Table 3.

Efficiency N utilization by dairy heifers raised in palisade grass pastures fertilized with urea (150 kg N/ha/yr, fertilized), mixed with forage peanut (mixed) and without N fertilization (control)¹

Items2	Treatments			SEM	P-value
	Fertilized	Mixed	Control
Nitrogen balance
N ingested, g/d	119	131	120	6	0.5498
N feces, g/d	52	59	52	2	0.3037
N urine, g/d	40	40	33	4	0.5612
ENU, %	56	54	55	2	0.8945
Urea, mg/dL	392	324	290	37	0.3312
Nmic, g/d	63	49	63	9	0.2786
EMPS, g/d	392	305	292	55	0.1758

1Average 2-yr evaluation (n = 28).

²ENU = efficiency of nitrogen utilization; Pmic = microbial protein; Nmic = synthesis of nitrogen compounds; EMPS = efficiency of microbial protein synthesis (g Pmic/kg TDN).