The present study was undertaken to investigate the effect of dietary, synthetic lycopene or tomato paste on laying performance and egg qualities in laying hens, and on lipid oxidation of stored eggs. One hundred and sixty 38-week-old Hy-line Brown laying hens were randomly housed in cages (two birds per cage, five cages per replicate) equipped with nipples and a trough-type feeder and subjected to one of four experimental diets. Each treatment had four replicates. A corn and soybean meal base diet was added with or without either synthetic lycopene to contain 10 or 20 mg per kg of diet, or with 17 g of tomato paste per kg of diet.The feeding trial lasted four weeks. Feed intake did not differ between dietary treatments.Laying hens fed diets containing lycopene or tomato paste laid lighter eggs (P<0.05) compared with those fed on the control diet. Egg production was higher (P<0.05) in tomato paste-fed layers, but lower (P<0.05) in those fed on a diet containing 20 mg/kg of lycopene compared with the control diet-fed counterparts. Dietary lycopene did not affect egg quality, except for yolk color, nor did serum lipid profiles. Malondialdehyde (MDA) content in serum samples and eggs that had been stored at 24°C for four weeks was reduced (P<0.05) by lycopene or tomato paste. Adding lycopene or tomato paste into a diet of laying hens increased the incorporation of lycopene into the liver and egg yolk. Collectively, the present study shows that addition of low levels of lycopene or tomato paste into the layers' diet is an effective nutritional strategy to enhance oxidative stability of fresh eggs.

The present study was undertaken to investigate whether dietary lycopene (LP) could prevent the copper-mediated oxidation of low density lipoprotein (LDL), and affect growth performance, relative organ weights, plasma and meat lipid profiles, and LP contents in plasma and tissues in broiler chickens. A total of 160 day-old male broiler chicks were randomly allotted into 16 pens with rice husk as a bedding material. Each experiment had 4 replicates, 10 chicks per replicate (n = 4 per treatment). A corn-soybean meal base diet was used as a control diet (CONT). To formulate the experimental diets, the base diet was added with LP at the levels of 10 (LP10) or 20 mg/kg (LP20), or 17 g/kg of tomato paste (TP17) which was equivalent to 5 ppm of LP. The experiment lasted 4 weeks. Growth performance and relative organ weights were not affected (p > 0.05) by any of dietary treatments. Dietary LP significantly lowered (p < 0.05) triglyceride and LDL cholesterol at 2 weeks of age, but did not affect them at 4 weeks of age. Total cholesterol in thigh meats was not altered by dietary treatments. LP was not detected in leg meats in all chicks, nor in liver or plasma of the CONT group. LP was found in liver and plasma, being the former greater in the concentration, of the chicks fed diets containing LP10, LP20, or TP17. At 2 and 4 weeks, the copper-mediated oxidation of LDL was delayed (p < 0.05) in either LP- or TP-fed chickens compared with the CONT group. In conclusion, LP lowers triglyceride and LDL cholesterol, is deposited into serum and liver, and prevents the LDL oxidation in broiler chickens, confirming the role of LP in the lipid-lowering and antioxidant properties in broiler chickens.