Effects of Dietary Lycopene or Tomato Paste on Laying Performance and Serum Lipids in Laying Hens and on Malondialdehyde Content in Egg Yolk upon Storage.

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 (<0.05) compared with those fed on the control diet. Egg production was higher (P<0.05) in tomato paste-fed layers, but lower (<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 (<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.