Forage base of modern poultry industry is quickly and significantly changing under the influence of constant usage of feed ingredients n terms of demand for meat food products. Therefore, to improve the nutritional value and to achieve a high degree of assimilation of the feed components in the body of birds the food additive Ecosorb is used.

Experimental studies were performed on ducklings-broilers under experimental facilities of the Department of feed technology, feed additives and animal feed of Bila Tserkva National Agrarian University.

400 animals per diem chicken-broiler of breed cherry valley were chsen for the experiment, which were divided on the basis of peers into 4 groups: group 1 is a control one and 3 experimental groups, 100 head (50 males and 50 females) in each.

Feeding the ducklings-broilers of all experimental groups during the whole experiment was the same. The ducklings-broilers of the 1-st control group were fed with complete feed without adding sorbents while the ducklings-broilers of the 2-d, 3-d and 4-th experimental groups were fed with complete feed with sorbent complete feed stuff chicken-broilers 2, 3 and
4 experimental groups was added to the sorbent Rcosorb in doses, respectively, of 0.57 g/kg, 0.78 g/kg 1 g/kg of feed. The main period of experiment lasted for 42 days.

To examine the exterior 10 ducklings at the age from 14 to 42 days were selected live weight of which corresponded to the average of the group. Secondary measurements were determined: a straight length of body, length of keel, tibia, metatarsus and chest girth.

As a result of research it was discovered that the addition of the feed additive in the composition of feed causes a perceptible change of type of the body structure. In particular, the length of the body of ducklings of the control and experimental groups was inconsistent and depended on their age and feeding factor.

The maximum length of the trunk was observed in ducks of the 4th group fed with the feed additive in an amount of 1 g/kg of feed that prevails counterparts in the control group for this indicator at 14; 28 - and 42-day-old respectively by 1.4 %; 4.7 and 4.3 %.

It was found that the length of the body of ducklings-broilers of the 2-nd experimental group, in whose composition of feed the sorbent in the amount of 0.57 g/kg of feed was added exceeded their peers in the control group at 14; 28 - and 42-day-old, respectively by 0.7 %; 2,3 and 2.2 %.

The length of the body of the poultry of the 3-rd group, in whose composition of feed the sorbent in the amount of 0.57 g/kg of feed was added in the amount of 0.78 g/kg of feed for all age periods was significantly lower compared with the control group, respectively by 0.7 %, 0.5 and 2.2%.

The indicator of breast development in birds is the length of the keel. It was revealed that the length of the keel of the ducklings-broilers of the 2-nd, 3-rd and 4-th research groups at 14-day age was inferior than that of their peers in the control group respectively by 1.9; 3.8 and 1.9 %.

During the period of rearing at 28-day-old age the ducklings pf the 3-rd experimental group had a length of keel 2.9 % lower compared with those of the control group, however ducklings of the 2-nd and 4-th experimental groups for this indicator exceeded the control group respectively by 1.9 and 9.4 %.

It should also be noted that at the age of 42 days, the length of the keel in the 3rd experimental group was lower by 0.7% compared with that of the control group. The ducklings of the 2-nd and the 4-th experimental groups had higher indicator by 2.6 and 9.9 % compared with analogues of the control group.

As a result of the research it was found that at the age of 14 days the length of the tibia of ducklings in three experimental groups was lower compared with their peers in the control group. respectively by 4.5; 7,7 and 2.9%

At the age of 28 and 42 days the ducklings of the 2-nd and the 4-th experimental groups had longer tibia than the birds in the control group -  their indicators exceeded respectively by 3.3 %; 1,5 and 4.1; 5,9 % (p<0.01), whereas the corresponding figure in young stock of the 3-rd experimental group was lower by 0.8 and 0.7 %.

Above all, it should be noted that the development of the chest, internal organs and meat quality of chickens are judged on indicators such as the width and girth of the chest which primarily depend on the level of feeding birds.

It was found that ducklings of the 2-nd, 3-d  and 4-th groups at the age of 14 nights for the length of the shank ducklings were inferior to the control counterparts 4.2 %; 6.4 and 2.0 %.

In particular, the youngsters at the age of 28 and 42 days age of the 4th experimental group surpassed ducklings control group respectively 5.8 and 2.6 %, while a young 2nd and 3rd experimental group 3,0; 1.5 and 1.3, 4.0 % were inferior in front of their peers in the control group.

It was found that feeding the ducklings-broilers of the 3-rd experimental group with the animal feed containing the sorbent in the amount of 0.78 g/kg of feed in all periods of growing leads to the decrease of the chest girth by 2.5 %; 2.1 and 1.4 %.

So, the chest girth of birds of the 2-nd and 4-th groups during all periods of growing was higher respectively by 2.4 ;0.5 % and 7.1(p<0.001) and 1.3% compared with the control group.

Summarizing the data received, one should noticed that in general for the growing period the ducklings of the 4-th experimental group which were fed with sorbent in the amount of 1 g/kg animal feed were superior to their peers from the control group by the body length, tibia length, metatarsus length and girth chest by 4.3 % respectively; 5,9; 2.6 and 7, 1%.

Key words: ducklings-broilers, additive Ecosorb, body length, keel length, tibia length, metatarsus length, chest girth,
animal feed.