The article highlights the results of research on determining the optimal level of valine in broiler chickens' feed. The scientific and economic experiment investigated the effect of different levels of valine in feed on live weight, absolute, average daily, relative weight gain and feed consumption in broiler chickens. At a day-old age, 330 broiler chickens of the "Ross-308" cross were randomly divided into 3 groups of 110 birds each, which received complete pelleted feeds that differed in valine levels. The broilers were fed complete pelleted feed. The amount of metabolizable energy of nutrients and biologically active substances in the feed for all groups ofbroilers was the same. At the same time, the feeds for broilers of the experimental groups differed in the content of valine. The nutritional value of the feeds varied depending on the age of the broilers: 1-10, 11-24, 25-37 and 38-45 days. The amount of total valine in the feed for the first group was respectively – 11.7; 10.6; 9.8; 9.3 g/kg, for другої – 12.2; 11.1; 10.2; 9.7 g/kg and for the third group – 11.2; 10.2; 9.4; 8.9 g/kg. That is, in the second group, broilers received a diet with an increased (up to 5%) valine content compared to the first group, and in the third group – with a reduced (up to 5%). The results of the research show that broiler chickens in the first (3325.1 g) and second (3402.2 g) groups at the end of rearing (45 days) had a live weight slightly higher than that recommended by Aviagen (3295 g). In the third group, broiler chickens did not reach the standard weight (3247 g). Compared to the control, the chickens receiving feed with an increased level of valine had a higher final live weight by 2.3%. The description of the growth of young broiler chickens using mathematical methods confirmed the S-shaped growth curve with a high coefficient of determination for each experimental group with a reliable approximation coefficient R2=1
SOROKUN et al. (Fri,) studied this question.