Table 5.

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

	Treatment1
	WR		CR			Treatment P-value2
Trait	PS	NS	PS	NS	SEM	Sys.	Supp.	S × S
n	6	6	6	6	—	—	—	—
Calf birth date, Julian d	82a	92b	91b	81a	2	0.61	0.80	<0.001
Calf birth BW, kg	38.0	36.6	38.9	37.3	1.1	0.27	0.06	0.92
Calf weaning BW, kg	247a	225b	235ab	245a	8	0.43	0.27	0.01
Calf adj. 205-d BW, kg	231	219	227	229	6	0.45	0.19	0.10
Initial feedlot BW, kg	243a	222b	233ab	244a	11	0.26	0.31	0.004
Reimplant BW, kg	456a	422b	440ab	444ab	11	0.68	0.04	0.01
ADG, kg/d	1.71	1.66	1.69	1.66	0.05	0.85	0.09	0.65
Final BW, kg	622a	591b	609ab	614a	13	0.52	0.10	0.02
Treated, birth to weaning,3 %	17	17	20	19	11	0.68	0.91	0.99
Treated, weaning to slaughter,4 %	0	12	3	11	5	0.83	0.05	0.62
DMI, kg/d	9.09	8.87	9.29	9.01	0.24	0.21	0.07	0.81
G:F, g/kg	188.5	187.5	183.3	185.1	7.0	0.31	0.91	0.70

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

¹WR-PS = dams supplemented 3 times per week 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 by CP supplementation treatment interaction.

³Percentage treated for respiratory and gastrointestinal disease between birth and weaning.

⁴Percentage treated for respiratory and gastrointestinal disease between weaning and slaughter.