Impact of Breed and Feed Restriction on Some Productive and Carcass Traits in Broiler Chickens

In this experiment we monitored, the performance of two commercial broiler strains (Cobb 500 and Hubbard classic) reared under different feed restriction systems. A total of 420 day-old broiler chickens divided into two breeds, 210 each, were randomly allotted to seven equal treatments, 30 birds each, with three replicates of 10 birds each. Based on the exposed feed restriction, group of birds was fed ad libitum throughout the whole experiment as a control (T0), another six groups were fed restricted as: T1 (8 h/day in 10-20 days of age), T2 (16 h/day in 10-20 days of age), T3 (8 h/day in 20-30 days of age), T4 (16 h/day in 20-30 days of age), T5 (8 h/day in 30-40 days of age), T6 (16 h/ day in 30-40 days of age). The data recorded included body weight, body weight gain, feed efficiency ratio, mortality and carcass traits. Results Indicated that, the highly significant measurements of live body weight, weight gain and better feed efficiency values under treatments were recorded for Cobb-500 broiler strain (1.800, 3.51 and 0.35 respectively) compared to Hubbard classic (1.775, 3.31 and 0.33, respectively). With regard to carcass traits, Cobb birds showed the highest highly significant (p& leq;0.001) dressing % and significant (p& leq;0.05) giblets wt. (79.4% and 130.14 gm. , respectively) compared to the Hubbard one (75.02% and 123.51 gm. , respectively). Body weight, weight gain and feed efficiency were not significantly (p& gt;0.05) affected by feed restriction in the two breeds. The control group showed (p& GreaterEqual;0.05) non-significantly higher body weight, gain and efficiency followed by short term restriction groups (8 hrs. ) at any stage of life cycle, while the lowest non significant values were obtained by long term restriction groups (16 hrs. ). The control group showed the highest significant (P& leq;0.05) dressing % and giblets wt. , followed by short term restriction groups (8 hrs. ) at any stage of life. In an overall conclusion it can be concluded that, Cobb-500 broiler strain is appeared to be the most economic to rear response to their performance records and feed restriction system did not significantly affect the performance of broiler chickens but resulted in improvement of farm economy.