Table 5.
Effect of antibiotic growth promoter or probiotic supplementation in the diet on broiler performance under a naturally occurring necrotic enteritis model.1
| Dietary Treatments 2 | |||||
|---|---|---|---|---|---|
| Item 3 | NC | PC | Probiotic | SEM 4 | p-Value |
| d 0–8 | |||||
| ADFI, g | 23.28 | 23.50 | 23.31 | 0.24 | 0.784 |
| ADG, g | 17.1 | 16.59 | 17.29 | 0.25 | 0.137 |
| FCR, g/g | 1.36 ab | 1.41 a | 1.35 b | 0.02 | 0.053 |
| d 9-14 | |||||
| ADFI, g | 57.21 | 56.09 | 56.84 | 0.64 | 0.474 |
| ADG, g | 41.97 | 40.38 | 40.59 | 0.59 | 0.134 |
| FCR | 1.36 b | 1.39 ab | 1.40 a | 0.01 | 0.043 |
| d 15–21 | |||||
| ADFI, g | 106.10 | 105.41 | 104.55 | 1.34 | 0.708 |
| ADG, g | 71.15 | 70.65 | 68.84 | 1.42 | 0.468 |
| FCR | 1.49 | 1.49 | 1.52 | 0.02 | 0.414 |
| d 22–28 | |||||
| ADFI, g | 161.89 a | 159.72 a | 154.75 b | 1.75 | 0.018 |
| ADG, g | 103.07 | 105.47 | 103.78 | 1.62 | 0.567 |
| FCR | 1.57 a | 1.51 b | 1.49 b | 0.01 | ˂0.001 |
| d 29–42 | |||||
| ADFI, g | 202.19 | 203.59 | 199.85 | 2.17 | 4.74 |
| ADG, g | 113.00 b | 119.53 a | 116.00 ab | 1.55 | 0.020 |
| FCR | 1.79 a | 1.70 b | 1.72 b | 0.01 | 0.001 |
| d 0–42 | |||||
| ADFI, g | 119.45 ab | 120.62 a | 116.80 b | 1.11 | 0.050 |
| ADG, g | 74.99 b | 77.69 a | 75.72 ab | 0.85 | 0.048 |
| FCR | 1.59 a | 1.55 b | 1.54 b | 0.01 | ˂0.001 |
a,b Within each row, means with different letters are significantly different (p < 0.05). 1 Data represent the mean value of 12 replicate pens of 30 birds. 2 Treatments include: negative control (NC): birds received a corn-soybean meal basal diet; positive control (PC): NC + virginiamycin (Stafac®20) at the level of 0.45 kg/ton from d 0-42; Probiotic: NC + PrimaLac at the level of 1.36 kg/ton in starter and grower 1 diets; 0.91 kg/ton in grower 2 and finisher diets. 3 ADFI: Average daily feed intake, ADG: average daily gain, FCR: feed conversion ratio. 4 SEM: Standard error of means.