Table 5.

Plasma glucose and urea concentrations of Bos indicus steers receiving a high-forage (Cynodon dactylon spp.) diet and supplemented or not (CONT; n = 10) with 13 (13NAR; n = 10) or 20 (20NAR; n = 10) ppm of narasin (Zimprova; Elanco Animal Health, São Paulo, SP, Brazil) throughout the experimental period¹

	Treatments				P-Value2
Item	CONT	13NAR	20NAR	SEM	T	D	T × D	CONT vs. NAR	13NAR vs. 20NAR
Glucose, mg/dL	68.6	70.0	68.7	1.37	0.73	< 0.0001	0.73	0.64	0.51
Urea, mg/dL	16.2b	13.5a	14.2ab	0.81	0.08	< 0.0001	0.81	0.03	0.53

¹Treatments were offered on a daily basis throughout the experimental period (day 0 to 140). Blood samples were collected on day 0 (prior to first treatment administration), 28, 56, 84, 112, and 140 approximately at 0600 h after treatment administration. Letters within the same line denote differences at the P ≤ 0.05 level.

²T = treatment effect; D = day effect = T × D = treatment × day interaction; CONT vs. NAR = unsupplemented vs. narasin-supplemented animals; 13NAR vs. 20NAR = dose effect of 13 vs. 20 ppm of narasin.