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. 2019 Feb 20;97(5):2202–2219. doi: 10.1093/jas/skz077

Table 1.

Descriptive statistics for age, weight, feed intake, feed efficiency and initial, final, and gain in body composition traits over a 10-wk feedlot RFI test and their correlations with midparent RFIp-EBV, DMI, and RFI for 59 Angus steers and heifers1 bred to vary in genetic merit for postweaning RFI

Correlations
Trait Units Mean SD Min. Max. RFIp-EBVmp DMI RFIf
RFIp-EBVmp kg/d 0.03 0.83 −1.00 1.13 1 0.41** 0.57***
Start BW kg 410 36 342 499 −0.04 0.68*** 0.00
ADG kg/d 1.40 0.20 0.97 1.95 −0.29* 0.17 0.00
TWT kg 454 38 383 548 −0.09 0.67*** 0.00
End BW kg 504 42 417 600 −0.14 0.64*** 0.00
DMI kg/d 12.0 1.1 9.5 14.5 0.41** 1 0.73***
FCR kg/kg 8.9 1.4 5.8 12.0 0.48*** 0.39** 0.42**
RFIf kg/d 0.00 0.82 −1.80 1.83 0.57*** 0.73*** 1
Start RIBFAT mm 5.2 1.6 2 10 0.55*** 0.44*** 0.48***
Start RUMPFAT mm 6.6 2.2 3 13 0.55*** 0.36** 0.49***
Start IMF % 4.8 0.7 2.8 6.2 0.34** 0.24† 0.28*
Start EMA cm2 59.1 4.5 50 70 0.03 0.44*** −0.04
End RIBFAT mm 10.6 2.0 7 16 0.57*** 0.55*** 0.57***
End RUMPFAT mm 14.1 2.8 9 22 0.59*** 0.42** 0.59***
End IMF % 6.5 0.6 5.1 7.7 0.21 0.19 0.28*
End EMA cm2 77.5 5.0 67 88 −0.09 0.37** −0.11
End RIBFAT-WT mm/kg 0.021 0.004 0.013 0.031 0.64*** 0.28* 0.56***
End RUMPFAT-WT mm/kg 0.028 0.006 0.015 0.043 0.63*** 0.14 0.55***
End IMF-WT %/kg 0.013 0.002 0.008 0.016 0.25* −0.28* 0.20
End EMAWT cm2/kg 0.154 0.010 0.138 0.182 0.09 −0.46*** −0.11
Gain in RIBFAT mm 5.4 1.3 3 9 0.22† 0.31* 0.29*
Gain in RUMPFAT mm 7.5 1.6 4 11 0.29* 0.24† 0.38**

1Comprising 29 steers and 30 heifers.

2RFIp-EBVmp = midparent EBV for postweaning RFI; TWT = midtest BW; FCR = feed conversion ratio; RIBFAT = subcutaneous fat depth at the 12/13th rib; RUMPFAT = subcutaneous fat depth at the Australian P8 rump site; IMF = intramuscular fat content of the eye muscle; EMA = cross-sectional area of the eye muscle between the 12th and 13th rib at the start of test; RIBFAT-WT = RIBFAT divided by BW; RUMPFAT-WT = RUMPFAT divided by BW; IMF-WT = IMF divided by BW; EMA-WT = EMA divided by BW; RFIf = RFI measured in the feedlot; RFI = residual feed intake; RFIp = RFI measured postweaning.

† P ≤ 0.1; *P < 0.05; **P < 0.01; ***P < 0.001.