Table 6.

Effects of dam winter grazing system and CP supplementation during the last trimester of gestation on carcass merit of steer progeny

	Treatment1
	WR		CR			Treatment P-value2
Trait	PS	NS	PS	NS	SEM	Sys.	Supp.	S × S
n	6	6	6	6	—	—	—	—
HCW, kg	376a	357b	368ab	371a	8	0.52	0.10	0.02
12th-rib fat, cm	1.26	1.16	1.21	1.19	0.08	0.84	0.31	0.58
Marbling score3	503	457	482	430	20	0.12	0.004	0.86
Empty body fat, %	29.93	28.73	29.26	28.80	0.61	0.48	0.06	0.38
LM area, cm2	88.5	88.4	90.3	89.7	1.9	0.21	0.75	0.85
Yield grade	2.94	2.69	2.74	2.77	0.18	0.55	0.26	0.16
Marbling:yield grade	171.8	171.6	178.1	155.7	8.3	0.41	0.06	0.07
Quality grade, % Sm4 or greater	84.5	76.5	88.2	64.6	9.0	0.57	0.04	0.28
Quality grade, % Md5 or greater	43.2	26.6	35.4	15.0	1.0	0.34	0.03	0.81

^a,bWithin a row, means without a common superscript differ at P < 0.05.

¹WR-PS = dams supplemented 3 times per wk with the equivalent of 0.45 kg/d 28% CP cake (DM basis) during gestation and grazed dormant winter range; WR-NS = dams not supplemented with CP during gestation, grazed dormant winter range; CR-PS = dams supplemented with the equivalent of 0.45 kg/d 28% CP cake (DM basis) during gestation and grazed corn residue between weaning and the subsequent calving season; CR-NS = dams not supplemented with CP during gestation, grazed corn residue between weaning and the subsequent calving season.

²Sys = winter grazing system treatment main effect; Supp = CP supplementation treatment main effect; S × S = winter grazing system × CP supplementation treatment interaction.

³Where 400 = small⁰.

⁴Sm = small quality grade, USDA low choice.

⁵Md = modest quality grade, USDA average choice.