TABLE 4.

Effects of sample type, ambient temperature, and diet on richness and diversity indices of bacterial phyla in the fecal and rumen liquor samples of steers fed either alfalfa silage or sainfoin silage

Diet and ambient temp (°C)Index value for sample typea
Rumen liquorFeces
RichnessDiversityRichnessDiversity
SMargalefShannonSimpsonSMargalefShannonSimpson
Alfalfa silage
    −11.195.780.690.52C95.780.650.51C
    −16.586.38BY0.870.72B86.37BY0.710.68B
    −18.794.970.580.4173.730.530.40
    −19.194.470.530.34D94.470.520.34D
    −19.3911.62AX0.851.07AX911.58AX0.821.05AX
    −20.294.110.480.29D83.600.480.29D
Total92.43C0.640.37102.73C0.600.37D
SE0.0000.1420.0690.0510.8330.3300.0520.048
Sainfoin silage
    −11.174.34C0.790.5485.05C0.670.51
    −16.597.29B0.720.68B97.29B0.780.70BY
    −18.784.35C0.530.4094.97C0.590.41C
    −19.194.47C0.490.34CY94.47C0.520.34CZ
    −19.3810.14A0.821.05A810.13A0.911.09A
    −20.294.11C0.470.29CY94.11C0.460.29CZ
Total92.43DZ0.630.37C92.43DZ0.620.37C
SE0.0000.1420.0750.0510.0000.1420.0650.050
  • a S, number of phyla present in the community. The richness and diversity indices shown were calculated from the proportions of the phyla Actinobacteria, Bacteroidetes, Deferribacteres, Deinococcus-Thermus, Firmicutes, Fusobacteria, Proteobacteria, Tenericutes, and Verrucomicrobia in the total bacterial populations of the samples. Values with different superscripts are statistically different (P < 0.05). ABC, the lack of a common letter for values in the same column denotes significant differences within the diet (P < 0.05); XYZ, the lack of a common letter for values in the same column denotes significant differences between the diets (P < 0.05). Index values do not represent numbers of operational taxonomic units; they are abstract values. Data presented are mean values for fecal and rumen liquor samples from two pens at six sampling times.