Table 2.

Nutritional profile (dry matter basis) of feedstuffs offered to cows during the experiment^1,2

Item	Pasture		Supplemental cubes	Sorghum-sudangrass hay
	A	B
Net energy for maintenance, Mcal/kg	1.14	1.62	2.00	1.00
Net energy for lactation, Mcal/kg	1.18	1.02	1.33	0.44
Crude protein, %	10.7	20.5	48.0	11.8
Neutral detergent fiber, %	57.7	19.6	24.0	61.5
Ca, %	0.98	2.07	0.32	0.76
P, %	0.27	0.32	1.26	0.25
Mg, %	0.29	0.41	0.67	0.31
K, %	1.62	2.72	1.86	4.11
Na, %	0.02	0.05	0.28	0.02
Co, mg/kg	1.61	3.05	1.10	0.69
Cu, mg/kg	8	12	15	11
Fe, mg/kg	3,855	5,120	303	1,566
Mn, mg/kg	106	144	36	54
Se, mg/kg	0.40	0.20	0.19	0.12
Zn, mg/kg	42	35	66	57

¹Values obtained from a commercial laboratory wet chemistry analysis (Dairy One Forage Laboratory, Ithaca, NY). Total digestible nutrients were calculated according to equations described by Weiss et al. (1992). Net energy for maintenance and lactation were calculated with equations described by the NRC (2000).

²Cows were maintained in a single pasture (A) dominated by bermudagrass (Cynodon spp.) and were supplemented with 12 kg of sorghum-sudangrass hay and 0.76 kg of cubes daily from day 93 until calving. Upon calving, cow–calf pairs were moved to an adjacent pasture (B) dominated by perennial ryegrass (Lolium perenne L.).