Because of their high growth rate, factory chickens are sensitive to necessary nutrients, mineral and biologically active substances. It is extremely important for them to have a balanced diet, particularly at an early age, in the first and second weeks of their life, when a chicken has not quite adapted to the environment, and is thrown to the influence of various stress factors. As is well known, the enzymatic system in the digestive tract in chickens is formed within 7-10 days. Whilst getting a significant proportion of nutrients and energy from the rest of yolk in the first 2-3 days. Therefore, in this period the rations for factory chickens must contain easily digestible nutrients, and feed ingredients must be chopped to a particle size of 0. 9-0. 12 mm in diameter. For this experiment, in the poultry house 500 heads of factory chickens were chosen, which were divided into 5 groups of 100 heads each. Starting from the first day, the chickens of the 1st (control) group were fed with an adequate combination feed and the poultry of the 2nd,3rd,4th,5th experimental groups got the same combined feed, but during the first 7 days with the mass particle of NuPro preparation, respectively – 1,2,3,4% in it. The results of the experiment showed that the introduction of the combined feed of 1-4% of mass particle of NuPro improved a rate of growth of experimental broilers. If the average daily weight gain for the 1st week in the control chickens was 21. 7 grams, then in their analogues of the 2, 3, 4 and 5th experimental groups it was by 6. 8; 8. 7; 7. 3 and 4. 2% more. The body weight of factory chickens of the 2nd-4th research groups in 42-day age and was also higher and amounted 2622. 8-2764. 1 against 2534. 8 g in control, – with a simultaneous reduction in the amount of growth by 1. 1-2. 2%. Inclusion of NuPro in the feed in the first week of factory chickens life increases the potential for improving of digestibility of nutrients, nitrogen fixation and mineral elements that appears to increase the growth intensity of poultry throughout the whole growing period; According to the overall assessment of the results of the experiment, the optimal dose of NuPro in the combined feed is 20 kg/t.
Key words: productivity, broiler chickens, doses, time of feeding, live weight, NuPro.