In the application, milk is used to mean co- lostrum and milk in general.

In several animal species, antibodies are transferred from the mother to the cub via the pla- centa during pregnancy. As for ruminants, maternal an- tibodies are not transferred through the placenta, making the immunity of a calf weak at the moment of birth. The formation of the passive immunity of a calf is thus totally based on the quality of milk obtained from the mother, specifically the quality of colos- trum.

Colostrum is used to mean milk that is ob- tained from the mother right after calving and 24 hours after the calving at the most. The quality of milk necessary to a newborn calf is used to mean the vitamin and albumen concentrations contained therein, as well as the concentrations of antibodies created in the mother's body, which antibodies protect the calf from infections. Of the milk antibodies of ruminants, immoglobuline G (IgG) is the most common one, and its effect on the protection of the calf and the mother against the diseases and infections caused by patho- genic organisms has been widely examined. In addition to immunoglobuline G, the milk of ruminants contains very small amounts of immunoglobuline A, D, E and M.

Traditionally, there has been an attempt to improve the quality of milk by increasing the vitamin amounts of the feeding of ruminants during pregnancy,

specifically the amount of E vitamin. The amounts of antibodies of milk have also been increased by vacci- nating, i. e. by immunising the ruminant by an antigen which induces the production of the antibody in the ruminant.

US patent application 2003/0074676 Al dis- closes a method for increasing the IgA concentration of a ruminant and its milk by immunising the ruminant with the desired antigen. In the method, pregnant ru- minants are given antigen at least via two different routes, such as by infusion into the udder, abdominal cavity, or intravenously, to achieve the immunity ef- fect. After this, the ruminant is given antigen via a third route, which is selected from the three routes referred to above, and which is different than the two routes previously used. The IgA-rich milk thus ob- tained is utilised in preparing pharmaceutical, cos- metic and/or veterinary compositions, as well as food products and/or food additives.

A problem with the use of prior-art immunisa- tion methods is the complicated medicinal procedures required by the method, which the breeder him- self/herself is not able to perform, the workload re- quired by the method and duration of the method.

Moreover, to enhance the immunisation, additional vac- cinations are recommended.

The objective of the invention is to disclose a novel and simpler method for increasing the concen- tration of the immunofactors of a ruminant's milk by giving the ruminant a hydrolytically processed yeast raw material. Moreover, the objective of the invention is to disclose a method for increasing the milk yield of a ruminant after calving, as well as a method for increasing the ruminant's immunity which was reduced after calving by giving the ruminant a hydrolytically processed yeast raw material.

Further, the objective of the invention is to disclose use of milk prepared according to the method of the invention for promoting the growth of animals, specifically the growth of calves.

As for the features characteristic of the in- vention, reference is made to them in the claims.

The invention is based on research work car- ried out, in conjunction with which it was surpris- ingly found out that the concentration of the immuno- factors of milk correlated with the growth, specifi- cally the growth of calves, and that the concentration of the immunofactors in milk could be increased by giving the ruminant a hydrolytically processed yeast raw material in conjunction with the feeding, e. g. in fodder. In the same connection it was found out that the hydrolytic yeast raw material accelerated the res- toration of the immunity response after calving and improved the milk yield.

In the methods of the invention, ruminants are given a hydrolytically processed yeast raw mate- rial in an amount which increases the concentration of the immunofactors of milk.

Immunofactors of milk include immunoglobuli- nes (IgA, IgD, IgE, IgG and IgM), proline-rich pro- teins (PRP), lactoferrine, glycoproteins, lactalbu- mens, sytocines, lycozymes, enzymes, leucocytes, nu- cleotides and/or other corresponding milk immunofac- tors.

In some preferred embodiments, immunoglobu- line A (IgA) serves as the immunofactor.

The yeast raw material can be any known yeast, such as e. g. brewery, baking yeast and/or other yeast suitable for food, and preferably brewery yeast.

A hydrolytically processed yeast material is used to mean a yeast raw material which is processed such that the cell structure thereof opens, i. e. de- grades. The cell structure can be decomposed e. g. by

means of acid, base and/or autolysis and/or enzymati- cally. The cell structure of yeast can also be decom- posed by thermal treatment, by means of a detergent and/or by subjecting the cell structure to a mechani- cal, hydrostatic and/or pneumatic force. The treatment is used to increase the effective concentration of oligo and/or polysaccharides, betaglucane and/or pro- teins on the surface of insoluble cell structures and/or to release the aforementioned components.

In hydrolysis, the acids to be used can in- clude e. g. conventional mineral acids, such as hydro- chloric acid, sulphuric acid, phosphoric acid, nitric acid, etc. , as well as strong organic acids, e. g. for- mic acid, acetic acid, propionic acid, etc. The pH range to be used in acid hydrolysis can be less than 4, e. g. 2 to 4. In alkali hydrolysis, the alkalis can include e. g. conventional alkali hydroxides, such as sodium hydroxide, potassium hydroxide, etc. , ammonium hydroxide or other alkalis which release oligo and/or polysaccharides.

Enzymes to be used in enzymatic hydrolysis include e. g. different proteases, e. g. acid and alka- lic proteases. In hydrolysis it is possible to use e. g. the enzyme contained in brewery yeast itself, whereby the hydrolysis is performed via autolysis.

Further, it is possible to use in the hydrolysis other added enzymes, proteases, ribonucleases and deami- nases. In enzymatic treatment it is also possible to use a combination of several enzymes, simultaneously and/or consecutively, e. g. papaine, ribonuclease and/or deaminase. Generally it is possible to use in the method the enzymes presented in the publications referred to below and/or other enzymes known per se which have the desired effect of degrading the cell structure, individually and/or in combination, e. g. in a manner as described in the publications referred to below.

In hydrolysis, yeast can be heated to a tem- perature of more than 40°C, in autolysis and enzymatic hydrolysis e. g. to 40-65°C and in acid and alkali hy- drolysis e. g. to 70-95°C. The duration of the heating can vary depending on the temperature, e. g. 1-12 h.

Hydrolytic decomposition of yeasts has been described e. g. in patent publication and application WO 96/38057 and GB 1032687. These methods and other known methods can be used for hydrolytic processing of yeast, whereby a hydrolytically processed yeast raw material product is specifically the obtained non- fractioned product as such, or an insoluble or soluble fraction.

If desired, the yeast raw material can be filtered before the hydrolytic processing.

A hydrolytically processed yeast raw material can be given to a ruminant in conjunction with feed- ing. It can be given together with a fodder, such as a coarse, concentrated and/or drink fodder or mixed in the fodder.

The aforementioned yeast raw material can be given to a ruminant before calving, e. g. 1-4 weeks, preferably about two weeks before calving. Before calving, the aforementioned yeast raw material can be given in an amount of 0.1-0. 3%, preferably 0.14-0. 25% and more preferably 0. 2% of a daily portion, calcu- lated in dry matter.

The aforementioned yeast raw material can be given to a ruminant also after calving, e. g. 2-12 weeks, preferably 5-10 weeks after calving. In a cor- responding manner, it is possible to give a ruminant, after calving, the aforementioned yeast raw material in an amount of 0.01-0. 1%, preferably 0.03-0. 07% and more preferably 0.04-0. 06% of a daily portion, calcu- lated in dry matter.

The milk prepared according to the present invention can be used for promoting the growth, spe- cifically the growth of calves.

The colostrum prepared according to the in- vention, whose concentration of immunofactors has been increased by means of a hydrolytically processed yeast raw material, is given to a calf right after the birth, usually within 0-12 hours, more preferably 0-6 hours from the birth. The colostrum/milk prepared ac- cording to the invention is given to a calf in the initial phase of breeding, till the age of about 4-14 days. One can proceed with giving the milk till the age of 4-5 weeks. In addition to the colostrum/milk, calves can be fed with any conventional drink, concen- trated and coarse fodder.

An advantage of the present invention is bet- ter milk in respect of its properties and effects.

Thanks to the invention, it is possible, simply by means of the mother's feeding, to increase the concen- tration of the immunofactors of colostrum. By giving a newborn calf the colostrum prepared in accordance with the invention, which colostrum has an increased con- centration of immunofactors, the growth and immunity of the calf are promoted at the same time, as is known. The method of the invention does not require any specific measures deviating from the everyday rou- tine measures, instead a hydrolytically processed yeast raw material can be given to the animal in con- junction with the feeding, e. g. in fodder. Further by giving the animal a hydrolytically processed yeast raw material, the milk yield after the mother's calving can be considerably increased. An advantage of the in- vention is also the fast improving of the mother's im- munity after calving and thus a fast recovery after calving.

In the following section, the invention will be described in detail by means of embodiment examples with reference to the accompanying drawings, in which Fig. la illustrates the effect of feeding on the IgA concentration of colostrum; Fig. lb illustrates the effect of feeding on the IgA concentration of milk, wherein the amount of IgA being secreted into milk has been calculated in relation to the energy-corrected yield; Fig. lc illustrates the growth of a calf dur- ing week 3-5 with respect to the IgA concentration of Oh colostrum; Fig. 2a illustrates the IgA concentration of the serum of the milk vein after the mother's calving; and Fig. 2b illustrates the milk yield (energy- corrected) after the mother's calving.

Example 1 In the test, the effect of a hydrolytically processed yeast raw material on the IgA concentration of a ruminant's milk, milk yield and immunity was ex- amined. Moreover, the effect of the aforementioned milk on the growth of calves was examined.

Hydrolytically processed yeast raw material As the yeast raw material, brewery yeast was used which was mechanically filtered using a fine fil- ter by vibrating the filter plates by a micro vibrator at a high frequency. The filtered brewery yeast was hydrolysed using acid. In the hydrolysis, the pH of the yeast sludge was maintained at a value of 2-3 us- ing a strong acid (4 h) and at a temperature of 70- 85°C. Then the pH was raised to a value of 4-5 and the product thus obtained was cooled. The product obtained was used as such or dried.

Test arrangement and feeding In a test farm, 23 mothers participated in the examination, which mothers calved within two months from the starting date of the test. The mothers were divided into three different feeding groups on a random basis. The ones included in the first group (8) were given conventional concentrated fodder with an addition of a hydrolytically processed yeast raw mate- rial (test fodder) during the test. The ones included in the two other groups (7+8) were given two different types of conventional concentrated fodder (control fodder). No differences were found out between the ef- fects of the control fodders, so the results of the mothers included in these groups were combined into one control group (15 altogether) when dealing with the results.

The feeding of the test fodders was started two weeks before the estimated calving time, and one proceeded with the feeding for eight weeks after the calving. The test fodder comprised 0.2% yeast prepara- tion of a daily portion, calculated in dry matter, be- fore the calving, and correspondingly 0.04-0. 06% dur- ing the examination time after the calving.

The calves which were born were divided into concentrated fodder groups according to birth order.

The calves were given milk for 4 days and after that whole milk that was soured with formic acid until the age of 14 days. After this, the calves were given soured drink fodder for three days in stages. The calves were weaned from the drink fodder at the age of 8 weeks. In addition to milk/drink fodder, the calves were given concentrated fodder and hay. The calves were weekly weighed, in the beginning and at the end of the test in two consecutive days. The effect on the growth was evaluated at the age of 3-5 weeks, whereby the variation caused by the changes in the feeding did

not affect the result. The daily growth was obtained by dividing the change in the weight by the number of days of the test period.

Determinations of IgA concentration In the test, colostrum and milk samples were collected 0,6 and 24 hours from the calving, and 1,4 and 8 weeks from the calving, and the IgA concentra- tions of the samples were determined. The results are shown in Figs. la and lb.

In addition to the IgA concentration of milk, the healthiness and welfare of the mother were fol- lowed. The improvement of the immunity response after the mother's calving was followed by measuring the IgA concentrations of the mother's milk vein serum 0,1, 2,3, 4 and 8 weeks after the calving. The results of weeks 1,4 and 8 are shown in Fig. 2a.

In determining the IgA antibodies, a commer- cial ELISA determination (Bethyl Laboratories Inc., Montgomery, TX, USA) was used. The milk samples were first treated with a 1% BSA buffer and centrifuged (50000 g) for fifteen minutes. The serum and milk sam- ples were diluted right into the buffer without pre- liminary treatment.

Milk yield The mother's milk yield was measured each time when milking. The yield result 1,3, 4,6 and 8 weeks after the calving is shown in Fig. 2b.

Results The IgA concentration of milk The results show that the feeding in accor- dance with the invention increased the IgA concentra- tion of colostrum. Fig. la shows that the IgA concen- tration of colostrum was at its highest at the point of time of calving and that it contained clearly more IgA antibody 0 and 6 hours after the calving than the

colostrum of the control group. Fig. lb shows the same effect of increasing the IgA concentration of feeding in accordance with the invention also later, at least for four weeks after the calving.

The effect of the IgA concentration of milk on a calf's growth The results obtained show that the antibody concentrations of milk had an effect on a calf's growth. Fig. lc shows that the IgA concentration of milk considerably correlates with the daily growth during three to five weeks (p=0.032).

The examination also showed that the improved composition of colostrum obtained by means of the mother's feeding in accordance with the invention af- fected the calf's passive immunity, increasing the an- tibody levels of serum, which is important from the standpoint of the calf's health.

Immunity response and milk yield of the mother The results of Fig. 2a show that the immunity response of the mothers in the test group reached the normal level faster than that of the mothers included in the control group. The IgA concentrations of the serum of the mother were strongly decreased and were at their lowest about a week or two after the calving, after which the levels started to raise.

The results in Fig. 2b show that the mothers in the test group also produced more milk than the mothers in the control group.

In conclusion about the results we state that by the present methods one obtains milk that is better in respect of its qualities and has an increased IgA concentration. In addition, colostrum/milk prepared in accordance with the methods has a considerably effect on a calf's growth. At the same time, the methods of the invention have positive effects on the mother's recovery after the calving and on the milk yield. The

improvement of the composition of colostrum/milk does thus not happen at the mother's expense, instead also they benefit from the use of the methods of the inven- tion.

The invention is not limited merely to the examples referred to above, instead many modifications are possible within the scope of the inventive idea defined by the claims.