Table 5.

Effects of prenatal¹ and postnatal² maternal protein supplementation on postweaning growth and carcass characteristics of calves fall born calves

Trait	Treatment				SEM	P value
	CON-CON3	CON-RES4	RES-CON	RES-RES		Prenatal	Postnatal	Prenatal×Postnatal
Yearling weight5, kg	280.1b	273.5b	276.7b	255.5a	5.7	0.02	< 0.01	0.10
ADG, kg/d (weaning to 1 yr of age)	0.48	0.47	0.45	0.48	0.04	0.32	0.39	0.26
Final body weight, kg	629.0a	633.5a	658.1b	637.8ab	7.7	0.03	0.31	0.11
ADG, kg/d (Feedlot)	1.79a	1.78a	1.89b	1.82ab	0.03	0.02	0.20	0.39
Hot carcass weight, kg	377.7	377.9	392.9	380.4	5.5	0.11	0.27	0.26
DRESsing percentage, %	63.6	64.0	63.6	63.7	0.4	0.55	0.46	0.69
Ribeye area, cm2	87.0	88.6	87.9	86.1	1.4	0.59	0.95	0.23
Yield grade	3.2	3.0	3.3	3.3	0.11	0.20	0.43	0.37
Back fat, cm	1.5	1.4	1.6	1.5	0.09	0.22	0.29	0.86
Marbling score6	364	369	376	353	16.0	0.91	0.59	0.41

^a–cMeans within row without a common letter differ (P < 0.05).

¹Prenatal treatment during conception and the first trimester of gestation.

²Postnatal treatment during early to mid-lactation.

³CON-CON = prenatal control diet and postnatal control diet.

⁴CON-RES = prenatal control diet and postnatal low protein diet.

⁵Yearling weight is adjusted to 365 d of age.

⁶Small = 300–399; Slight = 200–299.