Table 1.

Theoretical feed intake, milk yield, and weight gain for 500 kg beef cows with varying forage quality, milk production potential, and maintenance energy requirement

Diet energy availability	72.5% TDN			62.5% TDN			52.5% TDN
Milk yield classification	M Milk1	H Milk2	H Milk	M Milk	H Milk	H Milk	M Milk	H Milk	H Milk
Maintenance classification	M Maint3	M Maint	H Maint4	M Maint	M Maint	H Maint	M Maint	M Maint	H Maint
DMI, kg/d5	13.9	14.7	14.2	12.9	13.3	12.6	11.1	11.1	10.5
Diet ME, Mcal/kg	2.57	2.57	2.57	2.20	2.20	2.21	1.86	1.86	1.87
ME intake, Mcal/d	35.6	37.7	36.5	28.4	29.3	27.9	20.6	20.6	19.6
Maint3, kcal/kg BW0.75	142	142	167	142	142	167	142	142	167
Feed for maintenance, kg	5.7	5.9	6.9	6.8	6.8	8.0	8.1	8.1	9.4
Milk yield, kg/d	10.0	14.0	11.7	10.0	12.2	8.7	4.4	4.4	1.6
Feed for milk, kg	4.2	6.0	5.0	5.2	6.5	4.6	3.0	3.0	1.1
Feed for maternal gain, kg	3.9	0.0	0.0	0.9	0.0	0.0	0.0	0.0	0.0
Gain	1.06	0.00	0.00	0.19	0.00	0.00	0.00	0.00	0.00

¹Moderate milk production potential at peak lactation (10 kg/d).

²High milk production potential at peak lactation (14 kg/d).

³Moderate maintenance energy requirement (142 kcal ME/kg BW^0.75).

⁴High maintenance energy requirement (166.5 kcal ME/kg BW^0.75).

⁵Dry matter intake (kg/d) estimated according to NASEM (2016): kg body weight^0.75 × (0.04997 × NE_m² + 0.04631)/NE_m + 0.2 × milk yield, (kg/d).