Influence of Dietary Energy Source on Performance and Fatty Liver Syndrome in White Leghorn Laying Hens

White Leghorn laying hens were fed five levels (0, 1, 2, 4, and 8%) of dietary animal tallow, soybean oil, sunflower oil and rapeseed oil during six periods of 28 days each. Egg production showed a significant improvement with 1% soybean and sunflower oil, 2% rapeseed oil and animal tallow. Feed efficiency improved with energy density for hens fed animal tallow whereas vegetable oil showed improvement at the level of 1% in the diet. Egg weight and yolk weight improved with increasing energy in animal tallow treatments. Soybean and sunflower oil improved egg weight and yolk weight at 1% in the diet whereas rapeseed oil showed no improvement over the low fat control diet. Fatty livers were observed with a high level (8%) of dietary animal tallow and rapeseed oil whereas soybean and sunflower showed protection against fat accumulation at all levels (1, 2, 4, and 8%) tested.