SUMMARY

At the broiler farms A, B and C in three independent production cycles that lasted six weeks (42 days) Arbor Acres, Hybro and ISA-30 broiler strains were used. The day-old chicks were marked by the individual wing tags and weighted in the first and 42nd day of age. The data on body weight of chickens were calculated by the standard statistical methods and the regression - correlation analysis. Average body weights of clay-old chicks varied from 39.67 g (ISA-30, farm C) till 42.50 g (Hybro, farm B) and six weeks broilers from 1852.5 g (Hybro, farm B) till 1897.3 g (Arbor Acres, farm A). The regression coefficients (b) varied from 11.897 (ISA-30, farm C) till 20.22 (Arbor Acres, farm A), and correlation coefficients (r) from 0.164 (ISA-30, farm C) till 0.255 (Arbor Acres, farm A). All correlation coefficients were highly significant P<0.01but designated very low or low correlation. It was concluded that from practical standpoint the starting and the final body weight of fattening chickens are not in so direct relation on the individual level, but they are on the group (flock) level.

          Key words: broiler chicken, growth, final body weight, starting body weight.