The research was conducted in the vivarium conditions on Bila Tserkva National Agrarian University researching base. For the experiments it was generated 5 groups (one control and four experimental) for 100 heads each. Chickens were kept on the deep litter. Birds in the control group were fed supplementary feed additive cellulase enzyme inclusion; I, II, III, IV research groups were treated cellulose enzyme according the advanced biotechnology.

The experiment investigated: feed intake of broiler chickens, the dynamics of their weight and the average daily gain, survival of birds, a lot of internal organs in poultry (for 4 heads from each group), the cost of feed per gain. These values were subjected to biometric processing.

Live weight is the main indicator of the efficiency of poultry. The evolution of live weight growth reflects the features of the experimental chickens at different periods of growth.

These studies found changes in live weight of broiler chickens by cellulase action. It was proved that the use of feeding broiler feed new factor – cellulase enzyme supplements – increased growth and accumulation of mass.

At the beginning of the experiment, the control chicks and research groups hardly differed by body weight. In the final period of growth on the 42nd-day age, live weight of broiler chickens of I; II; III and IV  the study groups was, respectively, 2133,8; 2193,2; 2091,5 and 2080,3 vs 2003,4 g in the control group, which was 130,4; 189,8, 88,1; 76,9 g or 6,5; 9,5; 4,4; 3,8 % increase. Overall, for the entire period of the experiment poultry research groups had the average daily growth ahead of peers by 3,1 control; 4,4; 2,0; 1,.8 g or 6,6; 9,4; 4,3; 3,9%. In this case, the best performance obtained in the second experimental group, the introduction of 0,068 g/kg cellulase of the feed contributed to increasing live weight of poultry by
9,5 % relative to control.

The increase in live weight of broiler chickens in the experimental groups can be explained by the fact of the influence of cellulase hydrolyzed significant amount of cellulose, which was an anti-nutrient factor for birds, and this, in its turn, has a positive effect on growth transformation of nutrients in food products.

According to the live weight changes the absolute increment of experimental calves was observed. Throughout the experiment the body weight of control chickens was significantly lower than of those in the research group.

In sum, for the entire period of growing the largest absolute increase was found in chickens of II experimental group, which was administered to feed cellulase received in nutrient medium with the addition of an organic copper complex, the difference significant.

Along with the intensity of growth of broiler chickens significant indicator of their growth is fodder per 1 kg of live weight. During growing and maintenance of poultry 60–70% is spent on food. Therefore, reducing their cost is a factor that increases the economic efficiency of production.

During the period of the experiment feed intake chicks experimental groups was the same. As it can be seen from these data, the least cost feed 1 kg increase in body weight was observed in the second experimental group, the figure was lower than in the control, 8.4%.

Costs of feed per 1 kg increase in I, III and IV experimental groups were lower compared to the control, respectively, 6.0; 4.0 and 3.5%.

An important confirmation of the feasibility and efficiency of cellulase during growing broiler chickens was not only a performance of live weight poultry, but the mass of internal organs. Conducted research did not have the difference between the mass of the liver in broiler chickens experimental groups and the control calves. Similarly, supply the heart and lungs in birds I, III and IV of the study groups was on a par with those of controls.

It was established that the birds II experimental group tended to increase the average heart weight by 17,1%, or 1,8 g difference was unlikely.

Experimentally, it was found that the inclusion of animal feed broiler cellulase, which was obtained from Aspergillus terreus strain without adding to the culture medium copper (I experimental group), caused an increase in liver weight by 1.4% compared to the control group. However, the difference was only character tendencies.

Thus, the inclusion of animal feed cellulolytic enzymes led to the increased transformation of feed nutrients and growth performance of birds by 3,8-9,5% relative to those of the controlled group. Introduction of cellulase in the number of 0,068 g/kg helped reducing the cost of feed per 1 kg increase of 8.4% compared with the control. The use of the enzyme under study did not affect the weight of the internal organs of broiler chickens, but the introduction of cellulase obtained using advanced biotechnology to feed, causing a tendency of increasing the weight of the heart and lungs of birds of II experimental group.

Key words: broiler chickens, productivity, cellulase, weight, internal organs, the cost of feed.