RESULTS

Growth performance during the starter phase (1–10 days)

The nutrient composition of the experimental diets is presented in Table 1. The diets were categorized into PC and NC groups. The PC diets contained 150 kcal/kg more ME than the NC diets. In addition, the PC diets contained slightly higher fat concentrations and lower fiber concentrations than the NC diets.

The effects of emulsifier supplementation on broiler performance during the starter phase (1–10 days) are presented in Table 2. Initial BW did not differ among treatments (p > 0.05), indicating satisfactory flock uniformity. Final BW was significantly affected by dietary treatment (p = 0.02). The highest final BW was observed in T1 (339.30 ± 29.44 g), which did not differ from T5 (334.07 ± 28.92 g) but was significantly greater than T2 (324.61 ± 41.98 g). Treatments T3 (331.93 ± 33.40 g) and T4 (330.06 ± 43.80 g) showed intermediate values and did not differ significantly from either T1 or T2.

No significant differences were observed among treatments for ADG and FI (p = 0.10 and p = 0.89, respectively). However, FCR and cFCR were significantly influenced by dietary treatment (p < 0.01). The most favorable FCR and cFCR values were recorded in T1 (1.021 ± 0.01), followed by T5 (1.043 ± 0.00), T4 (1.043 ± 0.01), and T3 (1.046 ± 0.02), all of which were significantly improved compared with T2 (1.072 ± 0.02). FCG was not significantly affected by treatment (p = 0.07), ranging from 18.121 ± 0.36 to 18.576 ± 0.28. No mortality was observed in any treatment during the starter phase.

Items | T1 | T2 | T3 | T4 | T5 | p-value | SEM
Initial BW (g) | 40.60 ± 3.21 | 40.14 ± 3.21 | 40.43 ± 3.04 | 40.12 ± 3.06 | 40.14 ± 3.04 | 0.62 | 0.12
Uniformity (%) | 92.05 ± 0.61 | 91.89 ± 0.46 | 92.44 ± 0.97 | 92.37 ± 0.35 | 92.44 ± 0.50 | 0.49 | 0.12
BW (g) | 339.30 ± 29.44ᵃ | 324.61 ± 41.98ᵇ | 331.93 ± 33.40ᵃᵇ | 330.06 ± 43.80ᵃᵇ | 334.07 ± 28.92ᵃ | 0.02 | 1.53
ADG (g/day) | 29.87 ± 0.66 | 28.44 ± 1.13 | 29.15 ± 0.72 | 29.00 ± 0.82 | 29.39 ± 0.60 | 0.10 | 0.16
FI (g/day) | 30.50 ± 0.31 | 30.48 ± 0.97 | 30.49 ± 1.09 | 30.22 ± 0.36 | 30.66 ± 0.57 | 0.89 | 0.13
FCR | 1.021 ± 0.01ᶜ | 1.072 ± 0.02ᵃ | 1.046 ± 0.02ᵇ | 1.043 ± 0.02ᵇ | 1.043 ± 0.00ᵇ | 0.001 | 0.004
cFCR | 1.021 ± 0.01ᶜ | 1.072 ± 0.02ᵃ | 1.046 ± 0.02ᵇ | 1.043 ± 0.02ᵇ | 1.043 ± 0.00ᵇ | 0.001 | 0.004
FCG | 18.180 ± 0.26 | 18.576 ± 0.28 | 18.174 ± 0.31 | 18.121 ± 0.36 | 18.130 ± 0.08 | 0.07 | 0.06
Mortality (%) | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.00 ± 0.00 | – | –

The negative control diets were formulated to contain 150 kcal/kg lower ME than the positive control diets, mainly by reducing corn and increasing rice solvent bran inclusion. Nutrient values are calculated values.

Growth performance during the grower phase (11–24 days)

The effects of dietary emulsifier supplementation on broiler performance during the grower phase are presented in Table 3. Final BW at day 24 was significantly influenced by dietary treatment (p = 0.04). Birds receiving T3 (1,434.93 ± 145.15 g), T4 (1,425.89 ± 139.34 g), and T5 (1,423.61 ± 132.64 g) exhibited greater BW than birds receiving T2 (1,386.32 ± 148.31 g). The BW of birds in T1 (1,407.35 ± 146.32 g) did not differ significantly from either T2 or the emulsifier-supplemented treatments.

No significant differences were observed among treatments for ADG, FI, FCR, cFCR, or FCG (p > 0.05).

Cumulative growth performance during the starter and grower phases (1–24 days)

The cumulative performance of broilers from day 1 to day 24 is presented in Table 4. No significant differences were detected among treatments for ADG, FI, FCR, cFCR, or FCG (p > 0.05). Mortality remained low across all treatments, ranging from 0.67 ± 1.63% to 2.00 ± 4.90%, with no significant differences among treatment groups (p > 0.05).

Growth performance during the finisher phase (25–35 days)

The effects of dietary emulsifier supplementation on broiler performance during the finisher phase are presented in Table 5. Final BW at day 35 was not significantly affected by treatment (p = 0.15). Likewise, no significant differences were observed for ADG, FI, FCR, cFCR, FCG, or mortality (p > 0.05).

Cumulative growth performance during the grower and finisher phases (11–35 days)

The cumulative performance of broilers from day 11 to day 35 is presented in Table 6. Final BW, ADG, FI, FCR, cFCR, FCG, and mortality were not significantly affected by dietary treatment (p > 0.05). Mortality remained low, ranging from 0.00 ± 0.00% to 0.83 ± 1.86%, with no significant differences among treatments (p > 0.05).

Items | T1 | T2 | T3 | T4 | T5 | p-value | SEM
Initial BW (g) | 339.30 ± 29.44ᵃ | 324.61 ± 41.98ᵇ | 331.93 ± 33.40ᵃᵇ | 330.06 ± 43.80ᵃᵇ | 334.07 ± 28.92ᵃ | 0.02 | 1.53
BW (g) | 1,407.35 ± 146.32ᵃᵇ | 1,386.32 ± 148.31ᵇ | 1,434.93 ± 145.15ᵃ | 1,425.89 ± 139.34ᵃ | 1,423.61 ± 132.64ᵃ | 0.04 | 6.39
ADG (g/day) | 76.50 ± 3.85 | 75.69 ± 2.18 | 78.80 ± 4.32 | 78.21 ± 3.47 | 77.82 ± 2.57 | 0.56 | 0.63
FI (g/day) | 98.37 ± 3.94 | 99.35 ± 2.32 | 99.67 ± 5.30 | 101.07 ± 3.54 | 99.65 ± 2.48 | 0.82 | 0.67
FCR | 1.287 ± 0.04 | 1.313 ± 0.02 | 1.265 ± 0.02 | 1.293 ± 0.03 | 1.281 ± 0.04 | 0.20 | 0.006
cFCR | 1.287 ± 0.04 | 1.324 ± 0.03 | 1.274 ± 0.03 | 1.323 ± 0.08 | 1.290 ± 0.04 | 0.33 | 0.009
FCG | 22.224 ± 0.74 | 22.253 ± 0.51 | 21.490 ± 0.43 | 22.300 ± 1.37 | 21.763 ± 0.64 | 0.38 | 0.16
Mortality (%) | 0.00 ± 0.00 | 0.67 ± 1.63 | 0.67 ± 1.63 | 2.00 ± 4.90 | 0.67 ± 1.63 | 0.78 | 0.48

Items | T1 | T2 | T3 | T4 | T5 | p-value | SEM
Initial BW (g) | 40.60 ± 3.21 | 40.14 ± 3.21 | 40.43 ± 3.04 | 40.12 ± 3.06 | 40.14 ± 3.04 | 0.62 | 0.12
BW (g) | 1,407.35 ± 1463.32ᵃᵇ | 1,386.32 ± 148.31ᵇ | 1,434.93 ± 145.15ᵃ | 1,425.89 ± 139.34ᵃ | 1,423.61 ± 132.64ᵃ | 0.04 | 6.39
ADG (g/day) | 57.07 ± 2.49 | 56.00 ± 1.11 | 58.11 ± 2.77 | 57.70 ± 2.12 | 57.64 ± 1.69 | 0.55 | 0.40
FI (g/day) | 70.09 ± 2.38 | 70.65 ± 1.35 | 70.84 ± 3.53 | 71.55 ± 2.16 | 70.90 ± 1.42 | 0.89 | 0.42
FCR | 1.229 ± 0.04 | 1.262 ± 0.02 | 1.219 ± 0.01 | 1.241 ± 0.03 | 1.231 ± 0.03 | 0.10 | 0.005
cFCR | 1.229 ± 0.03 | 1.272 ± 0.03 | 1.228 ± 0.03 | 1.289 ± 0.07 | 1.239 ± 0.03 | 0.28 | 0.008
FCG | 21.341 ± 0.60 | 21.505 ± 0.48 | 20.824 ± 0.44 | 21.505 ± 1.25 | 21.021 ± 0.54 | 0.44 | 0.14
Mortality (%) | 0.00 ± 0.00 | 0.80 ± 1.79 | 0.67 ± 1.63 | 2.00 ± 4.90 | 0.67 ± 1.63 | 0.78 | 0.48

Items | T1 | T2 | T3 | T4 | T5 | p-value | SEM
Initial BW (g) | 1,407.35 ± 1463.32ᵃᵇ | 1,386.32 ± 148.31ᵇ | 1,434.93 ± 145.15ᵃ | 1,425.89 ± 139.34ᵃ | 1,423.61 ± 132.64ᵃ | 0.04 | 6.39
BW (g) | 2,468.16 ± 314.30 | 2,427.15 ± 272.17 | 2,474.15 ± 283.13 | 2,497.91 ± 314.58 | 2,487.38 ± 256.22 | 0.15 | 10.41
ADG (g/day) | 98.52 ± 4.63 | 94.21 ± 3.89 | 94.62 ± 8.46 | 97.48 ± 5.76 | 96.67 ± 7.57 | 0.78 | 1.17
FI (g/day) | 162.81 ± 7.55 | 165.54 ± 7.42 | 166.78 ± 10.43 | 167.37 ± 8.86 | 165.21 ± 6.93 | 0.91 | 1.50
FCR | 1.655 ± 0.10 | 1.757 ± 0.05 | 1.767 ± 0.08 | 1.720 ± 0.11 | 1.715 ± 0.10 | 0.33 | 0.02
cFCR | 1.655 ± 0.10 | 1.772 ± 0.05 | 1.767 ± 0.08 | 1.720 ± 0.11 | 1.726 ± 0.10 | 0.28 | 0.02
FCG | 27.593 ± 1.68 | 28.734 ± 0.77 | 28.754 ± 1.34 | 27.968 ± 1.74 | 28.067 ± 1.64 | 0.65 | 0.27
Mortality (%) | 0.00 ± 0.00 | 0.83 ± 1.86 | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.67 ± 1.63 | 0.54 | 0.20

Items | T1 | T2 | T3 | T4 | T5 | p-value | SEM
Initial BW (g) | 339.30 ± 29.44ᵃ | 324.61 ± 41.98ᵇ | 331.93 ± 33.40ᵃᵇ | 330.06 ± 43.80ᵃᵇ | 334.07 ± 28.92ᵃ | 0.02 | 1.53
BW (g) | 2,468.16 ± 314.30 | 2,427.15 ± 272.17 | 2,474.15 ± 283.13 | 2,497.91 ± 314.58 | 2,487.38 ± 256.22 | 0.15 | 10.41
ADG (g/day) | 86.19 ± 3.04 | 83.83 ± 2.31 | 85.76 ± 5.95 | 86.69 ± 4.22 | 86.12 ± 4.45 | 0.85 | 0.77
FI (g/day) | 126.73 ± 5.12 | 128.47 ± 3.88 | 129.19 ± 7.49 | 130.25 ± 5.65 | 128.50 ± 4.30 | 0.88 | 0.99
FCR | 1.471 ± 0.06 | 1.532 ± 0.02 | 1.508 ± 0.04 | 1.504 ± 0.06 | 1.494 ± 0.05 | 0.36 | 0.009
cFCR | 1.471 ± 0.06 | 1.559 ± 0.05 | 1.518 ± 0.04 | 1.538 ± 0.09 | 1.515 ± 0.07 | 0.30 | 0.01
FCG | 24.904 ± 0.94 | 25.682 ± 0.82 | 25.094 ± 0.60 | 25.399 ± 1.56 | 25.031 ± 1.11 | 0.77 | 0.19
Mortality (%) | 0.00 ± 0.00 | 1.63 ± 3.65 | 0.67 ± 1.63 | 2.00 ± 4.90 | 1.33 ± 2.07 | 0.82 | 0.54

Overall growth performance (1–35 days)

The cumulative performance of broilers throughout the entire experimental period is presented in Table 7. No significant differences were observed among treatments for ADG, which ranged from 68.01 ± 1.43 g/day in T2 to 70.20 ± 3.06 g/day in T4 (p = 0.79). FI was also comparable among treatments (p = 0.90), ranging from 99.24 ± 3.73 to 101.67 ± 4.10 g/day.

Similarly, FCR and cFCR were not significantly affected by treatment (p = 0.22 and p = 0.23, respectively). FCG ranged from 24.084 ± 0.82 in T1 to 24.871 ± 0.84 in T2 and did not differ significantly among treatments (p = 0.71). Mortality remained low across all treatment groups and did not differ significantly (p = 0.82).

Items | T1 | T2 | T3 | T4 | T5 | p-value | SEM
Initial BW (g) | 40.60 ± 3.21 | 40.14 ± 3.21 | 40.43 ± 3.04 | 40.12 ± 3.06 | 40.14 ± 3.04 | 0.62 | 0.12
BW (g) | 2,468.16 ± 314.30 | 2,427.15 ± 272.17 | 2,474.15 ± 283.13 | 2,497.91 ± 314.58 | 2,487.38 ± 256.22 | 0.15 | 10.41
ADG (g/day) | 70.10 ± 2.32 | 68.01 ± 1.43 | 69.58 ± 4.40 | 70.20 ± 3.06 | 69.91 ± 3.30 | 0.79 | 0.57
FI (g/day) | 99.24 ± 3.73 | 100.48 ± 2.58 | 100.99 ± 5.64 | 101.67 ± 4.10 | 100.54 ± 3.09 | 0.90 | 0.72
FCR | 1.416 ± 0.05 | 1.477 ± 0.02 | 1.452 ± 0.03 | 1.449 ± 0.05 | 1.439 ± 0.04 | 0.22 | 0.008
cFCR | 1.416 ± 0.05 | 1.503 ± 0.05 | 1.462 ± 0.03 | 1.482 ± 0.09 | 1.460 ± 0.06 | 0.23 | 0.01
FCG | 24.084 ± 0.82 | 24.871 ± 0.84 | 24.271 ± 0.57 | 24.577 ± 1.44 | 24.224 ± 1.00 | 0.71 | 0.18
Mortality (%) | 0.00 ± 0.00 | 1.63 ± 3.65 | 0.67 ± 1.63 | 2.00 ± 4.90 | 1.33 ± 2.07 | 0.82 | 0.54

Feed digestibility, AME, fecal characteristics, and gastrointestinal retention time

The effects of dietary emulsifier supplementation on fecal characteristics, gastrointestinal retention time, feed digestibility, and AME at 30 days of age are presented in Table 8.

Fecal scores did not differ among treatments (p = 0.86), with values ranging from 0.70 ± 1.10 in T2 to 1.42 ± 1.24 in T5, indicating generally normal to slightly wet feces across treatments.

Mean gastrointestinal retention time was significantly influenced by dietary treatment (p = 0.01). The longest retention time was observed in T1 (199.80 ± 31.25 min), which was significantly greater than those observed in T2 (162.20 ± 24.30 min), T4 (152.00 ± 18.56 min), and T5 (153.50 ± 11.61 min). Treatment T3 (180.67 ± 27.35 min) showed intermediate values and did not differ significantly from the other treatments.

No significant differences were observed among treatments for total tract digestibility (p = 0.73) or OM digestibility (p = 0.80). AME tended to be numerically greater in emulsifier-supplemented groups (3,085–3,111 kcal/kg) than in the NC group (2,951 kcal/kg); however, these differences were not statistically significant (p = 0.69).

Carcass characteristics

The effects of dietary emulsifier supplementation on carcass characteristics at 35 days of age are presented in Table 9. Carcass yield tended to differ among treatments (p = 0.053), with T1 (85.81 ± 1.23%) showing the highest numerical value and T5 (84.85 ± 1.68%) showing an intermediate value.

Items | T1 | T2 | T3 | T4 | T5 | p-value | SEM
Fecal score (0–3)* | 0.90 ± 1.34 | 0.70 ± 1.10 | 0.92 ± 0.92 | 1.08 ± 1.02 | 1.42 ± 1.24 | 0.86 | 0.20
Mean retention time (min) | 199.80 ± 31.25ᵃ | 162.20 ± 24.30ᵇ | 180.67 ± 27.35ᵃᵇ | 152.00 ± 18.56ᵇ | 153.50 ± 11.61ᵇ | 0.01 | 5.32
Total digestibility (%) | 83.17 ± 4.69 | 78.46 ± 8.93 | 83.35 ± 4.64 | 82.23 ± 6.10 | 82.77 ± 6.38 | 0.73 | 1.17
OM digestibility (%) | 85.26 ± 4.66 | 80.75 ± 9.24 | 84.62 ± 4.31 | 84.26 ± 5.64 | 84.39 ± 6.06 | 0.80 | 1.14
AME (kcal/kg) | 3,117.68 ± 102.75 | 2,951.05 ± 331.29 | 3,085.46 ± 150.91 | 3,111.24 ± 196.46 | 3,109.18 ± 210.73 | 0.69 | 39.38

However, no significant differences were observed among treatments for wing, inner breast, outer breast, drumstick, thigh, or abdominal fat percentages (p > 0.05).

Items | T1 | T2 | T3 | T4 | T5 | p-value | SEM
Carcass yield (%) | 85.81 ± 1.23 | 84.28 ± 1.75 | 84.03 ± 1.13 | 84.08 ± 1.73 | 84.85 ± 1.68 | 0.053 | 0.22
Wing (%) | 8.40 ± 1.37 | 8.68 ± 0.49 | 8.91 ± 0.47 | 8.94 ± 0.66 | 9.03 ± 0.67 | 0.35 | 0.10
Inner breast (%) | 5.29 ± 1.58 | 5.03 ± 0.19 | 5.09 ± 0.41 | 4.80 ± 0.43 | 5.01 ± 0.63 | 0.70 | 0.10
Outer breast (%) | 26.14 ± 1.61 | 27.20 ± 1.62 | 27.01 ± 1.14 | 26.69 ± 1.11 | 26.78 ± 1.17 | 0.45 | 0.18
Drumstick (%) | 11.71 ± 0.83 | 11.95 ± 0.64 | 11.99 ± 0.41 | 11.86 ± 1.06 | 12.03 ± 0.59 | 0.86 | 0.10
Thigh (%) | 16.05 ± 1.24 | 15.81 ± 0.76 | 15.37 ± 1.04 | 15.23 ± 1.23 | 15.16 ± 0.89 | 0.23 | 0.14
Abdominal fat (%) | 1.18 ± 0.19 | 1.13 ± 0.25 | 1.19 ± 0.35 | 1.07 ± 0.28 | 1.16 ± 0.28 | 0.86 | 0.04