The effect of ambient temperature, energy level and l-carnitine supplementation on the performance of broiler chicks [electronic resource].

Includes references.

This work was carried out to study the effect of different ambient temperature, dietary mitabolisable energy levels and L-Carnitine supplementation on the performance of broiler chicks [live body weight (LBW),. body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR), efficiency of protein utilization (EPU) and efficiency of energy utilization (EEU)] and carcass traits during rearing period from one up to 42 days of age. A total number of 1080 one day old unsexed Arbor Acres broiler chicks used in 3 x 3 x 2 factorial design experiment. Chicks were randomly allocated into 18 equal groups (60 chicks each) in 3 equal replicates each of 20 chicks. Groups (1- 6), (7 -12) and (13 - 18) were brooded in 30, 33 and 36°C respectively. Chicks brooded under every ambient temperature (AT) fed from 1 up to 21 days of age (starter period) three starter rations isonitrogenous (23% crude protein), differ in metabolisble energy level (ME) 2950, 3050 and 3150 kcal ME/kg supplemented or not with 50 mg/kg L-Carnitine (L-Car). In the finisher period (22 - 42 days) all chicks were fed finisher ration contained 20% crude protein and 3150 kcal ME/kg with or without L-Car supplementation. At the end of the experimental period (42 days of age) a slaughter test was performed on 54 birds (3 birds for each group). Results obtained indicated significantly (P :=:; 0.05) improvement in LBW at 21 and 42 days of age and BWG, FI, FCR, EPU and EEU during all the experimental periods studied (l - 21, 22 - 42 and 1 - 42 days of age) except FCR, EPU and EEU during 1 - 21 days of age where the effect was insignificant for chicks exposed to 30°C comparatively with those exposed to 33°C and 36°C. significant (P :=:; 0.05) improvement observed in LBW, BWG and FI during all the experimental periods, FCR, EPU and EEU during 1 -21 days of age in the groups fed diet containing 2950 kcal ME/kg diet compared with 3050 and 3150 kcal ME diet. Addition 50 mg/kg diet L-Carnitine significantly (P :=:; 0.01) improved LBW at 42 days of age and FCR, EPU and EEU during 1 - 21 and 22 - 42 days of age, while FI and abdominal fat significantly (P :=:; 0.5) decreased comparatively with unsupplemented groups. The performance and carcass traits Of broiler chicks were significantly (P :=:; 0.5) affected by interaction among AT, ME level and L-Car supplementation. It could be concluded that broiler chicks could start brooding with 30°C and fed starter diet containing 2950 kcal ME supplemented with 50 mg/kg L-Carnitine followed by finisher diet containing 3150 kcal ME supplemented with 50 mg/kg L-Carnitine.

Summary in Arabic.

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