الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 146 |  |  |
| | | from | 146 | | |
Abstract
Feed additives are commonly used in poultry feeds to improve their growth performance, increase feed consumption and utilization. Organic acids and etheric oils are used as natural alternatives for antibiotics growth promoters. The present study aimed to estimate the effects of organic acids either coated or uncoated, etheric oils and combination of both acids and oils on the growth performance, carcass traits, blood parameters as lipid profile and immune responses of broiler chicks. Two hundred one day old chicks were divided to 8 groups where the first one was the control group while the other 7 experimental groups were fed on diets supplemented with coated organic acids at concentrations of 11.9% fumaric, 6.9% sorbic, 5.6% malic and 5.6% citric acids (T1), low level of uncoated acids, 11.9% fumaric, 6.9% sorbic, 5.6% malic and 5.6% citric acids (T2), high level of uncoated acids, 23.8% fumaric, 13.8% sorbic, 11.2% malic and 11.2% citric acids (T3), coated organic acids combined with etheric oils blend contained, thyme, cumin and oregano oils at ratio of 1:1:1(T4), low level of uncoated acids with the same blend of etheric oils (T5), high level of uncoated acids combined with the same etheric oil blend(T6) and etheric oil blend (T7). The obtained results revealed that the BWs and BWGs were significantly (P<0.05) increased the groups of T3, T5, T6 and T7 compared to the control, T2, T1 and T4. The relative growth rate was not significantly affected except in T1 and T4 where it was decreased significantly compared to the control group. Feed consumption was higher in the groups of T3, T5 and T7 than the groups of control, T6, T2, T1 and T4. The FCR was significantly (P<0.05) improved in the groups of T6, T1, T2, T3, T4 and control. The dressing percentage was not increased but in the group of T4 it was significantly decreased compared to the control group. The breast percentage was increased in the groups of T3, T5, T6 and T7 compared to the control group while the thigh percentage was significantly increased in the T6 group but numerically increased in T3, T5 and T7compared to the control group. The relative weights of lymphoid organs (spleen and bursa) was significantly increased in T4, and T6 but numerically in other treated groups T1, T2, T3, T5 and T7 compared to the control group. The antibody titers against AI and ND vaccines at the 4th week were significantly (P<0.05) elevated in the serum of all treated groups compared to the control group but in the 3rd week it was significantly (P<0.05) elevated in the serum of T4, T5 and T6 but numerically in other treated groups compared to the control group. The serum levels of TG were not affected but the TC levels were significantly lowered in T5 and T7 but numerically in T3 and T6 compared to the control group. For HDL, the groups of T1 and T7 had significantly (P<0.05) higher levels than the control group. The serum levels of LDL were significantly lowered in the T3, T4, T5, T6 and T7 groups but numerically in T1 and T2 compared to the control group. Similarly the VLDL serum levels were significantly (P<0.05) lowered in T3 and T5 groups but numerically in T1, T2, T4, T6 and T7 compared to the control group. All treated groups significantly lowered the malondialdehyde level but the groups of T1, T3, T6 and T7 numerically elevated the glutathione reductase levels compared to the control group. The net return from raising the groups of T2, T3, T5, T6 and T7was higher than the control group with the highest net return found in T6 group. Finally, it recommended supplementing broiler diets with high levels of organic acids either alone or in combination with etheric oils improved growth performance, carcass traits, and immune response.