Table 8.
Item | SP2 | RP3 | RP-Arg4 | RP-GAA4 | RP-Cit4 | SEM | P-value |
---|---|---|---|---|---|---|---|
Excreta moisture, % | 67.53 | 60.11 | 67.90 | 59.52 | 60.74 | 1.29 | 0.062 |
Protein digestibility | |||||||
CP intake, g/d | 26.93b | 17.76a | 19.08ab | 18.66ab | 19.21ab | 1.12 | 0.043 |
CP intake per unit of BW, g/d | 13.45 | 8.84 | 9.38 | 11.31 | 9.32 | 0.64 | 0.105 |
CP excreted, g/d | 9.22b | 5.68a | 6.38a | 5.76a | 6.39a | 0.31 | 0.043 |
CP excreted per unit of BW, g/d | 4.59b | 2.83a | 3.19a | 3.48a | 3.06a | 0.15 | <0.001 |
CP retained, g/d | 17.71 | 12.07 | 12.73 | 12.89 | 12.83 | 1.01 | 0.386 |
CP retained per unit of BW, g/d | 8.86 | 6.01 | 6.29 | 7.83 | 6.26 | 0.57 | 0.511 |
CP apparent digestibility, % | 63.53 | 67.08 | 66.06 | 66.95 | 66.09 | 1.39 | 0.980 |
CP apparent digestibility per unit of BW, % | 31.71 | 33.38 | 32.42 | 40.91 | 32.03 | 1.22 | 0.070 |
Energy digestibility | |||||||
GE intake, kcal/d | 583.3b | 467.8ab | 503.3ab | 386.9a | 494.5ab | 21.75 | 0.049 |
GE intake per unit of BW, kcal/d | 291.3 | 232.9 | 247.4 | 233.3 | 239.8 | 11.44 | 0.452 |
GE excreted, kcal/d | 89.54b | 68.31ab | 74.16ab | 60.14a | 73.36ab | 3.01 | 0.028 |
GE excreted per unit of BW, kcal/d | 44.60 | 33.93 | 37.02 | 35.89 | 35.10 | 1.41 | 0.105 |
GE retained, kcal/d | 493.8 | 399.5 | 428.3 | 326.8 | 421.1 | 20.84 | 0.121 |
GE retained per unit of BW, kcal/d | 246.7 | 198.9 | 210.9 | 197.4 | 204.7 | 11.03 | 0.616 |
GE apparent digestibility, % | 83.64 | 84.98 | 84.85 | 84.58 | 84.82 | 0.63 | 0.971 |
GE apparent digestibility per unit of BW, % | 41.68a | 42.30ab | 41.49a | 51.60b | 40.99a | 1.19 | 0.019 |
GAA = guanidinoacetic acid; Cit = citrulline; CP = crude protein; BW = body weight; GE = gross energy.
a, b Differing superscripts indicate significant differences between means.
Statistical analysis of GE intake and GE retained were performed on log transformed data whereas values were actual data.
SP: standard protein diet with 17% CP.
RP: reduced protein diet with 13% CP.
l-Arg, GAA and l-Cit were added on top of the RP diets at 0.35%, 0.46% and 0.35% in diets, RP-Arg, RP-GAA and RP-Cit, respectively, to the level of Arg in SP.