Animal milk and especially cow's milk is an important source of nutrients and is widely consumed. Milk can further be processed into various milk-based products such as cream, cheese, butter, yogurt, desserts, ice-cream. Raw milk contains significant amounts of fat, protein and calcium and its composition varies widely among species.

Milk also contains contain many elements that are important for good health and nutrition. In particular, milk is a source of practically all vitamins and minerals required by mammals, such as fat soluble vitamins - vitamins A, D, E, and K, and water soluble vitamins, such as vitamins Bl, B2, B5, B6, B8 and B12. Also, minerals considered to be essential to the human diet are present in milk, such as sodium, potassium, chloride, calcium, magnesium, phosphorus, iron, zinc, copper, manganese, iodine, selenium.

To fulfill the daily need of micronutrients, it is known in the prior art to supplement milk with additional vitamins and minerals. For example, low fat milk is often supplemented with vitamin A, which is initially removed with a part of the fat. It is also known to fortify milk with vitamin D which is necessary for an optimum calcium absorption.

Vitamin fortification can be accomplished by the addition of vitamins at many different points in the processing system, for example after

separation, or on a continuous basis into the pipeline after standardisation. The vitamin addition can however be associated with a problem of

underfortification caused by uneven distribution of vitamins between the water and the fat phase. Moreover, certain added vitamins or minerals may interact with the milk components, leading to an undesired change in milk consistency, taste, or colour. In addition, some vitamins are considerably less stable when present in an isolated form, such as vitamin A. When added to a milk in such form, these will faster degrade and thus decrease in

concentration. Also, the isolated forms may be significantly less bioavailable than the forms as naturally present in cow's milk.

The present invention relates to a milk composition fortified with vitamins and minerals, as obtained from a cow by milking. Since the most vitamins and minerals present in milk originate from a cow's feed, such naturally fortified milk can be obtained by supplementing the feed with vitamins and minerals.

However, not all vitamins and minerals present in the feed end up in the milk, or at least in much lower amounts. For iodine, for example, only 10- 15% of the iodine fed is incorporated in milk. Moreover, feeding a cow with a supplement enriched with vitamins or minerals may in some cases have adverse effects on the health of the cow and for this reason may be restricted by regulations varying from country to country. For example, in the European Union selenium may not be present in cow's feed in an amount higher than 0.5 mg/kg dry matter. Since not all selenium appears in milk but is also consumed by the cow itself, the resulting milk has a much lower level of selenium than initially present in the feed. For selenium, the maximum amount allowed in a feed results in such low levels of Se in milk that such milk is generally not considered to be rich in selenium.

An aim of the present invention is to provide a milk composition which is believed to be healthier for a large group of consumers. "Healthier" means having a higher content of vitamins and/or minerals essential for the human diet. In particular, an aim of the present invention is to provide a milk composition rich in water soluble vitamins and minerals.

The present invention is based on the finding that the composition of a cow's milk can be altered by selective feeding of the cow based on the genotypes. More in detail, the concerned gene is the bovine diacylglycerol-o- acyltransferase 1 (DGAT1) gene. Because of polymorphism, it has two genetic variants K and A, which result in an amino acid substitution in the DGAT1 protein (lysine -alanine). Two types of alleles K and A result in three genotypes: KK, AA and AK.

The inventors have surprisingly found that the cows with the KK genotype fed with a feed rich in certain water soluble vitamins and minerals produce milk with higher amounts of those vitamins and minerals compared with the milk obtained solely by genetic selection of the cows receiving a regular diet, or by feeding all cows with a vitamin-rich diet.

In addition, the milk according to the present invention is healthier for human consumers than the milk of the cows having the AK or AA

genotypes or the milk of the cows receiving no feed supplement, since it contains more vitamins and minerals than the milk obtained from the AK and AA cows.

Accordingly, the present invention relates to a milk composition comprising at least one of the following vitamins and minerals: selenium, iodine, biotin, zinc, vitamin B12, vitamin B6, vitamin Bl and vitamin B2. The milk composition is specifically a cow's milk composition. Preferably, at least two of said vitamins and minerals are present, and more preferably, three or more. In a preferred embodiment, the milk composition comprises selenium, iodine or biotin, or any possible combination thereof. Particularly, the milk composition preferably comprises selenium and iodine, selenium and biotin, iodine and biotin, or selenium, iodine and biotin.

Selenium is beneficial for human health and is needed for the proper functioning of the immune system. Recent studies show that an elevated selenium intake may be associated with reduced cancer risk. Preferably, the milk composition according to the present invention contains selenium in an amount of at least 2.1 meg, preferably at least 2.5 meg and more preferably at least 2.8 meg per 100 g of the milk composition. In a preferred embodiment, the selenium content is at least 3.2 and more preferably at least 3.8 meg per 100 g of the milk composition. Yet more preferably, the selenium content is at least 4 meg per 100 g of the milk composition. Also higher amounts of selenium are possible such as at least 5 meg, preferably, at least 6.5 meg and more preferably, at least 7.5 meg per 100 g of the milk composition. In a preferred embodiment, the selenium content is at least 8.0 meg per 100 g of the milk composition. The milk composition according to the invention contains preferably not more than 30 meg selenium per 100 g of the milk composition.

Iodine is essential for the normal growth and development of a human body. In particular, it controls the functioning of thyroid glands, which in turn has a significant influence on the metabolic processes in the body. The milk composition according to the invention preferably comprises iodine.

Preferably, the composition comprises at least 7 meg, more preferably, at least 9 meg and even more preferably at least 11 meg iodine per 100 g of the milk composition. Preferred amounts are for example at least 15 meg, preferably at least 17 meg, more preferably, at least 18 meg and even more preferably at least 20 meg iodine per 100 g of the milk composition. The iodine content can also be higher, for example at least 22 meg, preferably at least 30 meg, more preferably at least 40 meg, and even more preferably, at least 60 meg per 100 g of the milk composition. In some embodiments, the iodine content can be at least 80 meg and preferably, at least 90 meg per 100 g of the milk composition. The milk composition according to the invention contains preferably not more than 200 meg iodine per 100 g of the milk composition.

Biotin is one of the eight essential vitamins of the B-complex. It functions as a carrier of carbon dioxide in carboxylation reactions and plays a crucial role in energy metabolism. The milk composition of the present invention preferably contains biotin. Preferably, the composition comprises biotin in an amount higher than 2 meg, more preferably, at least 2.5 meg, even more preferably at least 3 meg and yet more preferably, at least 3.5 meg per 100 g of the milk composition. Preferred amounts are at least 6 meg, preferably at least 7 meg and more preferably at least 8 meg biotin per 100 g of the milk composition. Higher amounts of biotin are also possible, such as at least 10 meg and preferably at least 11 meg per 100 g of the milk composition. The milk composition according to the invention contains preferably not more than 30 meg biotine per 100 g of the milk composition.

In a preferred embodiment, the milk composition comprises a combination of one or more of selenium, iodine and biotin, such as selenium and iodine, selenium and biotin, iodine and biotin, or selenium, iodine and biotin. Because of complex interactions during feed digestion and subsequently during milk production, it may be difficult to obtain certain combinations of microelements and/or vitamins in milk in desired amounts, for example of selenium with iodine.

In one preferred embodiment, the milk composition according to the invention and/or any of its embodiments comprises selenium and iodine. The milk composition comprises preferably at least 2.1 meg, more preferably at least 2.8 meg, yet more preferably at least 3.2 meg, even more preferably 3.8 meg and most preferably at least 4 meg selenium per 100 g of the milk composition in combination with an iodine content of preferably at least 7 meg iodine, more preferably at least 9 meg, and most preferably at least 11 meg iodine per 100 g of the milk composition. Also higher amounts of selenium and/or iodine are possible as mentioned previously, such as a composition comprising at least 2.1 meg selenium and at least 20 meg iodine per 100 g of the milk composition. A preferred composition in this embodiment comprises 2.1-30 meg selenium and 7-200 meg iodine per 100 g of the milk composition.

In another preferred embodiment, the milk composition according to the invention and/or any of its embodiments comprises selenium and biotin. The milk composition comprises preferably at least 2.1 meg, more preferably at least 2.8 meg, yet more preferably at least 3.2 meg, even more preferably 3.8 meg and most preferably at least 4 meg selenium per 100 g of the milk composition in combination with a biotin content of preferably at least 2 meg, more preferably at least 3 meg, and most preferably at least 3.5 meg biotin per 100 g of the milk composition. Also higher amounts of selenium and/or biotin are possible as mentioned previously, such as a composition comprising at least 2.1 meg selenium and at least 7 meg biotin per 100 g of the milk composition. A preferred composition in this embodiment comprises 2.1-30 meg selenium and 2-30 meg biotin per 100 g of the milk composition.

In yet another preferred embodiment, the milk composition according to the invention and/or any of its embodiments comprises iodine and biotin. The milk composition comprises preferably at least 7 meg, more preferably at least 9 meg, and most preferably at least 11 meg iodine per 100 g of the milk composition in combination with a biotin content of preferably at least 2 meg, more preferably at least 3 meg, and most preferably at least 3.5 meg biotin per 100 g of the milk composition. Also higher amounts of iodine and/or biotin are possible as mentioned previously, such as a composition comprising at least 11 meg iodine and at least 3.5 meg biotin per 100 g of the milk composition, or at least 20 meg iodine and at least 7 meg biotin per 100 g of the milk composition. A preferred composition in this embodiment comprises 7-200 meg iodine and 2- 30 meg biotin per 100 g of the milk composition.

In a further preferred embodiment, the milk composition according to the invention and/or any of its embodiments comprises all three elements being selenium, iodine and biotin. Such compositions preferably comprise at least 2.1 meg, more preferably at least 2.8 meg, yet more preferably at least 3.2 meg, even more preferably 3.8 meg and most preferably at least 4 meg selenium per 100 g of the milk composition in combination with an iodine content of preferably at least 7 meg, more preferably at least 9 meg, and most preferably at least 11 meg iodine per 100 g of the milk composition and a biotin content of preferably at least 2 meg, more preferably at least 3 meg, and most preferably at least 3.5 meg biotin per 100 g of the milk composition. Also higher amounts of one or more of selenium, iodine and biotin are possible as mentioned previously, such as a composition comprising at least 4 meg selenium, at least 11 meg iodine and at least 3.5 meg biotin per 100 g of the milk composition, or a composition comprising at least 4 meg selenium, at least 20 meg iodine and at least 7 meg biotin. A preferred composition in this embodiment comprises 2.1-30 meg selenium, 7-200 meg iodine and 2-30 meg biotin per 100 g of the milk composition.

In a preferred embodiment, the milk composition contains at least two of the vitamins and/or minerals from the list selenium, iodine, biotin, zinc, vitamin B12, vitamin B6, vitamin Bl and vitamin B2. Particularly

advantageous are combinations of selenium with iodine, selenium with biotin, iodine with biotin and selenium with both iodine and biotin. However, any other combinations are also possible, dependent on the desired vitamins or minerals composition in the milk.

Preferably, the milk composition comprises further at least one of the following vitamins and minerals: zinc, vitamin B12, vitamin B6 and vitamin Bl. The amount of zinc is preferably at least 0.35 mg and more preferably, at least 0.37 mg per 100 g of the milk composition. Even more preferably, the zinc content is at least 0.40 mg, more preferably at least 0.42 mg and yet more preferably at least 0.44 mg per 100 g milk composition.

Vitamin B6 is preferably present in an amount higher than 42 meg and more preferably, at least 46 meg per 100 g milk composition. Yet more preferably, the vitamin B6 content is at least 50 meg and preferably at least 75 meg, such as at least 76 meg per 100 g milk composition. Most preferably, the milk composition contains at least 80 meg vitamin B6 per 100 g milk composition.

Further, vitamin B12 is preferably present in an amount of at least 0.44 meg, more preferably, at least 0.46 meg and even more preferably at least 50 meg per 100 g of the milk composition. Yet more preferably, the vitamin B12 content is at least 0.58 meg and more preferably at least 0.60 meg per 100 g milk composition.

Vitamin Bl is preferably present in an amount of at least 27 meg and preferably at least 30 meg per 100 g milk composition.

The milk composition of the present invention may further comprise one or more of other vitamins and/or minerals, such as vitamin A, vitamin C, vitamin D, vitamin B3, vitamin B5, phosphorus, calcium, copper, iron, magnesium, manganese, potassium, and sodium.

The identity and the amount of various vitamins and minerals in milk can easily be determined using conventional mass spectrometry techniques. Particularly, the present inventors use inductively coupled plasma mass spectrometry (ICP-MS) to determine the content of iodine and selenium, inductively coupled plasma atomic emission spectrometry (ICP-AES) to determine the content of zinc, high performance liquid chromatography (HPLC) for biotin (vitamin B8), vitamin Bl, vitamin B2, and vitamin B6.

Liquid chromatography-mass spectrometry (LC-MS) was used for pantothenic acid (vitamin B5), and radio-isotope competitive protein binding assay - for vitamin B12.

In a preferred embodiment, the milk composition of the present invention is preferably naturally obtained, or unprocessed, i.e., it has a composition as obtained directly by milking a cow or cows. Preferably, the milk composition of the invention is natural cow's milk. The term cow's milk is used in this description in the meaning according to the Dutch Dairy Commodities Act ("Warenwetbesluit Zuivel"). Natural cow's milk particularly means a product obtained by milking of one or more cows, without anything being added to the product. Milk containing added substances may not be sold as milk according to the Dutch regulations but must be labeled, for example, as a milk drink or a milk product. Certain fat soluble vitamins such as vitamin A originally contained in the milk fat and separated during decreaming may, however, be added at a later stage to a (skimmed) milk to compensate the vitamin A loss. According to the present invention, it is particularly preferred that the milk contains no added water soluble vitamins and/or minerals and in particular, no vitamins and/or minerals selected from the list selenium, iodine, biotin, zinc, vitamin B12, vitamin B6, vitamin Bl and vitamin B2.

In another preferred embodiment, the milk composition is a raw milk, which particularly means unprocessed milk, as obtained by milking of a cow or cows, where nothing is added to or removed from and which neither has been heated above 40°C nor undergone a thermal treatment with an equivalent effect. In yet another embodiment, the milk composition is a processed milk obtained from the raw milk according to the invention by subjecting it to, e.g., decreaming, standardisation, homogenisation, pasteurisation, or sterilisation.

The milk composition further differs from a milk with added vitamins and minerals, in that the vitamins and minerals are present in the present milk composition in a bioavailable form, and preferably, in an organic form for minerals. Bioavailable form of an vitamin or mineral means that a

considerable part (generally more than 50 wt.%) of that vitamin or mineral is absorbed by human body after ingestion and reaches the blood system. If certain vitamin or mineral is absorbed for less than 1%, it is not bioavailable. In the present case, it means that at least a part of the vitamins and minerals is incorporated in milk constituents such as milk proteins or milk fat and is, therefore, more readily absorbed in the human body than when the same nutrients are present in an isolated form or in an inorganic form.

For selenium, it is preferred that at least a part of it present in the milk composition is milk protein bound. Protein bound selenium is generally incorporated into an amino acid such as selenocysteine or selenomethionine, forming a selenoprotein. In this preferred embodiment, selenium is present in the milk at least partly as a seleno-milk protein. In a preferred embodiment, at least 10 wt.% and more preferably at least 30 wt.% of selenium is milk protein bound. Yet more preferably, at least 50 wt.% of the selenium present in the milk composition is in the form of seleno-milk proteins and even more preferably, at least 80 wt.%. Most preferably, essentially all selenium, that is, more than 99 wt.%, present in the milk composition is milk protein bound. In another preferred embodiment, selenium is mostly bound to casein. Preferably, at least 55 wt.% of selenium is present in the casein fraction. The percentage of selenium bound to milk proteins can easily be determined by measuring the total selenium content in milk followed by the separation of the milk protein fraction and measuring the content of selenium in that fraction.

The milk composition according to the present invention has a major advantage that it naturally contains higher amounts of vitamins and/or minerals than found in conventional milk. It represents, therefore, a milk naturally rich in vitamins and minerals, in contrast to a milk which has been fortified afterwards by the addition of those vitamins and minerals. Therefore, the present invention provides milk which is particularly appreciated by the consumers, which are nowadays very keen to use natural products, without added constituents. An additional advantage of the invention is that, since the vitamins and minerals naturally occur in the milk of the invention, the supplier of the milk is not obliged to provide its detailed content on the milk package while for the milk fortified with added vitamins and minerals the detailed ingredient information is often mandatory.

It has been observed by the present inventors that the genotype of a cow has also an effect on the colour of the milk fat. In particular, the milk fat of KK cows has been found to have a more white colour than the milk fat of the cows of other genotypes. A more white colour of the milk fat, which is, for example, responsible for the colour of cream products, is more appealing to many consumers. Another advantage of the milk composition is therefore that the milk fat fraction has a more appealing, white colour. The colour of milk fat can be determined using YIE values (Yellowness index). In a preferred embodiment, the milk according to the invention has a YIE value of less than 90, more preferably, less than 73 and yet more preferably less than 60, as measured according to a BDI method of milk fat extraction, followed by a colour measurement on fat using 20 g of the extracted milk fat at 5°C.

In a further aspect, the present invention relates to a method to obtain milk comprising feeding of a cow having the KK genotype of the DGATl gene with a feed enriched with at least one water soluble vitamin or mineral selected from the list consisting of selenium, iodine, biotin, zinc, vitamin Bl, vitamin B2, vitamin B5, vitamin B6, and milking of the cow.

Preferably, the cows belong to the breeds of Holstein and Jersey. More preferably, the cows are Holstein Friesian. In the Netherlands, the frequency of the A allele in Holstein Friesian population is 0.6 and of the K allele 0.4 which makes the frequency of genotypes AA, AK and KK to be 0.36, 0.48 and 0.16, respectively. The genotype of a cow can be determined by methods known to a skilled person, such as Polymerase Chain Reaction (PCR) using two primers and two probes per allele to be detected (so-called Taqman assay). For that, cow's blood is normally used.

The frequency of KK cows is only 16%, which can be explained by the fact that the cows with the A allele are known to produce more milk than other cows. Therefore, the cows of AA and AK genotype are usually preferred and more often selected as dairy cows. It is further known that the K allele is associated with a higher content of fat and proteins in milk. Surprisingly, it has been now found by the inventors that a fat-rich milk of KK cows also contains higher amounts of water soluble vitamins and minerals.

In accordance with the present invention, the KK cows are fed with a diet enriched with water soluble vitamins and/or minerals. Said vitamins and minerals are particularly one or more of iodine, selenium, biotin, zinc, cobalt, vitamins Bl, B2, B5 and B6. In a preferred embodiment, the feed comprises selenium, iodine, or biotin, or any possible combination thereof. Particularly preferred are combinations of selenium with iodine, selenium with biotin, iodine with biotin, and selenium with iodine and biotin. Most preferably, selenium is present in the feed, either alone or in combination with iodine and/or biotin. More preferably, the feed further comprises zinc, or cobalt, or both zinc and cobalt. The feed preferably also comprises vitamin B6 alone, or in any possible combination with any of the preferred embodiments above. The feed may further comprise any of vitamins Bl, B2, B5, either alone or in any possible combination with the embodiments above.

The feed generally comprises a base roughage and/or base

concentrate, and a feed supplement rich in said vitamins and minerals. The base roughage can, for example, consist of maize silage or grass silage, yet other suitable base compositions can equally be used. Grass and maize silage are typical components of a winter diet for Dutch cows. The base concentrate can be of any type and is a conventional feedstuff typically having a dry matter (DM) content higher than 80 wt.% and a crude fat content lower than 10 wt.%.

The feed used is preferably rich in water soluble vitamins and minerals. This means that the feed comprises added vitamins and/or minerals and, particularly, it contains more water soluble vitamins and/or minerals than the basic level originating from basic roughage. Basic level for

unsupplemented feed is generally: for iodine - not more than 0.2-0.5 mg/kg DM, for selenium - not more than 0.08-0.1 mg/kg DM, for zinc - not more than 40-80 mg/kg DM and for cobalt - not more than 0.1-0.5 mg/kg DM.

Due to the possible toxicity of excessive amounts of vitamins and minerals, the feed preferably comprises less than 40 mg/kg DM of selenium and more preferably from 0.1 to 20 mg/kg DM of selenium and more preferably from 0.3 to 10 mg/kg DM. It is particularly preferred to use an organic source of selenium over inorganic selenium in the feed. Organic selenium

supplements for use in cattle feed are known to a skilled person. These are often based on selenium enriched yeast. The feed comprising selenium enriched yeast is therefore particularly preferred.

Iodine should preferably be present in an amount less than 50 mg/kg DM, which is a maximum tolerable level of iodine for cattle, and more preferably less than 20 mg/kg DM. It is more preferable that the feed comprises 5 mg/kg DM iodine or less, which is the maximum permitted level in the European Union (EU Regulation 1459/2005). Any suitable source of iodine for cattle can be used.

The milk composition obtained differs for individual cows and changes during the season. The composition of milk is also determined by the health status, lactation stage, parity and genetic background of the cow.

Furthermore, the composition and quantity of the vitamins and minerals supplied by the diet in addition to the supplements also depends on the vitamins and minerals of the other components in the diet of the cow (e.g. the roughage or the concentrate). Especially the composition of the roughage varies greatly during the season. However, with the information provided the skilled person will be able to prepare the milk composition according to the invention.

In addition to the health benefits of the milk composition according to the present invention for human consumers, supplementation of the feed with vitamins and minerals provides at the same time health benefits for the cow. In particular, biotin is necessary for the synthesis of keratin, a hard structural protein involved in the horn production, and also for the immune system of the cow. Supplementation with biotin, therefore, helps to prevent hoof disorders in ruminants. Also zinc is essential for the prevention of hoof disorders. Cobalt is needed for the synthesis of vitamin B12, while vitamin B12 is, in turn, essential for the growth, milk production and fertility of the cow. Iodine is needed by cattle for the formation of thyroid hormones which help control metabolic rate, growth, milk yield and fertility.

Selenium (Se) is an essential trace mineral for cattle. It is involved in proper immune function, acts as an antioxidant, and helps activate thyroid hormones. Selenium is only present in low amounts in basic forage. However, a too high amount of selenium is toxic, therefore the allowed amounts of selenium supplementation are restricted. In Canada and the United States, both organic and inorganic sources of selenium can be supplemented at 0.3 mg/kg of DM. In the European Union, inorganic selenium is fed to cows at a recommended level of 0.5 mg/kg of DM (Ministry of Agriculture, Fisheries and Food, 2000) and was initially the only authorized form of selenium. Recently, also a source of organic selenium has been approved for use in all livestock species in the European Union (EU regulation 1750/ 2006). Since selenium supplementation of cow's feed is restricted, the present invention provides an advantageous method to obtain milk that contains more selenium, starting from the allowed feed with the same Se content.

In yet another aspect, the present invention relates to a method to select a cow to be fed with a feed enriched with water soluble vitamins and/or minerals by choosing a cow with the KK genotype of the gene DGAT1. Said vitamins and minerals are preferably one or more of iodine, selenium, biotin, zinc, cobalt, vitamins Bl, B2, B5 and B6. In a preferred embodiment, the feed comprises selenium, iodine, or biotin, or any possible combination thereof. Particularly preferred are combinations of selenium with iodine, selenium with biotin, iodine with biotin, and selenium with iodine and biotin. Most preferably, selenium is present in the feed, either alone or in combination with iodine and/or biotin. More preferably, the feed further comprises zinc, or cobalt, or both zinc and cobalt. The feed preferably also comprises vitamin B6 alone, or in any possible combination with any of the preferred embodiments above. The feed may further comprise any of vitamins Bl, B2, B5, either alone or in any possible combination with the embodiments above.

Preferably, the feed comprises added vitamins and/or minerals and, particularly preferred, it contains more water soluble vitamins and/or minerals than the basic level originating from basic roughage. Therefore, the feed preferably comprises more than 0.2 mg/kg DM iodine, but less than 50 mg/kg DM. More preferably, it comprises less than 20 mg/kg DM and even more preferably, 5 mg/kg DM or less. The feed further preferably comprises selenium in an amount greater than 0.08 mg/kg DM and less than 40 mg/kg DM, more preferably from 0.1 to 20 mg/kg DM and more preferably from 0.3 to 10 mg/kg DM. The feed preferably comprises zinc in an amount greater than 40 mg/kg DM. Preferably, the feed also comprises cobalt in an amount greater than 0.1 mg/kg DM. It is particularly preferred to use an organic source of selenium over inorganic selenium in the feed. Organic selenium supplements for use in cattle feed are known to a skilled person. These are often based on selenium enriched yeast. The feed comprising selenium enriched yeast is therefore particularly preferred.

In one embodiment of this method one can test cows on beforehand to determine the genotype of a cow in case the genotype is not known and further only choose the cows having the KK genotype to be fed with a supplement with water soluble vitamins and/or minerals. Such selection can easily be implemented, for example, in an automated feeding system or in a milk robot system, where cows are identified and recognized by an electronic chip. Giving the feed supplement only to the cows having the KK genotype instead of all cows also saves costs since supplements fortified with minerals and vitamins are considerably more expensive than regular feed.

The present invention can also be practiced by feeding all the cows with a feed with water soluble vitamins and/or minerals, followed by milking. The milk of the KK cows can then be collected and kept separately, or can be pooled with other milk.

In a further aspect, the present invention relates to a method to test a feed for cows, comprising the steps of:

i) selecting at least one cow having the KK genotype of the gene

DGAT1,

ii) feeding the cow or cows selected in step ii) with a feed comprising at least one added water soluble vitamin and/or mineral,

iii) milking of the cow or cows, and

iv) analysing the composition of the milk.

Said vitamins and minerals are preferably one or more of iodine, selenium, biotin, zinc, cobalt, vitamins Bl, B2, B5 and B6. In a preferred embodiment, the feed comprises selenium, iodine, or biotin, or any possible combination thereof. Particularly preferred are combinations of selenium with iodine, selenium with biotin, iodine with biotin, and selenium with iodine and biotin. Most preferably, selenium is present in the feed, either alone or in combination with iodine and/or biotin. More preferably, the feed further comprises zinc, or cobalt, or both zinc and cobalt. The feed preferably also comprises vitamin B6 alone, or in any possible combination with any of the preferred embodiments above. The feed may further comprise any of vitamins Bl, B2, B5, either alone or in any possible combination with the embodiments above.

Preferably, the feed comprises added vitamins and/or minerals and, particularly preferred, it contains more water soluble vitamins and/or minerals than the basic level originating from basic roughage. Therefore, the feed preferably comprises more than 0.2 mg/kg DM iodine, but less than 50 mg/kg DM. More preferably, it comprises less than 20 mg/kg DM and even more preferably, 5 mg/kg DM or less. The feed further preferably comprises selenium in an amount greater than 0.08 mg/kg DM and less than 40 mg/kg DM, more preferably from 0.1 to 20 mg/kg DM and more preferably from 0.3 to 10 mg/kg DM. The feed preferably comprises zinc in an amount greater than 40 mg/kg DM. Preferably, the feed also comprises cobalt in an amount greater than 0.1 mg/kg DM. It is particularly preferred to use an organic source of selenium over inorganic selenium in the feed. Organic selenium supplements for use in cattle feed are known to a skilled person. These are often based on selenium enriched yeast. The feed comprising selenium enriched yeast is therefore particularly preferred.

According to the invention, the cows having the KK genotype represent the best selection for testing feed supplements enriched with water soluble vitamins and/or minerals. First, these cows produce milk with a higher content of those vitamins and/or minerals and are therefore more susceptible to these microelements present in a feed supplement. Second, the results of the tests carried out only on KK cows are more statistically homogeneous than of the tests wherein cows with any genotype are used. Therefore, a smaller population is needed to obtain statistically reliable results.

Accordingly, the invention is also related to a herd of cows, wherein at least 30%, preferably at least 50% and more preferably at least 80% of the cows has the KK genotype of the gen DGAT1. More preferably, the herd consists of KK cows only. A herd is defined as a group of cattle or other domestic animals of a single kind kept together for a specific purpose. For the purposes of the present invention, the herd comprises at least 10 cows which are kept for the milk they give. As said above, a typical herd of Holstein

Friesian cows in the Netherlands has a frequency of the KK genotype about 16%. In accordance with the present invention, the frequency of the KK cows in a herd can be increased by selection, in order to obtain a herd with mainly KK cows.

In a further aspect, the present invention relates to the use of the milk composition of the invention for the preparation of a milk based composition, such as milk, cheese, yogurt, cream, a dessert product, also including compositions prepared from milk components, such as milk powder, whey proteins, milk fat and so on. Furthermore, the invention relates to the products produced using the milk composition, and especially those products wherein the vitamins and minerals content of the milk composition is essentially maintained in the final product. These products are for instance suitable for food and feed applications or for food and feed supplements.

Preferably, the products are raw or processed whole milk, semi-skimmed milk, skimmed milk, no-fat milk, a milk drink, milk cream, creme fraiche, cheese, or yogurt.

In another embodiment, the invention relates to the products based on or obtained from the milk cream obtained from the milk composition. The products based on the cream fraction of the milk of the present invention are advantageous as they possess a more white colour than obtained from conventional milk. A more white colour is generally more appealing to consumers in cream applications, such as milk cream, whipped cream, cream deserts, etc.

The invention will now be illustrated by the following, non-limiting example.

Example

A test group consisted of 34 Holstein Friesian cows, of which 20 of the AA genotype, 11 of the AK genotype and 4 cows of the KK genotype of the gen DGATl. A control group consisted of 38 Holstein Friesian cows, of which 19 of the AA genotype, 16 of the AK genotype and 3 cows of the KK genotype of the gen DGATl.

The test group was fed with a ration enriched with vitamins and minerals and the control group had the same feed without the vitamins and minerals feed supplement. The feed compositions for both groups are given in Table 1. The amounts are given per cow per day.

Table 1

Ration Ration

Supply in ration per day per cow test control

group group

Grass silage, kg DM 4.66 4.66

Maize silage, kg DM 9.40 9.40

Wheat (83% DM), kg DM 1.25 1.25

Brewers grain (25% DM), kg DM 0.71 0.71

Beet pulp (27% DM), kg DM 1.32 1.32

Soy (48) (87% DM), kg product 2.44 2.44

LINEX (AVEVE) (88% DM) ⁱ , kg product 1 1

GLUCOLAC (960/110/16) (88% DM) ² , kg product 1.6 1.6

FCMMM ³ , kg product 0.31 0 ¹ LINEX - concentrate from linseed

² GLUCOLAC - concentrate with 960 VEM, 110 DVE, 14 RE

³ FCMMM is a vitamin and mineral supplement (see Table 2)

FCMMM is a vitamin and mineral supplement having a composition as described in Table 2.

Table 2

In the described feed supplement, iodine is used in the form of calcium iodate, selenium as organic selenium Optimin Sey EU 2000, zinc as zinc sulphate, cobalt as cobalt carbonate, vitamin B5 as d-Ca panthenate, vitamin B8. The carrier is DLP, de-lactosed permeate.

The nutritional values of both rations are given in Table 3. Table 3

Since no vitamins and minerals supplement was used in the feed of the control group, basic amounts refer to the amounts generally present in unsupplemented feed. For iodine this generally refers to not more than 0.2-0.5 mg/kg DM, for selenium not more than 0.08-0.1 mg/kg DM, for zinc not more than 40-80 mg/kg DM and for cobalt not more than 0.1-0.5 mg/kg DM.

The vitamins and minerals content of the milk composition obtained after 27 days of feeding cows with the described rations is presented in Table 4, Table 5 and Table 6. In Table 4, average values for the whole group of cows are given. The RDA (recommended daily allowance) values for the vitamins and minerals are also given.

Table 4

In Table 5 and Table 6 the content of vitamins and minerals in milk per genotype of the cows is given. The values are given in mg/100 g milk. Table 5 relates to the milk of the control group not receiving vitamins and minerals supplement, while Table 6 relates to the milk of the test group, as described above. Table 5 Control group

Table 6 Test group

In Table 7 the results of the colour measurements of the milk fat are shown. The values relate to the milk of the test group, which received the vitamins and minerals supplement as described in Example l.In this Table, Hunter L, a, b parameters with corresponding CIE tristimulus X, Y, Z values are used, wherein L is lightness, a: + red, - green, b: + yellow, - blue. The L, a, b parameters together with the Yellowness index of the milk fat YIE were obtained using Hunterlab Colorflex 45/0 supplied by Elscolab. YIE was obtained by the milk fat extraction according to a BDI method, followed by a colour measurement on fat using 20 g of the extracted milk fat at 5°C (solid milk fat). The BDI reagent was prepared from 100 g Na-hexametaphosphate, 48 ml Triton-X-100, lOOg urea, 200 ml isopropylalcohol and distilled water added to yield 2000 ml of the solution, which solution was placed in a water bath at 60-70°C until all components were dissolved.

Table 7

The results show that the milk fat of cows with KK genotype is more white than that of the cows with other genotypes.