of virginiamycin and a glycopeptide antibiotic derivative. 2. The method of -Claim 1 wherein the glycopeptide antibiotic derivative is ardacin. 3. The method of Claim 2 wherein the combination of virginiamycin and ardacin is present in an amount of from about 2.5 ppm to about 30 ppm of an animal feed composition. 4. The method of Claim 1 wherein the animals are broilers 5. An animal feed composition effective for, enhancing the feed efficiency and promoting the growth of animals comprising a supplement of an effective but non toxic quantity of a combination of virginiamycin and a glycopeptide antibiotic derivative in said feed composition. 6. The composition of Claim 5 wherein the glycopeptide antibiotic derivative is ardacin. 7. The composition of Claim 6 wherein the combination of virginiamycin and ardacin is present is an amount of from about 2.5 ppm to about 30 ppm. 8. A premix feed composition comprising from about 5% to about 75% by weight of a virginiamycin - ardacin combination.

Inventors: HEDDE RICHARD D, LINDSEY THOMAS O, HEDDE, RICHARD, D., LINDSEY, THOMAS, O.
Applicants: SMITHKLINE BEECHAM CORP, SMITHKLINE BEECHAM CORPORATION
Application year: 1992
Main classification: C07K5
IPC codes: A23K1, A61K38, A61P3