Table 4.

Total nutrient apparent digestibility and rumen ammonia 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	P	T × P	CONT vs. NAR	13NAR vs. 20NAR
Digestibility,%
Dry matter	59.6	59.0	59.6	0.64	0.73	<0.0001	0.67	0.74	0.48
Organic matter	62.6	62.4	62.8	0.51	0.82	< 0.0001	0.57	0.97	0.54
Crude protein	55.0	54.8	55.8	1.07	0.76	<0.0001	0.72	0.81	0.49
Neutral detergent fiber	70.0	69.4	70.0	0.62	0.73	<0.0001	0.88	0.71	0.49
Acid detergent fiber	68.8	70.0	69.1	0.63	0.45	<0.0001	0.79	0.70	0.23
Mineral	24.2	22.7	24.5	2.13	0.83	<0.0001	0.62	0.82	0.56

¹Treatments were offered on a daily basis throughout the experimental period (day 0 to 140). ²Samples for nutrient digestibility were collected from d 23 to 27 (period 01), 51 to 55 (period 02), 78 to 83 (period 03), 107 to 111 (period 04), and 135 to 139 (period 05) of the experimental period. ³Letters within the same line denote differences at the P ≤ 0.05 level.

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