Table 1

Table 3. Effect of non-protein nitrogen source and supplementation frequency on ruminants consuming low-quality forage

						P-Value^b
	Treatment^a					Con vs	Urea vs	D vs
Item	CON	UD	U2D	BD	B2D	Supp	Biuret	2D
Lambs (39 kg)
OM intake, g/kg BW	24.8	29.5	27.5	29.5	27.5	0.01	0.96	0.08
Total tract digestibility OM, %	42.8	51.4	51.2	51.0	48.7	0.009	0.49	0.56
N balance, g/kg BW	-0.012	0.042	0.013	0.041	0.041	0.02	0.36	0.34
Digested N retained^c, %	-54.4	16.3	6.5	28.6	19.4	0.003	0.45	0.56

Steers (491 kg)
OM intake, g/kg BW	16.1	17.7	17.3	18.1	17.4	0.009	0.29	0.08
Total Tract OM Dig., %	53.7	53.8	54.6	55.5	53.7	0.31	0.52	0.38
Bacterial N Production, g/kg BW	0.213	0.208	0.229	0.271	0.251	0.04	0.002	0.92
Bacterial Efficiency^d	24.1	20.8	24.2	26.2	26.9	0.84	0.05	0.28

Cows
Initial body condition score	4.85	4.85	4.86	4.87	4.89
BCS change	-0.55	0.20	0.21	0.18	0.02	<0.001	0.40	0.51

^a CON = control; UD = urea supplement every day; U2D = urea supplement every-other-day; BD = biuret supplement every day; B2D = biuret supplement every-other-day.

^b Con vs Supp = control vs supplemented treatments; Urea vs Biuret = urea vs biuret treatments; D vs 2D = daily vs alternate day supplementation.

^c Calculated as (Daily N retention, g/kg BW / Daily N digested, g/kg BW) ´ 100.

^d Calculated as g bacterial nitrogen/kg of OM truly digested in the rumen.