Abstract
Improving nutrient utilization in nutrient-restricted diets is an important strategy to reduce feed costs and maintain productivity in broiler production. Dietary emulsifiers are commonly used to improve lipid digestion and overall nutrient utilization in poultry diets. The objective of this study was to investigate the effects of a combination of lysophospholipids, synthetic emulsifier and monoglycerides (LEX) in energy- and amino acid-deficient broiler diets on growth performance, carcass traits, nutrient digestibility, and intestinal morphology from d 11 to 35. A total of 168 10-day-old Ross 308 male broiler chicks were randomly assigned to one of three dietary treatments in a completely randomized design, with seven replicates and eight birds per cage. The dietary treatments were as follows: 1) a positive control diet (PC) containing standard metabolizable energy and amino acid levels; 2) a negative control diet (NC) with 100 kcal/kg less metabolizable energy and 4.0% reduction in essential amino acids (lysine, methionine + cysteine, and threonine); 3) NC diet supplemented with 250 g/ton of LEX. Statistical analyses were conducted using the general linear model (GLM) procedure for one-way analysis of variance (ANOVA), with significance declared at P < 0.05. Broilers fed the LEX-supplemented NC diet exhibited improved (P < 0.001) growth performance, including body weight at d 35 (1,737.14 to 1,903.46 g), average daily gain (d 11-35; 58.49 to 64.95 g/d), and feed conversion ratio (1.60 to 1.41 g/g), compared to those fed the NC diet alone. Apparent digestibility of crude protein and crude fat in both the jejunum and ileum was higher (P < 0.001) in birds receiving the LEX-supplemented NC diet than in those on the NC diet. In addition, LEX improved intestinal morphology, evidenced by increased villus height (920.87 to 1,086.84 µm), crypt depth (126.74 to 161.28 µm) on day 35 (P < 0.05). However, there were no significant differences (P > 0.05) in carcass yield parameters, including breast and leg muscle weights and abdominal fat content, among the dietary treatments. In conclusion, supplementation of 250 g/ton of LEX to a broiler diet deficient in energy and amino acids effectively improved growth performance and nutrient utilization by enhancing protein and fat digestibility and promoting intestinal development. These findings suggest that a combination product based on lysophospholipids, synthetic emulsifier, and monoglycerides can serve as a practical and effective nutritional strategy to optimize production efficiency under nutrient-restricted feeding conditions in commercial broiler production.