Effect of dietary emulsifiers with different hydrophilic-lipophilic balance values on growth performance, nutrient digestibility, serum lipid profiles and meat quality of broilers

Energy is a major cost component in diets for poultry. We hypothesized that the dietary supplementation with emulsifier blends increases the efficiency of energy utilization and fat digestibility in broilers. To test our hypothesis, an experiment was conducted to evaluate the effect of blend of emulsifier on growth performance, nutrient digestibility, serum lipid profiles and meat quality of broilers. A total of 768 1-d-old Ross 308 male broiler chicks with an average initial body weight of 45.55 ± 0.34 g were used in a 35 days feeding trial. Broilers were sorted into 4 treatments, 12 pens per treatment, and 16 birds per pen. Dietary treatments consisted of corn-soybean meal based basal diet and the basal diet supplemented with 0.05%, 0.075% and 0.10% emulsifier. Tallow was used as a fat source in the diet and the calculated ME of starter, grower and finisher diets were 3000, 3100 and 3200 kcal/kg. Data were analyzed using the GLM procedure of SAS in a randomized complete block design. Pen served as the experimental unit. Linear and quadratic polynomial contrasts were used to examine responses to supplemental graded levels of emulsifier at 0.05%, 0.075% and 0.10% in the basal diet. Pearson’s correlation coefficients and probabilities were generated using the correlation procedures of SAS. The inclusion of 0.05%, 0.075% and 0.10% emulsifier blends (Sodium stearoyl-2-lactylate and Tween 20) in the basal diet linearly increased (P=0.0001) body weight gain (585.4, 600.5, 619.0, 626.6g) on d7-21, as well as during d21-35, (912.4, 983.3, 965.1, 973.8g). In addition, feed conversion ratio was also improved (linear effect P=0.0001) during d7-21, d21-35 as well as during the overall experiment period. Broilers fed with different levels of emulsifier blends also showed a linear increment (P < 0.05) in apparent total tract digestibility of dry matter (72.50, 73.19, 73.33, and 74.83%) and fat (78.74, 79.55, 80.05 and 81.13%). A linear reduction (P=0.051) in low density lipoprotein in the serum of broilers fed emulsifier blend was observed. The lightness value of breast muscle color linearly increased (P=0.001), the redness (51.53, 52.80, 52.85 and 54.09) and yellowness values increased (P=0.072 and P=0.094, respectively) with the increase in the level of emulsifier blends. With regards to relative organ weight, spleen weight was linearly (P=0.001) reduced with the increase in the supplemental levels of emulsifier blends. A positive correlation between emulsifier content in the diet and BWG, DM and fat digestibility, and breast muscle color indices, were also observed. In conclusion, emulsifier blend supplementation positively influenced growth performance and nutrient digestibility in broiler chickens.