Glycine max

Soybean, soya bean, soja bean, Manchurian bean

Annual summer herb up to 1 m high, usually erect though some varieties twine. The plant is entirely covered with fine brown or grey hairs. The trifoliate leaves usually drop before the seeds are mature. The climatic adaptation is about the same as that of maize - it needs warm but not too hot summers for development and can be grown on most types of soil, even if poor. After the plant is well started, it withstands short periods of drought and is not seriously retarded by a wet season. Less susceptible to frost than maize, cowpeas or field beans.

Straw. Residue of threshing of the beans from the plants. Low in digestible protein and high in fibre, but a relatively poor roughage. Should be combined with a good legume hay even for heifers and dry cows.

Hay. Digestive troubles may be caused by feeding soybean hay alone as it usually contains coarse woody stems; but this might be overcome to an extent by heavier rates of seeding and by early harvesting. The hay yield at full-bloom stage is approximately half that obtained when seeds are one half to three fourths developed. The percentage of leaves in the hay decreases with maturity.

Silage. Soybean is seldom ensiled alone because of its bitter taste; but it makes good silage if ensiled with maize, for example.

Pasture. Soybean is not a satisfactory pasturage for cattle as trampling damages the growing plant; it is used as pasturage for poultry and is an excellent supplementary pasturage for pigs. For the best results the beans should be allowed to ripen before the crop is grazed. Varieties at different stages of maturity can be mixed in the same pasture to secure a longer grazing period. A soybean pasture can be regrazed after about a month's regrowth.

As % of dry matter

DM

CP

CF

Ash

EE

NFE

Ca

P

Ref

Fresh, 20 cm, Chile

26.1

10.2

33.6

8.6

3.8

43.8

1.47

0.25

315

Fresh, 40 cm, Chile

26.1

11.3

35.4

8.4

3.5

41.4

1.33

0.26

"

Fresh, 80 cm, Chile

26.1

12.2

34.2

8.2

4.2

41.2

1.27

0.25

"

Fresh, mid-bloom,

fertilized, Puerto

Rico

16.0

16.6

31.0

11.8

2.8

37.8

1.57

0.25

32

Fresh, mature,

fertilized, Puerto

Rico

25.0

16.1

29.6

11.9

6.2

36.2

1.22

0.24

"

Hay, including all

leaves, South

Africa

13.9

35.5

5.5

2.5

42.6

0.94

0.18

489

Hay, overripe, few

leaves, South

Africa

19.5

25.7

12.1

7.4

35.2

0.78

0.31

"

Digestibility (%)

Animal

CP

CF

EE

NFE

ME

Ref

Fresh, mid-bloom

Sheep

76.0

57.0

51.0

74.0

2.31

32

Fresh, mature

Sheep

77.0

53.0

83.0

67.0

2.38

"

Vines, few leaves

Sheep

68.4

43.1

46.3

72.2

2.17

489

Vines, with leaves

Sheep

83.1

56.5

92.0

71.4

2.66

"

Nylon bag degradability

a

b

c

12hr

48hr

Ref

(%)

(%)

(/hour)

(%)

(%)

Soyabean meal, France

DM

18.9

79.7

0.0459

89.1

627

Soya husk

DM

12.4

43.5

0.0534

51.8

"

Soyabean meal

DM

24.7

77.2

0.0636

65.9

98.3

629

N

9.1

87.9

0.063

55.7

92.7

"

[P (rumen degradability at time t) = a+b*(1-exp(-c*t))]

Amino acid composition as % of crude protein

Aerial part

Ref

188

Arg

Cys

Gly

Hys

Ils

Leu

Lys

Met

Phe

Thr

Try

Tyr

Val

4.6

1.0

4.2

2.3

3.4

6.0

3.6

1.8

4.0

4.2

-

2.9

4.7