BE1022983B1 - Use of a product of low iron grown grain - Google Patents

Abstract

Use of a grain fraction (F) obtained from whole grains in a feed for animals, said grain fraction (F) having a reduced iron content of at least 25% by weight relative to a feed content initial iron of said whole grains, and said grain fraction (F) being obtained from whole grains selected from the group consisting of at least one cereal grain, at least one oleaginous grain, at least one legume grain and a mixture of these.

Description

"Use of a product of low iron cultivated grain" Technical field

The present invention relates to a use of a grain fraction derived from grains of cereals, oilseeds and / or legumes in a feed intended for animals, said grain fraction having a reduced iron content while retaining good properties and a good energy value.

Prior state of the art

Nowadays, the animal feed, and in particular the feeding of farm animals for which veal calves rely on the use of food rations, some of which is solid (for example the dry part of the cereal-based ration) and the other liquid (based on dairy products, for example breast milk). The use of such a diet should ensure a proper balance between the different nutrients essential for growth and proper and normal development of young calves.

Among these nutrients, it is well known that iron has a significant influence on several metabolic functions, including the amount of hemoglobin in red blood cells and the amount of red blood cells in the blood. This is why it is recognized that the iron (Fe) content is of great importance in certain types of animal feed.

The iron can come from various sources: on the one hand, iron can be naturally present in the raw material used to make animal feed and, on the other hand, iron can also be added to the food, in order to to achieve a desired iron content in the case where the initial content is insufficient. Finally, iron can also come from the friction of the raw material against metal elements in the processing facilities of the production line.

In addition, iron is known to have a significant influence on the color of animal flesh, and thus, after slaughter of the animal, on the color of the meat. In this respect, in certain animal breeding systems, such as the breeding of veal calves, it is desirable to obtain a meat with a color ranging from white to pink, an animal feed that is too rich in iron to cause injury. to obtain such a color of meat. Thus, some raw materials can not be part of the diet of some animals because of their too high iron content which has a direct impact on the appearance of the meat, mainly on the color of the latter.

In order to obtain meat of adequate color, it could be envisaged to use feeds where the iron content would be limited by increasing the proportion of liquid-type foods in the diet compared to the solid-type diet. because the liquid type feed typically has a particularly low iron content.

Unfortunately, the use of such a diet has a major disadvantage since the solid diet comprises fibers essential for the growth and good health of the calves. A diet solely or essentially liquid would indeed be responsible for significant nutritional deficiencies that should be avoided, especially in young animals. It would therefore be preferable, on the contrary, to use a diet in which the proportion of solid foods (fiber sources) in relation to the proportion of liquid-type foods would be increased. However, in this case, the iron content of solid foods often remains too high, which limits the share of solid foods that can be present in the calf's diet when a color ranging from white to pink is sought. The animal feed currently used, especially to feed farm animals and more particularly calves, very frequently includes maize, this cereal is also used in large part as a feedstock for calves, farmers and calf producers aiming to increase their share in the diet. Indeed, maize has good digestibility, good palatability, excellent nutritional properties such as a naturally low iron content, typically in the range of 30 mg / kg to 40 mg / kg, a good balance between fat content and starch content, as well as a good energy value.

However, as mentioned above and despite the fact that maize has a relatively low iron content, increasing the proportion of this cereal in the diet is inevitably responsible for too much iron. A use of such a diet is therefore opposed to obtaining a pink-white meat yet sought especially by consumers of veal. This problem is all the more marked with the use of a diet comprising other cereals, with oilseeds and with legumes whose iron content may be higher than those found for maize.

There is therefore a real need to date to use a fraction of grains obtained from cultured whole grains (for example grains of cereals, oilseeds and / or grains of legumes), this fraction of grains having to have a reduced iron content while maintaining good nutritional properties, including an appropriate fat and starch content, good digestibility and palatability, and a good energy value. Moreover, this fraction of grains must be able to be given to animals in higher proportions. There is also the need to be able to use processed products of said grain fraction as animal feed, these processed products also having to have a reduced iron content, while also retaining good nutritional properties, good digestibility and good palatability. as well as a good energy value. Summary of the invention

In the context of the present invention, it has been shown that a use according to the invention of a fraction of grains having a reduced iron content relative to the initial iron content of the whole grains, makes it possible to retain good properties. nutrients, including adequate fat and starch content, good digestibility and palatability, and a good energy value.

To meet the needs mentioned above, the invention relates to a use of a grain fraction (F) obtained from whole grains in a feed intended for animals, said grain fraction (F) having a reduced iron content of at least 25% by weight based on an initial iron content of said whole grains, and said grain fraction (F) being obtained from whole grains selected from the group consisting of at least one cereal grain, d. at least one oleaginous grain, at least one legume grain and a mixture thereof.

Advantageously, the use of a grain fraction (F) according to the invention is intended for animals that are farm animals.

Preferably, according to the invention, said animals are cattle, preferably calves, preferably beef calves.

In the context of the present invention, it has been shown that the use of a fraction of grains (F) as defined above (reduced iron content) is particularly suitable for use in the feeding of animals of breeding, and more specifically in the feeding of veal calves when it is a question of obtaining a white-rosé meat, while ensuring a right balance between the different nutrients of the food ration, the latter having to have a good balance between the fat content and the starch content, and a good energy value.

Preferably, according to the use according to the invention, said fraction of grains (F) has a reduced iron content of at least 40% by weight, preferably at least 45% by weight, preferably at least 50% by weight, preferably at least 55% by weight, preferably at least 60% by weight, based on an initial iron content of said whole grains.

Advantageously, according to the use according to the invention, said grain fraction (F) has a particle size distribution such that: D90> 1000 μm and Dg0 <6000 μm and Üg9.5 <7000 μm.

Preferably, according to the use according to the invention, said grain fraction (F) is obtained by a process comprising the following steps:

Step 1: a step of treating said whole grains,

Step 2: a step of separating said grains treated in step 1 so as to obtain a first grain fraction (F1) comprising first grain fragments having a particle size greater than one or more predetermined threshold values of size of particles and a second grain fraction (F2) comprising second grain fragments having a particle size smaller than said predetermined particle size threshold value (s), and

Step 3: a step of separating said first grain fraction (F1) obtained in step 2, on the basis of the size and / or shape of said first fragments, so as to isolate said grain fraction (F) having said reduced iron content.

Advantageously, according to the use of a grain fraction (F) according to the invention, step 1 of whole grain treatment of the process for obtaining said grain fraction (F) denotes fragmentation carried out by grinding, by friction treatment and / or abrasive treatment of whole grains.

Preferably, according to the use of a grain fraction (F) according to the invention, step 1 of the process for obtaining said grain fraction (F) is preceded or followed by a grain conditioning step .

Preferably, according to the use of a grain fraction (F) according to the invention, said grain conditioning step comprises one or more cleaning steps, one or more moistening steps and / or one or more polishing steps. .

Advantageously, according to the use of a grain fraction (F) according to the invention, said step 2 of separating the process for obtaining said grain fraction (F) is carried out by means of a device provided with a perforated screen whose perforations have a rectangular or oval shape.

Preferably, according to the use of a grain fraction (F) according to the invention, said perforations having a rectangular or oval shape have a length which is not less than 3.0 mm, preferably not less than 5 mm. , 0 mm, preferably not less than 7.0 mm, preferably not less than 10.0 mm, preferably not less than 12.0 mm, said length not being greater than 30.0 mm, preferably not more than 25.0 mm, preferably not more than 20.0 mm, preferably not more than 18.0 mm, preferably not more than 15.0 mm, preferably not more than not more than 14.0 mm, preferably not more than 13.0 mm, preferably not more than 12.0 mm.

Advantageously, according to the use of a grain fraction (F) according to the invention, said perforations having a rectangular or oval shape have a width which is not less than 0.5 mm, preferably not less than 0, 75 mm, preferably not less than 1.0 mm, preferably not less than 1.2 mm, said width not being greater than 6.0 mm, preferably not more than 5.0 mm, preferably not more than 4.0 mm, preferably not more than 3.0 mm, preferably not more than 2.5 mm, preferably not more than 2.0 mm, preferably not more than 1.5 mm, preferably not more than 1.2 mm.

Preferably, according to the use of a grain fraction (F) according to the invention, said grain fraction (F2) represents at most 50% by weight, preferably at most 45% by weight, preferably at most 40% by weight. % by weight, preferably at most 35% by weight relative to the total weight of whole grains.

Advantageously, according to the use of a grain fraction (F) according to the invention, said fraction (F2) represents at least 15% by weight, preferably at least 20% by weight, preferably at least 25% by weight relative to the total weight of whole grains.

Preferably, according to the use of a grain fraction (F) according to the invention, said separation of the first fraction (Fi) from step 3 of the process for obtaining said grain fraction (F) comprises a mechanical separation.

Preferably, according to the use of a grain fraction (F) according to the invention, said mechanical separation of the first fraction (F1) of step 3 of the process for obtaining said grain fraction (F) is carried out using a sieve or a plurality of sieves having different size meshes.

Advantageously, according to the use of a grain fraction (F) according to the invention, during the process for obtaining said grain fraction (F), an intermediate grain fraction (F ') is collected between a sieve in lower position and a sieve in the upper position, if said sieve in the upper position is present, or on the sieve in the lower position if a single sieve is used.

Optionally, according to the use of a grain fraction (F) according to the invention, in the process for obtaining said grain fraction (F), said grain fraction (F) is obtained by subjecting the fraction (F) at a subsequent separation step so as to subtract a grain fraction (F4) therefrom.

Preferably, according to the use of a grain fraction (F) according to the invention, said subsequent separation step in the process for obtaining said grain fraction (F) is carried out by means of aspirations.

Advantageously, according to the use of a grain fraction (F) according to the invention, in the process for obtaining said grain fraction (F), a fraction of grains (F3) is collected after passing through the whole sieves, specifically after passing through a sieve in the lower position.

Preferably, according to the use of a grain fraction (F) according to the invention, said grain fraction (F) represents at most 80% by weight, preferably at most 75% by weight, preferably at most 70% by weight. weight relative to the total weight of whole grains.

Preferably, according to the use of a grain fraction (F) according to the invention, said grain fraction (F) represents at least 45% by weight, preferably at least 50% by weight, preferably at least 55% by weight. % by weight relative to the total weight of whole grains.

Preferably, according to the use of a grain fraction (F) according to the invention, said grain fraction (F) is obtained from grains being corn kernels.

Advantageously, according to the use of a grain fraction (F) according to the invention, said grain fraction (F) obtained from grains being maize grains has a maximum iron content of 30.0 mg / kg preferably a maximum iron content of 25.0 mg / kg, preferably a maximum iron content of 20.0 mg / kg, more preferably a maximum iron content of 15.0 mg / kg, preferably a iron maximum of 13.0 mg / kg, preferably a maximum iron content of 12.5 mg / kg, more preferably a maximum iron content of 12.0 mg / kg.

The present invention also relates to a use of a grain fraction (F) transformed into a processed product.

Preferably, according to the use of a fraction of grains (F) converted into a product transformed according to the invention, said transformed product is obtained according to a step selected from the group consisting of grinding, flattening, toasting, flaking, extrusion, granulation, micronization and expansion process.

Advantageously, according to the use of a fraction of grains (F) converted into a product converted according to the invention, said transformed product is a flake, a granule, an extruded, a micronized product, a toasted product or an expanded product.

Preferably, according to the use of a fraction of grains (F) converted into a product transformed according to the invention, said transformed product having a reduced iron content of at least 25% by weight, preferably at least 30% by weight, preferably at least 35% by weight, preferably at least 40% by weight, preferably at least 45% by weight, preferably at least 50% by weight, of preferably at least 55% by weight, preferably at least 60% by weight, based on the initial iron content of the whole grain.

Preferably, according to the use of a fraction of grains (F) transformed into a processed product according to the invention, said transformed product is used in a feed intended for animals.

Detailed description of the invention

The grain fraction (F) or the processed products from the grain fraction (F) can be used in the solid type feed for animals such as farm animals, domestic animals, birds, fish , or insects.

As already indicated above, the whole grain used to obtain a feed intended for animals and based on a use of a grain fraction (F) according to the invention may be a cereal grain, an oilseed grain or a grain of legume.

Typical and non-limiting examples of cereal grain are corn kernels, wheat, barley, rice, oats, spelled and derivatives thereof.

Corn derivatives can refer to sweet corn and popcorn.

Oat derivatives may refer to naked avian, peeled oats and shelled oats.

Derived spelled may refer to peeled spelled.

A typical and nonlimiting example of oilseed grain is soybean.

Typical and non-limiting examples of legume grains are lupine, peas, and beans in general.

Preferably, the whole grain used to obtain a feed intended for animals and based on a use of a grain fraction (F) according to the invention is a cereal grain.

Preferably, the cereal used to obtain a feed intended for animals and based on a use of a grain fraction (F) according to the invention is corn and the derivatives thereof, or wheat. More preferably, the cereal used to obtain a feed intended for animals and based on a use of a grain fraction (F) according to the invention is corn.

Corn is often used as a feedstock for calves because of its good digestibility, taste and nutritional properties, for example because of its low fat content and its natural iron content. relatively low.

Advantageously, the corn can be heat-treated, more particularly in order to be transformed into corn flakes, in order to improve its digestibility and taste and to further reduce its iron content, while maintaining a low content of iron. fat.

In the context of the present invention, the expressions "grain" or "grains" are used indifferently.

In the context of the present invention, the expressions "the grain" or "the seed" are used indifferently.

In the context of the present invention, it has surprisingly been found that the grain fraction (F) used in a feed intended for animals has a reduced iron content of at least 25% by weight, preferably at least 30% by weight, preferably at least 35% by weight, preferably at least 40% by weight, preferably at least 45% by weight, preferably at least 50% by weight preferably at least 55% by weight, more preferably at least 60% by weight relative to the initial iron content of the whole grain.

The iron content can be measured spectroscopically, for example by spectroscopy using inductively coupled plasma and can be expressed in mg / kg.

Iron, although undesirable in proportions that are too important in certain types of animal feed, particularly in the feed for veal calves, is nevertheless accepted, even desirable, in small quantities. Indeed, iron is essential in the feed of farm animals to ensure certain metabolic functions as already mentioned above.

For the purposes of the present invention, it is understood that the iron content in the grain fraction (F) is at least 1.0 mg / kg, preferably at least 2.0 mg / kg, preferably at least 2.5 mg / kg.

Typically, whole corn kernels have an iron content ranging from 10.0 mg / kg to 50.0 mg / kg, depending on the variety.

In a preferred embodiment of the present invention, when the grain fraction (F) is derived from whole corn kernels (hereinafter referred to as corn kernel fraction (F)) and is used in a feed for to animals, the grain fraction (F) has a reduced iron content relative to the initial iron content of the whole corn kernel. The reduced iron content of corn kernel fraction (F) can be at least 1.0 mg / kg, preferably at least 2.0 mg / kg, preferably at least 2.5 mg / kg.

In addition, the reduced iron content of corn grain fraction (F) is at most 30.0 mg / kg, preferably at most 25.0 mg / kg, preferably at most 20.0 mg / kg. kg, more preferably at most 15.0 mg / kg, preferably at most 13.0 mg / kg, preferably at most 12.5 mg / kg, more preferably at most 12.0 mg / kg.

Good results for use of corn grain fraction (F) in an animal feed have been obtained for a reduced iron content in the range of 2.5 to 13.0 mg / kg.

In the context of the invention, the meat of the animals fed according to the use of a fraction of grains (F) according to the present invention has a pink to light color, preferably corresponding to a maximum of a shade of class 3, of preferably not more than a Class 2 shade, preferably a Class 1 shade on the classification chart of the National Inter-professional Meat and Poultry Office (OFIVAL, Paris) (Development and construction of the new color chart for veal, Final Report No. 00 10 32 009 of the Department of Livestock and Quality Technology, Institute for Livestock, 2010, page 42).

The reduced iron content values of the grain fraction (F) are also applicable to the transformed products from said grain fraction (F), as explained in detail below.

According to the present invention, the use of a grain fraction (F) implies that said fraction (F) is obtained according to the method which comprises at least the three steps described below.

In step 1 of the process of the present invention for obtaining a grain fraction (F) used in a feed for animals, the whole grain selected from the group consisting of at least one cereal grain, at least one oleaginous grain, at least one legume grain and a mixture thereof are subjected to a treatment. In the context of the present invention, the treatment refers to the action of reducing an entire grain or a derivative thereof in at least two grain fragments, so as to obtain at least first grain fragments and at least second fragments grains. Thus, the grains can be processed in any conventional grain treatment unit to reduce an entire grain into at least two grain fragments.

In the context of the present invention, the term "at least two grain fragments" refers to "two or more grain fragments".

Typical examples of grain processing are described in WO 2005/108533 A2, the entire contents of this application being incorporated herein by reference for all purposes.

In the context of the present invention, the treatment of step 1 denotes the fragmentation of the whole grains optionally packaged.

Specifically, the fragmentation can be carried out by crushing the whole grains, by friction treatment, by abrasive treatment, and / or by cutting the whole grains, preferably by a friction treatment and / or an abrasive treatment, more preferably by a abrasive treatment.

Whole grains can for example be crushed against or under a grinding wheel, or between two rollers.

Friction treatment may for example be carried out in a device in which the grains are brought into contact with one or more moving surfaces. In the case of an abrasive treatment, the grains are brought into contact with one or more moving surfaces having bar, pointed, rounded, or any other shape protuberances.

Examples of machines that can perform an abrasive grain treatment are Bühler's MHXM machine, Satake's "Mize degermer VBF10AM" machine, or a M300, M301 or M350 dehuller from CMF.

It is understood that those skilled in the art will implement the abrasive treatment, using the MHXM Bühler machine according to general practice, including applying all the optimal parameters (number of impact bars, pressure between the rollers,. ..), provided that the grain fractions (F1) and (F2) are formed, as described in detail below.

According to the invention, said processing step of the method for obtaining a grain fraction (F) used in a feed intended for animals may also comprise a packaging of said whole grains. Such conditioning may take place prior to step 1 or following step 1.

Conditioning, whether performed before step 1 or after step 1, may comprise for example one or more cleaning steps, one or more moistening steps and / or one or more polishing steps. The cleaning step is performed to remove undesirable elements from the grains. Non-limiting examples of undesirable elements in the process may be pebbles, gravel, sand, glass and other high-density materials, straw and other plant-based elements that are not the desired grains, materials of animal origin, dust, earth, paper, cardboard, metals, grains not having the desired color, ...

Optionally, the cleaning step can be carried out in such a way that undesirable and / or toxic substances, such as, for example, mycotoxins or (residues of) plant protection products (pesticides, herbicides, etc.) are at least partially eliminated.

Cleaning can be done in a conventional cleaning unit.

The cleaning may comprise a washing step with water, a suction step by air flowing through the grains, or a combination of both.

In the case of a washing with water, the water may be in various forms, for example in gaseous form, liquid or constitute an aqueous solution. Optionally, additives could be added to the water. Among the additives that can be added to water, there may be mentioned acids and surfactants.

Non-limiting examples of cleaning devices may be a drum screen, a magnetized drum, a silo in a tank that may have a central axis, a cleanser, and / or a classifier, a non-ferrous metal detector, a metal detector. color or a sieve. All these units can be supplied in particular by Bühler GmbH.

In a particularly advantageous form, the cleaning is carried out with a circulating air flow.

When a conditioning stage is carried out, an MTRA separator and / or an MTSC cleanser from Bühler GmbH could advantageously be used.

Advantageously, the undesirable elements can be sucked into a suction channel out of the cleaning and / or preliminary cleaning unit, where they are collected and separated from the space where the process of the present invention takes place.

According to one embodiment of the method of the present invention, said grain conditioning may optionally include a step of moistening said whole grain to obtain a grain having a certain moisture content. Typically, whole corn kernels have a moisture content of between 6% and 35% by weight based on the weight of the whole corn kernel. Optionally, if the moisture content is less than 15% by weight, based on the weight of the whole maize grain, said moisture content could be increased by at least 0.5% by weight, preferably from minus 1.0% by weight, preferably at least 1.5% by weight, more preferably at least 2.0% by weight based on the weight of said whole maize grain.

Said humidification step can be carried out according to the methods known from the state of the art.

Advantageously, the whole grain is moistened with water, preferably with water at room temperature. Moisture can be absorbed into the grain for a certain period of time.

In a particularly preferred embodiment of the present invention, the grains may be introduced into a rotating screw under water vapor for about 90 seconds.

According to another embodiment according to the invention, said conditioning of the grain may comprise a polishing step carried out for example by subjecting the whole grain to a series of compressions and relaxations, in order to soften the envelope of the whole grain by friction. .

Advantageously, the polishing step may be carried out in a polishing machine well known in the state of the art, such as, for example, the polishing machine Mist Polisher from Satake.

Advantageously, the polishing machine could comprise a rotating eccentric rotor surrounded by a chamber surrounded by a perforated polygonal screen. With each rotation of the rotor, the space between said rotor and the screen causes alternating compression and relaxation cycles, producing a friction action on the grain.

The grains thus packaged, i.e. for example cleaned and / or moistened and / or polished, can then be processed as described above according to the process of the present invention. In step 2 of the process according to the invention making it possible to obtain a fraction of grains (F) used in a feed intended for animals, the grains, once treated according to step 1 of the process and optionally packaged, are then separated. in two fractions, according to one or more particle size threshold values. More specifically, the grains are separated into a first grain fraction (F1) comprising first grain fragments having a particle size greater than one or more predetermined particle size threshold values and a second grain fraction (F2) comprising second grain fragments having a particle size smaller than said predetermined particle size threshold value (s).

In a preferred embodiment of the method, step 2 may be performed using a device provided with a perforated screen.

In this embodiment, the grains treated in step 1 and optionally packaged are introduced into said device provided with a perforated screen. This device is designed to retain grain fragments having a particle size larger than one or predetermined threshold particle size values, these retained fragments forming the fraction (Fi). In parallel, this device is arranged to pass grain fragments having a particle size smaller than said threshold values, these fragments passing through the device forming the fraction (F2).

Typically, the perforated screen of the device can be a screen made of metal, polymer, wood, or any other type of material.

Typically, the perforated screen comprises at least one perforation that can be of any type of shape, for example a hexagon, a pentagon, an octagon, a square, a rectangle, a circle, a triangle, an oval. Preferably, the perforation is in the form of a rectangle and / or an oval.

Advantageously, the length of the rectangular perforation or the length of the oval perforation is at least 3.0 mm, preferably at least 5.0 mm, preferably at least 7.0 mm, more preferably at least at least 10.0 mm, preferably at least 12.0 mm.

Advantageously, the length of the rectangular perforation or the length of the oval perforation is at most 30.0 mm, preferably at most 25.0 mm, preferably at most 20.0 mm, preferably at most at most 18.0 mm, preferably at most 15.0 mm, more preferably at most 14.0 mm, preferably at most 13.0 mm, preferably at most 12.0 mm.

In the context of the present application, the terms "length of the oval perforation" and "width of the oval perforation" denote respectively the dimension corresponding to the length and width of a rectangular perforation in which this oval would be inscribed.

Advantageously, the width of the rectangular perforation or the width of the oval perforation is at least 0.5 mm, preferably at least 0.75 mm, preferably at least 1.0 mm, preferably at least at least 1.2 mm.

Advantageously, the width of the rectangular perforation or the width of the oval perforation is at most 6.0 mm, preferably at most 5.0 mm, preferably at most 4.0 mm, preferably at most plus 3.0 mm, preferably not more than 2.5 mm, more preferably not more than 2.0 mm, preferably not more than 1.5 mm, preferably not more than 1.2 mm.

It is understood that one skilled in the art uses the optimal size of perforations of the device provided with a perforated screen of step 2, this size being adapted to the type of cultivated grain used and resulting from step 1.

For example, in the case of corn kernels, the length of the rectangular or oval perforation is advantageously between 5.0 mm and 18.0 mm, preferably between 7.0 mm and 15.0 mm, more preferably between 10 mm and 15.0 mm. , 0 mm and 14.0 mm.

Still in the case of corn kernels, the width of the rectangular or oval perforation is advantageously between 0.5 mm and 5.0 mm, preferably between 0.75 mm and 3.0 mm, more preferably between 1.0 mm and 2.0 mm.

The device provided with a perforated screen may for example be in the form of a filter sleeve.

In an advantageous embodiment, step 1 and step 2 of the process can be carried out in the same processing unit. In this case, the processing unit used in step 1 may for example comprise a device provided with a perforated screen.

In a particularly advantageous embodiment of the present invention, optionally packaged grains are subjected to step 1 and step 2 in an MHXM machine from Bühler.

In an alternative embodiment, in step 2, the grains, once treated according to step 1 of the process and optionally packaged, are then separated into two fractions, according to one or more density threshold values. More specifically, the grains are separated into a first grain fraction (Fi) comprising first grain fragments having a density greater than a predetermined threshold density value and a second grain fraction (F2) comprising second grain fragments exhibiting a specific grain size. density less than a predetermined threshold value of density.

Among the methods for density separation, centrifugation and suction separation may be mentioned.

In one embodiment of the method, the second grain fraction (F2) is directly collected after step 2.

In an alternative embodiment, the second grain fraction (F2) is sucked out of the perforated screen device by a suction channel to be collected in a space separate from the space in which step 2 occurs.

Optionally, the second fraction of grains (F2) preferably circulates through a cyclone after its exit from step 2 and before being collected.

In an advantageous embodiment of the present invention, the grain fraction (F 2) represents at most 50% by weight, preferably at most 45% by weight, preferably at most 40% by weight, more preferably at most 35% by weight. weight relative to the total weight of whole grains.

In an advantageous embodiment of the present invention, the grain fraction (F2) represents at least 15% by weight, preferably at least 20% by weight, preferably at least 25% by weight relative to the total weight of whole grains. .

In an advantageous embodiment of the present invention, the corn (F2) grain fraction represents at most 45% by weight, preferably at most 40% by weight relative to the total weight of whole grains.

In an advantageous embodiment of the present invention, the grain fraction (F 2) of maize represents at least 15% by weight, preferably at least 20% by weight, preferably at least 25% by weight relative to the total weight of the whole grains.

The fraction (F2) can optionally be used as animal feed. In step 3 of the process according to the invention making it possible to obtain a fraction of grains (F) used in a feed intended for animals, a second separation is carried out on said first fraction of grains (F1) obtained in step 2, so as to isolate said fraction of grains (F) having said reduced iron content. More particularly, a separation carried out on the basis of size and / or shape is carried out according to this third step of the process: the first fraction of grains (F1) is separated into at least two fractions, the fraction of grains (F) obtained at the end of this step 3 being one of these at least two fractions.

In a particularly advantageous embodiment of the present invention, the separation of the first grain fraction (F1) from step 3 comprises a mechanical separation.

In a particular embodiment of the present invention, the separation of step 3 is sieving separation. Separation by sieving can for example take place in a separator type machine. Advantageously, the mechanical sieving can be carried out using one or a set of sieves having meshs of different sizes.

Sieves can be arranged in different ways. Among other things, the screens may be vertically superimposed, or successively aligned along an inclined slope, or positioned in a combination of these two arrangements.

It is understood that the sieve having the largest mesh size will be located in an upper position, the screens being positioned by mesh size decreasing from top to bottom. The screen with the smallest mesh size is therefore in the lower position.

Advantageously, the sieve assembly comprises from 2 to 7 sieves, preferably from 2 to 6 sieves, preferably from 2 to 5 sieves, preferably from 2 to 4 sieves, more preferably from 2 to 3 sieves, preferably 2 sieves.

In a preferred embodiment of the present invention, the mesh size of the sieve in the lower position is at least 500 μm, preferably at least 750 μm, preferably at least 1000 μm, preferably at least 500 μm. at least 1100 μm, preferably at least 1200 μm, preferably at least 1300 μm, more preferably at least 1400 μm, preferably at least 1500 μm.

In addition, it is understood that the mesh size of the sieve in the upper position is at most 10 000 μm, preferably at most 9000 μm, preferably at most 8000 μm, preferably at most 7000 μm. pm, preferably at most 6000 pm, preferably at most 5600 pm.

Alternatively, a single sieve could be used instead of a set of sieves.

In the case where a single sieve is used, the mesh size of this sieve is at least 500 μm, preferably at least 750 μm, preferably at least 1000 μm, preferably at least 1100 μm. pm, preferably at least 1200 pm, preferably at least 1300 pm, more preferably at least 1400 pm, preferably at least 1500 pm.

In step 3 of the process, the first grain fraction (F1) is separated into at least two fractions, as indicated above. An intermediate grain fraction [hereinafter called grain fraction (F ')] can be collected between the sieve in the lower position and the sieve in the upper position, if said sieve in the upper position is present, or on the sieve in the lower position. if only one sieve is used. The fraction having passed through the sieve assembly, specifically the lower sieve as described above, is referred to as the grain fraction (F3).

The fragments that have not passed through the sieve in the upper position, if it is present, form a fraction comprising the fragments of size greater than the size of the sieve meshes in the upper position.

The grain fraction (F) as described above can be obtained by subjecting the fraction (F ') to a subsequent separation step, so as to subtract a fraction of grains (F4).

In the context of the present invention, the inventors have found that the grain fraction (F4) generally comprises the grain envelopes and the seeds of the small grains. It is well known that grain envelopes may contain mycotoxins. Typically, mycotoxins are undesirable because they can cause acute food poisoning, infertility, and / or other metabolic disorders, especially in livestock.

That said, the inventors have surprisingly found that the grain fraction (F) obtained by the process has a reduced concentration of mycotoxins. The term "reduced concentration of mycotoxins" corresponds in the context of the present application to a concentration of mycotoxins reduced by at least 30% compared to the initial mycotoxin concentration.

In an advantageous embodiment of the process, the subsequent separation step for subtracting a grain fraction (F4) from the grain fraction (F ') can be carried out using aspiration means. An example of suction means is an air suction channel.

In a particular embodiment of step 3 of the method, the grain fraction (F) is obtained using a separator type machine.

Among the separator-type machines that can be used in step 3 according to the invention, mention may be made of the MTRA and MTRB machines, both from Bühler GmbH.

The different grain fractions (F), (F3) and (F4) can be collected and their percentage proportions by weight based on the total weight of whole grains can be calculated.

In the process, the grain fraction (F) advantageously represents at least 45% by weight, preferably at least 50% by weight, preferably at least 55% by weight relative to the total weight of whole grains.

In the process, the grain fraction (F) advantageously represents at most 80% by weight, preferably at most 75% by weight, preferably at most 70% by weight relative to the total weight of the whole grains.

In the process, the grain fraction (F3) advantageously represents less than 10% by weight, preferably less than 8% by weight, preferably less than 5% by weight relative to the total weight of whole grains.

When present, the grain fraction (F4) advantageously represents less than 8% by weight, preferably less than 5% by weight, preferably less than 3% by weight relative to the total weight of whole grains.

A specific embodiment of step 3 is described in the experimental part.

In the context of the present invention, it has been surprisingly determined that the grain fraction (F), obtained from whole grains subjected to the process for obtaining a grain fraction (F) used in a feed intended for animals according to the invention, comprises fragments of grains whose fat content is reduced but adequate for animal feed. By the term "reduced but adequate", it is understood that the fat content of the grain fraction (F) is reduced by about 25% to 85% with respect to the initial fat content.

The fat content of the grain fraction (F) can for example be measured by the Soxhlet method and can be expressed in mg / kg or in percentage.

Typically, whole grain has an initial fat content of 4 to 5%.

In a preferred embodiment, the grain fraction (F) derived from the process of the present invention has a fat content of at least 0.5%, preferably at least 1.0%, preferably at least 1.5%, preferably at least 2.0%.

The grain fraction (F) resulting from the process has a fat content of at most 4%, preferably at most 3%.

Good results have been obtained for a fat content in the range of 2% to 3% in the grain fraction (F) of maize.

The fat content values of the grain fraction (F) are also applicable to the processed products of said grain fraction (F), as explained in detail below.

In the context of the present invention, it has been surprisingly determined that the grain fraction (F), obtained from whole grains subjected to the process for obtaining a grain fraction (F) used in a feed intended for animals, includes grain fragments whose starch content is increased but adequate for animal feed. By the term "increased but adequate", it is understood that the starch content of the grain fraction (F) is increased by at least 3% by weight, preferably by at least 4% by weight, preferably by at least 5% by weight, more preferably at least 6% by weight, preferably at least 8% by weight relative to the starch content of whole grains used in step 1 of the process. It is also understood that the starch content of the grain fraction (F) is increased by at most 25% by weight, preferably by at most 20% by weight, preferably by at most 15% by weight, preferably of at most 10% by weight, more preferably at most 8% by weight relative to the starch content of the whole grains used in step 1 of the process. This is particularly unexpected since the whole grains can be subjected, according to the invention, to various constraints such as grinding, cleaning, moistening or polishing. However, despite these various treatments and despite the various process steps to which whole grains and grain fractions derived from them are subjected, an increased starch content is observed for the grain fraction (F) with respect to the starch content of the grains. whole grains. This is particularly advantageous since the starch content of the whole grains but also of the grain fraction (F) obtained is adequate in terms of the nutrition of the farm animals and in particular the beef calves.

The starch content of the grain fraction (F) can for example be measured by Ewers method or enzymatic method and can be expressed in mg / kg or in percentage. The method protocol WV.FD.21 EG 152/2009 of the European Commission can for example be used.

The grain fraction (F) resulting from the process has a starch content of at least 68%, preferably at least 69%, preferably at least 70%, more preferably at least 71%.

The grain fraction (F) resulting from the process has a starch content of at most 85%, preferably at most 80%, preferably at most 75%.

The starch content values of the grain fraction (F) are also applicable to the transformed products of said grain fraction (F), as explained in detail below.

The energy value of the grain fraction (F) is the amount of energy that can be removed, for example during digestion. The energy value is evaluated and calculated on the basis of all energy nutrients, namely starch, sugars, other carbohydrates, fats and proteins. This energy value can be measured by calorimetric bomb and can be expressed in kJ / kg or kcal / kg.

Typically the energy value of an entire corn kernel is between 4400 kcal / kg and 4600 kcal / kg.

In a preferred embodiment of the present invention, the corn kernel fraction (F) resulting from the process has an energy value of at least 3500 kcal / kg, preferably at least 4000 kcal / kg, preferably at least 4300 kcal / kg.

The corn grain fraction (F) resulting from the process has an energy value of at most 5000 kcal / kg, preferably at most 4500 kcal / kg.

According to the present invention, it has been determined that the method makes it possible to maintain the energy value of a maize grain at a substantially constant level between the whole grain and the grain fraction (F).

The energy value of the grain fraction (F) is also applicable to the processed products of said grain fraction (F), as explained in detail below.

In the context of the present invention, it has been found that the reduction in the fat content is counterbalanced by the increase in the starch content. Thus, the grain fraction (F) maintains a good balance between the fat content and the starch content, and therefore, good nutritional properties, as well as a good energy value.

In one embodiment of the process for obtaining a grain fraction (F) used in a feed for animals, the grain fraction (F) has a particle size distribution such that: D90> 1000 Mm and Dgo <6000 Mm and D99.5 <7000 Mm In an alternative embodiment of the process, the grain fraction (F) has a particle size distribution such that: D90> 500 gm and D90 <4000 gm and D99.5 <5000 gm In another alternative form of the process, the grain fraction (F) has a particle size distribution such that: D90> 1500 gm and D90 <12000 gm and D995 <15000 gm In an advantageous embodiment of the invention, the particles of the Maize grain fraction (F) has a particle size in one of the following particle size distributions: D90> 1000 gm and D90 <6000 gm and D995 <7000 gm; or D90> 1200 gm and D90 <6000 gm and D995 <7000 gm; or D90> 1400 gm and D90 <6000 gm and D995 <7000 gm.

In a preferred embodiment of the present invention, the particles of corn grain fraction (F) have a particle size in one of the following particle size distributions:

DiO <1900 gm and D90 <5000 gm and D50 <3500 gm; or Di0 <1900 gm and D90 <4750 gm and D50 <3000 gm; or D10 <1900 gm and D90 <4750 gm and D50 <2884 gm.

For the purposes of the present invention, a particle size distribution of the grain fraction (F), in particular the corn grain fraction (F), expressed by Dxx <Y, designates a percentage (xx%) by weight of particles of the fraction of grains (F) having a particle size of less than or equal to Y.

For example, D90> 1000 gm means that 90% by weight of the particles of the grain fraction (F), in particular the grain fraction (F) of corn, have a particle size greater than or equal to 1000 gm.

In the context of the present invention, the particle size distribution of the grain fraction (F), in particular the grain fraction (F) of maize, can be determined by any appropriate means, inter alia by dynamic light scattering and by mechanical sieving, preferably by mechanical sieving. The mechanical sieving analysis is typically based on the mechanical separation of different subfractions of the grain fraction (F), in particular the grain fraction (F) of corn, on a series of superposed sieves.

The values D 50, D 0.8 and D 99.5 can be calculated from the percentages by weight of the subfractions obtained in each sieve relative to the total weight of the grain fraction (F). This calculation is carried out as follows: 1) Calculation of the percentage by weight of particles retained on each sieve 2) Expression of the cumulative weight percentage passing through each sieve

A typical particle size analysis method is described in detail in the experimental section.

According to the invention, it has been found, surprisingly, that the fraction of grains (F) resulting from the process of the present invention systematically has a reduced iron content of at least 25% by weight relative to the initial iron content. whole grains, while having a fat content reflecting good nutritional properties, good digestibility and good palatability.

In addition, surprisingly, despite the stresses to which whole grains and / or grain fractions are subjected, it has been shown, in the context of the present invention, that the fat content has been reduced. reduced and starch content increased, while maintaining good nutritional properties and good energy value.

The grain fraction (F) obtained according to the invention and used in a feed intended for animals can be transformed using known transformation methods. Among the known transformation processes, grinding, flattening, toasting, flaking, extrusion, granulation, micronization or expansion can be mentioned.

Among the processed products, mention may be made of flakes, flours, extrudates, granules, micronised products, toasted products and expanded products.

In one embodiment of the process for obtaining a processed product used in a feed for animals, the fragments forming the grain fraction (F) are subjected to a flaking process, during which the grains possibly moistened and / or cooked are flattened and turned into flakes. The flakes of the present invention may be prepared according to a plurality of methods well known to those skilled in the art and described in the state of the art, as for example in the document US 558393, the entire contents of this application being incorporated herein by reference for all purposes.

The inventors have found, surprisingly, that after flaking, the iron content is not significantly changed, but may even be slightly reduced. The flakes of the present invention have a reduced iron content of at least 25% by weight, preferably at least 30% by weight, preferably at least 35% by weight, preferably at least 40% by weight. % by weight, preferably at least 45% by weight, preferably at least 50% by weight, preferably at least 55% by weight, more preferably at least 60% by weight relative to the content in initial iron of the whole grain.

It is understood that the iron content in corn flakes is at least 1.0 mg / kg, preferably at least 2.0 mg / kg, preferably at least 2.5 mg / kg.

Typically, whole corn kernels have an iron content ranging from 10.0 mg / kg to 50.0 mg / kg, depending on the variety.

In a preferred embodiment of the present invention, the corn grain flakes have a reduced iron content relative to the initial iron content of the whole corn kernel. The iron content of the corn flakes may be at least 1.0 mg / kg, preferably at least 2.0 mg / kg, preferably at least 2.5 mg / kg.

In addition, the iron content of the corn flakes can be at most 30.0 mg / kg, preferably at most 25.0 mg / kg, preferably at most 20.0 mg / kg, more preferably at most. 15.0 mg / kg, preferably at most 13.0 mg / kg, preferably at most 12.5 mg / kg, more preferably at most 12.0 mg / kg.

Experimental part

The process for obtaining a processed product used in a feed intended for animals will be described in detail in the following example, the aim of which is purely illustrative and not limiting.

General method for obtaining the fraction (F) used in a feed intended for animals

A grain fraction (F) used in a feed for animals was obtained by subjecting whole corn kernels to the process described below.

Two different types of corn kernel, named CREIL and SW, were used, as shown in Tables 1 and 2. The respective initial iron contents of the CREIL and SW corn kernels are shown in Table 2.

A total of 9 samples were prepared and analyzed. Of these 9 samples, 5 were obtained from SW type maize and 4 were obtained from CREIL type maize.

Whole grains were first packaged. The package includes a cleaning with a flow of air circulating in a separator MTRA and MTRC cleanser, then a humidification by adding 1% water, for about 90 seconds.

The whole grains thus packaged were then treated by abrasion (step 1 according to the invention) carried out in an MXHM machine of the Bühler company.

The grains thus treated were then separated into two fractions, respectively (F1) and (F2) according to their particle size. The separation step was carried out in a device provided with a perforated screen also included in the Bühler MXHM machine. The perforations define the particle size threshold value separating fraction (F1) from fraction (F2). Said perforations are oval and have a width of 1.2 mm and a length of 12 mm. The crushed grains were introduced into said device provided with a perforated screen.

The fragments passing through the perforated screen, having a particle size smaller than the threshold value, represent the fraction (F2).

The fragments retained on the perforated screen, having a particle size greater than the threshold value, represents the fraction (F1).

The fraction (F2) was sucked by a suction channel out of the MXHM machine and then circulated through a cyclone before being collected.

The fraction (F1) was directed to an MTRB separator from the Bühler company in which it underwent a new separation (step 3). Step 3 was performed by adjusting the machine according to the parameters summarized in Table 1.

As indicated in Table 1 and according to this example, three grain fractions (F, F3 and F4) are obtained in step 3.

In the case of samples 1 to 6, the separator MTRB comprises two screens arranged one above the other. Fraction (F1) was introduced from the top of the separator and was evenly distributed over the top sieve, having mesh sizes of 7000 μm, to be separated from fragments larger than 7000 μm or larger. remaining impurities of large size. Large impurities may for example designate strands of straw, grains remaining whole.

In the case of samples 7, 8 and 9, the upper sieve has been removed, the MTRB has the lower sieve only.

Fragments of fraction (F1) having optionally passed through the upper sieve were then all distributed over the lower sieve having mesh sizes of 1500 μm. Fragments that passed through the lower sieve were pooled into a fraction (F3) whose fragments had a particle size of less than 1500 μm and which was collected.

The remaining fragments, having a particle size between 1500 pm and 7000 pm, were introduced into an air suction channel for a subsequent separation step, during which the lighter, lighter density fragments were directed to the top of the air intake channel to form the fraction (F4), which was collected. The remaining fragments, forming fraction (F), were sent down and collected.

The different parameters of the separator MTRB and the proportions of fractions (F1) (grouping the fractions (F), (F3) and (F4)) and (F2) have been recorded in Table 1 below.

The iron and fat content of the various fraction samples (F) was measured, and the results were recorded in Table 2 below. Details of the methods for analyzing iron and fat content are specified below.

Table 1: Process parameters and proportions of collected fractions

(*% by weight relative to the total weight of whole grains)

Table 2: Iron content and fat content of fraction (F)

'Percentage by weight' percentage by weight of fat with respect to the total weight of the fraction (F)

Granulometric analysis of fraction (F) was also performed. The details of the particle size analysis methods are specified below.

The grain fraction samples (F) were then flattened and flaked.

All samples were soaked in water for 8 hours and then boiled in water for one hour. The samples were then passed between two adjacent cold rollers rotating in opposite directions, in order to flatten the fragments of the grain fractions (F).

The samples were then baked in an oven until the resulting flakes became dry. The iron content and the fat content of the flakes obtained from the 9 samples were measured according to the methods of analysis of iron content and fat content described below. For all the samples, the iron content remained unchanged with respect to the iron content of the corresponding fractions (F). Method of analysis of iron content

The iron contents of the various grain fraction (F) and flake samples were measured by inductively coupled plasma spectroscopy. The samples were prepared as follows. 1000 mg of the grain fraction (F) or flakes were milled, then digested with 65% suprapur nitric acid in nanopure water, in a MLS TurboWave microwave digestion system, at a temperature of 260 ° C. The samples were then introduced into the inductively coupled plasma spectroscopy of the brand Varian Vista MPX axial, using the "Quant Fe 0-10 mg / L" mode. Method of Analysis of Fat Content The analysis of the fat content requires grinding of the samples. Since grinding can cause water loss, the water content of the samples has previously been determined. The water content was measured according to standard method ICC No. 110/1, at 130 ° C. for 90 minutes, with a thermogravimetric analysis apparatus TGA 701 from LECO corporation.

Each sample was milled using a Retsch ZM200 ultracentrifugal mill equipped with a 0.5 mm conidur screen, and homogeneous samples were prepared. The fat content of each sample was determined according to the Soxhlet Total Fat Method, with a reproducibility of ± 0.1%.

Particle size analysis of the fraction (F)

The grain fraction (F) was analyzed using the "Universal Laboratory Sifter" sieving device from Bühler. 250g of samples were placed in the sieving device and subjected to an eccentric movement for 5 minutes at a speed of 165 revolutions per minute (rpm).

This device comprises 7 screens, the latter having respectively meshes having the following dimensions: 1500 pm, 1900 pm, 2884 pm, 3350 pm, 4000 pm, 4750 pm and 5600 pm, in order to determine the particle size distribution of the various samples. The results are shown in Table 3 below.

Table 3: Particle size distribution of the fraction (F)

It is understood that the present invention is in no way limited to the embodiments described above and that many modifications can be made without departing from the scope of the appended claims.

Claims (29)

claims 1. Use of a grain fraction (F) obtained from whole grains in a feed for animals, said grain fraction (F) having a reduced iron content of at least 25% by weight with respect to a the initial iron content of said whole grains, and said grain fraction (F) being obtained from whole grains selected from the group consisting of at least one grain of cereal, at least one oilseed grain, from minus one grain of legume and a mixture of these. 2. Use of a grain fraction (F) according to claim 1, wherein said animals are farm animals. 3. Use of a grain fraction (F) according to claim 1 or 2, wherein said animals are cattle, preferably calves, preferably beef calves. 4. Use of a grain fraction (F) according to any one of the preceding claims, wherein said grain fraction (F) has a reduced iron content of at least 40% by weight, preferably from minus 45% by weight, preferably at least 50% by weight, preferably at least 55% by weight, preferably at least 60% by weight, based on an initial iron content of said whole grains. Use of a grain fraction (F) according to any one of the preceding claims, wherein said grain fraction (F) has a particle size distribution such that: D90> 1000 μm and Dg0 <6000 μm and Üg9.5 <7000 pm. The use of a grain fraction (F) according to any one of the preceding claims, wherein said grain fraction (F) is obtained by a process comprising the following steps: Step 1: a step of treating said whole grains , Step 2: a step of separating said grains treated in step 1 so as to obtain a first grain fraction (F1) comprising first grain fragments having a particle size greater than one or more predetermined size threshold values of particles and a second grain fraction (F2) comprising second grain fragments having a particle size smaller than said predetermined particle size threshold value (s), and Step 3: a step of separating said first grain fraction ( F1) obtained in step 2, on the basis of the size and / or the shape of said first fragments, so as to isolate said grain fraction (F) having said reduced iron content. 7. Use of a grain fraction (F) according to claim 6, wherein the step 1 of whole grain treatment designates a fragmentation carried out by grinding, by a friction treatment and / or by an abrasive treatment of the grains integers. The use of a grain fraction (F) according to claim 6, wherein said step 1 is preceded or followed by a grain conditioning step. The use of a grain fraction (F) according to claim 7, wherein said grain conditioning step comprises one or more cleaning steps, one or more moistening steps and / or one or more polishing steps. 10. Use of a fraction of grains (F) according to any one of claims 6 to 8, wherein said step 2 of separation is performed by means of a device with a perforated screen whose perforations have a shape rectangular or oval. 11. Use of a grain fraction (F) according to claim 9, wherein said perforations having a rectangular or oval shape have a length of not less than 3.0 mm, preferably not less than 5.0 mm, preferably not less than 7.0 mm, preferably not less than 10.0 mm, preferably not less than 12.0 mm, said length not being greater than 30.0 mm, preferably not greater than 25.0 mm, preferably not more than 20.0 mm, preferably not more than 18.0 mm, preferably not more than 15.0 mm, preferably not more than 14, 0 mm, preferably not more than 13.0 mm, preferably not more than 12.0 mm. Use of a grain fraction (F) according to claim 9 or 10, wherein said perforations having a rectangular or oval shape have a width of not less than 0.5 mm, preferably not less than 0 , 75 mm, preferably not less than 1.0 mm, preferably not less than 1.2 mm, said width not being greater than 6.0 mm, preferably not more than 5.0 mm preferably not more than 4.0 mm, preferably not more than 3.0 mm, preferably not more than 2.5 mm, preferably not more than 2.0 mm, preferably not more than 1.5 mm, preferably not more than 1.2 mm. 13. Use of a grain fraction (F) according to any one of claims 6 to 11, wherein said grain fraction (F2) represents at most 50% by weight, preferably at most 45% by weight, of preferably at most 40% by weight, preferably at most 35% by weight relative to the total weight of whole grains. 14. Use of a grain fraction (F) according to any one of claims 6 to 12, wherein said fraction (F2) represents at least 15% by weight, preferably at least 20% by weight, preferably at least less than 25% by weight relative to the total weight of whole grains. 15. Use of a grain fraction (F) according to any one of claims 6 to 13, wherein the separation of the first fraction (Fi) of step 3 comprises a mechanical separation. The use of a grain fraction (F) according to claim 14, wherein said mechanical separation is carried out using a screen or a plurality of screens having different size mesh. The use of a grain fraction (F) according to claim 15, wherein an intermediate grain fraction (F ') is collected between a sieve in the lower position and a sieve in the upper position, if said sieve in the upper position is present, or on the sieve in the lower position if only one sieve is used. The use of a grain fraction (F) according to claim 16, wherein said grain fraction (F) is obtained by subjecting the fraction (F ') to a subsequent separation step so as to subtract a fraction thereof. of grains (F4). 19. Use of a grain fraction (F) according to claim 17, wherein said subsequent separation step is carried out using suction means. 20. Use of a grain fraction (F) according to any one of claims 15 to 18, wherein a grain fraction (F3) is collected after having passed through all the sieves, specifically after having passed through a sieve. lower position. 21. Use of a grain fraction (F) according to any one of the preceding claims, wherein the grain fraction (F) represents at most 80% by weight, preferably at most 75% by weight, preferably at most 70% by weight relative to the total weight of whole grains. 22. Use of a grain fraction (F) according to any one of the preceding claims, wherein the grain fraction (F) is at least 45% by weight, preferably at least 50% by weight, preferably at least 50% by weight. less than 55% by weight relative to the total weight of the whole grains. 23. Use of a grain fraction (F) according to any one of the preceding claims, wherein said grain fraction (F) is obtained from grains being corn kernels. 24. Use of a grain fraction (F) according to claim 22, wherein said grain fraction (F) obtained from grains being maize grains has a maximum iron content of 30.0 mg / kg, preferably a maximum iron content of 25.0 mg / kg, preferably a maximum iron content of 20.0 mg / kg, more preferably a maximum iron content of 15.0 mg / kg, preferably an iron content maximum of 13.0 mg / kg, preferably a maximum iron content of 12.5 mg / kg, more preferably a maximum iron content of 12.0 mg / kg. 25. Use of a grain fraction (F) transformed into a processed product. 26. Use of said transformed product according to claim 24, said processed product being obtained according to a step selected from the group consisting of grinding, flattening, toasting, flaking, extrusion, granulation, micronization and a method of expansion. Use of a processed product according to claim 24 or 25, wherein said processed product is a flake, a granule, an extrudate, a micronised product, a toasted product or an expanded product. 28. Use of a processed product according to one of claims 24 to 26, said processed product having a reduced iron content of at least 25% by weight, preferably at least 30% by weight, preferably at least 35% by weight, preferably at least 40% by weight, preferably at least 45% by weight, preferably at least 50% by weight, preferably at least 55% by weight, weight, preferably at least 60% by weight, based on the initial iron content of the whole grain. 29. Use of a processed product according to one of claims 24 to 27 in a feed for animals.