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Means ± SEM for initial age and carcass characteristics of heifers by group1,2

 
Variable Group 1 Group 2 Group 3 Group 4 SEM P-value
Ryegrass, d 0 99 218 99
Grain, d 0 0 0 119
Age, d 407 400 393 386 9.89 0.51
BW, kg 288 268 275 284 8.36 0.31
Height, cm 122 121 122 121 1.58 0.92
Frame score 5.2 5.0 5.3 5.1 0.33 0.97
Ultrasound backfat, mm 0.085 0.115 0.098 0.117 0.14 0.23
Ultrasound REA,3 cm2 43.8 44.5 42.5 45.4 2.43 0.83
Intramuscular fat, % 3.6 3.7 3.6 3.6 0.25 0.97
1Analysis of initial group data was not significant between groups for any trait, n = 6.
2Group 1 = control (0 d, initial heifers), Group 2 = 99 d on ryegrass, Group 3 = 218 d on ryegrass, Group 4 = 99 d on ryegrass followed by 119 d on grain.
3Ultrasound REA = ultrasound ribeye area adjusted for rump fat thickness.



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Nutritional characteristics of ryegrass1,2

 
Variable February March April May June July
DM 370.8 746.7 604.4 1540.0 2286.6 1660.0
DM, % 22.1 45.8 17.1 22.2 24.5 47.4
CP 21.4 10.7 13.3 8.4 8.2 7.0
NDF 33.9 28.9 43.0 51.1 63.4 65.9
ADF 18.9 16.5 25.2 27.6 35.1 37.5
ADL 0.54 N/A 0.39 1.36 1.70 3.63
RFV 203.6 245.1 149.9 122.7 89.7 84.3
Low, °C –0.6 4.6 10.2 17.7 20.2 22.3
High, °C 11.6 17.6 23.7 30.2 30.0 35.1
1RFV = relative feed value (100 = nutritive quality of late bloom alfalfa).
2Average daily low (Low) and high (High) temperatures recorded in Celsius at the Milstead Weather Station, Shorter, AL.



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Oligonucleotide PCR primers

 
Gene1 Accession No. Primer sequence (5ʹ→3ʹ) Orientation Efficiency
%
PPARγ NM_181024.2 CGC ATG CCA CAG GCC GAG AA forward 97
CCG TCA AGA TCG CCC TCG CC reverse
BMP2 NM_001099141.1 AAG ATG AGC ACA GCT GGT CAC AGA forward 99
TCT TAC AGC TGG ACT TGA GGC GTT reverse
SMAD1 NM_001076223.2 ACC TCC GCA CAA AGA AGC TAA GGA forward 100
TTC ACC AAA GCA TCA ACG GCC TTC reverse
SREBP1c NM_001113302.1 CCA GCT GAC AGC TCC ATT GA forward 96
TGC GCG CCA CAA GGA reverse
SHH AF144100.1 TCA GAG GTG CAA GGA CAA GCT GAA forward 91
ACT GGT TCA TCA CGG AGA TGG CTA reverse
COUPTF1 NM_175804.2 AAC TTA CAC ATG CCG TGC CAA CAG forward 91
AGG CAC TTC TTA AGG CGG CAG TAT reverse
COUPTF2 NM_174402.3 CCC ATG TGG AAA GCT TGC AGG AAA forward 93
TCC AAA TCG TGT TGG TTG GTT GGG reverse
PREF1 AB050725.1 TTG CAA CCA GCA GGC GGT GT forward 101
GGG AGG GGA GGT TGG CGA CT reverse
WNT5a NM_001205971.1 ATT TCT CTC CTT CGC CCA GGT TGT forward 93
TGG TCC TGA TAC AAG TGG CAG AGT reverse
LPL NM_001075120.1 ACA CAG CTG AGG ACA CTT GCC forward 94
GCC ATG GAT CAC CAC AAA GG reverse
FAS AF285607.2 ACC TCG TGA AGG CTG TGA CTC A forward 90
TGA GTC GAG GCC AAG GTC TGA A reverse
SCD NM_173959.4 TCC TGT TGT TGT GCT TCA TCC forward 97
GGC ATA ACG GAA TAA GGT GGC reverse
EIF3K NM_001034489.2 TGA CAG ACA GCC AGC TAA AGG TGT forward 100
TCT TCT CCA CGA TGT TCT TGG GCT reverse
1Bone morphogenic protein 2 (BMP2), SMAD family member 1 (SMAD1), sterol regulatory element binding protein 1c (SREBP-1c), sonic hedgehog (SHH), chicken ovalbumin protein transcription factor 1 (COUP-TF1), chicken ovalbumin protein transcription factor 2 (COUP-TF2), preadipocyte secreted factor-1 (PREF-1), wingless-type MMTV integration site family, member 5a (WNT5a), lipoprotein lipase (LPL), fatty acid synthase (FAS), stearoyl-coenzyme A desaturase (SCD), eukaryotic translation initiation factor 3 subunit K (EIF3K).



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Least squares means ± SEM for performance, carcass traits, Warner-Bratzler shear (WBS), objective Hunter score color measures, and cook loss of heifers by group1,2

 
Variable3 Group 1 Group 2 Group 3 Group 4 SEM P-value
Ryegrass, d 0 99 218 99
Grain, d 0 0 0 119 d
Days on feed, d 0 99 218 218
ADG, kg·d–1 3.28a 2.06b 2.04b 0.11 0.0001
Final frame score 5.58 5.72 5.62 5.35 0.42 0.95
HCW, kg 308c 494b 548a 576a 19 0.0001
Backfat, mm 0.9c 6.4b 7.0b 12.3a 0.8 0.0001
Marbling score 386c 444b 494a 539a 23 0.0009
REA, cm2 47.0b 61.8a 69.4a 65.2a 3.0 0.0002
KPH, % 0.76c 1.92b 2.01b 2.26a 0.11 0.0001
Yield Grade 1.57c 2.32b 2.23b 3.11a 0.20 0.0001
24h pH 5.74 5.76 5.90 5.71 0.07 0.31
L*, lightness 34.4 36.7 35.8 38.7 1.4 0.19
a*, redness 15.8c 19.3b 20.1b 22.5a 0.8 0.0001
b*, yellowness 12.0c 15.0b 15.0b 17.0a 0.8 0.002
Cook loss, % 26.5a 11.0b 8.3b 8.2b 2.8 0.0001
WBS, kg 4.31a 4.75a 2.67b 2.54b 0.22 0.0001
1Group means within a row with different superscripts differ (P < 0.05), n = 6.
2Group 1 = control (0 d, initial heifers), Group 2 = 99 d on ryegrass, Group 3 = 218 d on ryegrass, Group 4 = 99 d on ryegrass followed by 119 d on grain.
3REA = ribeye area. Backfat is presented as adjusted backfat. Cook loss percentage is expressed on a wt/wt wet basis.
4Marbling Score: 300 = Traces; 400 = Slight; 500 = Small.



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Correlation of subcutaneous adipose tissue gene expression and adjusted backfat thickness1

 
Gene ADJ_BF2 PPARγ BMP2 SMAD1 SREBP1c SHH COUPTF1 COUPTF2 PREF1 WNT5a LPL FAS SCD
PPARγ 0.518 0.776 0.680 –0.289 –0.900 –0.859 –0.890 –0.749 –0.066 0.836 0.567 0.926
P < 0.01 P < 0.0002 P < 0.003 P < 0.26 P < 0.0001 P < 0.0001 P < 0.0001 P < 0.0002 P < 0.788 P < 0.0001 P < 0.011 P < 0.001
BMP2 0.286 0.776 0.216 –0.266 –0.638 –0.516 –0.525 –0.241 –0.524 0.859 0.418 0.726
P < 0.24 P < 0.0002 P < 0.42 P < 0.29 P < 0.003 P < 0.024 P < 0.021 P < 0.32 P < 0.021 P < 0.0001 P < 0.07 P < 0.0004
SMAD1 0.539 0.680 0.216 –0.148 –0.798 –0.687 –0.779 –0.823 0.623 0.410 0.321 0.757
P < 0.035 P < 0.003 P < 0.42 P < 0.58 P < 0.0001 P < 0.002 P < 0.0002 P < 0.0001 P < 0.008 P < 0.10 P < 0.20 P < 0.0004
SREBP1c 0.231 –0.289 –0.266 –0.148 0.309 0.320 0.363 0.289 –0.013 –0.179 –0.024 –0.186
P < 0.36 P < 0.26 P < 0.29 P < 0.58 P < 0.212 P < 0.20 P < 0.14 P < 0.25 P < 0.96 P < 0.48 P < 0.92 P < 0.46
SHH –0.429 –0.900 –0.638 –0.789 0.309 0.922 0.932 0.846 0.027 –0.800 –0.631 –0.934
P < 0.05 P < 0.0001 P < 0.003 P < 0.0001 P < 0.21 P < 0.0001 P < 0.0001 P < 0.0001 P < 0.90 P < 0.0001 P < 0.003 P < 0.0001
COUPTF1 –0.373 –0.859 –0.516 –0.687 0.320 0.922 0.906 0.894 –0.165 –0.668 –0.548 –0.839
P < 0.11 P < 0.0001 P < 0.02 P < 0.002 P < 0.20 P < 0.0001 P < 0.0001 P < 0.0001 P < 0.49 P < 0.001 P < 0.01 P < 0.0001
COUPTF2 –0.410 –0.890 –0.525 –0.779 0.363 0.932 0.906 0.865 –0.108 –0.707 –0.536 –0.894
P < 0.07 P < 0.0001 P < 0.02 P < 0.0002 P < 0.14 P < 0.0001 P < 0.0001 P < 0.0001 P < 0.65 P < 0.0005 P < 0.01 P < 0.0001
PREF1 –0.416 –0.749 –0.241 –0.822 0.289 0.846 0.894 0.865 –0.414 –0.444 –0.458 –0.730
P < 0.05 P < 0.0002 P < 0.32 P < P < 0.25 P < 0.0001 P < 0.0001 P < 0.0001 P < 0.07 P < 0.05 P < 0.04 P < 0.0003
WNT5a 0.201 –0.066 0.524 0.623 –0.013 0.027 –0.165 0.108 –0.414 –0.450 –0.137 –0.092
P < 0.40 P < 0.79 P < 0.02 P < 0.008 P < 0.96 P < 0.91 P < 0.49 P < 0.65 P < 0.07 P < 0.05 P < 0.57 P < 0.70
LPL 0.261 0.836 0.859 0.410 –0.179 –0.800 –0.668 –0.707 –0.445 –0.450 0.711 0.889
P < 0.27 P < 0.0001 P < 0.0001 P < 0.10 P < 0.48 P < 0.0001 P < 0.001 P < 0.0005 P < 0.05 P < 0.05 P < 0.0004 P < 0.0001
FAS 0.214 0.567 0.418 0.321 –0.024 –0.630 –0.548 –0.536 –0.458 –0.137 0.711 0.715
P < 0.37 P < 0.01 P < 0.07 P < 0.21 P < 0.92 P < 0.003 P < 0.01 P < 0.01 P < 0.04 P < 0.57 P < 0.0004 P < 0.0004
SCD 0.462 0.923 0.723 0.757 –0.187 –0.924 –0.839 –0.894 –0.730 –0.092 0.889 0.715
P < 0.039 P < 0.0001 P < 0.0004 P < 0.0004 P < 0.46 P < 0.0001 P < 0.0001 P < 0.0001 P < 0.0003 P < 0.70 P < 0.0001 P < 0.0004
1Pearson correlation coefficients and associated P-values for adjusted backfat and subcutaneous adipose tissue mRNA expression of PPARγ, bone morphogenic protein 2 (BMP2), SMAD family member 1 (SMAD1), sterol regulatory element binding protein 1c (SREBP-1c), sonic hedgehog (SHH), chicken ovalbumin protein transcription factor 1 (COUP-TF1), chicken ovalbumin protein transcription factor 2 (COUP-TF2), preadipocyte secreted factor-1 (PREF-1), wingless-type MMTV integration site family, member 5a (WNT5a), lipoprotein lipase (LPL), fatty acid synthase (FAS), and stearoyl-coenzyme A desaturase (SCD); n = 24.
2ADJ_BF = ultrasound carcass 12th rib fat thickness adjusted for rump fat thickness.