forage quality for dairy cattle full

7/25/2019 Forage Quality for Dairy Cattle Full

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FORAGE

QUALITY

FOR

DAIRY

CATTtE

J.

R.

Kawas,

R.

D. Shaver, J. A. Woodford,

N.

A. Jorgensen and D. A. Rehweder

De?artments of

Dairy

Science

and Agronomy

U

niversit

y

of Wisconsin-Madison

Quality -

represents the e x c ~ l l e n c e

productive worth, which a forage

possesses.

Forage

quality

rea1ly refers te

the

nutr i t ive

va1ue of th

feedstuff.

For

a

forage to

be

of high

quality

i t

must be

high in thre

factors:

1)

intake,

2)

digest ibi l i ty,

and

3)

ef

f

iciency of ut i l izat io

(Waldo and Jorgensen,

1981).

The f

actor of high intake

must

inc1ude

desirable

subfactor

of high

substitution for concentrate.

The

factor

high

digest ibi l i ty

subdivides

into

three

subfactors:

1)

the

total ce

wall fraction is spl i t into

potentia11y

digestible cel1 walls

and

indigestible cell walls; the

potentia1ly

digestible

cel1

walls must

b

high, 2)

the fractional rate of digestion of the potentially digestib

ce11

wal1s

must be

rapid,

and

3)

che

depression of digestibi1ity

at

h


2/11

recommendations have

been

presented

(Barnes,

1975; Barnes et a l .

Rohweder

et

al .

1976

a, b,

1978, 1981; Moore,

1977).

A

description of the

proPQsed market hay

grades appears

in Table

with the typical chemical composition

for

the proposed

hay

grades

was

established as

the assay of choice

for

estimating voluntary

i

and

ADF for

estimating dig

est

ibi l i tv

Table Z

Both

digestible e

concentration and

voluntary

intake

of digestible

energy should be

considered

when assigning

the

optimum

feeding

value to

a forage.

combination of both analyses

were

used to estimate

digestible dry

intake.

The

formulas used

to

calcu1ate relat ive

feed

value are

presented with

Table

2.

They were

derived

from regression

analys

of

intake and digest ibi l i ty

of dry

matter data for forages of kno

composition that

were fed

to sheep.

A comparison of cat t le and s

data suggest

on1y

small

differences

in

digest ibi l i ty

between spec

However, dry matter

intake

values for hays fed at

maintenance

lev

differ for

ca

t t le

and

sheep fed the

same

hays.

Cattle averaged 7

higher dry matter

intake than

sheep for

a l l

legumes in Grade 2, 6

higher

for

Grade

3,

60

higher for

Grade

4,

and

50

higher

for Gr

These values are comparable

to

the

work

of

Buchman and

Hemken

(19

which showed a 72 higher

dry

matter intake per unit body

weight

cat t le than

for

sheep. Donef5r et al . (196)

used expected stand


3/11

weeks

postpartum

and were

in positive energy balance at ini t ia t ion of

the experimento

Four

t r i a l s were

conducted

using a

4X4 Latin

square

design

for

each

stage

of forage maturity

fed

with

20,

37,

S4 and 71

concentrate (DM basis). The

concentrate

contained varying levels of

soybean meal

to

provide

isonitrogenously

balanced

diets .

Diets were

offered

ad

libitum,

four

times

daily.

The

feeding

periods

were

24

dav

long with the las t seven days used

for

data collection.

As

the level of

concentrate

feeding

increased,

digestible dry

matter

intake increased

regardless

of forage maturity, Figure

1. Digestible

dry matter

intake was

highest

for

diets

containing prebloom

alfa l fa

ha

at

a1l

1evels of

concentrate

feeding. A1though intake and digestibi l i

of

forages

are re1ated,

they

are separate

measures

of

quality.

Intake

is

dependent

upon structural volume, basically cell wa1l

content,

whil

digestibil i ty

is dependent upon cell wall content and avai1abili ty to

digestion Van

Soest, 1982).

The lat ter is affected by 1ignification

and

other

factors,

such as:

level of intake, rate of passage, and

part icle

s i z ~ In the study by Kawas

et

al .

1983),

the correlations

between ADF and NDF

intakes

with digestible dry matter

intake (

BW)

were

- .80

and

- .81,

respectively.

Thus,

intake

and

digest ibi l i ty

as

re1ated to

stage of maturity

-

chenica1 composition

-

leaf:stem

ratio

are measures

of

qua1ity.

tNeutra1

detergent

f i b e ~ i s highly correlated with

intake

Rohweder et


4/11

USE OF NDF AND ADF IN DIET

FORlfULATION

Because of

the

differences in

chemical

composition of feedstuffs, d

should be f ormulated on an energy

concentration

or a measurement su

NDF or ADF whi ch may predict energy va).l.Ie rather than forage te con

trate

ra t ios

. The

data

i n

i ~ u r

5

~ n

6

s u g ~ e s t

that

during

the

?riod o

10

t o

26

weeks po

stpartum,

hi gh producing cows should be

diets

containing

less

than 3

2%

N

DF

and

22

ADF

to maintain

a

positi

weight gain

while

producing over 30 Kg 4% FCM/day. The highest ou

of

4%

FCM occurred with dietary

NDF

and ADF levels of 24 to 26 and

to

21 ,

respectively. When

balancing these levels for energy outp

and weight gain, from the data

available

at

this time, a minimum

dietary

leve

l

of

28-31

N

DF

and

19

to

21 ADF

(DH

basis)

ls

sugges

f

or

cows

bet

ween 10 to

26

weeks

postpartum.

The higher

forage

qua

the

lower the

fiber

level , the more

forage

can be used in diet form

Mertens (198 2)

suggested

diets containing

36 NDF,

comprised

of

different forages and forage to concentrate

ratios,

would support a

output of 20 Kg 4%

FC}1.

This coincides with the data of Kawas et a

1983). The

level of ADF, 19 te

2

1 ,

is in agreement

with the

NRC

Cattle

1978).

However, a

cow

in

early

lactat ion,

f i rs t

10

weeks,

require a lower

dietary ADF level to achieve

maximum energy

outout.

Of

the fiber, approximatel

y

80

should come from

forage Jorgensen,


5/11

REFERENCES

Barnes,

R. F. 1975.

Predicting

digestible

energy

values of hays.

Proc.

of Laboratory l1ethods and Services \Jorkshop. ay

20-22,

1975. Salem,

OR.

Co-sponsored

by

the

Association of

American

Feed Control Officia1s, Inc., Assoc. Official

Anal.

Chem.

AAFCA-AOAC).

Barnes,

R.

F., D. A. Rohweder, and N.

A.

Jorgensen. 1977. The

proposed establishment of hay standards.

Presented at

the

34th

Southern Pasture and Forage Crop Improvement Conference, Auburn

AL:

April

12-14,

1977.

Bartley,

E.

E. 1976. Bovine

Saliva:

Production and Function.

Buffers and Ruminant Physiology and Metabolism. M S. Weinberg

and

A.

L. Sheffner, eds. Church and Dwight Co., ~ w York.

p.

6

Buehman, D.

T.,

and

R.

W Hemken. 1964. Ad

Libitum intake

and

digest ibi l i ty

o

several

alfalfa

haysbv

eatt le

and

sheep.

J.

Dairy Sei . ,

47:861-864.

Donefer

E., E.

W Crampton, and

L. E.

Lloyd. 1966. The predietion

of digestible energy intake potential NVI) of forages using


6/11

~ o h w e d e r D A.,

R

F.

Barnes, ~ n d N A Jorgensen.

1976a. The u

of chemica l ana1yses

ta

establish hay market standards. Pape

presented at the First nternational Svmposium on Feed Consum

Animal Nutr ient Requirements, and

Computerization

of Diets,

J

11-16,

19

7

6.

Logan,

UT

Rohweder,

D A.,

R

F.

Barnes,

an

N A J o r ~ e n s e n .

1976b. A

sta

dardized approach

to estab1ish market

value

for hay. Agron.

Abstr., p.

11

2 .

Rohweder,

D A., R

F.

Barnes,

and

N A Jorgensen.

1978. Propos

grading

standards

based

on

laboratory

analyses

f6r

eva1uating

quality.

J. Anim. Sci. , Vol.

47, No 3,

747-759.

Rohweder,

D

A., N A Jorgensen, and R F. Barnes. 1981. Propos

Grading

Standards

Based

on Laboratory

Ana1yses

for Eva1uating

Quality.

Proc. XIV

Int l . Grassl. Congr. pp.

534-538.

Lexin

KY.

Santini,

F. J . A

R Hardie, N A Jorgensen,

and

M

F. Finner.

Proposed

use of adjusted

intake

based on forage

partie1e

1eng

for

calculation

of roughage

indexes.

J. Dairy Sei. 66:811.


7/11

Table

l

Proposed market hay

grades for

legumes

grasses

and legume

grass mixtures - AFGe Hay Marketing Task

Force.

Grade

Prime

1

2

3

3rief

Description

Legume

prebloom

Legume

early

bloom

20

grass-veg.

Legume

mid

bloom 30

grass-E.

Head.

Legume

ful l

Checical

C o m p o s ~ c i o n ,

D ~

~ a s i s

CP

ADF

~ i D F

> 19 30 39

17-19 31-35 40-46

14-16 36-40 47-53

11-13

40-42

53-60


8/11


9/11

-

=

al

:?i

o

O

V I

3.0

2.5

2.0

1.5

1

CONCENTRATE %

OF

DMI

Figure

1 Change

n diges t ib le dry mat te r

in take

(DDMI) with

s tage of

a l f a l f a

matur i ty

and

concen t ra te

l eve l

PRE

16

-

u

C

Lo

.t:

-

G)

E

i=

m

e

~ ~

Q)

t::

O

ca

-

t-

8

~

Jn J

CONCENTRATE % OF DMI

Figure 2 Total

chewing

t ime hr /day)

a

re la ted

to change

in maturi ty

of

a l f a l f a and

concentra te

l eve l


10/11

-

Jo-

~

~

:e

.......

0\

3 9

3.7

3 5

3 3

3.1

2.9

..

\

,

fui

,

- . . . . . pre

'

' ...

- - ~

...

~ '

lo...

id

\ ~ m

~

ear l y

~

. , ,

1

% CONCENTRATE (%

t DMa)

Figure

3 Influence

of forage maturity

and

concentrate

level

on milk

fa t t e s t .

45

40

-

-

ca

0

35

-

m

~

~

30

O

u.

v 25

20

,,*---

-

- - -A

. ...--_

.

--_

~

~

CONCENTRATE,

% OF DMI

Figure 4

Change in

4

FCM

output

wi

stage

of

a l fa l fa

maturity

a

concentra te

leve

l .

4S

.-

.

' ' ' ;

..


11/11

-..

.....

PRE .

>.

40

* EARLY

ca

MIO

O

-

. ~ . *

Y

FULL

l

35

--.,

' - ~

y

* ....

.:

ft

30

'Y ' ........

cP.

....

v

25

'Y

,

t-

20

t

2f

-

-

1

........ f

o

' ...

-

..

l

.* .....

*

-

~

O

lIo ;;;J(

.

...

~

,

.

.... ....

U

-1

.........

==

....

a l

Y

-2 ... '

I

I I

,

15

20

25 30

35

40

45

50

%

NDF 1 ( DMI )

Figure 5. Influence of

dietary NDF

level

on 4 FCM

output

and

body

weight

(BW)

change.

..

, ~ - ~ ~ ' : - - > ~ ~ ~ ~ ' v . ; ~ f ; t ~ ~ r ; ~ ~ ~ ~ ~ 7 ' - ; f > ; ; ~ ~ : r ~ t r -

:>.

4 0

IV

e l

ti, 35

*

*

...

...-.

-lI:

U

lL

v

>-

co

O

-

a l

-

l)

a l

e

co

.l::

U

==

l

- ,

30

Y

~ *

y

.

25

'Y

~

20

2

1

...

'.... y

.* ~

*

.... *

'C-

...

,

.

....

-1

....

.

',

'Y

2

I

I

I

10

15

20

25

30

35 40

ADF

% of

C

DMI)

Figure 6. Iofluence of dietary

ADF

0 0 4

FCM outpu

t aod body

weight

(BW)

chaoge.

forage quality for dairy cattle full

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