Merck Manual

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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

NEmrequired (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 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.