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Composition of experimental diets

 
Treatment1
Item Control CDDGS2 WDDGS3 WDDGS+oil
Ingredient, % of DM
    Barley silage 55.0 55.0 55.0 55.0
    Barley grain, steam rolled 35.0
    Canola meal 5.0
    CDDGS 40.0
    WDDGS 40.0 37.6
    Corn oil 2.4
    Barley grain, ground 3.4 3.4 3.4 3.4
    Calcium carbonate 1.25 1.25 1.25 1.25
    Salt 0.15 0.15 0.15 0.15
    Molasses, dried 0.13 0.13 0.13 0.13
    Mineral and vitamin premix2 0.06 0.06 0.06 0.06
    Vitamin E (500,000 IU/kg) 0.003 0.003 0.003 0.003
    Flavoring agent3 0.003 0.003 0.003 0.003
Chemical composition4
    DM, % 51.3 ± 2.4 52.0 ± 2.0 52.7 ± 2.1 52.6 ± 1.6
    OM, % 93.3 ± 0.2 92.6 ± 0.1 91.4 ± 0.3 91.3 ± 0.1
    CP, % 13.0 ± 0.5 18.6 ± 0.3 23.5 ± 0.2 22.0 ± 0.6
    NDF, % 32.5 ± 2.7 38.5 ± 1.1 33.9 ± 1.4 33.3 ± 2.3
    ADF, % 18.0 ± 1.1 23.7 ± 0.6 23.6 ± 0.7 23.0 ± 1.6
    Fat, % 3.0 ± 0.1 5.4 ± 0.1 3.7 ± 0.2 5.6 ± 0.2
    Starch, % 35.8 ± 1.3 17.9 ± 0.9 16.8 ± 0.6 17.4 ± 0.7
    GE, Mcal/kg of DM 4.31 ± 0.03 4.42 ± 0.06 4.38 ± 0.06 4.50 ± 0.08
1Treatments were Control = 35% barley grain + 5% canola meal, CDDGS (corn-based dried distillers grains with solubles) = 40% corn dried distillers grains plus solubles, WDDGS (wheat-based dried distillers grains with solubles) = 40% wheat dried distillers grains plus solubles, or WDDGS+oil (WDDGS plus corn oil) = 37.6% wheat dried distillers grains plus solubles + 2.4% corn oil (DM basis).
2Per kilogram of dietary DM: 65 of mg Zn, 28 mg of Mn, 15 mg of Cu, 0.7 mg of I, 0.2 mg of Co, 0.3 mg of Se, 6,000 IU of vitamin A, 600 IU of vitamin D, and 47 IU of vitamin E.
3Anise 422 powder containing ground cumin, fennel, fenugreek, silicon dioxide, and wheat bran (Canadian Bio-Systems Inc., Calgary, AB, Canada).
4Determined using samples pooled by diet within each period; all values except DM are expressed on a DM basis (n = 4; mean ± SD).



View Full Table | Close Full ViewTable 2.

Ruminal fermentation variables of ruminally cannulated beef heifers fed a barley silage-based high-forage diet supplemented with barley grain and canola meal, corn or wheat dried distillers grains plus solubles (CDDGS or WDDGS), or WDDGS plus corn oil (WDDGS+oil; n = 16 per treatment)

 
Treatment1
Item Control CDDGS WDDGS WDDGS+oil SEM P-value
Total VFA, mM 151 139 144 144 5.0 0.09
VFA, mol/100 mol
    Acetate 60.3a 57.9b 60.5a 59.8a 0.70 <0.001
    Propionate 22.1ab 23.1a 20.9b 22.7ab 0.76 0.025
    Butyrate 12.4b 14.1a 13.5ab 12.6b 0.57 0.010
    Isovalerate 1.97a 1.83a 1.45b 1.51b 0.114 <0.001
    Valerate 1.69c 1.66c 2.23a 2.02b 0.061 <0.001
    Isobutyrate 1.06 1.01 1.02 0.96 0.049 0.18
    Acetate:propionate 3.42a 3.07b 3.54a 3.24ab 0.139 0.002
    NH3, mM 6.1c 6.3c 15.8a 14.0b 0.68 <0.001
Protozoa
    Total, n × 105/mL 7.9a 4.4b 4.0b 3.1b 1.31 <0.001
    Entodiniomorphs,2 % 99.3 99.8 98.6 98.8 0.37 0.11
    Holotrichs,3 % 0.7 0.2 1.4 1.2 0.40 0.12
a−cWithin a row, means without a common superscript letter differ, P < 0.05.
1Treatments were Control = 35% barley grain + 5% canola meal, CDDGS = 40% corn dried distillers grains plus solubles, WDDGS = 40% wheat dried distillers grains plus solubles, or WDDGS+oil = 37.6% wheat dried distillers grains plus solubles + 2.4% corn oil (DM basis).
2Entodiniomorphs = Entodinium + Diplodinium + Polyplastron + Eudiplodinium + Epidinium + Ophryoscolex.
3Holotrichs = Isotricha + Dasytricha.



View Full Table | Close Full ViewTable 3.

Ruminal pH of beef heifers fed a barley silage-based high-forage diet supplemented with barley grain and canola meal, corn or wheat dried distillers grains plus solubles (CDDGS or WDDGS), or WDDGS plus corn oil (WDDGS+oil; n = 16 per treatment)

 
Treatment1
Item Control CDDGS WDDGS WDDGS+oil SEM P-value
Ruminal pH2
    Mean 6.22ab 6.18b 6.34a 6.18b 0.061 0.025
    Minimum 5.41c 5.47bc 5.76a 5.57b 0.063 <0.001
    Maximum 6.89 6.84 6.85 6.83 0.051 0.67
    SD of mean pH 0.37a 0.32b 0.24c 0.29b 0.019 <0.001
Duration of pH, h/d
    <6.0 6.9ab 8.0a 4.0b 7.6a 1.27 0.021
AUC,3 pH × h/d
    <6.0 3.0a 2.9ab 1.0b 2.0ab 0.60 0.033
AUC/kg DMI, pH × min
    <6.0 20.7a 22.1a 7.6b 19.4a 4.63 0.026
a−cWithin a row, means without a common superscript letter differ, P < 0.05.
1Treatments were Control = 35% barley grain + 5% canola meal, CDDGS = 40% corn dried distillers grains plus solubles, WDDGS = 40% wheat dried distillers grains plus solubles, or WDDGS+oil = 37.6% wheat dried distillers grains plus solubles + 2.4% corn oil (DM basis).
2Ruminal pH determined for 4 d during which the animals were in the chambers.
3AUC = area under the curve.



View Full Table | Close Full ViewTable 4.

Nutrient intakes and total tract digestibility measured in beef heifers fed a barley silage-based high-forage diet supplemented with barley grain and canola meal, corn or wheat dried distillers grains plus solubles (CDDGS or WDDGS), or WDDGS plus corn oil (WDDGS+oil; n = 8 per treatment)

 
Treatment1
Item2 Control CDDGS WDDGS WDDGS+oil SEM P-value
Intake
    DM, kg/d 9.58a 8.42b 9.39a 8.84ab 0.367 0.001
    OM, kg/d 8.94a 7.78c 8.58ab 8.05bc 0.340 0.001
    CP, kg/d 1.24d 1.58c 2.18a 1.94b 0.079 <0.001
    NDF, kg/d 3.07 3.22 3.18 2.96 0.168 0.11
    ADF, kg/d 1.68c 1.98b 2.22a 2.05b 0.106 <0.001
    GE, Mcal/d 41.3a 37.2b 41.1a 39.7ab 1.66 0.016
Digestibility, %
    DM 70.9a 66.4b 69.0a 66.6b 0.79 <0.001
    OM 71.8a 66.4c 69.3b 66.5c 0.83 <0.001
    CP 64.1b 70.1a 70.8a 69.3a 0.89 <0.001
    NDF 51.3a 46.3b 50.4a 44.1b 2.24 <0.001
    ADF 31.8c 38.5ab 43.0a 37.5b 2.24 <0.001
    GE 69.8a 65.7c 68.4ab 66.8bc 0.96 <0.001
a−dWithin a row, means without a common superscript letter differ, P < 0.05.
1Treatments were Control = 35% barley grain + 5% canola meal, CDDGS = 40% corn dried distillers grains plus solubles, WDDGS = 40% wheat dried distillers grains plus solubles, or WDDGS+oil = 37.6% wheat dried distillers grains plus solubles + 2.4% corn oil (DM basis).
2Nutrient intakes and total tract digestibility determined for 4 d.



View Full Table | Close Full ViewTable 5.

Nitrogen intake and excretion measured in beef heifers fed a barley silage-based high-forage diet supplemented with barley grain and canola meal, corn or wheat dried distillers grains plus solubles (CDDGS or WDDGS), or WDDGS plus corn oil (WDDGS+oil; n = 8 per treatment)

 
Treatment1
Item Control CDDGS WDDGS WDDGS+oil SEM P-value
N intake, g/d 199d 252c 350a 310b 12.7 <0.001
N excretion,2 g/d 170d 206c 303a 259b 10.4 <0.001
Fecal excretion
    Output, kg/d 2.87 2.90 3.04 3.09 0.15 0.096
    Total N, g/d 71.1c 73.3c 101.9a 94.3b 4.17 <0.001
    Total N, % N excretion 42.1a 36.3b 33.8c 36.6b 1.13 <0.001
Urinary excretion
    Output, L/d 6.9c 6.8c 11.2a 9.9b 0.65 <0.001
    Total N, g/d 98.5d 133c 201a 165b 7.7 <0.001
    Total N, % N excretion 57.9c 63.7b 66.2a 63.4b 1.13 <0.001
    Urea N, g/d 53.4d 89.6c 140a 118b 5.8 <0.001
    NH3 N, g/d 0.9c 1.8b 4.6a 4.5a 0.41 <0.001
    Plasma urea N,3 mg/dL 6.6b 11.6a 12.1a 11.2a 0.63 <0.001
a−dWithin a row, means without a common superscript letter differ, P < 0.05.
1Treatments were Control = 35% barley grain + 5% canola meal, CDDGS = 40% corn dried distillers grains plus solubles, WDDGS = 40% wheat dried distillers grains plus solubles, or WDDGS+oil = 37.6% wheat dried distillers grains plus solubles + 2.4% corn oil (DM basis).
2Nitrogen intakes and excretion was measured over 4 d during the total collection period.
3Samples taken on d 21 (n = 16 per treatment).



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Daily methane emissions from beef heifers fed a barley silage-based high-forage diet supplemented with barley grain and canola meal, corn or wheat dried distillers grains plus solubles (CDDGS or WDDGS), or WDDGS plus corn oil (WDDGS+oil; n = 8 per treatment)

 
Treatment1
Item2 Control CDDGS WDDGS WDDGS+oil SEM P-value
DMI, kg/d 9.05a 8.57ab 8.13b 8.42ab 0.291 0.024
Methane
    g/d 228a 184b 191b 174b 11.7 <0.001
    g/kg of DMI 25.3a 21.5b 23.9a 21.1b 1.15 <0.001
    % of GE intake 7.8a 6.6b 7.3a 6.3b 0.36 <0.001
    % of DE intake 11.1a 10.0bc 10.7ab 9.4c 0.53 <0.001
a−cWithin a row, means without a common superscript letter differ, P < 0.05.
1Treatments were Control = 35% barley grain + 5% canola meal, CDDGS = 40% corn dried distillers grains plus solubles, WDDGS = 40% wheat dried distillers grains plus solubles, or WDDGS+oil = 37.6% wheat dried distillers grains plus solubles + 2.4% corn oil (DM basis).
2Methane emissions and corresponding DMI determined over 4 d during which the animals were in the chambers. Chamber (data for 2 animals) was the experimental unit.