Anim Biosci > Volume 33(2); 2020 > Article |
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Items (g/kg DM)1) | Corn silage | Concentrated mixture | Diet2) |
---|---|---|---|
Dry matter | 447.7 | 925.9 | 567.2 |
Organic matter | 961.2 | 922.3 | 951.5 |
Crude protein | 72.4 | 218.3 | 108.8 |
NDIN | 5.50 | 12.24 | 7.18 |
ADIN | 0.93 | 0.75 | 0.89 |
Ether extract | 25.1 | 28.3 | 25.9 |
Non-fibrous carbohydrates | 283.4 | 371.7 | 305.5 |
NDFap | 580.3 | 304.1 | 511.3 |
Neutral detergente fiber | 307.4 | 72.2 | 248.6 |
Lignin | 60.3 | 31.8 | 53.2 |
Total digestible nutrients3) | 606.4 | 734.2 | 638.4 |
DM, dry matter; NDIN, neutral detergent insoluble nitrogen; ADIN, acid detergent insoluble nitrogen; NDFap, neutral detergent fiber corrected for ash and protein.
2) Diet used during the experiment (e.g., diet consisted of 75% corn silage and 25% concentrate in the total dry matter).
3) NRC [14].
Items | Levels of restriction (% BW)1) | SEM | p-value | |||||
---|---|---|---|---|---|---|---|---|
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3.392) | 2.75 | 2.50 | 2.25 | 2.00 | Linear | Quad | ||
Intake | ||||||||
DM (kg/d) a) | 15.88 | 12.56 | 11.39 | 9.73 | 8.64 | 0.44 | <0.01 | 0.90 |
DM (% BW) | 3.22 | 2.75 | 2.50 | 2.25 | 2.00 | 0.06 | <0.01 | 0.27 |
CP (kg/d) b) | 1.79 | 1.37 | 1.24 | 1.06 | 0.94 | 0.05 | <0.01 | 0.68 |
EE (kg/d) c) | 0.42 | 0.33 | 0.29 | 0.25 | 0.22 | 0.01 | <0.01 | 0.91 |
NFC (kg/d) d) | 5.14 | 3.84 | 3.47 | 2.97 | 2.63 | 0.15 | <0.01 | 0.42 |
NDFCP (kg/d) e) | 7.77 | 6.42 | 5.83 | 4.98 | 4.42 | 0.22 | <0.01 | 0.40 |
TDN (kg/d) f) | 9.12 | 7.63 | 7.21 | 6.18 | 5.47 | 0.29 | <0.01 | 0.33 |
Nutrient digestibility (%) | ||||||||
DM | 54.75 | 57.38 | 61.62 | 60.65 | 61.63 | 2.59 | 0.29 | 0.76 |
CP g) | 51.88 | 48.15 | 59.25 | 55.46 | 61.77 | 2.63 | 0.03 | 0.12 |
EE | 77.55 | 83.75 | 85.17 | 83.23 | 82.09 | 2.25 | 0.11 | 0.11 |
NFC | 75.57 | 74.46 | 76.84 | 80.71 | 76.77 | 3.07 | 0.49 | 0.89 |
NDFAP | 51.02 | 54.10 | 56.67 | 54.47 | 56.25 | 2.28 | 0.11 | 0.57 |
TDN | 58.21 | 60.52 | 63.85 | 63.39 | 63.71 | 2.37 | 0.39 | 0.72 |
BW, body weight; SEM, standard error of the mean; p, probability; DM, dry matter; CP, crude protein; EE, ether extract; NFC, Non-fibrous carbohydrates; NDFap, neutral detergent fiber corrected for ash and protein; TDN, total digestible nutrients.
1) Regression equation: a) Ŷ = −1.93+5.26*X, R2 = 0.99; b) Ŷ = 0.27+0.88*X, R2 = 0.99; c) Ŷ = −0.30+0.61*X, R2 = 0.99; d) Ŷ = −0.07+0.14*X, R2 = 0.99; e) Ŷ = −1.08+1.82*X, R2 = 0.99; f) Ŷ = −0.394+2.43*X, R2 = 0.99; g) Ŷ = 0.388+2.61*X, R2 = 0.98, where X is the level of food restriction; R2 is the coefficient of determination; * significant by the t test, at 1% probability.
Items | Levels of restriction (% BW)1) | SEM | p-value | |||||
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3.392) | 2.75 | 2.50 | 2.25 | 2.00 | Linear | Quad | ||
N-ingested (g/d) a) | 298.13 | 218.50 | 211.15 | 171.04 | 161.70 | 12.86 | <0.01 | 0.46 |
N-milk (g/d) b) | 69.13 | 56.72 | 55.72 | 48.89 | 40.24 | 4.47 | 0.01 | 0.52 |
N-feces (g/d) c) | 144.27 | 113.32 | 86.05 | 75.75 | 61.45 | 9.03 | <0.01 | 0.86 |
N-urine (g/d) | 58.55 | 50.35 | 72.39 | 67.80 | 82.82 | 7.36 | 0.05 | 0.13 |
Nitrogen balance d) (g/d) | 26.17 | −1.89 | −3.00 | −21.40 | −22.81 | 7.62 | <0.01 | 0.75 |
NUEe) | 0.23 | 0.26 | 0.27 | 0.29 | 0.25 | 0.02 | 0.59 | 0.36 |
UUN (mg/dL) f) | 7.46 | 10.92 | 9.95 | 4.88 | 6.75 | 1.58 | 0.11 | 0.34 |
PUN (mg/dL) | 11.53 | 14.20 | 13.56 | 15.10 | 17.23 | 1.03 | 0.02 | 0.48 |
MUN (mg/dL) | 15.15 | 13.70 | 16.63 | 15.75 | 18.10 | 1.21 | 0.17 | 0.16 |
BW, body weight; SEM, standard error of the mean; p, probability; N, nitrogen; NUE, nitrogen use efficiency; UUN, urine urea nitrogen; PUN, plasma urea nitrogen; MUN, milk urea nitrogen.
1) Regression equation: a) Ŷ = −45.61+99.96*X, R2 = 0.97; b) Ŷ = 3.67+19.57*X, R2 = 0.96; c) Ŷ = −61.61+61.20*X; R2 = 0.98; d) Ŷ = 289.80–153.66*X+25.13*X2, R2 = 0.76; e) Ŷ = −98.41+36.39*X, R2 = 0.96; f) Ŷ = 23.77–3.66*X, R2 = 0.87 where X is the level of food restriction; R2 is the coefficient of determination; * significant by the t test, at 1% probability.
Items | Levels of restriction (% BW)1) | SEM | p-value | |||||
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3.392) | 2.75 | 2.50 | 2.25 | 2.00 | Linear | Quad | ||
Feeding | ||||||||
min/d a) | 440.4 | 240 | 204 | 153.6 | 132.6 | 28.2 | <0.01 | 0.09 |
min/kg DMb) | 27.37 | 19.17 | 16.87 | 15.62 | 14.36 | 2.64 | 0.02 | 0.61 |
min/kg NDFapc) | 55.69 | 37.5 | 33 | 30.56 | 28.08 | 5.16 | 0.01 | 0.32 |
Rumination | ||||||||
min/d d) | 456.6 | 415.2 | 367.8 | 339 | 311.4 | 28.8 | 0.02 | 0.60 |
min/kg DM | 2,219 | 1,828 | 1,980 | 1,785 | 1,818 | 149 | 0.26 | 0.60 |
min/kg NDFap | 1,087 | 935 | 1,013 | 912 | 929 | 76 | 0.47 | 0.73 |
Chewing | ||||||||
number/bolus | 49.86 | 38.31 | 49.39 | 39.19 | 42.46 | 6.22 | 0.55 | 0.66 |
number/d e) | 26,706 | 21,034 | 20,191 | 18,181 | 16,466 | 2,117 | 0.04 | 0.81 |
min/d f) | 896.4 | 655.2 | 571.2 | 492.6 | 444 | 30 | <0.01 | 0.24 |
min/kg DM | 54.71 | 52.67 | 47.46 | 50.62 | 48.05 | 3.74 | 0.62 | 0.86 |
min/kg NDFap | 111.5 | 103 | 92.8 | 99 | 94 | 7.2 | 0.39 | 0.65 |
Idleness | ||||||||
min/d g) | 543.6 | 784.8 | 868.8 | 947.4 | 996 | 30 | <0.01 | 0.26 |
BW, body weight; SEM, standard error of the mean; p, probability; DM, dry matter; NDFap, neutral detergent fiber corrected for ashes and protein.
1) Regression equation: a) Ŷ = −346.37+225.17*X, R2 = 0.96; b) Ŷ = −5.78+9.48*X, R2 = 0.95; c) Ŷ = −14.83+20.09*X, R2 = 0.94; d) Ŷ = 100.61+107*X, R2 = 0.97; e) Ŷ = −1809.76+7256.01*X, R2 = 0.99; f) Ŷ = −245+332.38*X, R2 = 0.99; g) Ŷ = 1685–332.38*X, R2 = 0.99 where X is the level of food restriction; R2 is the coefficient of determination; * significant by the t test, at 1% probability.
Items | Levels of restriction (% BW)1) | SEM | p-value | |||||
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3.392) | 2.75 | 2.50 | 2.25 | 2.00 | Linear | Quad | ||
Number of periods (n/d) | ||||||||
Feedinga) | 13.0 | 4.5 | 4.7 | 3.2 | 3.0 | 0.71 | <0.01 | 0.01 |
Ruminating | 14.5 | 12.75 | 12 | 13.5 | 12.75 | 1.19 | 0.65 | 0.42 |
Idling | 21 | 20.25 | 19.75 | 19.75 | 18.75 | 1.37 | 0.83 | 0.84 |
Time spent per period (min) | ||||||||
Feeding | 33.93 | 54.88 | 42.44 | 53.65 | 46.15 | 7.81 | 0.35 | 0.26 |
Ruminating | 31.96 | 33.09 | 34.47 | 25.04 | 24.54 | 4.25 | 0.35 | 0.21 |
Idlingb) | 26 | 39.14 | 45.64 | 47.96 | 53.98 | 3.4 | <0.01 | 0.81 |
Feed efficiency | ||||||||
g DM/hc) | 2,361 | 3,210 | 3,804 | 3,912 | 4,239 | 381 | 0.03 | 0.80 |
g NDFap/hd) | 1,154 | 1,641 | 1,945 | 2,000 | 2,167 | 193 | 0.02 | 0.71 |
Rumination efficiency | ||||||||
Boluses/d | 49.86 | 38.31 | 49.39 | 39.19 | 42.46 | 6.22 | 0.55 | 0.70 |
g DM/h | 2,219 | 1,828 | 1,980 | 1,785 | 1,818 | 149 | 0.26 | 0.48 |
g NDFap/h | 1,087 | 935 | 1,013 | 912 | 929 | 76 | 0.47 | 0.66 |
BW, body weight; SEM, standard error of the mean; p, probability; DM, dry matter; NDFap, neutral detergent fiber corrected for ashes and protein; h, hour.
Items | Levels of restriction (BW)1) | SEM | p-value | |||||
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3.392) | 2.75 | 2.50 | 2.25 | 2.00 | Linear | Quad | ||
Milk production (kg/d) | 13.05 | 11.60 | 10.70 | 10.67 | 8.26 | 1.10 | 0.09 | 0.47 |
Milk production corrected for 3.5 fat (kg/d)a) | 13.61 | 11.30 | 11.30 | 10.27 | 8.32 | 1.10 | 0.05 | 0.59 |
Final body weight (kg) b) | 485 | 457 | 455 | 433 | 438 | 80 | <0.01 | 0.57 |
Final and initial body weight difference (kg) | −24.25 | −25.04 | −56.31 | −52.92 | −69.94 | 23.04 | 0.56 | 0.66 |
Final body condition score | 3.81 | 3.81 | 3.88 | 3.69 | 3.63 | 0.13 | 0.65 | 0.34 |
Difference in body condition score | 0.06 | 0.00 | −0.13 | −0.25 | 0.00 | 0.09 | 0.16 | 0.29 |
Feed efficiency (kg of milk/kg of DM) | 0.79 | 0.95 | 0.90 | 1.10 | 0.91 | 0.12 | 0.49 | 0.50 |
Feed cost (U$/d) | 3.25 | 2.57 | 2.33 | 1.99 | 1.77 | 0.26 | - | - |
Reduction of food costs (%) | 0.00 | 20.90 | 28.42 | 38.87 | 45.62 | 7.7 | - | - |