The aim of this study was to investigate the influence of dietary fat sources and
lysolecithin on growth performance, visceral organ size, and histological intestinal
alterations in broiler chickens. Ninety-six 7-d-old male broiler chickens were assigned
to 8 treatments in a 2 4 factorial arrangement of treatments with 2 levels of lysolecithin
(0 and 145 mg/kg) and 4 different fat sources [poultry fat (PF), yellow grease from
Kagoshima (YG1), yellow grease from Kashima (YG2), and yellow grease from Hachinohe
(YG3)]. Each treatment had 4 replicates of 3 broiler chickens per cage until 49 d of age.
There was no difference in BW gain due to fat sources, lysolecithin, or lysolecithin fat
source interaction throughout the experiment. By feeding lysolecithin, feed efficiency
increased (Po0.05) during the growth period of 7 to 21 d of age, and the weights of the
duodenum, ileum, and total intestine decreased (Po0.05). Intestinal villus height, villus
area, and cell area were not different among treatment groups, except that ileal villus
height tended to decrease and ileal cell area tended to increase (P¼0.077) by feeding
lysolecithin. Increased duodenal cell mitosis and decreased jejunal tunica muscularis
thickness were observed (Po0.05) by feeding lysolecithin. Furthermore, on the villus
apical surface, more protuberated cells, cell clusters, and deeper cells at the sites of
recently exfoliated cells were observed by feeding lysolecithin. However, the protuberant
cells were not different among treatment groups. The Integrated Fluorescence Density
Values of Anti-Cluster of Differentiation 36 reaction in the jejunum were significantly
greater in the lysolecithin-fed groups, except YG2. These results indicate that feeding
lysolecithin improves feed efficiency during 7 to 21 d of age regardless of the fat type, and
causes epithelial hypertrophy