Table 2.

Effect of physical form and urea treatment of rice straw on feed intake, nutrient intake and apparent nutrient digestibility of dairy steers

Item	RS		UTRS		SEM	Significance1
	LFR	CHR	LFR	CHR		U	P	U×P
DM intake
Rice straw
kg/d	3.6	3.6	4.5	4.6	0.10	**	ns	ns
g/kg BW0.75	59.6	59.5	72.4	75.3	2.34	*	ns	ns
Concentrate
kg/d	1.2	1.3	1.2	1.2	0.04	ns	ns	ns
g/kg BW0.75	19.5	20.4	19.6	19.3	0.15	ns	ns	ns
Total
kg/d	4.7	4.9	5.7	5.7	0.11	*	ns	ns
g/kg BW0.75	79.1	80.0	92.0	94.6	2.47	*	ns	ns
Nutrients intake (kg)
Organic matter	3.9	4.2	5.0	5.1	0.07	**	ns	ns
Crude protein	0.3	0.3	0.4	0.4	0.01	**	ns	ns
Neutral detergent fiber	3.0	3.2	3.9	4.0	0.05	**	ns	ns
Acid detergent fiber	2.6	2.8	3.4	3.5	0.07	**	ns	ns
Apparent digestibility (%)
Dry matter	56.7	56.5	62.4	63.1	1.28	*	ns	ns
Organic matter	61.7	61.5	67.3	67.6	1.13	*	ns	ns
Crude protein	50.9	50.6	67.9	68.4	1.42	**	ns	ns
Neutral detergent fiber	55.8	60.0	65.7	64.7	1.02	*	ns	ns
Acid detergent fiber	51.3	55.6	60.2	60.0	1.26	*	ns	ns

¹U = Untreated rice straw vs urea-treated (3%) rice straw, P = Long form rice straw vs chopped (4 cm) rice straw, U×P roughage source and physical form interaction.

^*p<0.05,

^**p<0.01, ns = Non-significant (p>0.05).