Nutritive value of several forage commonly used for
dairy cattle in the suburb of Hanoi
Paul Pozy, Vu Chi Cuong, Le Van Ban, Doan Thi Khang
Armand Deswysen and Daniel Deharen 1. Introduction
Giving appropriate diets to dairy cattle, is supplying a well-balanced diet in
nutrients such as crude protein, minerals and vitamins in order to meet their
requirements for meat and milk production, and foetus development. Providing
enough feeds and ensuring good operation of digestive system, reducing
production cost of milk, means using useful available feedstuffs in local areas.

In order to calculate the quality of nutritients needed by dairy cow, It must
be known clearly the nutritive value of available feedstuffs. The nutritive value of
a feed is determined throughout the percentage of each nutrients in this feed
digested by animal Digestibilities are normally determined by using experiments
on sheep (in vivo digestibility) Aerts, et al., 1984; De Boever et al., 1987).

With the above target, from April 1999 to May - 2001, different kinds of
grass such as natural grass, cultivated grass and other feedstuffs used dairy cattle
in Hanoi suburban were implemented to predict the in vivo digestibility and energy
value of feeds.

2. Materials and methods
Digestibilities and nutritive value of feeds had analysed and determined in
Hanoi suburban. Experiments had made on 17 adult rams of Bach thao breed,
averaging 25 kg (7 sheeps during April, 1999; 10 sheeps during Oct, 2000).

feed (or diets) (PDIME).

Protein values digestible in the intestine: PDIN = PDIA + PDIMN

PDIE = PDIA + PDIME

3. Results and discussion
Despite the plant composition of grass mix, its changing quality, and
quantity of each grass in mix, there is a little change in the chemical composition
of natural grass, except percentage of crude protein: high in July and low in
January. It is also rich in nutrients in August (in table 1). This results indicated that
the harvesting period is very important.

The results also show that Pennisetum purpureum grass has similar
chemical compositions around year (table 1). Further more, two rice straws have
nearly the same chemical composition (table 1)

Natural grass harvested in the winter and rice straw have voluntary dry
matter intake (g DM/kg W
0.75
) which is similar or significant higher than that of
Setaria sp grass: 57g DM/kg W
0.75
(Pozy et al, 1995). Voluntary dry matter intake
(g DM/kg W
0.75
) of natural grass, harvested from April until Oct, is higher than
that of tropical grass (71g DM/ W
0.75
) (Xande et al, 1989). Pennisetum purpureum

mate intake if ensiled Pennisetum grass was given. Agricultural by-products such
as ensiled corn stover or corn stover, can also include in dairy cattle’diets.

Rice straw can not be a main roughage in diets given to dairy cattle in areas
around Hanoi. If used rice straw replaces grass when lack of grass, it is needed to
be added feed rich in nutritients and crude protein.
Acknowledgements
To achieve this project, we had received useful helps from Dong Anh
Station Veterinary and Breeding Dairy Cattle Project of National Institute of
Animal Husbandry, as well as many students of Economy Department of HAU.
Thanks to the CUL, the Vietnamese and Belgian governments for funding his
study.

On this occasion, we also would like to give thanks to related organizations
and friends.
Summary
A series of feeding trials on sheep was conducted to determined the
nutritive value of several forage commonly used for dairy cattle in the suburb of

(%)

CP

(%)

Natural grass

January

March

April

June

August

Oct

Dried grass
22.10

20.40

49.70


64.70

63.00

70.40

65.80

68.10
10.70

14.80

12.70

19.30

11.10

12.70

10.90

Penniseutum purpureum

Experiment in 1999 year


93.10

74.10

9.00

Corn term (after harvested young seed)

8.70

87.10

73.00

8.70

Rice straw

Experiment in 1999 year

Experiment in 2000 year
92.80

85.10

Nutritive value (g/kg DM)
Voluntary
dry mater
intake
(gDM/kgW
0.75)

Dry
mater

Organic
mater

NDF

Nitrogen

PDIA

PDIN

PDIE

UFL

Natural grass



53.5

61.8

49.3

57.4

57.9

63.2

54.9

58.3

66.2

54.6

64.4

62.4

65.6

57.6

54.1


26

44

33

59

88

80

126

57

79

63

74

82

85

117

58


66.1

69.9

70.4

72.9

72.6

70.9

69.2

53

73

90

91

99

102

0.76

0.78


58.3

67.1

70.6

49.4

0.75

Rice straw

1999

2000

40.7

38.9

44.4

43.6