Table 5.
Effect of essential oils on ileal bacterial populations of broilers on day 28
| Item a | Total bacteria | Lactobacillus | Escherichia | C. perfringens |
|---|---|---|---|---|
| Treatment | ||||
| Basal diet, unchallenged | 9.13 | 7.70 | 6.09 | 3.00 |
| 60 mg/kg EO, unchallenged | 9.08 | 7.76 | 6.27 | 2.79 |
| 120 mg/kg EO, unchallenged | 8.85 | 7.71 | 5.90 | 2.94 |
| 240 mg/kg EO, unchallenged | 9.13 | 7.76 | 5.91 | 2.84 |
| Basal diet, challenged | 9.26 | 7.99 | 6.13 | 2.96 |
| 60 mg/kg EO, challenged | 9.33 | 8.18 | 6.56 | 3.04 |
| 120 mg/kg EO, challenged | 9.08 | 7.98 | 5.76 | 2.95 |
| 240 mg/kg EO, challenged | 8.91 | 7.80 | 5.60 | 2.95 |
| SEM | 0.058 | 0.081 | 0.098 | 0.051 |
| P-value | ||||
| Challenge | 0.421 | 0.135 | 0.887 | 0.462 |
| EO | 0.365 | 0.877 | 0.092 | 0.953 |
| Challenge × EO | 0.469 | 0.882 | 0.742 | 0.789 |
| Linear b | 0.215 | 0.662 | 0.071 | 0.619 |
| Quadratic b | 0.502 | 0.708 | 0.780 | 0.931 |
a Values are means of eight replicates per treatment, and expressed as log10 (copy/g digesta). EO, essential oils; unchallenged, birds without challenge of C. perfringens; challenged, birds challenged with C. perfringens from day 14 to 20; SEM, pooled standard error of the mean; Challenge × EO, interaction between C. perfringens challenge and EO supplementation
b When interaction between C. perfringens challenge and EO supplementation was not significant, linear and quadratic polynomial contrasts were performed on the main-effect means to EO dosages