For highly productive cows quality of protein feed depends not so much on the amount of proteins in rations, but also on content and optimal correlation of amino acids. The scarcest for the organism of animals are such irreplaceable amino acids, as a lysin, methionine, tryptophane, as only small amount of them comes with forage of plant origin.

Therefore the objective of the research was to set the optimal levels of raw protein, easy- and hard soluble factions, lysin and methionine in the rations of highly productive cows during the first 100 days of lactation.

A test was carried out on six groups of highly productive cows of Black and White breed with 10 heads in each.

The basic diet balanced after the detail norms of feeding was fed to the animals of the control group. The animals of tested groups, except basic diet, were additionally fed with experimmental feed or additive with the changed level of protein and amino acid.

In the tested period cows of the control group were left on the rations of setup period, and to the cows of the tested group, with the aim of increase in their rations of content of hard soluble faction of protein, instead of peas and soy-bean fed the extruded mixture (5 % wheat, 45 % peas and 50 % soy-bean). In addition, for the increase of concentration of lysin and methionine, instead of ordinary mill cake of sunflower the mill cake of sunflower immobilized of L- lysin was fed to the cows of  the 2-d tested group.

To the cows of the third tested group had mill cake of sunflower and mill cake of soy, with 50% immobilized and on 50% non immobilized but extruded. The cows of the fourth tested group were fed with immobilized mill cake of sunflower and mill cake of soy. The rations of cows of the 4th and the 5th of the tested groups differed from the rations of cows of the 3d tested  group only in diminishing daily amount of the mixed fodder on 0,5 and 1 kg accordingly, and additionally 1 kg of immobilized mill cake of sunflower.

In a preparatory period of the experiment cows of the control, 2d, 3d, 4th and 5th tested groups after day's yield did not differ substantially, and in further period average daily yields changed, depending on content in the rations of raw protein, it’s hard soluble faction, lysin, methionine.

The greatest natural milk yields were given by the cows of 2-d, 3-d, 4-ht and 5-th tested groups that prevailed cows-analogues of the control group, accordingly, on 1,8 kg; 4,7 (Р<0,01); 2,2 and 3,2 kg, or on 3,28 %; 9,9; 4,7 and 6,7% .

In milk of tested cows, except for the 5th tested group, the increase of content of fat is marked also by 0,01-0,04%.  Advantage after average daily milk yields was also marked, comparatively with the control group and presented: in the 2-d tested group – 1,5 kg, or 3,7%; in the 3-d tested group – 4,4 kg (P<0,01), or 11%; in the 4-th tested group – 2,1 kg, or 5,2%; in the 5-th tested group are 2,6 kg, or 6,5% .

The milk from the tested group cows as compared to control, though not too noticeable, showed diminished content of protein (3,07-3,08 against 3,10% in control).

The cows of the 3-d tested group had the best results in milk productivity, that got rations with an increase level of raw protein to 18,6% and it’s hard soluble faction presented 40,3% of the consumed raw protein. At the same time the level of lysin from a dry substance presented to a 1,1%; methionine – 0,63% .

During the first 100 days of lactation living weight of cows is changing. If at the beginning of period of milking living weight of cows of all experimental groups was practically identical, then in 80 days of experiment for the cows of the control group it diminished on 35,8 kg, or 6,48%; the 2-d tested group – on 31,3 kg, or 5,61%; the 3-d – on 24,5 kg, or 4,35%; the 4-th tested group – on 29,8 kg, or 5,32%; the 5-th tested group – on 26,2 kg, or 4,67%.

From the 50 cows of the tested groups in milking period 6 of cows of the 1-st control group and all cows of the tested groups were impregnated and their ration contained higher levels of raw protein it’s hard soluble faction, lysin and methionine. For the cows of the 2-d, 3-d, 4-th and 5-th tested groups, comparatively with control, a service-period was less long by 34 days, 41, 35 and 37 days and lower index of insemination – on 0,30; 0,40, 0,30 and 0,40, or 20,0% 26,7, 20,0 and 26,7%.

Thus, with the aim of providing of high milk yield, obtaining milk of high food and technological quality and increase profitability it is recommended in the economies of central zone of Forest-steppe of Ukraine in the rations of highly productive cows (45 kg and more milk daily) achieve the level of raw protein in a period of milking to 18%; the level of lysin to 1,1%; methionine to 0,63%; the content of hard soluble faction of protein to 40-50% of it’s general amount.

Key words: cows, protein, lysin, methionine, hard soluble faction, easily soluble faction, milk productivity, live weight, reproductive ability.