Table: Nutrient Requirements of Pregnant Replacement Beef Cows a

Nutrient Requirements of Pregnant Replacement Beef Cows ^a

Months Since Conception:	1	2	3	4	5	6	7	8	9

NE_mrequired (Mcal/day)
Maintenance	5.98	6.14	6.30	6.46	6.61	6.77	6.92	7.07	7.23
Growth	2.29	2.36	2.42	2.48	2.54	2.59	2.65	2.71	2.77
Pregnancy	0.03	0.07	0.16	0.32	0.64	1.18	2.08	3.44	5.37
Total	8.31	8.57	8.87	9.26	9.79	10.55	11.65	13.23	15.37
*MP required (g/day)*
Maintenance	295	303	311	319	326	334	342	349	357
Growth	118	119	119	119	119	117	115	113	110
Pregnancy	2	4	7	18	27	50	88	151	251
Total	415	425	437	457	472	501	545	613	718
*Calcium required (g/day)*
Maintenance	10	11	11	11	12	12	12	13	13
Growth	9	9	9	8	8	8	8	8	8
Pregnancy	0	0	0	0	0	0	12	12	12
Total	19	19	20	20	20	20	33	33	33
*Phosphorus required (g/day)*
Maintenance	8	8	8	9	9	9	10	10	10
Growth	4	4	3	3	3	3	3	3	3
Pregnancy	0	0	0	0	0	0	7	7	7
Total	12	12	12	12	12	13	20	20	20
*Average daily gain (kg/day)*
Growth	0.39	0.39	0.39	0.39	0.39	0.39	0.39	0.39	0.39
Pregnancy	0.03	0.05	0.08	0.12	0.19	0.28	0.40	0.57	0.77
Total	0.42	0.44	0.47	0.51	0.58	0.67	0.79	0.96	1.16
*Body wt (kg)*
Shrunk body	332	343	355	367	379	391	403	415	426
Gravid uterus mass	1	3	4	7	12	19	29	44	64
Total (kg)	333	346	359	374	391	410	432	459	490
Total (lb)	733	761	790	823	860	902	950	1,010	1,078
^a Mature weight, 533 kg (1,173 lb); calf birth weight, 40 kg (88 lb); age at breeding, 15 mo; breed code Angus; see Table: Mean Nutrient Content of Feeds Commonly Used in Beef Cattle Diets ^a Mean Nutrient Content of Feeds Commonly Used in Beef Cattle Diets ^a for abbreviations. The concentration of vitamin A in all diets should be 2,200 IU/kg (1,000 IU/lb) of dry matter. Adapted, with permission, from Nutrient Requirements of Beef Cattle, 2000, National Academy of Sciences, National Academy Press, Washington, DC.