Influence of a Combination of Glycerol Polyethylene Glycol Ricinoleate and Bi-Distilled Oleic Acid in Powder Form on Growth Performance, Nutrient Digestibility, Excreta Nitrogen and Liver Fatty Acid Profile of Broilers Fed Reduced-Energy Diets

Abstract

The present study aimed to evaluate the effects of an emulsifier in powder form composed of glycerol polyethylene glycol ricinoleate and bi-distilled oleic acid on the growth performance, nutrient digestibility, excreta nitrogen and liver fatty acid profile of broilers fed reduced-energy diets. A total of 720 male ROSS 308 chicks were divided into four homogeneous groups (9 pens/20 chicks per group): positive control (PC), negative control (NC, -70 kcal/kg of AME), EMUL1 and EMUL2 fed an NC diet + 250 and 500 mg/kg of emulsifier. Body weight, average daily gain, average daily feed intake and feed conversion ratio (FCR) were evaluated. Excreta were collected at 24 and 42 d directly from polyethylene trays and pooled to determine the apparent total tract digestibility of dry matter, crude protein, ether extract and gross energy. The apparent metabolizable energy (AME, AMEn) and nitrogen ammonia in excreta were determined. Performances were improved in EMUL1 and EMUL2 during the trial (p < 0.05). The digestibility of nutrients in EMUL1 and EMUL2 was increased in comparison to NC and PC (p < 0.05). Excreta nitrogen ammonia was reduced by EMUL2 at 42 d (p < 0.05). Glycerol polyethylene glycol ricinoleate and bi-distilled oleic acid in powder form modulated liver fatty acid profiles, enhancing oleic acid content in EMUL1 chickens (p < 0.05), while γ-linolenic acid and arachidonic acid were enhanced in EMUL2 (p < 0.05). Based on the findings, it is recommended to administer solidified glycerol polyethylene glycol ricinoleate and bi-distilled oleic acid in diets with reduced energy content for appreciable advantages in terms of growth through higher nutrient digestibility and better hepatic fatty acid composition.

Keywords: body weight; digestibility; emulsion; fats; linoleic acid; nutrition; oleic acid; soybean oil.

Figure 1

Nitrogen ammonia content in excreta evaluated at 24 and 42 d. Values are presented as means ± SEM. Pairwise comparisons mark statistically significant differences as follows: * = p < 0.05. Abbreviations = PC: positive control; NC: negative control; EMUL1: emulsifier supplemented at 250 mg/kg of complete feed; EMUL2: emulsifier supplemented at 500 mg/kg of complete feed.

Figure 2

Relative values of fatty acid classes’ hepatic tissues shown at the end of the trial (42 d). Values are presented as means ± SEM. Pairwise comparisons mark statistically significant differences as follows: * = p < 0.05 vs. NC and # = p < 0.05 vs. EMUL2. Abbreviations = PC: positive control; NC: negative control; EMUL1: glycerol polyethylene glycol ricinoleate and bi-distilled oleic acid supplemented at 250 mg/kg of complete feed; EMUL2: glycerol polyethylene glycol ricinoleate and bi-distilled oleic acid supplemented at 500 mg/kg of complete feed; SFA: saturated fatty acid; MUFA: monounsaturated fatty acid; PUFA: polyunsaturated fatty acid; n-6 PUFA: n-6 or ω-6 polyunsaturated fatty acid; n-3 PUFA: n-3 or ω-3 polyunsaturated fatty acid.

Figure 3

Indexes for desaturation and elongation enzymes involved in lipogenesis activity. Data are presented as mean ± SEM. Pairwise comparisons mark statistically significant differences as follows: # p < 0.05 vs. EMUL2 and ° p < 0.05 vs. PC. Abbreviations = PC: positive control; NC: negative control; EMUL1: glycerol polyethylene glycol ricinoleate and bi-distilled oleic acid supplemented at 250 mg/kg of complete feed; EMUL2: glycerol polyethylene glycol ricinoleate and bi-distilled oleic acid supplemented at 500 mg/kg of complete feed; Δ5D: delta-5-desaturase; Δ6D: delta-6-desaturase; SCD1: stearoyl-CoA desaturase 1; Elovl-5: elongase-5; Elovl-6: elongase-6.