Dietary prilled fat and layer chicken performance and egg composition.

Prilled and poultry fat were fed at 2% to 58-wk-old hens and at 4% to 2-wk-old hens for 8 wk. Comparisons by dietary fat source were made within age groups for BW, feed consumption, egg production, egg weight, yolk cholesterol, and fatty acid composition, egg quality, plasma cholesterol, dietary fatty acid utilization, dietary ME, and gastrointestinal transit time of feed. Old hens fed prilled fat had lower egg weight, increased egg production, lower plasma high density lipoprotein (HDL) cholesterol (P < 0.08), and reduced energy. Young hens fed prilled fat were lighter in weight and had lower plasma total and low density and very low density lipoprotein cholesterol. Young hens fed prilled fat had a lower utilization of stearic acid (P < 0.07) but a higher utilization of linoleic acid. In both groups, prilled fat increased yolk saturated fatty acids and decreased polyunsaturated fatty acids. Gastrointestinal transit time of feed was increased by 29 to 31 min (P < 0.09) in young hens fed prilled fat.