IL33118A - Growth promotion in animals comprising the administration of 1-methyl-5-nitroimidazol-2-ylmethyl carbamate thereto - Google Patents

Description

33118/3 -1-3 οπ31 π η»"»π ' ya iTjn *m»p GROWTH PROMOTIOli IN ANIMALS OOMPRISIIG THE ADMINISTRATION OF l-METHYl*-5»NITROIMI ZOL~ 2-YU-IETHYL CARBAMATE THERETO MERCK & CO., C:31183 -la- 33118/2 This invention is concerned with the promotion of growth in animals.

It is known that the growth rate of animals can be accelerated by administration of certain classes of substances, e.g. antibiotics, surfactants and estrogens.

The administration of each of these classes of substances had disadvantages, however, which have prevented their universal acceptance. Thus, it is believed that antibiotics and surfactants, while effective under certain conditions, principally act to suppress diseases and do not elicit a true growth response. Although the growth-promoting advantages of estrogens are well known, their use presents certain inherent difficulties and hazards. Thus, estrogens frequently downgrade the animal to which they are administered. Another disadvantage is that some of the estrogenic material may remain in the edible portions of the animal and could presumably produce an adverse effect on an Individual when consumed.. Further, the known substances have principall been administered by injection or implantation procedures, which are both costly and time-consuming* It has now been flmnd that the disadvantages of the prior art substances and methods oan be overcome, and that growth promotion can be achieved by orally administering l-methyl-5-nitroimidazol-2-ylmethyl carbamate to animals in conjunction with their normal feed or drinking water. li-Hethyl-5-nitroimidazol-2-ylmethyl carbamate is a known compound and is claimed in our prior Paten -2- 33118/2 No. 25931. The effectiveness of this compound against various protozoal diseases is known. Thus, the said patent olaims a method of preventing or controlling entero-hepatitis in commercially reared poultry that comprises administering l^methyl-5-nitroimidazol-2-ylmethyl carbamate to the poultry, and also claims elements of poultry sustenance (including turkey feedstuffs and water-dispersible powders) containing l-methyl~5-nitroimidazol-2-ylmethyl carbamate .

It has now been unexpectedly found that 1-meth l-5-nltroimidazol-2-ylmethyl carbamate effects a remarkable growth-promoting response in animals, partitularly poultry and svine, when administered within clearly defined concentrations in the animal feed and/or water. Injection and/or implantation is unnecessary and the animals orally ingest the l-methyl-5-nitrolmidazol-2-ylmeth l carbamate free choice with their feed.

In accordance with the present invention, there is provided a method for promoting the growth of non-human animals that comprises administering to the animals a feedstuff containing from 0.0015$ to 0.03$ by weight of l-methylr5-nitroimidazol-2-ylmethyl carbamate or water containing from 0.00075$ to 0.015$ by weight of l-methyl-5-nitroimidazol-2-ylmethyl carbamate.

The l-methylT5-nitroimidazolr2-ylmethyl carbamate is conveniently incorporated directly in the animal feed and/or water. Any suitable method for dispersing the material in the feed can be used. The amount of l-methyl-5-nitroimidazol- 2-ylmethyi carbamate added to the animal feed and/or water may : be varied within the limits stated in. order to obtain the maximum : benefits. Preferably, an animal feed contains from 0.003 to 0.013^ and water contains 0.0015 to 0.0065$ by weight of l-methyl- 5-hitroimidazol-2-ylmethyl carbamate in order to obtain optimum growth under desirable conditions, these quantities resulting in • ¾diainiB ration of substantially equal amounts of the growth promotant to the animal, because an animal will normally ingest twice the unit volume of water as it will feed5 Accordingly, a concentration of 0.006 wt $ in feed is equivalent to a concentration Of P„Q03 wt 5¾ in water or a combined concentration of 0.0015 wt ≠ in water plus 0,003 wt % in feed,,, Feedstuffs and/or water supplemented with l-methyl-5- nitroimidazol-,2-ylmethyl carbamate are particularly suitable for the commercial rearing of poultry and swine ; By utilizing such supplemental diets, it is not only possible to greatly accelerate the growth of the. poultry and swine but the feed efficiency (i.e. the number of pounds of feed needed to produce a one pound gain in weight) is greatly increased,, resulting in greater economic •■■benefits:*; ' The following examples illustrate specific embodi-nients of this invention and are not to be considered a limita-tion thereof.

EXAMPLE 1 This example illustrates the comparative growth of turkeys infected with histomoniasis which are fed a basal ration containing varying concentrations of l-methyl-5-nitro-imidazol-2-ylmethyl carbamate, as against a control group of turkeys infected with histomoniasis which are fed a basal ration only and a control group of non-infected turkeys which are fed a basal ration only.

White turkeys 2 to 3 weeks of age and of both sexes are brooded in electrically heated, wire-floored brooders in isolation areas. Feed and water are provided without restriction. A commercial non-medicated turkey starter ration is used as the basal ration. It has the following ingredients: Turkey Basal Ration Meat and bone meal Choline chloride Fish meal Niacin Poultry by-product meal Folic acid Dehulled soybean meal Animal Fat Corn gluten meal Menadione sodium bisulfite Dehydrated alfalfa meal Vitamin E Pulverized oats Vitamin A palmitate Ground corn Ethoxyquin (preservative) Wheat middlings D-activated animal sterol Brewer's dried yeast Calcium carbonate Dried corn and whey fer- Calcium iodate mentation solubles Zinc oxide Dried extracted streptomyces Cobalt carbonate fermentation residue Defluorinated phosphate Methionine hydroxy analogue Salt calcium Manganous oxide Calcium pantothenate Copper hydroxide The medicated feed is prepared by adding appropriate amounts of l-methyl-5-nitroimidazol-2-ylmethyl carbamate to the basal ration to provide graded concentrations in the feed. The feed is uniformly blended by thorough mixing just prior to use. All groups of the experimental turkeys are housed in identical brooders in rooms with uniform temperature and light control. Each brooder contains 20 pens containing 3-5 turkeys each.

All of the turkeys (with the exception of the non-infected control groups) are infected with histomoniasis as follows: Stock cultures of Histomonas meleagridis (initially obtained from cecal walls of infected birds) are grown with a small amount of sterile rice starch overlaid with a modified Balamuth and Sandza serum medium (Balamuth, W. and Sandza, J.G. , "Single standardized culture medium for physiological studies on E.histoyltica. " Proc. Soc. Exp. Biol. & Med. 57:161-163, 1944) . Transfers are made into fresh medium 3 times weekly. The turkeys are infected by intercloacal inoculation with 48-hour cultures adjusted to contain the desired number of organisms. On the third day after inoculation, the birds are randomly placed in the cages and weighed. At the same time, feed and water is provided without restriction.

The growth promotion activity of l-methyl-5-nitro-imidazol-2-ylmethyl carbamate is evaluated on the basis of the observations and records of growth of the turkeys. The percent weight gain is calculated for each pen of birds as the percent increase of the terminal mean weight over the initial mean weight. The percent relative weight gain for a ed b com arin the ercent wei ht gain for the pen with the average percent weight gain of the non-infected non-medicated bontrol groups taken as 100%. The results of 11 tests are summarized in Table 1, below: TABLE 1 Summary of Growth Response of Turkeys Fed Graded Feed Con-centrations of l-Methyl-5-nitroimidazol-2-ylmethyl carbamate Beginning 3 Days after Inoculation with Histomonads l-Methyl-5-nitroimidazol- No. No. Average 2-ylmethyl carbamate of of Relative Group % Tests Cages Wt. Gain % A None (Infected Controls) 11 74 62 B 0.0015 7 18 101 C 0.003 8 20 109 D 0.006 9 26 111 E 0.013 9 18 126 F None (Non-infected controls) 11 21 100 As shown in Table 1, the data on relative weight gain show that the histomonad infection caused a significant depression in the infected, non-medicated control birds (Group A) . This significant depression, however, is completely prevented by dietary medications of 0.0015% or more l-methyl-5-nitro-imidazol-2-ylmethyl carbamate. Remarkably, however, the growth of the infected turkeys fed 0.003% to 0.013% l-methyl-5-nitro-imidazol-2-ylmethyl carbamate (Groups C-E) averaged 9% to 26% greater than the growth of the corresponding non-medicated, non-infected controls (Group F) over the same period of time.

This remarkable increase in growth represents a true growth promotion response to l-methyl-5-nitroimidazol-2-ylmethyl carbamate over and above the maintenance of "normal" weight gains through protection against the histomonad infection. 1 EXAMPLE 2 2 This example illustrates the comparative growth of 3 turkeys having no exposure to histomoniasis when fed the basal 4 ration only (feed content shown in Example 1) as against a control group of turkeys having no exposure to histomoniasis 6 which are fed the same basal ration containing from 0.003% to 7 0.03% l-methyl-5-nitroimidazol-2-ylmethyl carbamate. The tests, 8 which- are summarized in Table 2, are conducted in animal rooms 9 in a one-story masonry building where facilities and procedures 0 are designed to minimize any introduction of infectious diseases 1 into the building or into the animal quarters. The floor and 2 roof of the building are of concrete slab construction and the 3 walls and partitions are of cinder block. Inside surfaces 4 of walls and ceilings are coated with high-gloss waterproof paint, and floors are covered with a non-skid, waterproof paint. 6 Prior to introduction of animals into a room, the room and all 7 equipment in it are thoroughly cleaned and washed with a large 8 amount of hot water under pressure from a hose. Under these ? conditions of operation for more than 15 years, bacterial or 0 viral disease has not been recognized clinically in the poultry 1 in this building. 2 For these tests, day-old Beltsville (small white) 3 or Wrolstad turkeys are obtained from commercial hataheries 4 and reared in electrically-heated, metal, wire-floored battery 5 brooders in temperature-controlled animal rooms in the building t> described above. Water and feed are supplied without restriction. For each set of experiments initiated at one time, at least 50% 8 more turkeys than are required of the same breed are fed basal ration for 1 to 5 days and then individually weighed. Turkeys 0 in the middle two-thirds of the weight distribution are then divided into groups of either 4 or 5 turkeys equally balanced according to individual weights. All groups of turkeys in each experiment are fed experimental diets made from one blended lot of base ration. The groups of turkeys and the experimental diets are separately assigned at random to the pen locations for the experiment. One to three of the groups of turkeys in each experiment are fed the non-medicated basal ration to serve as normal growth controls.

The experimental diets are fed to the turkeys from 2-6 days to 2-4 weeks of age, and the effect of the diet supple-ment is evaluated in terms of relative weight gain of each group calculated as a percentage of the average weight gain of the corresponding control birds (as 100%) .

The results of these tests, conducted with turkeys under conditions of freedom from exposure to histomoniasis or other diseases, are summarized in Table 2, below.

TABLE 2 Effect of l-Methyl-5-nitroimidazol-2-ylmethyl carbamate on Growth of Turkeys from 1/2 to 4 Weeks of Age l- ethyl-5-nitroimidazol- 2-ylmethyl Group Carbamate % Weight Gain 1 None 393. Og. 2 0.003 + 3.2% 3 0.006 + 1.0% 4 0.012 ; + 1.9% 0.015 + 1.6% 6 0.02 + 4.2% 7 0.03 + 0.6% It is observed from the data on Table 2 , that the average growth response for the birds fed at each level of concentration is positive. The individual group averages from +1.0% to +4.2% increased weight gain over that of the controls. More important, however, the overall average growth improvement for all birds receiving 0.003% to 0.03% l-methyl-5-nitroimidazol-2-ylmethyl carbamate is +2.2%. Thus, the data conclusively show that l-methyl-5-nitroimidazol-2-ylmethyl carbamate is an effectiv growth promotant, since the results are obtained in the absence of disease.

EXAMPLE 3 This example illustrates the effect of feeding swine a basal ration containing 0.006% l-methyl-5-nitroimidazol-2-ylmethyl carbamate as compared to a control group of swine fed on basal ration only.

The pigs used in the test are at an average of four weeks. The animals are randomly assigned by descending order of weight within a litter. The swine are individually weighed each 28 days and group weighed at an average of 75 pounds. The trial is terminated at 112 days. The basal ration has the following composition: Swine Basal Ration Corn meal Zinc oxide Dehydrated alfalfa meal Copper oxide Wheat middlings Iron carbonate Dried whey product Calcium iodate Soybean meal D-activated animal sterol Meat and bone meal Riboflavin supplement Calcium carbonate Vitamin B,2 supplement Salt Niacin Manganous oxide Choline chloride Calcium pantothenate Vitamin A supplement (palmitate) A summary of the results obtained are set forth in Table 3, below.

TABLE 3 Effect of 0.006% l-Methyl-5-nitroimidazol- 2-ylmethyl carbamate on Growth of Swine Period (Days) 112 112 112 112 140 140 140 140 Test 1 1 2 2 3 3 4 4 Drug No Yes No Yes No Yes No Yes No. Animals 5 5 5 5 5 5 5 5 Feed Efficiency 3.81 3.70 3.80 3.33 3.93 3.72 3.72 3.48 Avg. Daily Gain 0.76 0.89 0.54 0.92 1.14 1.33 0.99 1.20 As shown in Table 3, the swine which receive 0.006% l-methyl-5-nitroimidazol-2-ylmethyl carbamate as a feed supple-ment show an extraordinary increase in average daily gain as compared to the control groups. By calculation, it is seen that the overall average daily gain of the swine receiving the supplement is 0.23 pound (21%) greater than the control groups .

It is also seen that feed efficiency (i.e. pounds of feed utilized/1 pound gain in weight) is increased when supplemented by l-methyl-5-nitroimidazol-2~ylmethyl carbamate. Thus, an overall averaging of the feed efficiency data shows that the control groups require 3.82 pounds of feed to produce a gain of one pound of body weight while the treated groups require 3.56 pounds of feed to produce a one pound gain in weiyht. Accordingly, it takes an average of 0.26 pounds (7%) less of the supplemented feed to produce a one pound increase in animal weight.

Duplication of the above tests, at levels of 1-methyl-5-nitroimidazol-2-ylmethyl carbamate of 0.003% and 0.012%, 1 As stated above, the benefits of this invention 2 are also realized by administering l-methyl-^-nitroimidazol- 3 2-ylmethyl carbamate in animal drinking water or in the feed l|. and drinking water. Of course, when administering the drug in the drinking water or in the feed and drinking water, the 6 dosage levels are adjusted so that the total daily intake is 7 equivalent to from 0.0015$ to about 0.03$ in the animal feed. -12- 33118/3

Claims (5)

1. A method for promoting the growth of non-human animals, that comprises administering to the animals a feedstuff containing from 0.0015$ to 0,03$ by weight of l-methyl-5-nitroimidazol-2-ylmethyl carbamate or water containing from 0.00075 to 0.015$ by weight of l-methyl-5-nitroiraldazol-2-ylmethyl Carbamate.

2. A method according to Claim 1 in which the feedstuff contains from 0.003$ to 0.013$ by weight of l-methyl-5-nltro-imidazol-2-ylmeth l carbamate.

3. A method for promoting the growth of non-human animals that comprises adminietering to the animals water containing from 0,00075$ to 0.015$ by weight of l-methyl-5-nitroimidazol-2-ylmethyl carbamate.

4. A method according to Claim 3 in which the water contains from 0.0015$ to i|p065$ by weight of l-methyl-5-nltrolmidazol-2-ylmethyl carbamate.

5. A method of promoting the growth of non-human animals by the administration of a feedstuff and/or water containing l-methyl-5-nltrolmidaz0l-2-ylmethyl carbamate, substantially as hereinbefore described in any one of the foregoing Examples. For the Applicants . DR. R TNERS ND.ed