Table 3.
Breast and carcass weight and yield of broilers added with increasing levels of humic substances in the feed, probability level, and type of effect associated with humic substances.
| Level of Humic Substances, % | Effect of Humic Substances | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Response Variables a,b | Positive Control | 0.00 | 0.15 | 0.30 | 0.45 | SEM c | p-Value | Lin | Quad | Cub |
| 10 days of age | ||||||||||
| Breast weight, g | 48.1 | 50.7 | 48.7 | 48.4 | 48.8 | 1.721 | 0.84 | 0.41 | 0.91 | 0.45 |
| Breast yield, % | 17.6 | 17.2 | 17.1 | 16.9 | 17.3 | 0.271 | 0.37 | 0.94 | 0.24 | 0.53 |
| Carcass weight, g | 118.2 | 127.6 | 122.4 | 122.0 | 122.1 | 3.686 | 0.52 | 0.30 | 0.46 | 0.79 |
| Carcass yield, % | 43.6 | 43.3 | 42.9 | 42.6 | 43.2 | 0.464 | 0.61 | 0.77 | 0.27 | 0.67 |
| 24 days of age | ||||||||||
| Breast weight, g | 239.4 | 231.0 | 237.5 | 234.0 | 225.8 | 6.301 | 0.57 | 0.50 | 0.24 | 0.85 |
| Breast yield, % | 22.1 | 21.1 | 21.4 | 21.6 | 21.3 | 0.303 | 0.23 | 0.57 | 0.42 | 0.79 |
| Carcass weight, g | 572.8 | 566.5 | 582.6 | 550.6 | 545.5 | 14.765 | 0.36 | 0.16 | 0.48 | 0.27 |
| Carcass yield, % | 52.8 | 51.8 | 52.4 | 51.0 | 51.5 | 0.806 | 0.55 | 0.60 | 0.95 | 0.34 |
| 38 days of age | ||||||||||
| Breast weight, g | 566.7 | 548.9 | 553.4 | 540.4 | 563.3 | 14.283 | 0.50 | 0.38 | 0.35 | 0.34 |
| Breast yield, % | 23.3 | 22.6 | 22.6 | 22.2 | 22.6 | 0.358 | 0.23 | 0.48 | 0.21 | 0.35 |
| Carcass weight, g | 957.8 | 947.9 | 949.7 | 927.8 | 977.0 | 19.670 | 0.26 | 0.25 | 0.13 | 0.22 |
| Carcass yield, % | 39.4 | 38.9 | 38.8 | 38.2 | 39.3 | 0.460 | 0.10 | 0.15 | 0.13 | 0.17 |
a Data are means of eight replications per treatment with pooled data of three birds in each replication. b There were no statistical differences among treatments, p > 0.05. c Standard error of the mean.