RESPONSES OF BROILER CHICKS TO STARVATION PERIOD LENGTHS AND EFFECTS ON GROWTH PERFORMANCE, DIGESTIBILITY, CARCASS YIELD, BLOOD INDICATIONS AND ECONOMICS SHORT TITLE: FEED RESTRICTION AND ITS EFFECTS ON BROILER PERFORMANCE

The study aimed to evaluation the effects of feed restriction with different levels on growth, carcass yield, digestibility of nutrients and some blood evidences in broilers .One hundred twenty Arbor Acres, unsexed-one-day chicks were used. It had divided into 4 experimental groups, each with 3 replicates (10 chicks̸ replicate). The first treatment chicks were fed a commercial diet constantly during starting and growing periods, whereas feeds in the other treatments were restricted as follows: the second treatment starved for 3 hours \ day (from 4.00 to 7.00 pm), the third treatment starved 6 hours \ day (from 1.00 to 7.00 pm) and the last treatment starved 9 hours \ day (from 10.00 am to 7.00 pm). All chicks had full access to drinking water during the experimental period. The obtained results showed that broilers served ad libitum had significantly higher live body weight, and body weight gain compared with the treated broilers. Feed restriction significantly lowered blood LDL (in the last treatment), highest HDL (in the third), increased and improved insignificantly giblets weights or giblets percentage and FCR in the whole period respectively (in the last), improved carcass weight, dressing percentage (in the third) and enhanced significant digestion coefficient of CP for the third too. In conclusion, feed restriction had not negatively affected growth performance or metabolic responses, and it positively affected total feed costs, economic efficiency and relative economic efficiency for high level starved broilers. Therefore, the results support feed restriction by starvation methods for broiler chickens.