TABLE 2

Differences in concentrations and molar proportions of SCFA in ileal and cecal digesta of low- and high-RFI broiler chickens fed either ad libitum or restrictivelya

ParameterValuebSEMP value
Ad libitum feedingRestrictive feeding
Low RFIHigh RFILow RFIHigh RFIFLRFIFL × RFI
Ileum
    Concn (µmol/g)
        Total SCFA61.857.348.149.23.990.0090.6720.483
        Acetate56.152.243.544.03.610.0060.6280.549
        Propionate0.70.60.50.70.070.4620.2230.064
        Butyrate0.50.30.20.40.160.7070.8610.240
        Isobutyrate4.54.23.83.80.420.2240.7310.702
        Valerate0.05b0.05b0.01b0.12a0.020.4050.0240.033
        Isovalerate0.02b0.02b0b0.07a0.010.3900.0170.026
        Caproate0.09b0.07b0.05b0.17a0.030.2020.0620.008
    Molar proportions (%)
        Acetate90.891.190.789.30.450.0340.1910.055
        Propionate1.11.11.01.40.110.2690.0600.079
        Butyrate0.630.390.480.730.210.6470.9920.245
        Isobutyrate7.27.27.67.90.510.2810.8460.767
        Valerate0.06b0.08b0.04b0.23a0.040.1540.0140.040
        Isovalerate0.03b0.04b0b0.12a0.020.1840.0030.014
        Caproate0.15b0.12b0.12b0.35a0.050.0480.0630.012
Ceca
    Concn (µmol/g)
        Total SCFA160.4154.6140.6118.513.290.0460.3040.544
        Acetate131.9127.4109.993.411.300.0200.3620.600
        Propionate8.46.46.77.21.060.6820.4570.247
        Butyrate15.6b16.3b19.7a11.8b1.760.8980.0500.020
        Isobutyrate1.0b1.3b1.0b2.2a0.180.023<0.0010.025
        Valerate1.61.31.91.60.200.1280.2200.878
        Isovalerate1.11.31.01.70.210.4360.0310.183
        Caproate0.80.60.50.60.160.2240.9140.413
    Molar proportions (%)
        Acetate82.282.577.679.41.210.0030.4130.546
        Propionate5.3a4.0b4.7ab5.8a0.500.2550.7690.020
        Butyrate9.7b10.6b14.5a9.4b1.040.0900.0540.006
        Isobutyrate0.7b0.9b0.8b2.1a0.190.003<0.0010.009
        Valerate1.00.81.41.40.11<0.0010.5390.554
        Isovalerate0.7b0.9b0.7b1.6a0.150.0240.0030.046
        Caproate0.50.40.30.500.090.9300.6760.110
  • a Data are presented as least-squares means and pooled SEM. n =7 per FL group, residual-feed-intake (RFI) rank, and sex except for n =8 high-RFI ad libitum females. RFI was calculated for the experimental period from 9 to 30 days posthatch. FL, feed intake level; SCFA, short-chain fatty acids.

  • b Different letters within a row indicate significant differences (P 0.05).