THE EFFECTS OF DIETARY-FAT ON GROWTH-PERFORMANCE, CARCASS COMPOSITION, AND FEED-EFFICIENCY IN THE BROILER CHICK

In two experiments broiler chicks were fed nonisocaloric diets with ei ther 0, 3, or 7% added lard. Megacaloric percentages of all major nutr ients were the same in all diets. In Experiment 1 (broiler chicks 0 to 5 d of age), added dietary lard did not affect body, heart, spleen, o r pancreas weight. Liver weight was suppressed by the inclusion of lar d in the diet, yet liver composition changed, becoming higher in prote in and lower in fat. Yolk sac weight decreased during the first 5 d po sthatch, with the decrease being most pronounced by 3 d of age. There were no differences in feed consumption due to treatment in Experiment 1. In Experiment 2 (broiler chicks 6 to 11 d of age), added dietary f at resulted in differences in liver, body, and fecal excreta compositi on. Chicks given 7% added lard had lower liver fat throughout the tria l than chicks fed no added lard. Additionally, these chicks had a high er body protein content at 6 and 7 d of age. However, body fat only in creased in chicks fed 7% added lard by 11 d of age. Furthermore, chick s receiving 7% added lard had elevated fecal fat at Day 6, but did not consume more feed than chicks receiving 0 or 3% added lard. Additiona lly, chicks fed lard had lower liver weights than those fed 0% added l ard.