Abstract
After hatching, broiler chicks transition from relying on yolk lipids to dietary nutrients. Providing dietary oils with a fatty acid profile similar to that of the yolk, particularly rich in oleic acid, may facilitate this metabolic shift. This study evaluated the effects of different oil sources in the pre-starter diet on growth performance, nutrient digestibility, and organ development in broiler chickens. A total of 2,016 one-day-old male Ross-308 broilers were allocated to three pre-starter diets (0-4 d) containing 30 g/kg of soybean oil, safflower oil, or sunflower oil (12 replicates of 56 birds). Pancreas, liver, and residual yolk weights were assessed at 3 d. Ileal digesta were collected at 4 d to determine DM, CP, ash, ether extract digestibility, and ileal digestible energy. After pre-starter diets, all birds were fed common diets based on three phases (7-10 d, 11-28 d, and 29-36 d). Growth performance was monitored until 36 d. No significant differences were observed in BW, BW gain, feed intake, or feed conversion ratio among treatments during any growth phase. However, ether extract digestibility differed (P < 0.001), with broilers fed safflower oil exhibiting the highest values, followed by sunflower oil, and the lowest in birds fed soybean oil. Ileal digestible energy differed (P = 0.012), with broilers fed safflower oil exhibiting higher values compared to birds fed sunflower oil. In addition, birds fed soybean oil exhibited greater pancreas weight than those fed safflower oil, with sunflower-fed birds showing intermediate values. Although early dietary lipid source did not affect growth performance, it influenced ether extract digestibility and pancreatic development. Future research should investigate the effect of early lipid nutrition on immune responses and performance under challenging conditions.