Table 6 Faecal excretion (mg/kg body weight/day) and apparent digestibility (App. digestib.) (%) of crude protein (CP) and minerals of cats fed diets with varying protein concentrations and qualities. n = 10 / diet, Mean and SEM
P values (polynomial contrasts) | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Low protein quality | High protein quality | SEM | Interaction | Low protein quality | High protein quality | Protein concentration | Protein quality | ||||||||
36.7% | 45.0% | 56.1% | 36.2% | 43.3% | 54.9% | Lin. | Quadr. | Lin. | Quadr. | Lin. | Quadr. | ||||
Faecal CP excretion | 423 | 600 | 553 | 418 | 458 | 625 | 20.9 | 0.076 | – | – | – | – | 0.004 | 0.524 | 0.609 |
App. digestib. of CP | 89.7 | 87.7 | 90.7 | 89.0 | 89.7 | 89.5 | 0.30 | 0.133 | – | – | – | – | 0.376 | 0.117 | 0.943 |
Faecal Ca excretion | 74.0 | 92.5 | 109 | 93.0 | 93.7 | 117 | 4.71 | 0.522 | – | – | – | – | 0.012 | 0.871 | 0.411 |
App. digestib. of Ca | 40.8 | 22.0 | 18.0 | 17.3 | 19.2 | 8.85 | 3.32 | 0.394 | – | – | – | – | 0.086 | 0.547 | 0.257 |
Faecal P excretion | 33.7 | 44.5 | 47.8 | 43.1 | 44.2 | 54.8 | 1.92 | 0.305 | – | – | – | – | 0.018 | 0.895 | 0.123 |
App. digestib. of P | 65.6 | 49.2 | 49.1 | 46.8 | 47.5 | 41.6 | 1.95 | 0.165 | – | – | – | – | 0.062 | 0.274 | 0.038 |
Faecal Na excretion | 3.12 | 4.09 | 3.70 | 2.43 | 2.74 | 3.81 | 0.21 | 0.260 | – | – | – | – | 0.009 | 0.683 | 0.005 |
App. digestib. of Na | 95.4 | 93.7 | 95.8 | 95.5 | 95.5 | 94.8 | 0.24 | 0.057 | – | – | – | – | 0.963 | 0.122 | 0.153 |
Faecal Mg excretion | 3.47 | 4.59 | 4.23 | 3.99 | 4.14 | 4.94 | 0.15 | 0.121 | – | – | – | – | 0.054 | 0.496 | 0.243 |
App. digestib. of Mg | 34.9 | 10.3 | 14.0 | 13.1 | 13.6 | 6.01 | 2.74 | 0.237 | – | – | – | – | 0.123 | 0.280 | 0.119 |
Faecal K excretion | 3.15 | 3.95 | 3.07 | 3.16 | 2.63 | 3.29 | 0.18 | 0.069 | – | – | – | – | 0.612 | 0.996 | 0.244 |
App. digestib. of K | 97.5 | 96.2 | 97.7 | 96.6 | 97.1 | 96.6 | 0.13 | 0.005 | 0.314 | 0.001 | 0.698 | 0.022 | – | – | – |
Faecal Ox excretion | 0.80 | 0.94 | 0.96 | 0.98 | 0.87 | 0.98 | 0.04 | 0.330 | – | – | – | – | 0.458 | 0.818 | 0.389 |