Items | Supplementation level of RP (g/kg of DMI) | SEM | Contrasts | ||||
---|---|---|---|---|---|---|---|
|
|
||||||
0 | 2 | 4 | 6 | L | Q | ||
Napier grass (DM) | |||||||
kg/d | 5.7 | 5.8 | 5.8 | 5.8 | 0.03 | 0.484 | 0.293 |
% BW/d | 2.1 | 2.2 | 2.2 | 2.2 | 0.11 | 0.675 | 0.256 |
g/kg BW0.75 | 86.7 | 87.0 | 88.2 | 87.3 | 0.43 | 0.612 | 0.567 |
Concentrate intake | |||||||
kg/d | 2.6 | 2.6 | 2.7 | 2.6 | 0.11 | 0.328 | 0.193 |
% BW/d | 1.0 | 1.0 | 1.0 | 1.0 | 0.05 | 0.142 | 0.153 |
g/kg BW0.75 | 40.1 | 40.0 | 40.4 | 40.2 | 0.27 | 0.167 | 0.351 |
RP intake | |||||||
kg/d | 0a | 0.17b | 0.34c | 0.51d | 0.02 | 0.012 | 0.973 |
% BW/d | 0a | 0.06b | 0.13c | 0.19d | 0.01 | 0.025 | 0.703 |
g/kg BW0.75 | 0a | 2.6b | 5.2c | 7.6d | 0.05 | 0.011 | 0.545 |
Total DM intake | |||||||
kg/d | 8.3a | 8.5ab | 8.8b | 8.9b | 0.03 | 0.001 | 0.447 |
% BW/d | 3.1a | 3.2a | 3.3ab | 3.4b | 0.04 | 0.002 | 0.732 |
g/kg BW0.75 | 126.8a | 129.6b | 133.8c | 135.1c | 0.41 | 0.001 | 0.487 |
CT intake | |||||||
g/d | 0.0a | 20.2b | 40.1c | 61.2d | 2.42 | 0.012 | 0.043 |
% total intake | 0.0a | 0.24b | 0.47c | 0.69d | 0.06 | 0.001 | 0.011 |
SP intake | |||||||
g/d | 0.0a | 17.7b | 35.7c | 53.6d | 2.11 | 0.001 | 0.021 |
% total intake | 0.0a | 0.21b | 0.41c | 0.61d | 0.05 | 0.001 | 0.001 |
Apparent digestibility (%) | |||||||
Dry matter | 65.1 | 65.7 | 66.3 | 64.9 | 0.52 | 0.162 | 0.457 |
Organic matter | 67.1 | 67.5 | 67.7 | 66.9 | 0.91 | 0.218 | 0.312 |
Crude protein | 65.9 | 66.1 | 66.7 | 66.1 | 0.32 | 0.112 | 0.178 |
Neutral detergent fiber | 73.2 | 73.5 | 73.1 | 72.8 | 0.64 | 0.231 | 0.732 |
Acid detergent fiber | 62.7 | 62.6 | 63.1 | 63.0 | 0.55 | 0.125 | 0.435 |
Items | Supplementation level of RP (g/kg of DMI) | SEM | Contrasts | ||||
---|---|---|---|---|---|---|---|
|
|
||||||
0 | 2 | 4 | 6 | L | Q | ||
Ruminal pH | 6.7 | 6.7 | 6.6 | 6.6 | 0.09 | 0.144 | 0.221 |
Ruminal temperature (°C) | 39.7 | 39.8 | 39.4 | 39.0 | 0.14 | 0.175 | 0.337 |
Ruminal NH3-N (mg/dL) | 17.5 | 17.7 | 18.1 | 17.9 | 0.06 | 0.235 | 0.283 |
BUN (mg/dL) | 9.7 | 10.3 | 10.4 | 10.1 | 0.11 | 0.120 | 0.311 |
Total VFA (mmol/L) | 97.3 | 99.8 | 99.3 | 97.5 | 1.25 | 0.243 | 0.675 |
VFA (mol/100 mol) | |||||||
Acetic acid (C2) | 69.5 | 69.0 | 68.5 | 69.1 | 0.20 | 0.123 | 0.139 |
Propionic acid (C3) | 18.7a | 18.9a | 20.9b | 20.5b | 0.15 | 0.013 | 0.421 |
Butyric acid (C4) | 11.8 | 12.1 | 10.6 | 10.4 | 0.57 | 0.144 | 0.111 |
C2:C3 | 3.7a | 3.7a | 3.3b | 3.4b | 0.06 | 0.034 | 0.476 |
Methane estimation (mM/L)1) | 30.9a | 30.7a | 29.3b | 29.6b | 0.16 | 0.021 | 0.121 |
Total direct counts | |||||||
Bacteria (×1010 cell/mL) | 9.8 | 10.0 | 10.5 | 10.2 | 0.52 | 0.198 | 0.257 |
Protozoa (×105 cell/mL) | 10.5a | 7.6b | 5.0c | 4.2d | 0.72 | 0.017 | 0.143 |
Fungal zoospore (×106 cell/mL) | 2.7 | 3.1 | 3.3 | 3.1 | 0.44 | 0.156 | 0.423 |
RP, rambutan peel powder; DMI, dry matter intake; SEM, standard error of the mean; L, linear; Q, quadratic; BUN, blood urea nitrogen; VFA, volatile fatty acids.
1) Calculated according to Moss et al [17]. CH4 estimation = 0.45(acetate)–0.275(propionate)+0.4(butyrate).