Effects of dietary dried olive pulp inclusion on growth performance and meat quality of broiler chickens

Two hundred 10-d-old broiler chickens were used to study the effects of different dried olive pulp (DOP) inclusion rates on growth performance and meat quality. Broiler chickens were assigned to 4 experimental treatments (5 replicates of 10 broiler chickens each) for 32 d. The broiler chickens of each treatment were offered a different combination of grower (d 11 to 22; grower phase) and finisher (d 23 to 42; finisher phase) diets in terms of DOP content. The experimental treatments were: control (C), grower and finisher diets with no DOP; treatment 1 (T1), grower and finisher diets with 25 and 50 g DOP/kg, respectively; treatment 2 (T2), grower and finisher diets with 50 g DOP/kg; and treatment 3 (T3), grower and finisher diets with 50 and 80 g DOP/kg, respectively. Feed intake and body weight were recorded to calculate weight gain and feed conversion ratio (FCR). Fatty acid (FA) composition, oxidative stability, pH at 24 h post-mortem (pH(24)), color properties, cooking loss, and tenderness (as shear force) were determined in the breast muscle obtained from 2 broiler chickens/replicate pen of each treatment at d 42. The FCR was greater in T2 and T3 compared to C (P = 0.013) during the grower phase. During the finisher phase, FCR was greater in T3 when compared to C (P = 0.014), and to T1 and T2 (P = 0.031). The addition of DOP increased 18:1n-9 and total monounsaturated FA (P < 0.001) in the breast muscle in a dose dependent manner. Reduced oxidative stability, lower pH(24), and increased lightness of breast meat in T3 compared with C (P = 0.003, 0.004, and 0.001, respectively), and with T1 and T2 (P = 0.004, 0.020, and 0.012, respectively) were observed at d 42. In conclusion, broiler chickens utilize DOP supplemented diets more efficiently when dietary DOP inclusion is increased gradually with age, i.e., by using a combination of grower and finisher diets with a maximum of 25 and 50 g DOP/kg, respectively. Breast meat can be enriched with 18:1n-9 FA by DOP addition; however, DOP should not exceed 50 g/kg diet because it can be detrimental to breast meat oxidative stability, pH24, and color.