DIFFERENCES IN CHEMICAL COMPOSITION AND DIGESTIBILITY OF BEET AND CANE MOLASSES

8/17/2019 DIFFERENCES IN CHEMICAL COMPOSITION AND DIGESTIBILITY OF BEET AND CANE MOLASSES

1/9

Animal Feed Science and Technology,

13 (1985 ) 83--91 83

Elsevier Science Publishers B.V., Amste rdam -- Printed in The Netherlands

D I F F E R E N C E S I N C H E M I C L C O M P O S I T IO N N D D I G E S T I B IL I T Y

O F B E E T N D C N E M O L S S E S

A. STEG and J.M. VAN DER MEER

Institu te for. Livestock Feeding and Nutrition Research, P.O. Box 160,

Lelystad The Netherlands)

(Received 27 December 1983; accepted for publication 21 May 1985)

ABSTRACT

Steg, A. and van der Meer, J.M., 1985. Differences in chemical composition and

digestibili ty of beet a nd cane molasses. Anim. Feed Sci. Technol., 13: 83--91.

Digestibility of beet and cane molasses was tested in vivo with wether sheep at two

levels of in clus ion of molasses in the r ati on (15 and 30%) as well as in vitro with ru me n

fluid.

In vivo, cane molasses was less digestible tha n beet molasses, irrespective of t he level of

inclusion in the rati on. The level of inclusion of the molasses did not have a significant

effect on the calculated organic matte r digestibility of the products. Increasing the ratio

of molasses to hay (or hay + sugar beet pulp ) linea rly increased in vitro OM digestibility

of the mixtu res irrespective of the molasses ty pe tested. Digestibility in vitro of cane

molasses was only slightly lower than that of beet molasses. Chemical characteristics of

bot h molasses are discussed in relat ion to possible expl anat ions for the differences

between results obt aine d in vitro and in vivo.

INTRODUCTION

O f f i c i a l f e e d s t u f f s t a b l e s ( T a b l e I ) s h o w r a t h e r l a rg e d i ff e r e n c e s in

c h e m i c a l c o m p o s i t i o n , a n d a l s o i n d i g e s t ib i l it y , o f b e e t a n d c a n e m o l a s s e s f o r

r u m i n a n t s . A c c o r d i n g t o E n g l is h a n d F r e n c h t a b l e s o r g a n ic m a t t e r d ig e st i-

b i l i t y ( D o

M )

o f c a n e m o l a s s e s is a t l e a s t a s h i g h a s t h a t o f b e e t m o l a s s e s. I n

v ie w o f t h e v e r y l o w a sh c o n t e n t , o n e m a y w o n d e r , h o w e v e r , w h e t h e r t h e

E n g l is h b e e t m o l a s s e s w a s r e a l ly b e e t m o l a s s e s . T h e D a n i s h a n d D u t c h f i g u r es

s u g g e s t a n a p p r e c i a b l y l o w e r DOM v a l u e f o r c a n e m o l a s s e s t h a n f o r b e e t

m o l a s s e s . D u t c h d a t a o r ig i n a t e f r o m a f e w d i g e s t i b il i t y t r ia ls w i t h w e t h e r

s h e e p , a n d t h e d i f f e r e n c e i n d i g e s t ib i l it y b e t w e e n c a n e a n d b e e t m o l a s s e s w a s

s u p p o r t e d b y d i f f e r e n c e s f o u n d in p ig s ( R i j p k e m a e t al . , 1 9 7 5 ) . T h e hi gh

l e v el s o f i n c l u s i o n o f m o l a s s e s i n t h e s h e e p t ri a ls ( 3 0 - - 5 0 o f d r y m a t t e r )

w e r e c r i ti c iz e d a s n o t b e i n g p r a c ti c a l a n d m i g h t h a ve i n f l u e n c e d t h e d i f f e r e n c e

b e t w e e n t h e m o l a s s e s ty p e s . I n t h is s t u d y 1 a s er ie s o f tr ia l s w a s p e r f o r m e d

1This study was done in cooperation with, and partly sponsored by, the allied molasses

trading companies.

0377- 8401/ 85/ 03.30 © 1985 Elsevier Science Publishers B.V.


2/9

8

TABLE I

Some tabulated figures concerning beet and cane molasses

Feed tables Dry matter In dry matter Digestibility

(g/kg) (g/kg) (%)

Ash CP OM CP NFE

Beet molasses/cane molasses

United Kingdom

(A.D.A.S., 1975) 750]750 69/87 47]41 87/88 34]35 90]90

France

(I.N.R.A., 1978) 775]739 116/123 103/56 89/91 60]60 93]93

Denmark

(Andersen et al.,

1979) 770]700 .99]117 137165 94]87 71/47 98]90

Netherlands

(C.V.B., 1977) 764]738 1 1 0 1 1 0 2 1401 41 90]83 65]0 95 ]87

Fed. Rep. Germany

(D.L.G., 1982) 770]737 108] 97 131/50 86]84 58/35 91187

to test cane and beet molasses at two levels of inclusion in the di et of sheep.

In vitro, additi onal inf orm ati on was collected over a wider range of molasses

to ha y (+ sugar beet pulp) ratios.

MATERIALS AND METHODS

Feeds

Fou r lots of 65 kg of cane molasses were collected f rom four molasses

trading companies and carefully mixed to form the test sample. For beet

molasses the sample was collected from one produ cti on site.

As basic feeds a good quality grass hay with a high protein content and

a batch of dried sugar beet pulp low in sugar cont ent were selected.

xperiments with wethers

A series of digestibility trials with adu lt wet her sheep (live weight abou t

90kg) was performed to test cane and beet molasses at two levels of

inclusion. Daily rations were:

A. 400 g grass hay , 400 g dried be et pulp + 400 g beet molasses;

B. 400 g grass hay , 400 g dried bee t pulp + 400 g cane molasses;

C. 500 g grass hay , 500 g dried be et pu lp + 200 g beet molasses;

D. 500 g grass hay, 500 g dried bee t pulp + 200 g cane molasses.

For practical reasons two change over experiments were carried out, one

with 4 animals per treatment (400 g molasses) and one with 8 animals per


3/9

8 5

t r e a t m e n t ( 2 0 0 g m o l a s se s ) . T h e l a t te r n u m b e r o f a n im a l s w a s c o n s i d e r e d

n e c e s s a r y b e c a u s e o f t h e l o w l ev e l o f i n c l u s io n o f t h e t e s t f e e d i n t h e r a t io n .

T h e e x p e r i m e n t a l p e r i o d s l a s te d f o r 2 1 d a y s , o f w h i c h t h e fi r st 1 1 d a y s w e r e

c o n s i d e r e d a s a n a d a p t a t i o n t o t h e r a t i o n . P r i o r to p e r i o d I , t h e r e w a s a n

a d d i t io n a l a d a p t a t i o n p e r i o d o f t w o w e e k s . T h e f a e c e s p r o d u c e d i n th e l as t

t e n d a y s o f ea c h p e r i o d w e r e c o l le c t e d q u a n t i t a t i v e ly , w e i g h e d a n d s a m p l e d

f o r c h e m i c a l a n a ly s is . F o r e a c h p e r i o d a t l e a s t 8 s a m p l e s o f e a c h ra t i o n c o m -

p o n e n t w e r e a n a l ys e d . M o l as s e s a n d b e e t p u l p w e r e m i x e d p r i o r t o f e ed i ng .

T h e d i g e s t ib i l i ty o f t h e h a y a n d t h e d r i e d s ug a r b e e t p u l p w a s t e s t e d

s e p a r a t e l y .

E x p e r i m e n t s i n v i t r o

T h e m o l a s s e s w e r e t e s t e d i n v i t ro ( v an d e r M e e r , 1 9 8 0 ) , as s u c h a n d a f t e r

m i x i n g w i t h g ra ss h a y o r g r a ss h a y + s u g a r b e e t p u l p a t v a r i o u s r a t i o s . S o m e

c a s e i n w a s a d d e d t o t h e m i x t u r e w i t h r u m e n j u i c e t o i m p r o v e av a i la b le N

c o n t e n t .

R E S U L T S

h em ica l a n a ly s is

T h e c h e m i c a l c o m p o s i t i o n o f t h e f e e d s is g iv e n in T a b l e II . F o r b e e t

m o l a s s e s , 2 7 o f t o t a l N w a s p r e s e n t a s b e t a i n e N a n d 3 3 i n a m i n o a c id s .

F o r c a ne . m o l a s s e s t h e s e f ig u r e s w e r e 1 a n d 2 3 , r e s p e c t i v e ly . A s o n l y sm a l l

T A B L E I I

C o m p o s i t i o n o f p r o d u c t s s t u d i e d ( g / k g d r y m a t t e r )

B e e t C a n e G r a s s D r i e d s u g a r

m o l a s s e s m o l a s s e s h a y b e e t p u l p

D r y m a t t e r ( g / k g) 8 0 3 7 8 8 8 9 3 8 9 1

C r u d e a s h 8 0 1 2 6 1 1 4 4 9

C r u d e p r o t e i n ( N × 6 . 2 5 ) 1 4 8 5 9 2 1 4 1 1 0

H e x a n e e x t r a c t 3 3 3 1 8

C r u d e f i b r e 1 3 2 7 1 1 9 2

N e u t r a l d e t e r g e n t f i b r e - - - - 5 6 4 4 3 2

A c i d d e t e r g e n t f i b r e n . a I n . a 3 0 1 2 3 5

S u g a r 6 9 5 6 3 9 n . a 1 0 5

A n h y d r o u r o n i c a c id s 1 9 8 1 5 1 - - - -

S u m o f a m i n o a c id s 7 0 2 2 n . a n . a

B e t a i n e 5 2 1 n a n a

A m m o n i a 1 1 n a n a

G r o s s e n e r g y ( M J / k g D M ) 1 6 . 6 1 5 . 1 1 8 . 0 1 7 . 8

l n . a ~ n o t a n a l y s e d


4/9

8

amou nts of NH 3 were recovered, for bot h molasses types the origin of 7--8 g

N per kg dry mat ter was not determi ned. According to HPLC-analyses, 87%

of to tal sugars in beet molasses was sucrose a nd o nly traces of fructo se and

glucose were found. In cane molasses, besides sucrose (61%), significant

amounts of fructose (18%) and glucose (13%) were found. Pectin-like com-

pone nts were meas ured as their a nhyd ro uronic acids. The colour developed

on addition of carbazole after hydrolysis with 0.5 M H2SO4 was measured

at 530 nm, calibrated against galacturonic acid and glucuronic acid. Although

this met hod is sensitive for high fructose cont ent s no such influence could be

proved.

i g e s t i b i l i t y i n v i t r o

The average results of the two 'inclusion level' experiments are given in

Table III. In addit ion, t he average results of tests of cane and beet molasses

alone (averages of 8 samples) are given.

TABLE III

Organic matter digestibility, in vitro, of hay/molasses and of hay/beet pulp/molasses

mixtures at different levels of inclusion of molasses

Molasses Hay -{- molasses

inclusion (%)

Beet pulp (10%)-t-hay + molasses

Beet Cane Beet Cane

0 77.1 79.7

10 79.5 80.0 82.2 81.1

30 82.9 82.9 86.7 84.8

50 87.9 86.4 89.4 87.1

70 91.1 90.7 93.1 92.5

100 98.6 97,2 -- --

The hay used was of very good quality, with high digestibility in vitro.

As expected, digestibility was still slightly higher with the combination of

90% hay and 10% sugar beet pulp. Inclusion of increasing amo unt s of

molasses led to increasing digestibility of the tota l. In each of the four

comp aris ons the regression b etw een DOM and level of molasses inclusion

(0--100%) was not significantly different from linear. So, no clear associative

effects were foun d. In almos t all comparisons cane molasses based mixtures

were slightly less digestible than beet molasses based mixtures, but the

difference was small . In our standard proc edur e for testing feeds in vitro, we

predict digestibility in vivo from digestibility in vitro with the help of a

relationshi p f or a series of similar pro duc ts for wh ich digestibility in vivo is

known (van der Meer, 1980). As no standard samples of a molasses type

were available, calibr ation in this case was done with c onc ent ra te mix ture s


5/9

8

a n d c o n c e n t r a t e i n g r e d i e n t s , r a n g i n g i n DOM i n v i t r o f r o m a b o u t 6 0 t o

a b o u t 9 2 , s o i n a ll c a se s b e l o w t h e d i g e s t ib i l it y o f t h e m o l a s s e s s a m p l e s .

T h e p r e d i c t e d DOM i n v i v o w a s t h e n 9 6 . 0 + 0 . 8 a n d 9 4 . 8 + 0 . 5 f o r b e e t a n d

c a n e m o l a s s e s , r e s p e c t i v e ly .

i g e s t i b i l i t y i n v i v o

N e t i n t a k e o f d r y m a t t e r w a s a b o u t 3 5 g p e r k g m e t a b o l i c liv e w e i g h t p e r

d a y . D a l l y f e e d r e f us a l s w e r e a l w a y s le s s t h a n 1 5 g / a n im a l , t h e s e b e i n g

m a i n l y s m a l l p a r ti c l e s o f s oi l o r i g i n a t in g f r o m t h e h a y . D i g e s t i b i l i t y v a l u e s

w e r e c o r r e c t e d f o r t h e s e r e fu s a ls .

M e a n O M - d ig e s t i b il it y w a s 8 2 . 9 , 8 0 .0 , 8 0 . 6 a n d 7 9 . 2 f o r th e t r e a t m e n t s A ,

B , C a n d D , r e s p e c t i v e ly . F o r e a c h t r e a t m e n t , d i f f e r e n c e s b e t w e e n a n i m a l s

i n le v e l o f O M - d i g e s ti b i li ty o f t o t a l r a t io n s w e r e v e r y a c c e p t a b l e w i t h

s t a n d a r d e r r o rs o f 1 . 2 3 ; 0 . 3 3 ; 0 . 4 7 ; 0 . 6 2 f o r t h e t r e a t m e n t s A , B , C a n d D ,

r e s p e c t i v e l y .

R a t i o n d i g es t i b il it y w a s s ig n i f ic a n tl y h ig h e r ( P ~ 0 . 0 5 ) w i t h 4 0 0 g o f

m o l a s s e s t h a n w i t h 2 0 0 g ( A v e r su s C ; B v e rs u s D ) . R a t i o n s c o n t a i n i n g b e e t

m o l a s s e s w e r e v e r y si g ni fi ca n t l y ( P ~ 0 . 0 0 5 ) m o r e d ig e s ti b le t h a n r a t i o n s

c o n t a i n i n g c a n e m o l a s s e s a t t h e s a m e l e v e l o f i n c lu s i on . I n t e r a c t i o n b e t w e e n

m o l a s s e s t y p e a n d l ev e l o f i n c l u si o n w a s n o t s ig n i fi c a nt .

T h e d i g e s t ib i l i t y o f t h e f e e d o n t e s t w a s c a l c u l a t e d b y a s s u m i n g t h e

d i g e s t i b i li ty o f t h e o t h e r r a t i o n c o m p o n e n t s t o b e i d e n t ic a l t o t h e a v e ra g e

o u t c o m e o f t h e t ri al i n w h i c h t h a t s p e ci fi c r a t io n c o m p o n e n t w a s t e s te d . T h e

m e a n r e s u l t s a r e c o l l e c t e d in T a b l e IV . T h e d a t a f o r t h e gr as s h a y a n d t h e

s u g a r b e e t p u l p a g r e e d v e r y w e l l w i t h t h e a v e r a g e O M - d i g e s ti b i l i t y i n v i t ro

( c o r r e c t e d a s gi ve n b y v a n d e r M e e r , 1 9 8 0 ) w h i c h w e r e 7 0 . 3 + 0 . 5 a n d 8 7 . 3 +

0 . 6 , r e s p e c t i v e l y .

T h e r e w a s n o s i g n if ic a n t e f f e c t o f th e l ev e l o f i n c l u s io n o f e i t h e r b e e t o r

c a n e m o l a s s e s in t h e r a t i o n o n t h e c a l c u l a t e d d i g e s t ib i l it y o f o r g a n ic m a t t e r ,

c r u d e p r o t e i n , n i t r o g e n - f re e e x t r a c t o r d i g e s t i b i li ty o f e n e r g y .

D i g e s t i b il i t y o f o r g a n ic m a t t e r , c r u d e p r o t e i n , N F E a n d G E w a s s ig n if i-

c a n t l y h i g h e r ( P ~ 0 . 0 2 5 ) f o r b e e t m o l a s s e s t h a n f o r c a n e m o l a s s e s , w h e n t h e

TABLE IV

Calcula ted diges t ibi l i ty (%) of the feeds tuf fs tes ted (Means and SE)

OM CP NF E GE

Grass ha y 69 + 0.1 73 + 0.5 68 -+ 0.3 65 + 0.4

Sug ar be et pul p 87 + 0.6 66 + 1.1 90 -+ 0.5 84 -+ 0.7

Beet mol ass es B4 92 + 1.9 81 + 3.0 95 + 1.8 91 + 2.1

B2 91 + 1.1 71 + 1.4 95 + 1.2 90-+ 1.8

Can e mo la ss es C4 83 + 0.6 25 + 5.1 88 -+ 0.5 80 + 0.3

C2 82 -+ 1.5 17 + 7.5 87 + 1.5 77 + 2.4


6/9

88

two levels of irmlusion were taken together and for the 200 g inclusion level.

Except for crude protein, differences between beet and cane molasses at the

400 g inclusion level were not significant, possibly because of the small

number of animals used in that comparison.

Feeding values were calculated for the average data according to Van Es

(1978). Table V gives the results, calculated on an organic matter basis and

compared with tabulated data (Veevoedertabel, 1982).

TABLE V

Calculated protein and energy values of the two molasses types (per kg organic matter)

Beet molasses Cane molasses

Veevoedertabel B4 B2 Veevoedertabel C4 C2

g DCP 97 126 111 0 17 12

VEM 1160 1197 1181 1039 1047 1032

DIS USSION

hemical composition

Ash content of the beet molasses studied was relatively low (average for

INI~A, Denmark, CVB and DLG abo ut 110 g/kg dry matter) and of cane

molasses somewha t higher than tabulated. The diffe rence in ash con ten t

enlarged the diff ere nce in sugar con te nt on a dry ma tt er basis. On an organic

matter basis the difference in total sugar content was small (75 and 73% for

beet and cane molasses, respectively) which agreed well with the Dutch

CVB-table. Almo st 90% o f to tal sugars in the bee t molasses was recov ered as

sucrose and only small amounts were found of fructose and glucose. About

60% of total sugars in cane molasses was found to be sucrose and about

30% f ruct ose + glucose. These dat a agree reaso nably well with i nfor mat ion

of B.P. Baker (personal communication, 1981) and Le Dividich et al. (1978).

So, in both molasses types the chemical characteristics of almost 10% of

total sugars were no t determ ined. According to Baker (1981), part of this

undetermined fraction is unfermentable sugars, which are not sugars, but

reducing agents, possibly formed by the combination of normal reducing

sugars with nitrogen c ompou nds. For beet molasses significant quantit ies of

raffinose should be present. In our analysis, however, only traces of raffinose

were found.

Abo ut 27% of tot al N of beet molasses was recor ded in betaine and about

33% in amino acids, leaving the origin of about 35% of the N unrecovered.

Most of the N in cane molasses was not recovered in amino acids, so for both

molasses types the origin of 7--8 g N per kg dry mat ter was not known.


7/9

9

T h e a n a ly s e s p e r f o r m e d a l l o w e d u s t o p a r t i t io n t h e o r ga n ic m a t t e r o f b o t h

m o l a s s e s t y p e s in t h e fo l l o w i n g m a n n e r ( ) :

B e e t m o l a s s e s C a n e m o l a s s e s

S u c r o s e 6 6 4 4

F r u c t o s e 1 1 3

G l u c o s e 1 1 0

B e t a i n e 6 - -

A m i n o a c i d s 8 3

O t h e r s u b s t a n c e s 1 8 3 0

A c c o r d i n g t o J u s t, c i te d b y E l K h i d i r a n d V e s t e r g a a rd T h o m s e n ( 1 9 8 2 ) , c a n e

m o l a s s e s c o n t a i n s a b o u t 2 0 h e m i c e l l u l o s e o n a d r y m a t t e r b a si s, a n d b e e t

m o l a s s e s a b o u t 9 . W h e n a p p l y i n g t h e N D F - a n a l y s is a c c o r d i n g t o V a n S o e s t

t o o u r s a m p l e s, h o w e v e r , o n l y t r a c es w e r e f o u n d in b o t h m o l a s se s t y p e s .

A n a l y si s o f a n h y d r o u r o n i c a c i d s e x p l a i n e d t h e r e m a i n i n g p a r t o f t h e c o m -

p o s i t i o n o f b e e t m o l a s s e s a n d f o r a g r e a t p a r t a l s o f o r c a n e m o l a s se s .

A c c o r d i n g t o B a k e r ( 1 9 8 1 ) i n c a n e m o l a s s e s a ls o , s i g n if ic a n t a m o u n t s o f

s o l u b le g u m s a n d o r g a n ic a c i d s c o u l d b e r e c o v e r e d a n d s m a ll a m o u n t s o f

w a x e s , s t e ro l s , e t c . In t h e s a m p l e s d i s c u s s e d a m o u n t s o f o t h e r o r g a n ic a c i d s

w e r e n o t s i g n i f i c a n t .

igestibility in vitro

I n c r e a s in g t h e r a t io o f m o l a s s e s t o h a y o r t o h a y + s u g a r b e e t p u l p

i n c r e a s e d O M - d i g e s ti b i li t y o f t h e m i x t u r e s l in e a r l y f r o m z e r o u p t o 1 0 0

m o l a s s e s , i r re s p e c t i v e o f t h e m o l a s s e s t y p e t e s t e d . T h i s f i n d i n g se e m s n o t to

a g re e w i t h d a t a o f E 1 K h i d i r a n d V e s t e rg a a r d T h o m s e n ( 1 9 8 2 ) , w h o f o u n d a

c u r v i li n e a r r e l a t i o n s h i p b e t w e e n t h e r a t i o o f c a n e m o l a s s e s t o h a y a n d t h e

d i g e s t ib i l it y o f th e m i x t u r e s a f t e r 4 8 h o u r s o f i n c u b a t i o n i n v i t r o : a d d i t i o n

o f 1 0 , 4 0 a n d 7 0 m o l a s s e s t o h a y e n h a n c e d t h e d i g es t i b il it y o f t h e m i x t u r e

s l i gh t l y m o r e t h a n w o u l d b e c a lc u l a t e d f r o m O M d i g es t ib i li ty o f th e h a y

( 6 6 . 7 ) a n d t h e c a n e m o l a s s e s ( 9 7 . 5 ) , r e s p e c t i v e l y . T h e r e is , h o w e v e r , a n

a p p r e c i a b l e d i f f e r e n c e i n t h e d i g e s t i b i li t y o f t h e h a y u s e d , w h i c h i n i ts e l f

c o u l d e x e r t a n i n f l u e n c e o n t h e e x i s t e n c e o f s o -c a l le d a s s o c ia t iv e e f fe c t s . I t

m a y b e s e e n f r o m t h e d a t a o f E1 K h i d i r a n d V e s te r g a a rd T h o m s e n ( 1 9 8 2 )

t h a t t h e l a rg e s t a s s o c ia t iv e e f f e c t w a s f o u n d a f t e r a d d i t i o n o f 1 0 m o -

la ss es t o t h e h a y , p r o b a b l y b e c a u s e o f th e s t im u l a t io n o f m i c r o b ia l a c t i v i t y

in t h e r u m e n j u ic e .

D i g e s t i b i li t y i n v i t r o o f m o l a s s e s w a s v e r y h i g h , t h e b e e t t y p e b e i n g o n l y

s l ig h t ly h i g h e r t h a n t h e c a n e t y p e . T h e l ev e l o f d i g e s t ib i l it y is c o m p a r a b l e

w i t h t h e d a t a o f E1 K h i d i r a n d V e s t e r g a a rd T h o m s e n ( 1 9 8 2 ) . B e c a u s e o f t h e

v e r y h i g h l e v e l o f d i g e s t ib i l it y , f o r o u r d a t a , c a l i b r a t i o n b y e x t r a p o l a t i o n in -

s t e a d o f i n t e r p o l a t i o n o f i n v i t r o t o i n v i v o d a t a w a s d o n e , w h i c h i s l es s c o r r e c t .


8/9

9 0

igestibility in vivo

In contr ast to the data obta ined in vitro t here was a clear-cut effec t of

molasses type on digestibility, that of cane molasses being lower than that

of beet molasses, irrespective of t he level of inclusion in the ration.

The level of inclusion of molasses in the ration did not have a significant

influence on the calculated digestibility of the test feed. For both products

the lowest level of inclusion of molasses resulted in slightly but not

significantly lower digestibility of prote in and energy. The digestibility of

nitrogen-free extracts for both beet and cane molasses was very much like

Dutc h tabul ated data. Digestibility of crude protei n was slightly higher. For

beet molasses the t abul ate d Dcp is also lower than was dete rmine d in

another trial at 30% inclusion (Rijpkema et al., 1975). For cane molasses,

tabul ated digestibility of crude protein according to Ve evoedertabel is zero.

In previous trials Dcp was even negative (Rijpkema et al., 1975). The better

CP digestibility of the cane product tested may partly be explained by a

higher protein conte nt. But even when the difference in protein conte nt

between beet and cane molasses is taken {nto consideration, digestibility of

the crude protei n in cane molasses is poor.

When beet and cane molasses are compared, the disagreement between

differences found in vitro and in vivo needs further consideration. As the

digestibility of both molasses types in rumen fluid is almost equal, the

difference in vivo will originate from a difference in the rate of disap-

pearance from the rum en or fr om a differen ce in passage rate thro ugh the

intestinal tract or both. From the data of E1 Khidir and Vestergaard

Thoms en (1982) it ma y be concluded, that even cane molasses is ferme nted

very quickly in rumen fluid; after 6 hours of incubation more than 93% of

the fermentable organic matter had disappeared. No comparison was made

with beet molasses, however.

From our data there is an indication for a faster rate of passage of the

rations containing cane molasses through the intestinal tract, because dry

matter content of the faeces produced on those rations was, on average,

lower (abo ut 3% and abou t 2% for the 30 and 15% inclusion rates,

respective ly). However, the reas on for such a dif fere nce in passage rate.is, as

yet, unclear.

R E F E R E N E S

A nders en P . E . , K l a u s e n , S . and Sorens en M . , 1 9 7 8 . T a b e l l e r o v e r f o d e r m i d l e r s sa m -

m e n s a e t n i n g m . m . , L a n d b r u g e t s B r e v s k o le ,

C o p e n h a g e n .

A n o n . , 1 9 7 8 . A l i m e n t a t i o n d e s R u m i n a n t s . P u b l . I . N . R . A . , V e rs a il le s .

C . V . B ., 1 9 7 7 . V e e v o e d e r t a b e l P u b l . C . V .B . , L e l y s t a d .

D e u t s c h e L a n d w i r t s c h a f t s G e s e l ls c h a f t, 1 9 8 2 . F u t t e r w e r t t a b e l l e f ii r W i e d er k a ii e r, P u b l .

D . L . G .

E 1 K h i d i r , O . A . a n d V e s t e r g a a x d T h o m s e n , K . , 1 9 8 2 . T h e e f f e c t o f h i g h l e v el s o f m o l a s s e s

i n c o m b i n a t i o n

w i t h h a y o n d i g e s t i b il i ty o f o r g a n i c m a t t e r ,

m i crob i a l pro t e i n s ynt hes is

and vo l a ti l e f a t t y ac i d produ ct i on i n v i t r o . A n i t a . F e e d S e i . T e c h n o l . , 7 : 2 7 7 - - 2 8 6 .


9/9

9

Le Dividich, J., Chr iston, R., Pei niau, J. and Aumai tre, A., 1978. Prox imate c hemical

analysis of final cane molasses and effect of feeding 30% molasses on intestinal

sucrase and malta se activities in the rat. A nim. Feed Sci. Technol., 3: 15--22.

Ministry of Agriculture, :Fisheries and Food, 1975. Energy Allowances and Feedi ng

Systems for Rumi na nts , Tech. Bull. 33., H.M.S.O., Londo n.

Rijpke ma, Y.S., Smits, B. and Steg, A., 1975. O nderz oeki ngen aan neven- en afval-

prod ukte n bij herkauwers en varkens. Bedr. ontw., 6, 2,14 3.

Van Es, A.J.H., 1978. Feed evaluation for ruminants. I. The systems in use from May

1977 onwards in The Netherlands. Livest. Prod. Sci., 5: 331--345.

Van der Meer, J.M., 1980. De termi nation of the in vitro digestibility for the predi ction of

the in vivo organic mat ter digestibilit y coefficients of feeds for rumi nant s. IVVO-

documentati on, Report no. 67, Lelystad.

Documents

DIFFERENCES IN CHEMICAL COMPOSITION AND DIGESTIBILITY OF BEET AND CANE MOLASSES