Milk of good quality is a very bland food with a slightly sweet taste, very little odor, and a smooth, rich feel in the mouth. Because of its bland flavor, the presence of minute quantities of abnormal constituents frequently results in off-flavors. Dairy producers and processors have, of necessity, been so concerned with the control of off-flavors, that until recently little attention has been given lower temperatures than prevailed with can collection systems. Most people associate the palatability of milk with its 'richness'. It is generally assumed that milk fat is one of the most important constituents in contributing to the desirable flavor of milk.

In many countries the most common flavor defect of milk is feed flavor. The incidence in different countries is hard to assess because evaluations are based only on subjective judgments, and opinions regarding the intensity of the off-flavor that constitutes a defect are very variable. Likewise, levels that are objectionable to consumers are equally variable. The presence of feed or weed flavors in a high proportion of milk samples in a number of surveys indicates that the off-flavors may be detected by, and are presumably objectionable to, many consumers.

Understanding the mode of transmission of flavor substances in the cow's body assists practical control of feed flavors. The respiratory system and the digestive tract are both important in transmitting flavor substances to the milk odors from some feeds pass into the cow's blood from air in the lungs, and are then carried to the udder and appears. in the milk. Some flavor-producing substances are absorbed by the blood from the digestive tract, and are then transmitted to the udder. For some feeds, both the respiratory and digestive tracts are involved in the transmission of flavor to milk. Some feeds, such as garlic and onion, release volatile flavors after partial digestion in the rumen. odors belched from the rumen are inhaled into the lungs and transferred to the blood. This pathway provides a more rapid transfer of feed flavors from ingested feed than direct absorption from the digestive tract.

Fortunately, blood provides a two-way street for transportation of feed flavors. When the concentration of the flavor substances is higher in the milk in the udder than in the blood, the substances transfer from the milk to the blood. If sufficient time is allowed after the feed is consumed, the flavor substances are eliminated from the blood, partly by transfer of volatile substances to the air in the lung, and partly by metabolism of the substances. In either case, they are eliminated from the cow's body.

The time interval between eating and milking is an important factor influencing the intensity of feed flavors. Whether the off-flavor resulted from only breathing the odor of silage, or from eating the silage, the feed flavor was most pronounced from 2 to 3 hr. later, but had been eliminated from the milk 5 hr. later. These results show why feeds commonly used in dairy rations will not cause objectionable flavors if they are fed after milking, and withheld from the cows during the 4-5 hr. before milking.

Not all feeds respond to flavor control. Some flavor substances accumulate in cow body tissues, particularly in the fat. They then transfer to the blood, and hence to the milk, over long periods of time. one of the most lingering flavor defects reported resulted from eating potatoes grown on a field treated with benzene hexachloride (for nematode control). A mothball-like flavor was still detectable in the milk three weeks after this feed was discontinued.

Flavors from some weeds persist for longer than 12 hr. after they are eaten, and therefore such weeds must be kept out of a cow's ration. In selecting feeds for a dairy ration, one criterion must be that either the feed does not impart an undesirable flavor to milk, or the flavor can be controlled by withholding the feed for a reasonable time before milking. It is impracticable to withhold feed for more than 5 hr., as prod production will suffer. Flavors from many feeds can be controlled by withholding the feed 2-4 hr. before milking.

Reports on some feeds and their effect on milk flavor are inconsistent. For example, sugar beets, beet pulp, and beet tops do not normally cause objectionable flavors, but are sometimes responsible for fishy flavor. The difficulty appears to be sporadic, varying with each individual cow and with different lots of feed. The quantity of feed consumed, its quality, and in some cases its maturity, may influence its flavor- producing characteristics.

Flavours are useful when a part of dairy ration consists of unconventional feedstuffs having pungent/bitter taste/odour, for instance Guar Meal (Cyamopsis tetragonoloba).

See attached article for reference.

Article Effect of Replacing Groundnut Cake with Guar Meal (Cyamopsis...

Thank you for your valuable sharings of Akhir Pebriansyah and M.S.Mahesh

Dear Ebrahim Bani Hassan,

Your suggested the example like ration bitter..if the food intake was decreases in cattle it will affect milk production right...then how to improve the milk production with feed flavors. How about Molasses flavor impact in cattle feed...

Can you explain elaborately.....

The milk flavour is very important in milk products consumption ,also in changing the food quantity and it is may be evidence for some diseases as digestive disturbances and mastitis.

Dear Ghassan,

Thank you for your reply...

But  am not talking about milk flavor. Am asking about the feed flavor role in the dairy cattles...

Note that the feed flavor is given by certain additives and these in turn, change the  milk flavor.

Flavours are useful when a part of dairy ration consists of unconventional feedstuffs that improve feed intake in dairy cattle

Some flavors, i.e. essential oils (thymol, eugenol, vanilin or limonen), are added in the ratio to maximise DMI, especially during the summer, when DMI decreases and ratio nutrients C% must increase.

Adding flavor should be done gradually, in order to reach the balance of their costs (ROI) and milk yield, but do not forget the palatability of the feeds and forages you deal with. Choose flavors which has the lower inclusion  rate, not to impact the whole DM of the ratio (I'm using 1-5g/cow/day).

Other factors that should be taken into consideration before adding the flavor in to cow's ratio: feeding management, feeds and forages management and other feed stuffs available in the market for making the ratio.

Impact, from my experience, is beneficial, resulting increased milk yield due to a correct estimation of DMI intake and a better conversion of feed in nutrients (some flavours have also matrix values for energy and protein). Is cheaper and safer to increase the DMI, rather to increase the nutrients C% which can lead to metabolic disorsers and so on.

Hope it helps.