Table 1.
Performance characteristics and standard deviations (± SD) of broilers (400/group) that received ampicillin, a feed additive based on organic acids (FA) or a synbiotic preparation (SA) compared to the control groups.
| NC | CC | AB | FA | SA | P-value | |
|---|---|---|---|---|---|---|
| Initial weight, g | 46 ± 0.62 | 46 ± 0.89 | 46 ± 0.24 | 46 ± 0.51 | 46 ± 0.37 | 0.15 |
| BW d17, g | 471 ± 18.1 | 453 ± 15.8 | 473 ± 50.8 | 468 ± 16.2 | 455 ± 29.5 | 0.32 |
| BW d38, g | 1967 ± 102,8 | 1928 ± 48.8 | 1972 ± 110.1 | 1995 ± 63.4 | 1960 ± 79.3 | 0.62 |
| ADFI d1–17, g/d | 31.0 ± 1.2 | 30.3 ± 1.0 | 30.5 ± 2.9 | 30.8 ± 1.0 | 30.3 ± 1.7 | 0.67 |
| ADFI d -38, g/d | 149.1 ± 5.1 | 148.9 ± 5.1 | 147.9 ± 7.0 | 146.8 ± 6.3 | 148.9 ± 7.8 | 0.95 |
| FCR d1–17, g/g | 1.34 ± 0.05 | 1.37 ± 0.05 | 1.30 ± 0.05 | 1.34 ± 0.05 | 1.36 ± 0.04 | 0.11 |
| FCR d1–38, g/g | 1.64 ± 0.14 | 1.68 ± 0.06 | 1.62 ± 0.03 | 1.62 ± 0.03 | 1.63 ± 0.04 | 0.13 |
| Mortality, % | 3.00 | 4.25 | 3.50 | 5.75 | 2.75 | 0.478 |
NC, negative control without E. coli challenge; CC, E. coli challenge control; AB, ampicillin; FA, feed additive based on organic acids; SA, multistrain synbiotic; BW, body weight; ADG, average daily weight gain; ADFI, average daily feed intake; FCR, feed conversion ratio; mean values ± standard errors.