Akademik Veri Yönetim Sistemi
2020 International Poultry Scientific Forum, Georgia, Amerika Birleşik Devletleri, 27 - 28 Ocak 2020, ss.8, (Özet Bildiri)
A 49-d trial was conducted to determine the impact of dietary amino acid
(AA) density and stocking density (SD) on growth performance, carcass
traits, meat quality, and white striping (WS) occurrence in broiler chickens. A total of two hundred eighty eight Ross 308 male broilers consisting
of 6 replicate cages with 8 broilers per replicate were used. Treatments
were arranged in a 3 × 2 factorial and consisted of 3 AA densities [normal (Norm), 10% lower than Norm (10%low), or 20% lower than Norm
(20%low)] and 2 different SD (High; 35 kg/m2
or Low; 26 kg/m2
). Data
were analyzed as a completely randomized design using the GLM procedure of SAS. Decreasing AA density decreased overall growth performance, carcass and breast yields and breast fillet dimensions linearly,
whereas leg and rib cage yields increased linearly (P < 0.01). High SD
decreased hot carcass, breast, wings, and rib cage weights in birds fed on
Norm AA diets (P < 0.05). High SD increased the length of breast fillet (P
< 0.05). Cooking loss, breast lightness (L*) and redness (a*) at 48 h postmortem increased linearly with decreasing AA density (P < 0.01), whereas
breast ultimate pH (pHu
) decreased linearly (P < 0.001). Low SD caused a
decrease in breast yellowness (b*) at 24 post mortem in birds fed on norm
AA diet (P < 0.05). Nitrogen content of breast fillets decreased linearly
with decreasing dietary AA density (P < 0.05). Breast muscles having severe WS contained higher fat when compared with breast muscles with
moderate or no WS (P < 0.05). As the dietary AA density decreased, occurrence of no WS breast fillets increased, whereas occurrence of moderate WS fillets decreased (P < 0.005). However, dietary AA density did not
affect the occurrence of severe WS fillets. Stocking density did not affect
the occurrence of WS. Breast fillets having severe WS had higher pHu
and
less b* than normal breast fillets (P < 0.05). There were no differences for
water holding capacity and cooking loss between different degrees of WS.
Taken together, growth depression created by lowering dietary AA density
regardless of SD resulted in a decrease in mean WS score. Severe WS fillets were heavier and had higher pHu
, fat, and lower b* but no difference
in water holding capacity compared to no WS fillets.