The analysis of literary sources testifies that the questions of selenium additions influence into the mixed fodder on the slaughter and meat qualities of broiler chickens (yield of the half eviscerated and eviscerated carcass, it’s morphological composition and development of internal organs) are studied yet not enough.

Only in the separate scientific works there is data about positive influence of additions of certain doses of selenium in the mixed fodders for different types of agricultural bird on some indicators that characterize their meat qualities and development of internal organs.

At the same time, the results, obtained by different scientists are contradictory and, to our opinion, they should be estimated as orientation, which needs further verification and clarification.

In this connection, the study of selenium different doses additions influence of in the mixed fodders on the for slaughter and meat qualities of broiler chickens was the aim of researches.

Experimental researches are executed on the broiler chickens of cross-country race СОВВ 500. For carrying out scientific and economic experience there were formed, on the principle of analogue, four groups of one day old chickens (100 heads in each).

Feeding of broiler chickens during the period of growing (42 days) was made by the dry nutritions mixed fodders in accordance with existent norms. The experiement groups birds mixed fodders was additionally added with different amount of selenium, mg/kg: the second group – 0,2; the third – 0,3 and the fourth – 0,4. The first control group chickens did not get selenium addition. Sodium selente was used as a source of selenium. At the end of the experiment the 4 broiler chickens of each group were slaughtered according to the existing recommendations.

It is being established that feeding of experience groups bird during the period of growing with the mixed fodders enriched by selenium allowed to promote not only living mass of broiler chickens but also their half eviscerated carcasses mass. So, that average mass of the half eviscerated carcasses of chickens of the second experiement group was by 1,8 %, the third – by 7,0 % (Р<0,01) and the fourth – by 3,3 % (Р<0,05) higher, as compared with analogical index in a control group (1545,0 g).

The mass of the eviscerated carcass of all the young experience groups also advantageously differed from the control. However, statistically a difference appeared reliable only in the third experiment group the chickens of that exceeded on this index the persons of the same age from a control group by 67,0 g, or by 5,3 % (Р<0,01).

Mass of edible parts rose in the experiment groups. Comparatively with a control, in the second experience group a difference presented 1,1 %, in the third – 6,3 % (Р<0,01) and the fourth – 4,3 % (Р<0,01).

The yield of edible parts is largely determined by specific gravity of muscles that present basis of carcass. On this index the chickens of experiment groups exceeded the persons of the same age from a control group (40,3–41,3 % against 40,0 %). The absolute mass of muscles difference between the bird of control and experiment groups was statistically reliable in favour of  the last and presented in the second group – 5,1 % (Р<0,01), in the third – 8,7 % (Р<0,001) and fourth – 4,3 % (Р<0,05).

Additions of selenium in the mixed fodder positively influenced on mass of liver, heart and muscular stomach of broilers. Yes, if for the of control group bird specific gravity of edible entrails presented 4,5 %, then in the experience groups she appeared higher, accordingly on 0,3 %, 0,2 and 0,9 %.

The special differences between groups after attitude of mass of uneatable parts it is not educed toward foods. This index in control and second experiment groups was identical and presented 1:1,36. For third and fourth experience groups bird on unit of mass of uneatable parts was, accordingly, 1,34 and 1,39 foods.

Correlation of mass of bones to mass of muscles was higher for the chickens of experiment groups, comparatively with control on 4,8–8,4 % and presented in the second and the third – 2,61, in the fourth – 2,70.

Thus, the introduction of the feed for broiler chickens of selenium from a calculation 0,3 mg/kg most notedly affected the meat productivity, in particular, assisted the reliable increase of mass of the half eviscerated and eviscerated carcass, accordingly by 7,0 and by 5,3 %, and also the masses of edible parts of carcass by 8,7 %, in the consequence of the best development of muscular tissue and edible entrails.

Key words: selenium, dose, mixed fodders, broiler chickens, meat productivity.