Table 2.
Meta-ANOVA of the association between tannin source and measured growth outcomes.
| Variable | Random-Effects Model | Heterogeneity | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 95% CI | p-Value | |||||||||
| k | SMD | Lower | Upper | I 2 | τ2 | τ | Q | df | ||
| ADFI, g/day | ||||||||||
| Chestnut (Ch) | 5 | 2.9020 | −0.7572 | 6.5612 | 97.6 | 17.1981 | 4.1471 | 90.69 | 6 | <0.0001 |
| GMTA | 7 | −0.5921 | −1.7603 | 0.5761 | 94.3 | 2.3387 | 1.5293 | |||
| Grape extract | 1 | 1.3074 | 0.9121 | 1.7027 | -- | -- | -- | |||
| GSP | 7 | 0.8966 | −0.0135 | 1.8067 | 93.8 | 1.4162 | 1.1901 | |||
| Grape pomace | 2 | 1.7150 | −0.0379 | 3.4680 | 81.2 | 1.3052 | 1.1425 | |||
| Ch/Qu | 1 | −1.1924 | −1.5816 | −0.8031 | -- | -- | -- | |||
| Gallnut tannic acid | 2 | 0.7042 | 0.0700 | 1.3383 | 71.3 | 0.1494 | 0.3866 | |||
| ADG, g/day | ||||||||||
| Chestnut | 5 | 6.4894 | −3.6569 | 16.6357 | 98.2 | 133.1920 | 11.5409 | 140.33 | 7 | <0.0001 |
| GMTA | 7 | −22.5090 | −32.1307 | −12.8873 | 96.8 | 162.8086 | 12.7596 | |||
| Grape extract | 1 | 1.0764 | 0.6928 | 1.4601 | -- | -- | -- | |||
| Quebracho (Qu) | 2 | 6.0871 | 4.2437 | 7.9306 | 0.0 | 0 | 0 | |||
| GSP | 7 | 1.6444 | 0.5049 | 2.7839 | 94.7 | 2.2453 | 1.4984 | |||
| Grape pomace | 2 | 2.6567 | −0.3419 | 5.6553 | 90.9 | 4.2610 | 2.0642 | |||
| Ch/Qu | 1 | −1.1924 | −1.5816 | −0.8031 | -- | -- | -- | |||
| Gallnut tannic acid | 2 | 0.6481 | −0.8556 | 2.1518 | 94.6 | 1.1142 | 1.0556 | |||
| FBW, kg | ||||||||||
| Chestnut | 5 | 1.7184 | −0.0760 | 3.5128 | 96.6 | 4.0292 | 2.0073 | 77.54 | 8 | <0.0001 |
| GMTA | 3 | −0.2500 | −0.7892 | 0.2892 | 0.0 | 0 | 0 | |||
| Grape extract | 1 | 1.9873 | 1.5476 | 2.4269 | -- | -- | -- | |||
| Quebracho | 2 | 0.0868 | −0.6090 | 0.7826 | 0.0 | 0 | 0 | |||
| Carob pods | 3 | 0.7726 | −1.1539 | 2.6992 | 97.6 | 2.8320 | 1.6829 | |||
| GSP | 6 | 0.9624 | −0.1213 | 2.0461 | 94.2 | 1.7380 | 1.3183 | |||
| Grape pomace | 2 | 5.5956 | −2.2497 | 13.4409 | 95.6 | 30.6831 | 5.5392 | |||
| Ch/Qu | 1 | −0.3416 | −0.7021 | 0.0190 | -- | -- | -- | |||
| Gallnut tannic acid | 2 | 0.4981 | −0.4853 | 1.4816 | 88.2 | 0.4443 | 0.6666 | |||
| FCR | ||||||||||
| Chestnut | 2 | −2.8044 | −7.0268 | 1.4179 | 98.9 | 9.1831 | 3.0304 | 54.46 | 7 | <0.0001 |
| GMTA | 7 | −1.7433 | −3.5702 | 0.0836 | 96.6 | 5.8898 | 2.4269 | |||
| Grape extract | 1 | −0.4968 | −0.8603 | −0.1333 | -- | -- | -- | |||
| Carob pods | 3 | 0.8295 | −0.0430 | 1.7020 | 89.7 | 0.5374 | 0.7331 | |||
| GSP | 7 | −2.4528 | −3.5728 | −1.3328 | 94.3 | 2.1331 | 1.4605 | |||
| Grape pomace | 2 | −1.4908 | −6.1186 | 3.1371 | 96.6 | 10.7723 | 3.2821 | |||
| Ch/Qu | 1 | 0.8517 | 0.4775 | 1.2259 | -- | -- | -- | |||
| Gallnut tannic acid | 2 | −0.0982 | −2.6187 | 2.4223 | 98.0 | 3.2399 | 1.8000 | |||
ADFI: average daily feed intake; ADG: average daily gain; FCR: feed conversion ratio; FBW: final body weight; k: number of studies; SMD: standard mean difference; I2: Higgens statistics; Q: X2 statistics; τ2: heterogeneity variance of actual effect size; τ: standard deviation of true effect size: df: degree of freedom.