Effect of carotenoid and melatonin supplementation on bill colour score
| Sources of variation . | d.f. . | ϰ2 . | P . |
|---|---|---|---|
| Carotenois supplementation | 1 | 19.92 | <0.0001 |
| Melatonin supplementation | 1 | 4.87 | 0.0273 |
| Carotenoid + melatonin supplementation | 1 | 0.36 | 0.5501 |
| Sources of variation . | d.f. . | ϰ2 . | P . |
|---|---|---|---|
| Carotenois supplementation | 1 | 19.92 | <0.0001 |
| Melatonin supplementation | 1 | 4.87 | 0.0273 |
| Carotenoid + melatonin supplementation | 1 | 0.36 | 0.5501 |
Differences in bill colour scores (post-experimental minus pre-experimental scores) were analysed using an ordinal model for multinomial data with a cumulative logit link function [PROC GENMOD (SAS Institute, 2001)].