Effects of housing systems and feed additive on growth, carcass traits, liver function, oxidative status, thyroid function, and immune parameters of broilers.

The effects of rearing Cobb500 broiler chickens under 3 different housing systems (floor litter, floor plastic, and batteries) without or with feed additive (Butinov) on broiler performance, blood parameters and carcass traits were evaluated. Three hundred 1-day-old chicks were distributed in a 3 × 2 factorial arrangement (6 treatments each of 5 replicates). The results showed that reared broilers on litter or plastic floors had high values (P ≤ 0.01) of bird's weight (BW), weight gain (WG), and feed intake (FI) throughout the entire study period (1-42 d of age) compared with rearing on batteries. Rearing broilers in the different housing systems and with or without feed additives did not affect (P ≥ 0.05) total feed conversion (FCR). Different rearing systems or feed additives did not influence broiler chicks' carcass traits and some serum blood parameters. The plastic floor system significantly increased (P ≤ 0.05) blood serum corticosterone compared with litter and batteries. Feed additive (Butinov) decreased the level of T (P ≤ 0.05) in blood serum. Plastic floors or batteries significantly increased (P ≤ 0.01) the level of antibody titer against avian influenza virus (HIAV) compared to chicken reared on a litter floor. The results suggested that using housing systems of litter or plastic floors could improve broiler growth performance without adversely affecting carcass traits and blood characteristics compared with rearing in batteries. Also, broiler diets' feed additive (Butinov) and their interaction with rearing systems did not improve broiler growth performance.