Residual feed intake divergence during the preweaning period is associated with unique hindgut microbiome and metabolome profiles in neonatal Holstein heifer calves

Table 2 Body measurements and growth performance during preweaning period in least-efficient (L-eff, n = 13) or most-efficient (M-eff, n = 13) heifer calves

Week	RFI		SEM¹	P-value
	L-eff	M-eff		RFI	Time	RFI × Time
Weekly body weight, kg
1	43.62	42.31	1.36	0.30	< 0.01	0.11
2	46.25	44.91	1.36
3	50.38	49.48	1.36
4	56.39	54.69	1.36
5	61.76	59.72	1.36
6	67.41	63.38	1.36
Weekly body length, cm
1	111.82	111.37	1.59	0.89	< 0.01	0.90
2	114.81	115.92	1.59
3	117.99	118.31	1.59
4	121.18	122.19	1.59
5	125.17	125.01	1.59
6	128.54	128.47	1.59
Weekly hip height, cm
1	81.42	81.90	0.82	0.98	< 0.01	0.40
2	83.06	83.52	0.82
3	84.57	84.30	0.82
4	85.88	85.36	0.82
5	87.45	87.49	0.82
6	89.54	89.18	0.82
Weekly hip width, cm
1	16.49	16.16	0.32	0.11	< 0.01	0.34
2	17.74	17.61	0.32
3	18.88	18.18	0.32
4	19.56	18.84	0.32
5	20.36	19.60	0.32
6	21.33	20.36	0.32
Weekly wither height, cm
1	77.50	77.80	0.80	0.81	< 0.01	0.53
2	78.29	79.25	0.80
3	80.54	80.60	0.80
4	81.64	81.64	0.80
5	83.25	83.45	0.80
6	85.08	85.14	0.80
Weekly body weight gain², kg/d
1	0.10^b	0.37^a	0.10	0.94	< 0.01	< 0.01
2	0.38	0.37	0.10
3	0.59	0.65	0.10
4	0.86	0.75	0.10
5	0.77	0.72	0.10
6	0.91^a	0.52^b	0.10
Cumulative body weight gain, kg	23.83	23.68	0.50	0.94
Cumulative starter DMI, kg	19.98	10.90	1.66	< 0.01

¹Standard error of the mean
²Average daily gain per week (kg) = (final BW – initial BW)/7
^a,bDifferent letters indicate significant differences due to the main maternal effect (P < 0.05)