الفهرس 
Acknowledgment
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Abstract
The present study was conducted to evaluate the effect of adding FO and SO either singly or in combination as sources of omega 3 fatty acids to broiler diets on productive performance, carcass traits, blood biochemical parameters, meat chemical composition and enrichment of broiler meat with omega 3 fatty acids.
A total number of 168 birds one-day old (Ross-308) unsexed broiler chicks were obtained from local commercial source ,weighed and randomly distributed into 7 equal groups each of 24 chicks (8 chicks/replicate). The initial average weight of the experimental chicks was (45.7 g). The chicks were individually weighed weekly and feed consumption was recorded. Control diet was formulated to contain approximately the same levels of crude protein (23% for starter, 20% for grower finisher ) and metabolizable energy (3070 &3170 kcal ME/kg diet) as recommended by NRC(1994). In the first group, birds were fed ad libitum on starter and grower-finisher control diets without addition of either FO or SO and vitamin E. This group was assigned as a control to which the other treated groups were compared. Chicks in the second, third and fourth groups were fed ad-libitum on starter and grower-finisher basal diets containing 3.0% fish oil, 3.0% soybean oil and their combination (1.5%FO + 1.5%SO), respectively. Birds in the fifth, sixth and seventh groups were fed on the same diets containing the same levels of oils as in the previous experimental groups but with 400 mg vitamin E/kg diet.
Experimental period was extended for 6 weeks duration in two feeding phases, starting (0-3 weeks) and growing-finishing (4-6 weeks). Growth performance including body weight development and gain, feed intake were recorded and feed conversion indices were calculated. Three randomly selected birds from each group were slaughtered at the end of the experimental period for carcass traits, meat chemical composition and blood samples collection. Serum biochemical parameters were measured and total omega-3 fatty acids in broiler meat were determined.
The following results were obtained:
1. At the end of experiment (42 days), the best cumulative weight gain was recorded for the group fed diet supplemented with mixture of fish oil, soybean oil and vitamin E (2070.73g), followed by birds in group six fed on diet supplemented with soybean oil and vitamin E (1992.45g), while control group had the worst value (1797.82g). The dietary combination of fish oil & soybean oil with vitamin E improved body weight gain and feed conversion ratio at both 21 and 42 d of age.
2. Regarding the feed consumption in the whole experimental period, the seventh group recorded the highest feed intake (3384.7g, while the lowest feed intake was recorded in the fourth group which fed on mixture of fish oil and soybean oil without vitamin E (2988.3g).
3. No significant differences (P<0.05) were observed in feed conversion ratios of broilers in the different experimental groups during starting period except the third and sixth groups fed on soybean oil with or without vitamin E (1.41±0.06 & 1.33±0.03). During the whole experimental period, groups fed on a combination of FO, SO without or with vitamin E (groups 4 &7) and FO supplemented group with vitamin E (group 5) recorded better feed conversion values (1.63± 0.04, 1.65±0.05 and 1.64±0.05, respectively). Groups fed on SO diet without vitamin E and control recorded the highest and worst feed conversion values (1.74±0.05 and 1.73±0.03 respectively).
4. There was a significant increase (P<0.05) in the carcass weight in group 7 fed mixture of oils and vitamin E (1456.3±56.77g) compared to the other treated groups and control. group 7 fed on mixture of oils with vitamin E had the highest dressing percentage (69.13±0.52%), followed by fifth group fed on FO with vitamin E (68.9±0.51), while the lowest dressing percentage was recorded in the control group (67.21±0.26).
5. The liver percentages of the groups fed on diets supplemented with FO, SO and their combination with vitamin E were significantly higher than the control and other treated groups fed diets without vitamin E supplementation. Fifth group supplemented with FO with vitamin E recorded the highest liver weight % (2.03), however the lowest was recorded in the control group (1.38). Liver weights % of the birds in the second and fourth groups were nearly similar (1.45 & 1.42 %). Gizzard weight as a percentage of live body weigh differed was significantly in all treated groups. Birds in group 4 fed on diets supplemented with mix of FO and SO recorded the highest gizzard % (2.56), followed by SO supplemented group (2.50), while FO supplemented group with vitamin E recorded the lowest values (2.26). There were no significant differences in heart weights percentages among all the treated groups.
6. Dry matter, crude protein and ash content of broiler breast and thigh meat were not significantly affected among the different experimental groups; however the fat content was significantly higher in the oil supplemented groups compared to the control.
7. There were significant differences of the total serum protein, albumin and lipid profile including cholesterol, triglycerides, HDL and LDL among all the treated groups. The seventh group fed on a combination of FO, SO with vitamin E recorded the lowest lipid profile values (76.0±12.79, 39.37±7.92, 35.10±5.3, 38.77±4.14 mg/dl) for cholesterol, triglycerides HDL and LDL, respectively. Supplementation of FO with or without vitamin E decrease triglycerides and LDL. Birds fed FO and SO combined with vitamin E in group 7 recorded the lowest total serum protein and albumin values (2.27±0.19 , 1.23±0.37 g/dl), while the highest values were recorded in the control group (3.37±0.35, 1.60±0.52g/dl).
8. The highest value of omega-3 was recorded in the fish oil supplemented group with vitamin E (931.3±38.4 mg/100g meat), followed by the seventh group fed on combination of FO and SO with vitamin E (740.4±27.6 mg/100g meat). The lowest omega-3 value was recorded in the control group (58.2±5.3mg/100 mg meat). Fish oil supplemented groups’ registered higher omega-3values (196.5±12.7, 931.3±38.4 mg/100g meat than soybean oil supplemented groups (122.6±8.9, 560.2±19.8mg/100gmeat).
9. The highest economical feed efficiency was recorded in the birds fed on diet supplemented with SO (47.76 %) followed by birds in the control group (46.62 %) while the worst value was recorded in FO supplemented group (15.25 %).
10. It could be concluded that adding either fish oil or soybean oil with vitamin E to enrich the poultry meat with omega-3 is a good matter which is of great value for human health.