FR2673377A1 - Process for improving the organoleptic qualities of uncastrated domestic animals - Google Patents

Abstract

The process for improving the organoleptic qualities, especially the smell, flavour and tenderness, of uncastrated male domestic animals comprises, shortly before slaughter of the animal in question, abolition of the action of androgenic and non-androgenic steroids by active or passive anti-LHRH immunoneutralisation, while maintaining almost up to slaughter the advantages associated with the animal's male character.

Description

 The present invention relates to a method for improving organoleptic qualities, in particular odor, palatability and tenderness, of non-castrated male domestic animals, including cattle, sheep and male pigs.

 The benefits of using the whole male on the castrated male in the fattening of domestic animals for meat production have been underlined for several decades by zootechnicians. They relate to a higher growth rate, especially in cattle and sheep, a better use of the food ration and a leaner but more muscular carcass in all domestic species (SC SEIDEMAN et al., Of Animal Science, 1982, 55 (4) 826-840 and M. BONNEAU, INRA Animal Prod., 1988, 1 (2) 133140).

 The main disadvantages of this use of the whole male, mentioned in the journals cited above, concern the unpleasant smell and taste in male pigs and sheep, the less tenderness of the meat of whole male cattle and sheep and justify the practices. current surgical castration.

 Indeed, if androgenic steroids including androstenediol, androstenedione and testosterone are the determining elements of the expected benefits in all domestic species for faster growth and better utilization of the food ration, they are made responsible for less tenderness of whole cattle and sheep meat.

Non-androgenic steroids or 16androstenes derivatives, including androstenone, in male pigs, are responsible in part for the unpleasant odor and palatability of the meat of a number of whole male pigs at puberty, which are meat and are an obstacle to its marketing in the fresh state.

 Skatole, a product derived from tryptophan and produced by intestinal microbial flora, is a compound responsible in part for the unpleasant odor and palatability of whole male pork meat. Its production depends on environmental factors, nutrition, race. Its accumulation in the adipose tissue is more important in the boar and would be related to the secretions of gonadal sex steroids.

Experimentally, attempts have already been made to reduce or eliminate the development of male character in young animals or the secretion of testicular hormones, especially testicular steroids, including by active or passive immunoneutralization of testicular hormones, in particular the hormone gonadotropin releasing hormone (GnRH), also known as Luteinizing Hormone Releasing Hormone (LHRH). Tests have been conducted on pigs to lower the tissue level of 5 -androstenone in the group of 16-androstenes by active immunization directed against this compound (ED WILLIAMSON et al.
Liverstock Production Science, 1985, 12, 251-264) or by passive immunization against this same compound (R. CLAUS,
Immunization with Hormones in Reproduction Research, ed.

Nieschlag, 1975). The suppression or decrease in the secretion of testicular steroids can be investigated by the immunoneutralization of the gonadotropic hormone LH, specific to the species in question (R.E. FALVO et al., J.

Anim. Science, 1986, 63, 986-994) or by the anti-LHRH immunoneutralization of endogenous LHRH. Only active anti-LHRH immunization has been advocated by different authors. In pigs, the lowering of 6 '-androstenone was obtained by this method (A. CARATY and M. BONNEAU, CR Acad Sci Paris, 1986, 303, Series III (16) 673-676, RE FALVO et al., J. Anim. Sci., 1986, 63, 986-994).

 In sheep, B. D. SCHANBACHER (Am J.Physiol., 1982, 242, E201-E205) advocated anti-LHRH immunization to delay testicular development and to produce a castration effect in male lambs. In cattle, P.S. ROBERTSON (Rec., 1979, 105, 516-517) describes an anti-LHRH immunological castration.

 Anti-LHRH immunoneutralization assays described in laboratory animals (ARIMURA et al.

Endocrinology, 1973, 93, 1092-1103; FRASER H.M. et al., J.

Endocr. 1974, 63, 399-406; MAKINO T. et al. Contraception, 1973, 8 (2), 133-145; CARELLI C. et al., Proc. Natl. Acad.

Sci., USA, 1982, 79, 5392-5395) and on several domestic species (JEFFCOATE et al., Theriogenology, 1978, 10 (4), 323-335, ROBERTSON IS et al., Veterinary Record., 1979, 105 , 556, SCHANBACHER, BD Am, J. Physiol., 1982, 242,
E201-E205) have shown that it is possible to stop the secretion of testosterone, the involution of the testes and its accessory glands, the cessation of spermatogenesis and, in terms of behavior, the disappearance of the libido.

 This work led to suggest the use of an immunoneutralization, including anti-LHRH, early to replace the traditional surgical castration for breeding purposes.

 In US Pat. No. 4,556,555, a method for the passive immunization of animals prior to puberty is thus described with the aid of an antiserum containing antibodies directed against gonadotropin.

 International patent application WO 90/11298 discloses a method of anti-LHRH immunization at birth to improve the quality of meat in pigs.

 International Patent Application WO 88/00056 discloses an anti-LHRH immunological castration method intended to improve the social and sexual behavior of male animals as a replacement for surgical castration which affects the rate of growth. Bulls are vaccinated at the age of 8 to 40 weeks and then receive several boosters.

 An anti-LHRH vaccine sold under the trademark VAXSTRATE by the Australian company WEBSTERS is used in cows.

RE Falvo et al. (J. Animal Sci 1986, 63: 986-994) immunized several groups of boars using LHRH-human seroglobulin conjugates as a complete adjuvant of
Freund or adjuvant muramylpeptide. The authors observed, after vaccination and several boosters, high titres of anti-LHRH antibodies, but with the need to practice repeated boosters to maintain the high antibody titre.

IS Robertson describes a method of immunization with
LHRH conjugated with tetanus toxoid or thyroglobulin and suggests that the immunological approach would allow late castration with the expected benefits in terms of weight gain. He concludes, however, that efforts are still to be made to arrive at a method of castration usable in practice, whether at the level of the method itself or adjuvant, Freund's adjuvant being proscribed in practice.

 Finally, A. Caraty and M. Bonneau (C. Acad Sc, Paris, t 303, Series III, No. 16, 1986) practiced anti-LHRH immunization in male pigs. The authors suggest that blocking steroid production 2 to 3 weeks before slaughter would exploit the high potential of this type of animal for meat production by avoiding the problems posed by the accumulation of steroids. androsterone in adipose tissue. They conclude, however, that important progress remains to be made in immunization techniques before it is possible to propose active anti-LHRH immunization as a technique for use in pig farming.

 In addition, late-onset immuno-immunization poses in practice the important problem of the safety of the treatment and in particular of the local reactions caused by the vaccines, in particular the oily vaccines, with the risks of rejection or decommissioning of the resulting meat. .

 Improved organoleptic qualities in cattle and sheep have not been suggested.

 The Applicant has precisely found an industrially applicable method for improving the organoleptic properties of animals, a process in which, shortly before the slaughter of the animal, the action of androgenic and non-androgenic steroids is substantially eliminated by active immunoneutralization or passive anti-LHRH, while maintaining practically until slaughter the benefits due to the male character of the animal.

 According to a first preferred embodiment of this method, the animal is administered with an anti-LHRH vaccine, preferably in emulsion, preferably before the fattening phase of the animal, and then, shortly before the slaughter of the animal. animal, an anti-LHRH vaccine is again administered.

 In pigs, it is particularly advantageous to administer, before slaughter, the anti-LHRH vaccine with an aqueous-type adjuvant, especially aluminum hydroxide gel and / or saponin.

 This administration is preferably carried out 15 to 21 days before slaughter.

 On the other hand, in cattle, and possibly in sheep, the administration preceding slaughter is preferably carried out with an emulsion adjuvant, and preferably 1 to 2 months before slaughter. This administration is preferably carried out at least 4 weeks, and preferably several months, after the first administration.

 In all cases, it is preferred for the emulsion vaccine for the first administration and, in cattle, for the second administration, that the vaccine is in the form of a water-in-oil emulsion. However, other forms of emulsion are conceivable.

 This vaccine, preferably of the emulsion type, is designed, according to the invention, for the induction of a first low intensity immune response, with no notable or even measurable effect on the secretion of gonadal steroids. The emulsion formulation is preferred, but the other formulations are usable as soon as they produce this same effect.

 The pre-slaughter administration is done with a vaccine formulated to produce at this time the significant suppression or lowering of steroid secretion without adverse local or general reaction, which may impair the appearance or quality of the steroids. the meat.

In a preferred manner, in particular for pork, the conjugate, in aqueous solution, is put under the two following formulations: the first in water-in-oil emulsion, stable, made of a mixture of highly purified mineral oils and nonionic surfactants for the induction of a low intensity immune response, with no measurable effect on secretion of gonadal steroids, the second, non-emulsified, with aluminum hydroxide gel and saponin, triggering a rapid and intense immune response resulting in the production of antibodies
Neutralizing LHRH, sufficient to result in the decrease or suppression of gonadal steroids and the decreased associated transport of skatole of intestinal origin.

The emulsion used is, unlike that obtained with the aid of the complete or incomplete adjuvant of
Freund, a stable emulsion to prepare a ready-to-use vaccine. The inflammatory skin reaction remains very weak and localized at the points of administration of the two vaccine formulations and is expressed in the form of papules well circumscribed on external examination. Its internal development remains limited to the superficial dermis.

It disappears without leaving any apparent granuloma at the time of slaughter of the animals.

 According to another embodiment of this method, the animal is administered to the animal, a few days before slaughter, in particular 5 to 15 days before, serum or anti-LHRH hyperimmune plasma or anti-LHRH monoclonal antibodies.

Passive anti-LHRH immunization leading to the decrease or even suppression of the secretion of androgenic and non-androgenic steroids was obtained by intramuscular administration of equine hyperimmune plasma. Worn to a sufficient level, measured by the LHRH antibody titre of the serum of the recipient animal, it causes the reduction of plasma testosterone on the 3rd day; maintained at the same level for the next 12 days, it is sufficient to cause the lowering of the tissue androsterone below 0.50 microgram / g, for which the unpleasant odor and the particular palatability of the pork This passive immunization method has shown that maintaining the significant decrease in testosterone for 12 days is sufficient to lower the tissue androsterone concentration below the set threshold. This passive immunization can be envisaged by the use of monoclonal antibodies against
LHRH secreted by hybridomas or porcine hetero-hybrids.

 The mode of administration of these formulations is preferably transcutaneous, in particular using a needleless injection device, by pressurized jet, in particular according to the patent application FR-A-2,652,257.

 The method according to the invention has the important advantage of being perfectly safe, in particular not to induce local reactions likely to result in the decommissioning of meat.

 The inflammatory skin reaction remains localized at the points of administration of the two vaccine formulations and is expressed in the form of papules well circumscribed on external examination. Its internal development remains limited to the superficial dermis. It disappears without leaving any apparent granuloma at the time of slaughter of the animals. The inflammatory reaction, limited in time and at the points of administration, reflects the tolerance to the two vaccine formulations and is obtained by the transcutaneous administration thereof, carried out using a needleless injector.

 Anti-LHRH immunization requires conjugating the LHRH peptide, non-immunogenic under the economic conditions of its use, with an immunogenic protein, called carrier, by a covalent bond.

LHRH or GnRH, whether natural or synthetic, is composed of 10 amino acids, numbered from 1 to 10, ranging from the amino-terminal to the carboxy-terminus according to the following formula
pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly NH2 1 2 3 4 5 6 7 8 9 10
These symbols, by convention, represent: pGlu, pyroglutamic acid; His; histidine; Trp, tryptophan
Ser, serine; Tyr, tyrosine; Gly, glycine; Leu leucine
Arg, arginine; Pro, proline.

The anti-LdIRH immunogenic conjugates described by the various authors can be made with respect to the hapten with
a) total or modified LHRH in one or more of its parts to obtain the desired amino-terminal, carboxy-terminal or intermediate conjugation,
b) with one of its peptide fragments composed of 5 to 7 amino acids, modified or otherwise, to obtain the desired aminoterminal, carboxyterminal or intermediate conjugation,
c) with an agonist carrying a substituted amino acid, most commonly 6, to obtain an intermediate conjugation.

 With regard to the carrier protein, bovine serum albumin, human serum albumin, thyroglobulin, ovalbumin, human or equine globulins were used.

 The conjugating agents used can be classified into three broad categories: activating agents, homobifunctional agents, heterobifunctional agents. While for activating agents, the bond between the two molecules is between two functions already present, for the others, the bond is via a hydrocarbon residue called ligand.

 Among the activating agents, mention may be made of the periodic acid used to oxidize the oligosaccharide residues of the glycoproteins to aldehydes, on which the amine groups of the other molecule entering the conjugate will subsequently react.

 Carbodiimides are widely used as activators for the coupling of antigens on proteins and among them the most commonly used is probably N-ethyl-N '- (3-dimethylamino-propyl) carbodiimide hydrochloride (EDC). which makes it possible to carry out the reaction in an aqueous medium. Their action leads to the formation of an amide bond between a carboxyl group of a protein, activated intermediately in the form of an O-alkylisourea, and an amine group carried by another molecule. Their advantage lies in their ease of use.

 Homobifunctional agents are molecules that have two identical reactive groups separated by a hydrocarbon chain. Among them are glutaraldehyde, which reacts on two primary amine groups, alkyl or aryl bisisothiocyanates, which react on primary amines and thiols, bisdiazotized benzidine, which copulates with the aromatic residues of tyrosine. Let us remember for the record bismaleimides and bisamidinates. The major disadvantage of the homobifunctional agents is to poorly control the nature of the conjugates formed because these agents can react on two molecules of the same nature and lead to the formation of oligomers or polymers.

 To remedy this, chemists have introduced heterobifunctional agents, in which the two groups have different specificities. In the general case, one of these groups is an N-hydroxysuccinimide ester which, under mild conditions, reacts on the free amino groups of the proteins to give on the one hand N-hydroxysuccinimide and on the other hand the protein carrying the a covalent bond amide the coupling agent on which the 2nd function is located.At generally, it can react on the thiols provided by the molecule to be coupled, these thiols being either initially present in the molecule in the form of cysteine residues ( these may be constitutive or, in the case of peptides, introduced intentionally during the synthesis), or provided by agents such as imino-2 thiolane or N - ((2-pyridyl) 3-dithiopropanoyloxy) succinimide (SPDP), after reduction.

 Natural LHRH is preferred to agonists such as (D-Lys6) -LHRH by comparing the immunogenic activity of the conjugates prepared with these two peptides.

 Carbodiimide is preferred over glutaraldehyde as the naturally occurring LHRH conjugating agent on alpha globulin.

Human or equine alpha-globulin, fraction IV-1 and
IV-4 is preferred to human or bovine serum albumin.

 Preferably, the vaccines comprise the same active ingredient, preferably comprising a d-globulin-LHRH conjugate; the LHRH is preferably in the natural form and O -globulin of human or equine origin, in particular fractions IV-1 and IV-4, The conjugate is preferably obtained by addition to 1 volume of α -globulin mixture and LHRH in solution of 2 to 20 mg / ml in NaCl 0.9% from 0.5 to 2 volumes of solution of N-ethyl-N '- (dimethylamino-3-propyl) carbodiimide hydrochloride (EDC) in solution at 2, 5% in 0.9% NaCl.

After stirring, the mixture is left overnight and then purified by gel permeation chromatography.

 The subject of the invention is also the new vaccines described and usable for the process according to the invention.

 It also relates to assemblies in the same package containing an equal number of doses of vaccine to be administered before slaughter and vaccine to be administered as a first injection. Preferably these vaccines are packaged in reduced volume and increased concentration for administration by transcutaneous jet, for example according to the aforementioned French patent application.

 The invention will now be described in more detail by means of tests comparing several products and methods of vaccination according to the invention.

 A. Greater Immunogenic Activity of the Conjugate Keeping the Largest Carboxy End Portion of the LHRH Peptide and Choice of the LHRH Conjugate of Natural Formulation Better Than the Agonist (D-Lys6) -LHRH .

 Al. Anti-LHRH immunization of whole male pig and OFA male rat.

 A comparison of the activity of two anti-LHRH vaccines consisting of conjugates between naturally occurring LHRH (B1 and B2) or (D-Lys6) -LHRH (Al and A2) and human albumin conjugates obtained by carbodiimide in aqueous phase and SPDP respectively, put in an oil-in-water emulsion and administered intramuscularly in pigs and subcutaneously in rats, leads to the following conclusions: - Greater activity of the vaccine-based Naturally occurring LHRH: mass of conjugated LHRH peptide lower than conjugated peptide (D-Lys6) -LHRH for recruitment of more animals with an immune response (Tables 1 and 3).

- Dose effect which results in recruitment of a higher number of animals with an immune response by the same conjugate (Table 3).

Al.l Preparation of conjugates (D-Lys6) -LHRH-albumin by SPDP.

 The preparation of the (D-Lys6) -LHRH-albumin conjugates is carried out in 3 steps: preparation of (N- (pyridyl2) -dithio-3-propanoyl-D-Lys6) -LHRH, preparation of N (3-mercaptopropanoyl) ) albumin, then coupling.

 (NE - (2-pyridyl) -3-dithio-propanoyl-D-Lys6) -LHRH is prepared by reacting an excess of SPDP on LHRH in aqueous solution (6 moles of SPDP per mole of LHRH), and after overnight at 4 ° C, centrifuging the resulting product.

This is dissolved in 8M urea and the (pyridyl-2) dithio groups present are assayed.

 N- (3-mercaptopropanoyl) albumin is obtained by the action of 0.2 mmol of SPDP on 1 g of human albumin dissolved in 100 ml of 0.1M phosphate buffer and then, after a night of contact at 4 ° C. and acidification at pH 6 by reduction with dithiothreitol, which is then purified by gel filtration chromatography The thiol and protein assay provides the average level of substitution.

 The coupling is carried out taking a (pyridyl-2) dithio group for 1.25 thiol group. The pH is brought to 7-7.5 and then, one hour later, the yield is determined by measuring the pyridine thione-2 released.

 The average level of substitution is deduced.

Finally, the conjugate is purified by chromatography and is concentrated by ultrafiltration.

 A1.2 Preparation of the LHRH-albumin Conjugate with Carbodiimide

 To 300 mg of LHRH and 300 mg of human albumin dissolved in 30 ml of 0.9% NaCl are added 1000 mg of N-ethyl-N '- (dimethylamine-3-propyl) carbodiimide hydrochloride dissolved extemporaneously in 40 ml of NaCl. 0.9%. After stirring, the mixture is left overnight at room temperature in the dark. Then it is chromatographed on a Sephadex G-50 gel; the fractions corresponding to the conjugate are collected, possibly concentrated and frozen.

 From the fractions containing the uncoupled LHRH is determined the amount of un-coupled LHRH and thus the average conjugation level. It is reproducible and ranges from 8 to 10 mg of coupled LHRH per 100 mg of albumin.

 From the UV spectra of the conjugate before and after chromatography, the yields of the conjugate chromatography and hence the amount (or concentration) of conjugated LHRH are deduced.

A1.3 Dosing techniques
The antibody titre is determined according to the technique described by JEFFCOATE et al., Acta. Endocr., Copenh., 1974, 75: 625-635.

Testosterone is assayed directly on plasma by an RIA technique using Testosterone radioligand
C19-carboxymethyl ether (125I) histamine.

The binding to the labeled peptide is determined after labeling with iodine 125 of the different peptides according to
COPPOLAND et al., Endocr., 1979, 104: 1504-1506 and titration according to the technique described by JEFFCOATE et al., Acta
Endocr., Copenh., 1974, 75, 625-635.

A.1.4. Illustrations - Rats Trials
Table 1: Anti-LHRH antibody response as measured by iodine-labeled LHRH binding rate 125
Table 2: Effect of anti-LHRH immunization on plasma testosterone concentration
Dosage
Al vaccines: 50 / cig of (D-Lys6) -LHRH conjugated
B1: 12 Xg conjugated LHRH - Whole male swine trials
Table 3: Anti-LHRH antibody response as measured by iodine-labeled LHRH binding rate125
Dosage
Al vaccines: 0.5 mg conjugated (D-Lys6) -LHRH
A2: 6 mg conjugated (D-Lys6-) LHRH
B1: 0.15 mg conjugated LHRH
B2: 1.20 mg conjugated LHRH
Table 1
Anti-LHRH antibody response measured by the rate of
iodine-labeled LHRH binding
RESEARCH OF ANTIBODIES (Z BO / T) IN THE SERUM (1/100)
AT RAT

<tb> | <SEP> INJECTIONS <SEP> | <SEP> TIME <SEP> | <SEP> GROUP <SEP> A1 <SEP> | <SEP> GROUP <SEP> B1 <SEP> | <SEP> TITLE <SEP> |
<tb> | <SEP> | <SEP> (SEM) <SEP> | <SEP> 50g <SEP> Diy56-LHRH / HSA / AE1 <SEP> | <SEP> 12 <SEP> g <SEP> LHRH / <SEP> EDC / HSA / AEL <SEP> | <SEP> B / T = 50% <SEP> |
<tb> | <SEP> | <SEP> | <SEP> | <SEP> | <SEP> |
<tb> SC <SEP> O
<tb> | <SEP> | <SEP> | <SEP> - <SEP> | <SEP> - <SEP> | <SEP> - <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> - <SEP> | <SEP> - <SEP> | <SEP> - <SEP> |
<tb> | <SEP> | <SEP> | <SEP> - <SEP> | <SEP> - <SEP> | <SEP> - <SEP> |
<tb> | <SEP> | <SEP> | <SEP> |
<tb> | <SEP> SC <SEP> | <SEP> 4 <SEP> | <SEP> 0.0 <SEP> | <SEP> 15.4 <SEP> | <SEP><100<SEP> |
<tb> | <SEP> | <SEP> | <SEP> 7.8 <SEP> | <SEP> 7.6 <SEP> | <SEP><100<SEP> |
<tb> | <SEP> | <SEP> | <SEP> 0.0 <SEP> | <SEP> 35.3 <SEP> | <SEP><100<SEP> |
<tb> | <SEP> | <SEP> | <SEP> 0.0 <SEP> | <SEP> 51.1 <SEP> | <SEP> 100 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> | <SEP> | <SEP> |
<tb> | <SEP> | <SEP> 5 <SEP> | <SEP> 4.3 <SEP> | <SEP> 91.1 <SEP> | <SEP> 1600 <SEP> |
<tb> | <SEP> | <SEP> 14.1 <SEP> | <SEP> 85.3 <SEP>: <SEP> 980
<tb><SEP> | <SEP> | <SEP> | <SEP> 5.9 <SEP> | <SEP> 70.8 <SEP> | <SEP> 270 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 15.8 <SEP> | <SEP> 94.9 <SEP> | <SEP> 2100 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> | <SEP> | <SEP> |
<tb><SEP> | <SEP> | <SEP> 6 <SEP> | <SEP> 0.0 <SEP> | <SEP> 64.3 <SEP> | <SEP> 120 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 11.3 <SEP> | <SEP> 67.9 <SEP> | <SEP> 220 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 11.7 <SEP> | <SEP> 96.1 <SEP> | <SEP> 2400 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 0.0 <SEP> | <SEP> 68.3 <SEP> | <SEP> 280 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> | <SEP> | <SEP> |
<tb> | <SEP> | <SEP> 7 <SEP> | <SEP> 14.5 <SEP> | <SEP> 72.5 <SEP> | <SEP> 400 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 0.0 <SEP> | <SEP> 92.4 <SEP> | <SEP> 2100 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 0.0 <SEP> | <SEP> 64.2 <SEP> | <SEP> 200 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 11.5 <SEP> | <SEP> 67.2 <SEP> | <SEP> 240 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> | <SEP> |
<tb> | <SEP> | <SEP> 8 <SEP> | <SEP> 19.6 <SEP> | <SEP> 70.4 <SEP> | <SEP> 310 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 0.0 <SEP> | <SEP> 93.8 <SEP> | <SEP> 3200 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 9.2 <SEP> | <SEP> 68.7 <SEP> | <SEP> 2200 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 0.0 <SEP> | <SEP> 38.8 <SEP> | <SEP> 310 <SEP> |
<tb> fital
<Tb>
Table 2
Effect of anti-LHRH immunization on concentration
plasma testosterone
DOSAGE OF PLASMA TESTOSTERONE (NG / ML)
AT RAT

<tb><SEP> | <SEP> INJECTIONS <SEP> | <SEP> TIME <SEP> | <SEP> WITNESSES <SEP> | <SEP> GROUP <SEP> A1 <SEP> | <SEP> GRDUPE <SEP> B1 <SEP> |
<tb><SEP> | <SEP> | <SEP> (SEM) <SEP> | <SEP> | 50 <SEP> g <SEP> Dly56-LHRH / PDP / HSA <SEP> | 12 <SEP> G <SEP> LHRH / EDC <SEP> / HSA <SEP> |
<tb><SEP> |
<tb> | <SEP> | <SEP> | <SEP> | <SEP> | <SEP> - <SEP> |
<tb> | <SEP> SC <SEP> | <SEP> 0 <SEP> | <SEP> 0.40 <SEP> | <SEP> - <SEP> | <SEP> - <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 0.26 <SEP> | <SEP> - <SEP> | <SEP> - <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 0.47 <SEP> | <SEP> - <SEP> | <SEP> - <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 0.00 <SEP> | <SEP> - <SEP> | <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> | <SEP> | <SEP> |
<tb><SEP> | <SEP> SC <SEP> | <SEP> 4 <SEP> | <SEP> 2.25 <SEP> | <SEP> 4.16 <SEP> | <SEP> 2.51 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 1.05 <SEP> | <SEP> 5.83 <SEP> | <SEP> 2.38 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 2.34 <SEP> | <SEP> 4.43 <SEP> | <SEP> 3.63 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> | <SEP> 4.17 <SEP> | <SEP> 0.58 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> | <SEP> | <SEP> |
<tb> | <SEP> | <SEP> 5 <SEP> | <SEP> 3.90 <SEP> | <SEP> 2.99 <SEP> | <SEP> 0.00 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 1.76 <SEP> | <SEP> 2.33 <SEP> | <SEP> 0.00 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 5.05 <SEP> | <SEP> 2.95 <SEP> | <SEP> 0.00 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 6.67 <SEP> | <SEP> 1.54 <SEP> | <SEP> 0.00 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> | <SEP> | <SEP> |
<tb> | <SEP> | <SEP> 6 <SEP> | <SEP> 2.01 <SEP> | <SEP> 3.26 <SEP> | <SEP> 0.00 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 4.47 <SEP> | <SEP> 0.09 <SEP> | <SEP> 0.00 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 4.69 <SEP> | <SEP> 1.10 <SEP> | <SEP> 0.00 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 1.96 <SEP> | <SEP> - <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> |
<tb> | <SEP> | <SEP> 7 <SEP> | <SEP> 2.28 <SEP> | <SEP> 1.32 <SEP> | <SEP> 0.00 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 1.92 <SEP> | <SEP> 0.89 <SEP> | <SEP> 0.00 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 1.89 <SEP> | <SEP> 1.59 <SEP> | <SEP> 0.00 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 1.65 <SEP> | <SEP> 2.17 <SEP> | <SEP> 0.00 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> | <SEP> | <SEP> |
<tb> | <SEP> | <SEP> 8 <SEP> | <SEP> 0.97 <SEP> | <SEP> 1.75 <SEP> | <SEP> 0.00 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 1.91 <SEP> | <SEP> 1.48 <SEP> | <SEP> 0.00 <SEP> |
<tb> | <SEP> | <SEP> | <SEP> 2.71 <SEP> | <SEP> 1.91 <SEP> | <SEP> 0.00 <SEP> |
<tb><SEP> | <SEP> | <SEP> | <SEP> 1.22 <SEP> | <SEP> 2.33 <SEP> | <SEP> 0.00 <SEP> |
<tb> fital
<tb> TABLE 3
ANTI-LHRH ANTIBODY RESPONSE NESUREE SPEAKING FIXING RATES
FROM LHRH MARKETED TO IODINE 125

<SEP> SEARCH <SEP> OF <SEP> ANTIBODY <SEP> ANTI-LHRH <SEP> IN <SEP> THE <SEP> SERUH <SEP> (DIL. <SEP> 1/50) <SEP> |
<tb><SEP> | <SEP> TITLE <SEP> (S / T = 502)
<tb> TEHPS <SEP> (SEH.) <SEP> | <SEP> D <SEP> LY56-LHRH-PDP-HSR / RE1 <SEP> 0.5 <SEP> g <SEP> (A1) <SEP> | <SEP> D <SEP> LY56-LHRH-PDP-HSA / RE1 <SEP> 6 <SEP> G <SEP> (A2) <SEP> | <SEP> A1
<tb><SEP> | <SE> Mo <SEP> pigs <SEP> No <SEP> pigs <SEP> | <SEP> No <SEP> pigs
<tb><SEP> | <SEP> 211 <SEP> 219 <SEP> 231 <SEP> 243 <SEP> 257 <SEP> | <SEP> 205 <SEP> 221 <SEP> 227 <SEP> 245 <SEP> 251 <SEP> | <SEP> 221
<tb><SEP> | <SEP> | <SEP> |
<tb> T0 <SEP> lere <SEP> inj. <SEP> | <SEP> |
<tb><SEP> T3 <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 0 <SEP> 71.8 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 150
<tb><SEP> T4 <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 0 <SEP> 67.3 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 100
<tb> T5 <SEP> 2eNe <SEP> inj. <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 0 <SEP> 53.4 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 50
<tb><SEP> T6 <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 17.2 <SEP> 58.5 <SEP> 42.1 <SEP> 6.6 <SEP> 0 <SEP> | <SEP> 55
<tb><SEP> T7 <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 7.5 <SEP> 48.5 <SEP> 36.7 <SEP> 5 <SEP> 0 <SEP> | <SEP><50
<tb><SEP> T8 <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 7.7 <SEP> 44.1 <SEP> 28.8 <SEP> 5 <SEP> 0 <SEP> | <SEP><50
<tb><SEP> T9 <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> | <SEP> 5 <SEP> 37.5 <SEP> 22.6 <SEP> 5 <SEP> 0 <SEP> | <SEP><50
<tb> TEHPS <SEP> (SEH.) <SEP> | <SEP> LHRH-CCARBO) -HSA / RE <SEP> 1 <SEP> 0.150 <SEP> mg (B1) <SEP> | <SEP> LHRH- @ CARSD) -HSA / RE1 <SEP> 1.2mg <SEP> (B2) <SEP> | <SEP> B1 <SEP> B2
<tb><SEP> | <SEP> Mo <SEP> pigs <SEP> | <SEP> No <SEP> pigs <SEP> | <SEP> No <SEP> pigs <SEP> No <SEP> pigs
<tb><SEP> | <SEP> 213 <SEP> 225 <SEP> 247 <SEP> 255 <SEP> 261 | <SEP> 209 <SEP> 215 <SEP> 235 <SEP> 211 <SEP> 259 <SEP> | <SEP> 247 <SEP> 235 <SEP> 259
<tb><SEP> | <SEP> | <SEP> |
<tb> T0 <SEP> lere <SEP> inj. <SEP> |
<tb><SEP> T3 <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> |
<tb><SEP> T4 <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> |
<tb> T5 <SEP> 2nd <SEP> inj. <SEP> | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 | <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> |
<tb><SEP> T6 <SEP> | <SEP> 0 <SEP> 0 <SEP> S1.2 <SEP> 5 <SEP> 25.1 | <SEP> 48.9 <SEP> 56.2 <SEP> 78.2 <SEP> 51.4 <SEP> 90.1 <SEP> | <SEP> 200 <SEP> 130 <SEP> 990
<tb><SEP> T7 <SEP> | <SEP> 0 <SEP> 0 <SEP> S1.7 <SEP> 5 <SEP> 49.1 | <SEP> 64.7 <SEP> 49.9 <SEP> 86.3 <SEP> 52.3 <SEP> 92.9 <SEP> |
<tb><SEP> T8 <SEP> | <SEP> 0 <SEP> 0 <SEP> S0.5 <SEP> 5 <SEP> 36.5 | <SEP> 54.1 <SEP> 48.9 <SEP> 80.7 <SEP> 59.3 <SEP> 90.5 <SEP> | <SEP> 150 <SEP> 140 <SEP> 640
<tb><SEP> T9 <SEP> | <SEP> 0 <SEP> 0 <SEP> 74.4 <SEP> 5 <SEP> 34.5 | <SEP> 54.4 <SEP> 40.1 <SEP> 68.5 <SEP> 51.8 <SEP> 89.1 <SEP> | <SEP> 220 <SEP> 220 <SEP> 490
<Tb>
A2: Comparative trial of two anti-LHRH vaccines composed respectively of a conjugate LHRH- &alpha; -globulin with carbodiimide and a conjugate (D-Lys6) -LHRH-t-globulin with SPDP put in oil-in emulsion -water and administered intramuscularly (IM) or transcutaneously (ID) in pigs.

A2.1 Preparation of conjugate D-Lys6) -LHRH- &alpha; - globulin by SPDP
The method described in Example A1 is employed in exactly the same way, but replacing the 10 mg / ml albumin with o -globulin at 6 mg / ml.

 The overall yield of (D-Lys6) -LHRH coupled is of the order of 45 to 50%.

 Moreover, it is possible to modify at will the degree of substitution of the o -globulin, thus the level of conjugation, by acting on the concentrations of SPDP and / or α -globulin during the preparation of the &alpha; - globulin.

 A2.2 Preparation of human LHRH-α-globulin conjugate by carbodiimide (EDC).

 The method described in Example A1 is employed in exactly the same way but replacing human albumin with human α-globulin. The level of conjugation is 24 to 28 mg of LHRH fixed per 100 mg of human i-globulin.

 A3.3 The efficacy of the LHRH-α-globulin conjugate vaccine with carbodiimide is superior to the second. Efficacy is expressed as the number of animals with complete disappearance of plasma testosterone (Table 4).

Table 4

<tb><SEP> LHRH- &alpha; -glob.EDC <SEP><SEP> (1,2 <SEP> mg) <SEP> | D-Lys6 <SEP> | -LHRH- &alpha; -glob.SPDP <SEP><SEP> (6 <SEP> mg)
<tb><SEP> IM <SEP> + <SEP> ID <SEP> IM <SEP> + <SEP> ID
<tb> Deletion
<tb><SEP> of <SEP> 5/10 <SEP> 2/10
<tb> testosterone
<Tb>
A.3 Predominance of the immune response of male pigs to the carboxyterminal moiety of the carbodiimide conjugated LHRH peptide or its agonist (D-Lys6)
LHRH conjugated with SPDP on human d-globulin.

 It is determined by comparing the binding percentages of anti-LHRH and anti- (D Lys6) -LHRH sera by two labeled fragments of LHRH, respectively LHRH (3-10) deleted from its aminoterminal fraction and LHRH (1-10). in the form of a free acid and thus deleted from the amide fraction of its natural carboxyterminal fraction. These two fractions respectively recognize, more specifically, the antibodies directed against the carboxy-terminal moieties on the one hand, and the amino-terminal moieties on the other hand.

The predominance of the response to the carboxy terminal moiety of the peptide results in a number of animals displaying antibodies that bind only the peptide
LHRH (3-10) excluding binding of free acid LHRH (10/58 for anti-LHRH serum and 3/10 for anti- (D-Lys6) -LHRH serum).

 No serum showed 100% binding of the LKRH free acid fraction, which would reflect an exclusive recognition of the amino-terminal fraction.

The mixed responses, the most frequent, show a better recognition of the amino-terminal fraction by the anti-(D-Lys6) -LHRH sera than that of the anti-serum
LHRH. In the latter, only 3 sera out of 58 have a recognition greater than 40% of the aminoterminal fraction, against 4 out of 10 for the serum anti- (D Lys6) -LHRH.

 B. Greater immunogenic activity of the LHRH-α-globulin conjugate produced by cabodiimide, compared to that obtained with the conjugate prepared with glutaraldehyde.

 B.1 Preparation of LHRH-d-globulin conjugate by glutaraldehyde

 To 10 mg of LHRH and 50 mg of human ok-globulin (Serva) dissolved in 5 ml of 0.1 M phosphate buffer pH 7.5 are added, dropwise over a period of 30 minutes, 2.5 ml of glutaraldehyde solution at 10 mg / ml, shaking gently after each addition. After allowing the mixture 2.5 h at room temperature, the reaction is stopped by addition of 25 mg of sodium bisulfite dissolved in 0.5 ml of water. The conjugate is dialyzed at 4 C against the 10mM NaCl 150mM-phosphate buffer pH 7.5, and is then concentrated by ultrafiltration.

 B.2 Comparative pork trial of anti-LHRH vaccines formulated with identical amounts of conjugated LHRH. Efficacy is expressed by the number of animals with complete disappearance of plasma testosterone (Table 7).

Table 7

<tb><SEP> LHRH- &alpha; -glo. <SEP> with <SEP> carbodiimide <SEP> LffRH-a-glo. <SEP> with <SEP> glutaraldehyde
<tb><SEP> Administration <SEP> IM <SEP> or <SEP> ID <SEP> Administration <SEP> IM <SEP> or <SEP> ID
<tb> Deletion
<tb> of <SEP> testosterone <SEP> 5/10 <SEP> 0/10
<tb> plasma <SEP>
<Tb>
C. Greater immunogenic activity of the conjugate using human α-globulin compared to that obtained with the conjugate using human serum albumin.

 Efficacy is expressed as the number of animals with complete disappearance of plasma testosterone (Table 8).

Table 8
Pigs tests - intramuscular injection

<tb><SEP> LHRH-HSA <SEP> with <SEP> carbodiimide <SEP> LHRH-α-glo. <SEP> with <SEP> carbodiimide
<tb> Deletion
<tb> of <SEP> testosterone <SEP> 0/5 <SEP> 3/5
<tb> plasma
<Tb>
D. Immunogenic Activity of the Conjugate Using Equine Globulin, Fraction IV-1, equivalent to that Obtained by Conjugate Using Human α-Globulin.

 D.1 Preparation of conjugate LHRH-O (equine globulin with carbodiimide.

 The method described in Example A1 is employed in exactly the same way, but replacing human albumin with equine α-globulin (fraction IV-1).

 D.2 Administration to the rat subcutaneously 2 times at 4 week intervals of a vaccine at the dose of 12 μg of LHRH conjugated to the alpha; human or equine globulin.

Table 9
Tests on rats

<tb><SEP> Human LHRH-α-globulin <SEP><SEP> LHRH - Globulin <SEP> Equine
<tb><SEP> fraction <SEP> IV-1 <SEP> fraction <SEP> IV-1
<tb><SEP> with <SEP> carbodiimide <SEP> with <SEP> carbodiimide
<tb> Deletion
<tb> of <SEP> the <SEP> testosterone
<tb> Plasma <SEP> 12/12 <SEP> 12/12
<Tb>
E. Greater builder activity of the oil-in-oil emulsion of the invention on other emulsions (Table 10).

 Tests on pork using the same conjugate composed of LHRH and human alpha-globulin by carbodiimide and administered at the same dose under the same volume by the transcutaneous 5-point route.

 The emulsions examined are: an oil-in-water fluid emulsion (B), the emulsion of the invention (formula C of the table), a commercial emulsion to be diluted with the antigen (E), an oily phase to emulsify with the conjugate (F).

 For all these formulas, the final amount of antigen per dose is the same.

 The emulsions are produced under the usual conditions for those experts in formulation of this type.

Table 10

<tb><SEP> Mulsions <SEP> B <SEP> C <SEP> E <SEP> F
<tb> Deletion <SEP> of <SEP> la
<tb> testosterone <SEP> 2/5 <SEP> 4/4 <SEP> 1/5 <SEP> 3/5
<tb> plasma
<tb> Number <SEP> of animals <SEP> presenting
<tb> a <SEP> concentration <SEP> of <SEP> 2/5 <SEP> 4/4 <SEP> 3/5 <SEP> 3/5
<tb> 1 '<SEP> Androstenone <SEP> Tissue
<tb> below <SEP> of <SEP> 0.5 <SEP> pg / g <SEP>
<Tb>
F. Efficacy of passive anti-LHRH immunization for the improvement of organoleptic qualities of meat, measured by the lowering of tissue androstenone.

Table 11
Adrosterone content of adipose tissue in control animals and in those subjected to passive anti-LHRH immuno-neutralization by an equine hyperimmune anti-D (Lys6) -LHRH plasma administered at a volume of 300 ml on day 16, 13, 9 and 5 before slaughter.

<Tb>

<SEP> Witnesses <SEP> Treated
<tb> Number <SEP> of animals <SEP> presenting
<tb> a <SEP> concentration
<tb> of androsterenone <SEP> lower <SEP> 2/5 <SEP> 5/5
<tb> to <SEP> 0.50 <SEP> yg / g <SEP> of <SEP> tissue
<tb> adipose
<Tb>
(significant difference at risk a = 0.2)
G. Efficacy and Tolerance of Formulations Containing O -globulin Conjugated LHRH by Carbodiimide in Water-in-Oil Emulsion (1st Vaccine) and Aluminum Hydroxide-Saponin Gel (2nd Vaccine), administered at the same dose of conjugated LHRH at the beginning of fattening and 18-21 days prior to transcutaneous slaughter using a needle-free injector called Pigjet.

 Two tests were carried out in two stages, respectively groups 1, 3 and 5 for the first and groups 2 and 4 for the second (tables 12 and 13).

 G.1 The efficacy of anti-LHRH immunoneutralization is increased for an equal volume of vaccine by multiplying the points of transcutaneous administration.

Table 12

<tb><SEP> Groups <SEP> i <SEP><SEP> 2 <SEP> 3 <SEP> 4 <SEP> 5
<tb><SEP> 1 <SEP> vaccine <SEP> 1 <SEP> ml <SEP> 1 <SEP> ml <SEP> 1 <SEP> ml <SEP> 0.4 <SEP> ml <SEP> 0, 4 <SEP> ml <SEP>
<tb><SEP> (5 <SEP> points) <SEP> (5 <SEP> points) <SEP> (5 <SEP> points) <SEP> (10 <SEP> points) <SEP> (2 <SEP > points)
<tb><SEP> 2nd <SEP> vaccine <SEP> 1 <SEP> ml <SEP> 1 <SEP> ml <SEP> 0.4 <SEP> ml <SEP> 0.4 <SEP> ml <SEP> 0.4 <SEP> ml <SEP>
<tb><SEP> (5 <SEP> points) <SEP> (5 <SEP> points) <SEP> (2 <SEP> points) <SEP> (10 <SEP> points) <SEP> (2 <SEP > points)
<tb> Deletion <SEP> or
<tb> decrease <SEP> marked <SEP> | <SEP> 10/12 <SEP> | <SEP> 10/11 <SEP> | <SEP> 9/12 <SEP> | <SEP> 11/11 <SEP> | <SEP> 8/11
<tb> of <SEP> the <SEP> testosterone
<tb> (number <SEP> of animals)
<tb> Concentration <SEP> of
<tb> androstenone
<tb> tissue <SEP> 11/12 <SEP> ND <SEP> 10/23 <SEP> ND <SEP> ND
<tb> below <SEP> of <SEP> 0.5 <SEP> g / g <SEP>
<tb> (number <SEP> of animals)
<Tb>
ND: not determined
G.2 The tolerance to the vaccines used is judged by the evolution of the cutaneous inflammatory reaction, noted from 0 to 4 in an animal according to the importance of the papules appearing after the administration; a papule appears at each point of administration. The summation of the scores in each group is summarized as follows: mean score at the end of the first week following administration (Ad. 1) and mean score at the time of slaughter for each of the vaccines (Ab) ( Table 13). The best tolerance is observed with the use of vaccines in group 4.

Table 13
Tolerance by transcutaneous administration observed during the 2 tests carried out (test 1 groups 1, 3 and 5, test 2 groups 2 and 4).

<Tb>

<SEP> Groups <SEP> 2 <SEP> 3 <SEP> 4 <SEP> 5
<tb><SEP> Vaccines <SEP> 1 <SEP> or <SEP> 2 <SEP> the <SEP> vac. <SEP> 2nd <SEP> vac. <SEP> the <SEP> vac. <SEP> 2nd <SEP> vac. <SEP> the <SEP> vac. <SEP> 2nd <SEP> vac <SEP> the <SEP> vac. <SEP> 2nd <SEP> vac. <SEP> the <SEP> vac. <SEP> 2nd <SEP> vac.
<Tb>

Number <SEP> of <SEP> points
<tb> of administration <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 2 <SEP> 10 <SEP> 10 <SEP> 2 <SEP> 2
<tb><SEP> Al <SEP> 42 <SEP> 11 <SEP> 31 <SEP> 11 <SEP> 41 <SEP> 16 <SEP> 33 <SEP> 11 <SEP> 30 <SEP> 10
<tb> Ab <SEP> 2 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 3 <SEP> 0 <SEP> 0 <SEP> 2 <SEP> 0
<tb> Number <SEP> of animals <SEP> 12 <SEP> 11 <SEP> 12 <SEP> 11 <SEP> 11
<Tb>

Claims (28)

 A method for improving the organoleptic qualities, in particular the odor, palatability and tenderness, of the meat of uncastrated male domestic animals, in which, shortly before the slaughter of the animal concerned, the the action of androgenic and non-androgenic sterols, by active or passive anti-LHRH immunoneutralization, while practically maintaining the advantages of the male character of the animal until the time of slaughter.  2. Method according to claim 1, characterized in that it firstly administers an anti-LHRH vaccine, then shortly before the slaughter of the animal, an anti-LHRH vaccine is again administered.  3. Method according to claim 2, characterized in that a vaccine designed to induce a first low intensity immune response, without significant or even measurable effect, on the secretion of gonadal steroids and in that before slaughter, a vaccine is formulated to produce the significant suppression or lowering of steroid secretion without adverse local or general reaction, which may affect the appearance or quality of the meat.  4. Method according to any one of claims 2 and 3, characterized in that the anti-LHRH vaccine administered in the first place is before the fattening phase of the animal.  5. Method according to any one of claims 2 to 4, characterized in that the vaccine against LHRH administered first is an emulsion vaccine.  6. Method according to any one of claims 2 to 5, characterized in that, for pork, is administered before slaughter, the anti-LHRH vaccine with an aqueous type adjuvant.  7. Method according to claim 6, characterized in that, as an aqueous-type adjuvant, aluminum hydroxide gel and / or saponin are used.  8. Method according to claim 6 or 7, characterized in that the vaccine is administered as an aqueous adjuvant 15 to 21 days before slaughter.  9. Method according to any one of claims 2 to 5, characterized in that, for cattle and sheep, is administered, before slaughter, an anti-LHRH vaccine with emulsion adjuvant.  10. Method according to claim 9, characterized in that the emulsion vaccine is administered one to two months before slaughter.  11. The method of claim 9 or 10, characterized in that the emulsion vaccine is administered from four weeks to several months after the administration made in the first place.  12. Method according to any one of claims 4 and 9 to 11, characterized in that, for pork, the emulsion vaccine is an emulsion vaccine oil-in-oil.  13. The method of claim 12, characterized in that the water-in-oil emulsion is made of a mixture of highly purified mineral oils and nonionic surfactants.  14. Process according to any one of Claims 2 to 13, characterized in that an immunogenic anti-LHRH conjugate comprising total or modified LHRH is administered, a peptide fragment of LHRH of 5 to 7 modified amino acids or no, or - an LHRH agonist, coupled to an immunogenic carrier protein selected from - bovine or human serum albumin, - thyroglobulin, - ovalbumin, - human or equine globulins.  15. The method of claim 14, characterized in that the conjugate comprises LHRH coupled to equine alpha-globulin, in particular fractions IV-1 and IV-4.  16. The method of claim 15, characterized in that the LHRH and alpha-globulin are coupled by a carbodiimide.  17. Method according to claim 1, characterized in that 11 animals are administered, a few days before slaughter, serum or hyperimmune anti-LHRH plasma.  18. The method of claim 1, characterized in that the animal is administered to the animal, a few days before slaughter, anti-LHRH monoclonal antibodies.  19. The method of claim 17 or 18, characterized in that the administration is made from five to fifteen days before slaughter, subcutaneously or intramuscularly.  20. A method according to any one of claims 2 to 16, characterized in that it is administered transcutaneously, preferably at several points, with the aid of a needle-less jet injection apparatus under pressure.  21. An anti-LHRH vaccine designed to induce a weak, immeasurable, or even measurable, immune response to the secretion of gonadal steroids and comprising as an active ingredient an alpha-globulin-LHRH conjugate.  22. An anti-LHRH vaccine designed to produce the significant suppression or lowering of secretion of steroids without adverse local or general reaction, which may affect the appearance or quality of the meat, and comprising as an active ingredient a conjugate alpha-globulin-LHRH.  23. Anti-LHRH vaccine according to claim 21 or 22, characterized in that it is in water-in-oil emulsion.  24. An anti-LHRH vaccine according to claim 23, characterized in that the emulsion comprises a mixture of highly purified mineral oils and nonionic surfactants.  25. Anti-LHRH vaccine according to claim 21 or 22, characterized in that it is an aqueous adjuvant.  26. anti-LHRH vaccine according to claim 25, characterized in that it comprises an aluminum hydroxide gel and / or saponin.  27. Vaccine according to any one of claims 21 to 26, characterized in that the conjugate is obtained by addition to 1 volume of equine alphaglobulin mixture, in particular fractions IV-1 and IV-4, and total LHRH in solution of 2 to 20 mg / ml in NaCl 0.9% from 0.5 to 2 volumes of solution of N-ethyl-N 'hydrochloride (dimethylamino-3-propyl) carbodiimide in 2.5% solution in 0.9% NaCl.  28. An anti-LHRH vaccination assembly comprising in the same package an equal number of doses of a vaccine to be administered in first injection and a vaccine to be administered before slaughter, according to any one of claims 21 to 27.