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Ingredients and chemical composition of diet

 
Diet ingredient, % (as-fed basis) Content
Sorghum-Sudan baylage 50.0
Concentrate 50.0
Composition baylage (DM basis)
    DM, % 61.1
    CP, % 11.7
    NDF, % 22.4
    TDN, %1 14.0
    ME, Mcal/kg2 2.13
Composition concentrate (DM basis)
    DM, % 87.2
    CP, % 13.2
    NDF, % 9.5
    TDN, %1 79.3
    ME, Mcal/kg2 3.10
1TDN = (105.2- 0.667 * NDF) * 0.88
2ME = (TDN * 1.01 *.04409)- 0.45



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Oligonucleotide polymerase chain reaction primers

 
Gene1 Accession no. Primer sequence (5’3’) Orientation Efficiency
NPY NM_001014845.3 TAG CGG AGC GTG ATT GCC CG Forward 100%
GGG GGT GTC CGG AGC AGG TT Reverse
AGRP EU374213.1 GGG CAC CCC TCT TGT AGA GCC Forward 95%
GGC CCA CAC GTG ACT GCT TCC Reverse
POMC NM_174151.1 GCC GCT GAA CAT CCT CGC CC Forward 100%
CTC CAG GCA CCA ACC ACG CA Reverse
RLN3 XM_002688750.1 GCA GTG GCC TCC AGC GAG TG Forward 96%
CCC TGG GGT TCC CTG CCA GT Reverse
MC3R XM_002701108.1 CGT GCT GTC TGC ACT CGG CT Forward 93%
TTG CCG TTC CTG ACC ACG GC Reverse
MC4R FJ430565.1 GCA AGC GGC AGG CTC GACG Forward 96%
GGC AGC CTC AGC ACC TTT CTC C Reverse
RXFP1 XM_610789.5 TGT GTC TGC AGT TAC GTG CTT TGG Forward 93%
GCC AGG GAC CCC AGA AGC TG Reverse
GnRH NM_177514.2 TCA CCT TCA GCT GCC TCT TCA TCA Forward 100%
TCA GCC GAG CTC GTG GTA TAT TGT Reverse
GnIH NM_001127268.1 CTG GAA AGG CTG TCC TCT CT Forward 92%
CCA ACC TGC CAC TGA GAT TT Reverse
FSHβ NM_174060.1 ACG TAC CCA GTA GCC ACT GAA TGT Forward 97%
AGC CTA CGC ACA TGT ACA CAC AGA Reverse
LHβ NM_173930.1 GCC CTG TCT GTA TCA CTT TCA CCA Forward 95%
TTA GAG GAA GAG GAT GTC TGG GAG Reverse
Leptin NM_173928.2 TCG TGA CCT TCT TTG GGA TTT Forward 91%
CAC ACT GGA ATA CTT CCC TCT C Reverse
EIF3K NM_001034489.2 TGA CAG ACA GCC AGC TAA AGG TGT Forward 100%
TCT TCT CCA CGA TGT TCT TGG GCT Reverse
1Neuropeptide-Y (NPY), agouti-related protein (AGRP), Pro-opiomelanocortin (POMC), relaxin-3 (RLN3), melanocortin 3 receptor (MC3R), melanocortin 4 receptor (MC4R), relaxin/insulin-like family peptide receptor 1 (RXFP1), gonadotropin releasing hormone (GnRH), gonadotropin inhibiting hormone (GnIH), and pituitary mRNA expression of follicle stimulating hormone beta polypeptide (FSHβ) and luteinizing hormone beta polypeptide (LHβ), and eukaryotic translation initiation factor 3 subunit K (EI3K).



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Growth and performance traits of steers by residual feed intake (RFI) group1,2

 
Variable Low Average High P-value
RFI –1.27 ± 0.16c 0.03 ± 0.08b 1.51 ± 0.18a 0.0001
Initial BW, kg 351 ± 12 345 ± 6 345 ± 14 0.91
Initial hip height, cm 127 ± 0.8 127 ± 1.3 125 ± 1.9 0.87
Dry matter intake, kg 438 ± 16b 483 ± 7.9a 544 ± 19a 0.0005
Final BW, kg 466 ± 15 455 ± 7 457 ± 17 0.94
Gain, kg 115 ± 6.2 111 ± 3.1 113 ± 7.2 0.84
ADG, kg·d–1 1.64 ± 0.09 1.58 ± 0.04 1.67 ± 0.10 0.83
1Values are least square means (lsmeans) ± SEM
2n = 8 (low), 34 (average), 6 (high)



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Carcass and meat quality traits by residual feed intake (RFI) group1,2

 
Variable Low High P-value
Yield grade3 2.6 ± 0.3 2.7 ± 0.4 0.85
REA, cm2 68.4 ± 5.6 63.9 ± 4.8 0.15
Back fat, mm 7.9 ± 0.7 7.4 ± 0.8 0.61
Marbling score4 474 ± 29 470 ± 33 0.93
L*, lightness 35.5 ± 1.0 34.9 ± 1.1 0.68
a*, redness 23.7 ± 1.0 22.5 ± 1.2 0.46
b*, yellowness 23.2 ± 1.0 22.5 ± 1.1 0.66
1Values are lsmeans ± SEM
2n = 8 (low), 6 (high)
3USDA Yield Grade: 1 to 5 scale, where 1 = leanest and 5 = fattest
4Marbling Score: 300 = Traces; 400 = Slight; 500 = Small; etc.
5Average group were sold at auction pre-harvest and therefore carcass data for these steers are not available



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Correlation of hypothalamic GnRH gene expression with pituitary gonadotropin gene expression1

 
FSHβ LHβ GnRH
FSHβ 0.953 0.589
P < 0.0001 P < 0.03
LHβ 0.953 0.783
P < 0.0001 P < 0.01
GnRH 0.589 0.783
P < 0.03 P < 0.01
1Pearson correlation coefficients and associated P values for arcuate nucleus mRNA expression of gonadotropin releasing hormone (GnRH) and pituitary mRNA expression of follicle stimulating hormone beta polypeptide (FSHβ) and luteinizing hormone beta polypeptide (LHβ). n = 8 (low), 6 (high).