MARDI Res. Bull . ,8,2 : (267-279)

HE ENERGY REQUIREMENTS FOR MAINTENANCE OF STALL-FET)KEDAH-KELANTAN CATTLE IN MALAYSIA

C. DEVENDRA'-

Kev+tords: Energy requirements, Cattle, Maintenance, Metabolisable energy,Digestible energy.

RINGKASAN

S l r t u ka j i an t c l ah d i l apu rkan n rengena i kcpe r l ua r r t enaga un tuk 'ma in t cnance bag i l e r r bu - l en r t r u

Kc t l uh -Kc lan t l Ln dc *asa . Dua pc r cubu ln t e l ah d i j a l ankan vang t c l ah n r c l i ba t kan se j un r l uh l l e ko r l en r t r uj i t n t an . bc run ru r d i an ta ra 3 - . 11 : t ahun dengan pu ra ta be ra t badan d i an ta ra l 9 -1 h i ngga l l 7 kq . Tekn i k

rang c l igunakan adalah dcngan cara rrcnghadkan pcngamhi lan maklnan supara bcrat badan Iang tctap

t l i p cm lch i . d i n rana pengan rb i l an makanan ha r i an ac i a l ah merupakan kcpc r l uan un tuk ' i na i n tenance ' .

Bagi tu juan in i . rurnput Napier (PP) 1-ang te lah dipotong semasa umur l ima mingeu te lah c i igunakan. Bagi

mcnsuranqkan pcrubahan-perubahan i ang ber laku ke atas herat baclan. tcmpu h pcrcublan te lah dikawal

di antara 22 hingga 32 minggu. dan keper luan untuk 'maintenance'd iperbetulkan mengikut perubahanberat badan.

[ ) i d l l an r kec l ua t l ua pe rcubaan . bc ra t bac lan ha i *an -hu i *un t c l uh d i t c t l r pk l n . I n i t c l ah d i

tunj t rkkarr d i n l r r . l r pcrublr l ran berut baci ln terhaclup j lnuku rnasa percuhuan l r t la lah nl rs ing-nrasins () .S

t l an - l . I kg . saha ja . Pc r rga r rh i l r u r b l r h l r n ke r i ng ( [ )N I I ) seh lga i pc ra tus bc ra t t r adan bas i ke t l Lu r - r i r . u r

percubaan in i adalah 1.139 dan 1.16qr. Di dalam percubaan pertama. DMI adalah berhubungan secara

be rkcsun de r rgun pu r i r t u bc ra t badan ( r : ( ) .S l J . P , i 0 . 05 ) .

Tc l l r h r i i t i l r p l r t r b r r l l r * l r p r r n r t l r k cpc r l r u l n t cn rq l r L l n tuk ' l l l i r ' r t c r l r nce l r r l l r l l r h 10 .1 I k c ' r l \ l t - ko\ \ ' "

' l r t l r u 615 .9 K . J \ l F . k ! \ \ "

' . [ ' cn l a rn t , i ] an bahan kc r i r r g ad i r l r r h bc rhubung r j cng rn l r c r kcsan scka l i

( r - { l . l i J J . [ ' 0 l ) 5 ) t l i t i e l a rn : l L l l r l r v r t u r l r n pc r cubaan pe rcub lu r r r i n i . Kcpc r l L l u r i n i l r t l r l l r h l r b i h t r ng l it l r t r i p l t d l t n i l l i l - l l . l K . l k r : \ \

- r , r r t , : t c l . r l t r l r i , r p L r r k l r r t t l i l n t l i l r t c t i r p i i i r r t r l r i r t i ; r l l r l t l r r u r p i r \ l i r ' n l l ( l ! ' l l ! l i l l

n i l i r i v l t ng t c l i r h t l i c r r t l l r r r gkun t l r r r i I S . . \ . [ ] c rd l r r l r r k r i n J l r t J l r l ) r nan tu l n i n i . s l r t u j r r t l u r r l r n t n r cn lL i k cp l l l g xpt cnag l r r - l n t uk ' n l r i l r t c l l r r ce [ r r r ! i l cn rb r r - l cn rhL r Kc t l ah -Kc l r n t i r n t l cu i r : l r r l cn t l r n . r r . L rn l r n i r cn r t b i r t l l r n t l ir r n t l r r a 100 -5 (X ) k r t dan sesua i un tuk pc r t l r k l r n l r n d i t l l r l l i l l k r i r t d r r r t g r r t l ; r t l i l . t r r k rn . l ) c r l t r r t l L r t l c l l r l tt l i t c kank l t n kc l r t l r s be rku r l r r r gn r l t l a t a -d r r t a r ncngcna i ha iu : r r r l l r i uan \ l l ng n r t n l gL l t t l l r n pc r t l r n r l r l r l r a r r

bc r l t t ba t l en . Adan ra r r r r i as i d i da l an r kepc r l L l r n un tuk n l a i n t cnancc bc rhub t rng lu r t l cng rLn j cn i s j cn i s

nrakl tnr tn d l rn kcrr t r tukinarr sehab-sebabnru l r i lu j r r r :a d ib incln i :krrn.

INTRODUCTION

Thccnc rqvcos t ( ) f n ra in t cnancc i sdc f i nedas thcnu rnbe ro f j ou les requ i rec ibvanan i rna l i ncncrgv equi l ibr ium. \ {ost of the basic in fornrut ion t rn nra intenunce reqLl i remcnts ha\c bccnder i l 'ed f rom calc l r imetr ic s tudics. The rnaintenance rcqui remcnts l i r r - rnt l in most fccdinq tublcsha" 'e been der ived main lv f rcnr erpe r inre l r ts \ \ ' i th fast ing aninra ls ancl nra i l r tcnancc values ha\esubscquent ly been calculated f rom str . rd ics on basal rnct l r t r ( ) l ism. Most c l f the basic in format ion\ \ 'as der ivcd f rom thc car l ' r 's tudies of KEt- t -NER anci h is col leagues at \ lockcrn. AR\tsu\ ancl h isassociates at Pennsvlvania State Col lece. BTTNFDICI ' and RITZ, \ I . \ \ i r r Neu Hampshire andMot- t -c ; ,+no in Copenhauen. These. together wi th the pract ica l teecl ing t r ia ls of HAE( 'KF-R.HI t - t - and FoRBLS in the U.S.A. . ancl H/ \NSEN and FRIEDERI( 'KSoN in Scanc' l in i rv ia prov idedmuch of the basicdata l rorn which both the Amer ican tota l d ieest ib le nutr ients (T.D.N.) andEuropean s ta rch equ i \ a l en t (S .E . ) f eed ing svs tem. More recen t l v . t he wo rk has beenconsiderablv extended by the deta i led studies bv BlnrrER and h is col leagucs at the Rou' l t t ,Scot land. FL ' \TT and h is co- \ \ 'orkers in Belstv i l le . U.S.A. and VAN ES and h is associates in

Feed Resources and Animal Nutr i t ion Branch. N{ARDI. Serdans. Sclangor

26',7

\ \ ' l r gcn inu t :n . t i r c \ c thc r . l i r n t l s . l c l r c l i nq t o t i r c usc t o t l u r o l t hc n re t u [ - ro l i s l r [ r l c c r t c rg r ( \ 1 .E . ) andne I c l t c rg \ ( \ f - - . ) s \ s t cn l \ . B t t< tD r (1915 ) un r l K t . l . tB I :R (19 -17 ) cs tub l i s i r c t l r c l l t t i onsh ipl rc tuccrr [ ras l t i n tet i rbol isnr t rnc l bor lv s izc in an crr r i r i r ica l nrarrner . C 'onsidc l inS nraturc ( ) r I lc l l rn r i r t t uc l i r i n ra l s . t l r c r p ro t l uccc i l r n c rpo r t cn t i a l c r ; uu t i on o f t hc t r pe ( J - k \ \ ' l l . r r he te Q i s t i t cl r l r su l c r r c rg r (hca t )pn r t l uc t i o r r i n c l r k r r i cs pc r l - l hou rs . \ \ ' i s t hc [ . r od - r * c i gh t c rp rcssec i i t tk i l o g i ' l u r r s . l r r r c l k n l l r c c ( ) l l \ l i t n t s ( ) n t h i s l . r a s i s t h c c c l u u t i o n s Q - 7 0 . - 5 \ \ 4 ' ' 1 + ( l l R ( ) t ) \ . 1 ( ) - 1 5 ) a n t l

( J - 11 : 6 \ \ ' r ! 5 ( ' (K I I I I J t : t t . l t ) i i ) \ \ c r c p roduccd l r ( ) n t l r c t l ns idcn r t i on o f i l l t n t l l l n . l r r . r . r r nu l s o l 'l r l l r r z c s r c s ; l e e t i r c l r .

Tlre studl' of BRoor' ( 19.1-5 ) shclwe d that bodv weight raised approximatell to the power ctf( ) .7- i is a measure of basal energv produccd. M.qt 'xaRt. . r and Lctos l t (19-56) rer" ieu 'ed the valuesr-cpor tec l for maintenunce neecis and concludcd thut there was no adequatc basis for decid ingi ' rc tueen \ \ { j 7 ancl \ \ i ' t5 t i r r basal metatro l isnr ne-eds. Thc r . - .R.C. ( 'omrni t tec on AnirnalN utr i t ior r in thc LI . S.A. i ras adopted the ( ) .7. - { p() \ \ cr of nc isht a- . def in ing the mctabol ic s ize of anI tn inta l . arrd th is tcnderrcv is a lso l re ing f i r l loucd in Europc. In v ie l r o f thcse consic lcrat ion. i t isnovn w' idc lv acccptcd cvcn' r . r 'hcrc thut thc f ract ionul p() \ \ 'c r 0 7-5 of bodv ueight has t rcen u ' ide l rl rccc l r tcd ant l is currcnt l r used uni rersal l r in a l l tccc i ins standarc ls . - l 'h is funct ion has a lso beenrusscl in thc studicr rcoor tcd hcre .

l -hc meintenancc rcqui rcnrcnt i -s r . rot an at rsolutc f igure as i t is in t lucnccd by 'agc.Ph 'ns iok rs i ca l uge o f ' t hc an i rna l . nan rc l v t hc p ropo r t i on o f t he ma tu rc uc iqh t und c l c r c i opn ren tthui h l rs bcen l r t ta tnecl . t r1-rc < l l t l ic t . c ;ual r t r i ind quant i t 'u o l ' .ncrgr ant l i r rotc i t . i sLrppl r .e l t \ t r ( ) l u t l c l t t l i l l l r c t o t . s \ i l a l r l r . l c l l l t ) e r - i i t i l r u . r r r r t t l l r n t l r l r i n l l r l l . n e r t - i t ' e l l i r i f L ) : ! l i r . / i n ! \ i t u i r t i ( ) n .

t i e r ' r c ' ( ) l u \ e r c r \ c l r r t t l r r t l e t i r ( t l ( ) l r \ l ' r e t r r e e n l l r u \ e l l i a i r ) l \ . l l r L l s . t i r t ' r ' r t . r [ . l i . i r n r e n l , ' l

r l l l r i r l t c l l i i l l c c r L - q u l r e l n e n t s i . s u t r j c c t c c l t o c o r n p l e r i r r r a r o f l u c t o r s .

Thc d l r i i r cncrg \ rc t ; u i rc rncn ts f i r r rn l r in tcnancc has t rcc r r uc l l t loc r . rn rc r t tcd i l l t c lnpcnt tc

fcg lo r )s b l rscd or i sc rc l r l s tu t l i cs rn thc L :n i tec i Krngc f t r r r (A( iR . l ( ' t t . l - t R . . \ t . R I :s t . \ t t . ( ' t l( ' o t \ ( ' r r . . 1 9 6 - s ) . t h c L : . S . r \ . ( N . \ n o r ' ' , \ r R I ' s t , , \ t t ( n ( ' o [ ' r < 1 . . 1 9 6 6 ) . S o u t h A f r i c a( l - t ' i f t \ ( ; I l . 1 9 6 l ) u n u i s t l i n J l p a r r ( H . r s t t t z - t r \ l t , ( , r t l . . 1 9 6 3 ) B v c o n r p a r i s o n . a n c l u s f a r u s t h c

auth( ) r i s auarc . thc rc appcars to bc or r l v one repor t concern ing cncrgr rcqu i rcnrc r t ts f i r r

r t r a i r r t e n a n c c o l t r o p i c a l c a t t l c ( P \ I t t a n c l \ l i l t t ; . . r t . . I 9 7 5 ) . T h c s c c o n s i d c r u t i o n s t t l q e t h e i ' .

n to t t 'u 'a tcd s tud ies a in ted a t es tab l i sh in -q thc L 'ncrg \ and pr ( ) te in l c t lu i t 'enrun t \ e ( )ncL- rn i l tg

c o n t i n u i n g ' u r r t r k r r i t h K e c l t r h - K c l a n t a n c u t t l c . u n t l t h c p r e s c n t p u p c r c l c a l s \ \ i t h n r a i n t c n a n c c

nceds. i \ rev ieu o f thc rcsu l ts o f i r r res t iga t ions or r nu t r i t ron anr l thc pcr l i r rn rur rcc on Kedah-

Ke lan tan ca t t le has prcv ioush bccn repor tec l (Dr : \ ' t - . \ l )R . . \ and L i r t r . l97E) .

MATERIAI,S AND METHODS

Animals

Two t r ia ls were carr ied out . the f i rs t involv ing f ive bul ls weighing approximately 19,1 kgl ive weight , and the second seven bul ls weighing approximately 217 kg l ive weight . The bul lswcre about 3 to 3t4 veat's of age and were drenched before the start of the trial. The two trialslasted fbr 32 and 22 weeks respectively. The bulls wgre stall-fed for the entire duration of thetrials and had excess to ample clean drinking water. The stalls were cleaned and washed everymorning in the course of which the animals were alsc'l bathed. All animals were weighed at thestar t and end of the exper iment and a lso once weekly on the same day. The in i t ia l and f ina l l iveweights were based on the mean value of three consecutive days reading at the start and end ofeach t r ia l .

( l )

268

(2) Feeding

Theanimalswerefedwi thchoppedNapier grass(Penrt i . te tut l tpurpt t retun)cutatabout f iveweeks of age and fed twice dai ly , a t about 09.00 and 1-5.00 hrs. The chemical composi t ion of th isgrass is given in Table I ' The amount of grass given to each animal was calculated in accordancewi th a check on the ef f 'ect on l ive weight at three day in tervals , wi th the object ives of keeping thein i t ia l l ive weight of each animal constant . In th is way, the amount of grass of fc ied wascomplete ly ut i l ised.

TABLE 1. CHEMICAL COMPOSITION OF NAPIER GRASS(PEI{IVISETUM PT]RPUREUM) CUT AT ABOUT FIVE WEEKS OF AGE

(% DRY MATTER BASIS)

Const i tuent Trial 1 Trial2

Crude protein (N x 6.2,5)Crude fibre

Ether extract

Ash

Nitrogen-free extract

P

Ca

Mg

Gross energy (MJ/kg)

10.725.82 . 19 . 3

52.10 . 1 20 . 1 70 . 1 1

1.1.613

t 1 aI l . - )

24.6

8 . 952.90 . 1 10.2,50 . 1 2

l -5. 13

(3) Digestibititytrials

Two digestibil i ty trials were carried out, the grass in trial 1 being tested with adult sheep,and in t r ia l 2 , d igest ib i l i ty was conducted wi th the same exper imenta ibul ls dur ing which t ime,faeces was collected during the last seven days of the trial. For the latter purpose total collectionof the faeces was made from animals in situ. Errors due to loss of faeces at collection wereminimised by collection of the faeces as it was produced throughout the day. The techniquesused to sample the faeces, and the chemical methods used for analyses were as have beenpreviously descr ibed (DeveNonn, 1975).

(4) Determination of maintenance requirement

The main source of error in the determination of the maintenance requirement is themeasurement of l ive weight change and to this extent, the measurements were done accurately.This error can however, be also minimised by using as long an expenmental period as is feasible.A 12 weeks period has been used for goats (DeveNDRA. 1967), andthis was used as a first guide.However, in view of possible wider fluctuations in l ive weight in cattle, a longer duratio-n wasconsidered desi rable (22 - 32 weeks) . TRowBRTDGE. MouLroN and Harcs l rvr -s ; do in factadvocate the determination of maintenance requirements over a relatrvelv long period.

269

Calculat ion of the maintenance requi rement was achieved f rom the general tbrmula:

D a i l y D O M i n t a k e ( D ) : a W k - t Cwhere W is the mean l ive weight ,

k is the exponent relating body weight to surface areaG is the dai ly change in l ive weight , anda and b are constants.

a Wk is the maintenance requl rement which is assumed to be proport ional to l ive weight(W;t t 'z-s . b wi l l vary in re lat ion to whether the energy in the t issues is being stored or lost .

The method used was that of adjusting food intake to keep live weight constant. Underthese condi t ions, the dai ly in take becomes the maintenance requi rement of the sta l l - fed bul ls .The technique a imed at keeping in i t ia l l ive weight as constant as is feasib le. Var iat ions in l iveweight between steers were attributed to random variations in l ive weight, and the respectiveintakes of digestible organic matter (DOM) were corrected accordingly. An increase in l iveweight dur ing the exper iment was corrected by subtract ing f rom the dai ly DOM intake, theamount of DOM required to offset that amount of gain. Likewise, a loss in weight was correctedby adding to the dai ly DOM intake, the amount of DOM responsib le fbr that l ive weight loss.The correction factors used fbr this purpose were those suggested by KNorr. Hooc;soN andELLtNcroN (193,1) : 3. -53 lb and 2.73 lb TDN for every pound of l ive weight increase or loss.equivalent to 3.37 lb and 2.61 DOM respect ive ly . Based on these cct r rected DOM intakes, themean maintenance ree u i rement wzrs determined.

RESULTS

Table 2 summarises the changes in l ive weight during the entire duration of both trials. Thebul ls in t r ia l I were about 2, : l kg l ighter than the mean l ive weight of the bul ls in t r ia l 2 . I t can bes e e n t h a t t h e l i v e w e i g h t c h a n g e s w e r e s m a l l ( - 0 . l i t o + 1 . 2 k g ) . F i g u r e l i l l u s t r a t e s t h e c h a n r r e s i nl ive weight in both t r ia ls .

Toble -l presents data on feed uti l isation in both trials. The drl ' marter intakcs (DN'll ) u,ere1. l t9 and 1.46ct of l ive weight for t r ia ls I a1{_2 respect ive lv . The DNII and orsanic mat ter in take(OMI )pe run i tme tabo l i cbodywe igh t (Wt t t ' r ,we re65 .2and56 .2g lday .and60 .8an< l -53 .6g /c lay

for trials I and 2 respectively.

Daily DMI was significantly correlated with mean live weight only in trial 1 and gave avalue of r : 0 . t124 (PL 0.05) .

The digestibil i ty of organic matter and energy in Napiergrass by the bulls in trial 2 is shownin'[able 1. It was found the mean organic matter and energv digestibil i ty w ere 61.6 +] .6 and 56.4

,1. 6 -ilc respectively.

Table 5 brings together calculations on the mean maintenance requirement of the bulls. Ineach trial, the main daily digestible DMI was corrected for cost of gain or loss in l ive weight inaccordance with the mean live weight changes using the factors suggested by KNorr, Hoocsoxand Et-t-INcroN (1934). The mean maintenance requirements were 2.I5+ 0.21 kg DOM/dayand 1.93+ 0. 12 kg DOM $gy for trials I and 2 respectively, giving a mean value of 2.04 kg DOMor 0.034 kg DOM/kg fV''"F_uJ. This value is equivalent to 147.2 kcal or 615.9 KJ of meta-bolisable energy (ME)/kg wu'/) based on a value of 1 lb rDN : 1814 cal (Bnooy, 1945). Swpr(1957) has suggested a value of 1 lb TDN : 2000 cal. In order to enable a meaningful comparisonbetween-animals and between-trials, the {ajly maintenance requirement was expressed asdigestible organic matter (DOM) per 200 kgO 7s live weight; this is indicated in the last column.

270

TABLE ] . L IVEWEIGHT DATA (KG)

A n i m a i I n i t i r r lN t l . l i r c ue i r t h t

F ina ll ive weight

L ive weightchange

Mearrl ive u 'c ight

:05.7, -1+ . +

1 tt5.0n 7 . l16.+. I

Nletabol ic l i r e-rvcisht (w)" rs Kg

-)-1.3159.89-50. I l'lfi..5-5

.+-5 .8-l

-_5 1 .7 : l . ,1 .91

Trial I

I231-5

206.8_-f_ . +

187.2178.01 6 3 . 1

201.6- - 1 0 . +

1 8 2 . 7I7-5.-il6-5 .0

- t . 3

+.1.0.1. -5

- 3 . I+ 1 . 9

1 9 3 . 6 * 1 0 . 7 i 9 2 . 8 | 1 1 . 3 - 0 . 8 l t i l . 0 I I l . ( )Mean

Tr ia l2

I231-567

21-5.9)17 .3225.020-s.0196.8l-s0.9206.,1

217.0216. l226.8206.1I 96 .6_ - ) ' _ +2 I 0 . 9

+ l . l- 1 . 1

+ 1 . 8+ 1 . 1- 0 . 2- 1 I

+.1.6

2 1 6 . 5216.1225. e

l0- i .61 e 6 . 7l-i I .610E.6

-56.4.1-56. -lE

58. l65.1.3052.,536 3 . 1 I-5.+. 9 I

Mean 216.8 r - 6 .1 2 1 8 . 0 r 6 . 3 , 1 4T I . L 2 r 7 . 1 - 6 . 2 5 6 . 5 8 * 3 . 1 6

TABLE 3. FEED INTAKE DATA

An ima lN o .

Fresh grassintakc/day'

( k g )

D \ { l / da r(ke)

D N l l a s ' 1 o fmean l i v c ue igh t

D \ i l / ( * ' ) " : kg( g id i lv )

O \ l l i da r ON{ i i (W) { ' : : kg( k g ) ( g i d a v )

l rial I

I

23I

5

Mean

: - 1 . + /

1 1 . 1 1

t -r.93

19.35

1 5 . %

1 8 . - 5 8 r 1 . 7

.1.50

+ . + . 1

: . n l

3 . 7 1

3.06

3.56 f 0 .31

l . l 9

I . IJ9

I .-+.+2.09l .116

1 . 8 9 + 0 . 1 2

3 1 . 6

- i7.9

5. . r . l

7 6 . 1

66. |J

6 5 . 1 1 . 1 . 7 9

6 1 . 3

53 .9

63 .0

11 .3

56 .0

62.252.7

60 .E+ .1 . - l l

1 . 0 7 7 3 . 8

1 . 0 1 5 l . J

1 . . l ] ] s . l

3. -.16 69.l

) .77 '60 . {

Trial 2

I

2

3-+5

6

7

1 8 . ( t

1 5 . 6 1

19.20l l ) i

l -s.3120..131 5.05

t . .16

2 .99

3.67

2.,10

2.91

3.92

2.89

1 . 6 0

l .38

1 . 6 3

| . t 7

1 . 5 0

r.-56

I .39

-sE.551.-+60. I

12 .3

-s3 .3

59.3

50. I

3 . 1 3 + 0 . 1 9

1 . 3 0

l. E-s

3 . 5 0

1 2 9

1.80

. ) . / +

: . / )

1..16 + 0.06Mean 1 6 . 5 9 + 1 . 0 3 . 1 8 + 0 . 1 8

277

56.2 + 2 .33 3 . 0 3 1 0 . 1 8 5 3 . 6 + 2 . 2

T

c.l :..1 =

3!= \

. :

r,

^ : l ' lX q -y -

v {

v :T t r Yi - -

. t i

:i

-'-\

3 . a :

; \ -

,IIIIIIIII

I

III

,tt,III,,

IIi \

IIIIII

fI

tIIIIIIIIt

- c . x t r -o l

(3>1) lq8re,n a,,rt1

272

TABLE .1 . D IGESTIB IL ITY DATA

An in ra lNo .

I

2-l

l

-5

6

1

\ l can

DMI i da r( k g )

ONl l ic la l( k g )

oNld iucs t ib i l i t r ( '

\ l c l r n l i r c s c i - s l r t( K g )

t 05 .7

l . i1. l

I S5 .0

l r - 1

I 6 - l . l

I S + ( l r l l ( )

I I ( ) . 5

I 1 6 . 7

l l - i .9

l0-i. ()

l (Xr.7

l . i l .6

l ( ) s . l

t l ? 1

l0( ). 7

( ( ) r r c c t c ( l n r . i i n t cn l r ncc t o ri r t c r casc o r l oss i n l i r encisht (kr : DONl,rdar )

r )

Diges t i b i l i no l ene rg r ' ( ' i

< t I

. 5 1 . 0

6 l . 8

-5E. 8

- r l . _

-56 . 9

61. +

.56.- l * -1.6

\ l a i n t cnancc r cqu i r cn r c r r t 0 lca t t l e o f ( 100 ) r r - r kg I i r c uc i r : h t

( ks [ )O \ l r ' d l r )

I . ()(l

L r \

l . ( | l

I . -1.r

l .N - r

l . { ) { r

1 . 6 .1

l . s l i 0 . 1 9

1 . 0 1

3. 973 . 1 6

| ) l+. - r+

1 .99

-1.0-5

+ . 1 0

3. ( )-5

1 . 5 6 I 0 . 1 I

3 . 7 E3 . 0 1+ . l +1.8.5t . e l1 . t ]t . e l

r . l 0 * 0 . t I

6 3 . 0

5 -5 .8

69 .6

61 .6

66 .3

69 . I

6 i . 6

6 -1 .61 I . 6

T, ' \ B l -E .5. C'A l -C- t ' L , ' \TI ON OF \1 ' \ INTF. \ ANC' I : R t : O L ' I Rt : .Nl I -NI 'S

. \ n i n r a lN o .

' f r ia l I

I

l

l

5

N l can

Tr ia l 2

I

l

-1

5

()'7

\ l c l r n

O r c r a l l\ 1 can

t ) ( ) \ l I d a t

( k g . )

l . 6 l

l . - i 9

l . - i 6

l . l 1

L r 9

1 . 0 $ + 0 l ( ,

l . l . r

l . s +l . l 6

l . l s

L S I

t . l I

1 . 7 S

I . 9 6 * 0 l l

2.02

L( rh

t 5.r

1 . ( ) l

t ]

l . - h

l . t a l r ) l l

L l l

I S 6

t . t l

1 . 16

i . f ' l

1 . . 17

L (r7

l . 9 . i l . 0 . l l

l. ( )-1

l 5 e

t t 5

L r l

t l l

l. ( )-1

l . l o ' 0 . 1 9

. ! . t J

Usinc the data in Tuble 5. the regrcssion equat ions were determined bv appl-v ing theequat ion Y : a+bX. where Y is the maintenance requi rement (g DOM/day) and X is the l i r .eweight (kg) . The v 'a lue of a and b were der ived bv making use of the method of product moment.The equat ions der ived were Y : -0. (X)78r-0.01 i2X and Y : - 1 .369-5+0.01-50X for t r ia ls I and2 respect ive lv .

DISCUSSION

The mean dai lv DMI as percentage of l ive weisht f rom both t r ia ls was 1 .68. i . This f isure isident ica l to the v 'a lue of l .6 l i1 i determine d for pen- fed Kambing Kat jang goats ar mainrenance(De l ' pNoRR. 1967 ) .

The mean maintenance requi rcment of Kedah-Kelantan bul ls deterrn ined in th is s tudr , ' r ' , 'as6 l -5 .9KJMEikq \U) 75 idav . I t i so f i n te res t t ocompare th i sn ' i t ho the rpub l i shedes t ima tes (T rb le6 ) .

TABLE 6 . THE ENERGY'REQUIRENIENTS I . 'OR 1 \ IA INTENANCE OF CATTLEFRON1 THE EXPERI ] \ IENTS REPORI 'ED CON{PARED TO OTHER PUBLISHED

EXPERI \ IENTAL VALUES

Tl 'pc of cat t lc

Japancse b lack cou s JapanHolste in con s JapanJersev crossbred Ncrr ,ca t t l e Zea landH o l s t e i n U . S . A .co\! s

Bec l ca t t l e

Be e f ca t t l c

Angus s tec rs

Bee fstee rs

Holste in con,s

A l l c a t t l e

A l l c a t t l e

Brow n Su, iss xSahiu 'a l bul ls

A l l c a t t l e

Kedah - Ke lan tanhrul ls

. \ l e t abo l i sab le enc re rB t l i nea r cqua t i ( ) n

I 6 - 5 I . - )17 12. t-I 7+t . S

1 r r 7

6 l l . +l l 5 9 9

73E..5

"1-5t.0

6 0 1 . 6

-539. -l

626 .6

160.1

* *Oig"r , i f , f "

. " . . rgr '" ' ' [3t mui t ip le re gression

Locat ion NIEi (rv;o t ipuf

(KJr'cla] )oE71ia';r.s1"+ +

(KJ i dar )

9-\l +f i l f . l

5 71. - i

nJ"..,r..

I l r o d r ( l 9 + 5 )\ \ inchcr te r ( l9- i i )C ia r r c t t . \ 1c r c r anc l[ -o lgreen ( 19- i9 )

L u i t i n q h ( l 9 6 l )

F{ashizunre c l r r1. ,( l e 6 t )l l L r t t o n ( 1 9 6 1 )

F lu t t . c l r r l . .( l e6 -+ )

Flat t c l o / . , ( 1969)

A . R . C . ( l e 6 - 5 )

N . R . C . ( 1 e 6 6 )

Pi i t le and Nludsal( 197-5 )M . A . A . F . ( 1 9 7 . 5 )

Present resul ts

L ' . S . . \ .

L ] . S . A .

L i . S , A .

Sor-r thA f r i ca

ts- i . I6 1 9 . l

-+67. ( )

I 3-i-+. :I -1( )+. lI +t9. Ii97 l+ 7 i . 6

I 1 0 1 . 5

+9-+.7-1-+8.E',l 1 1

- ) l

-s07. -56 l - ) .9

-l-rq.l I

llill60.5. (rU . S . A .

U . K .U . S . A .Ind ia

U . K .Malavsia

) '7 1

The r'; l lrrt- i lete rrrirri i ir: I I ' r ! - . - . " i . . , , - r I r ! \ ' . J 1 1 \ . : . . .

' l : t l { ; i . i i i : . ; , r : . i t r t r ; : l i i ; l . i , - r , . . ;' - i a i a . r l i : ' r ; . . ' i . . ; , : ; ; : i 1 , , , ; : t . t i . .

rg i lu i rcn ieni r n in i lue. ; ' r . " r ! -1 I ' i j : . \ t i l l l r . ; t , i ! . , r r r , , . ; r . , r , ; r .Jr . i : ! : , i i j l t is , an,_ j l l is r f i . . . iLr i : : i r . , , .an in ls i anl thc in teract ior i bc lu 'een typc i . : i ia i i r ) ; i a i td a{e . ' i -nd e;* l ter iment : o i ' f t I ' I1- r i r r r a : : rBENEOiC' t ' (1938), tu lARSTON (194E) ani l MlTcr in l - I - . HAMri - rcN and HarNns ( l94i )havc a i :shown that the prevail ing piane ot nutrit ion wil l affect estimates of fasting heat production.

The MtNtsrnY OF ACRICUL"TURE. FrsueRrEs and Fooo. (Menr. 1975) have suggestedthat the minimum net energy for maintenance may be calculated from the equation f 'N4 :-i.O; +0.961 W. where FM is the fasting metabolism and W is the l ive weight in kg. Including a 5ar.safety margin, the ME allowance for maintenance (M,,') gave the equation M* : g.3 ; 0.091W. Using this equation, the daily maintenance allowani-e for a 200 kg Lve weiehibeef cartle wascalculated to be 27 MJ/head ME. This is equivalenr ro 507.5 KJ/'{p:is tg or IsZ.+ KJ/w{} 7s koME with or without the 5cic saf-etv marsin respectively. The value of Oi-i.q Xllwi) 7s tg l, le i ithe present exper iments is approximatel r , 28i2 h igher compared to the MAAF (197-5)recommendations. The N{e-cp ( 197-5) values are higher compared ro the value of '131.2 to :t4ti.EKJ/V/-l ') 75 kg reported for Brown Swiss x Sahiwal bulis in lnciia.

The somewhat higher maintenance requirement in the present stuclv can be attributable ttrdifferences in the degree of activity since it is known that the daily maintenance requirementsare influenced to a large extent by the ciegree of exercise. In the present experiments. the activltvincrement a l though apparent ly smal l . was never theless h igher than the resul ts . repor ted inIndia. on Brown Swiss x Sahiwal bulls based on open-circuit metabolism apparatus (Parlr- andMuocel . 197,5) . Compared to thc indian resul ts . the present data is about 30. t h ieher . Undergrazing condi t ions the actr r i t r incremenr u ' i l l be even h iqher s ince walk ing and erazinr u, i i1fur ther increase maintenancc- needs. This incre: rse mav be as much as 30 to 40. t . I t is perhap-,worth st ress inc that the maintenance requi remcnt or ar i anlmai is the sum of the basai metabol l ;rates 0f a l l the indiv iaual organs and par ts . and as rhese r ncrcase u, i t i i srze anci p lane of nuin t r r . '1 .i t is loe icai that there ts increascLl L- l ic i ! : ' . cr r r ts n,h ic l - r consi ; tu t , is an adde, l malntc l ta t lcc chet 'g , :

- i : r - ; ; : , , t 1 . , .j . ; F i t :1, . : . t r r ' ,

r i l i ' l : : " i i r i

Onc i rc ior th l t rna-v be ; ls t ; i ;c : ia ted wi t l rin t l - " r prer ; t : r i . t t I t , i ; ' . i l r l i j a l : t ( ) i : l ) i r : i l i tnr i i lo l i rC t , ' . , . r t -L , i : ; ' ; t " i , ; i , l , ' a r I [ { : } ' , ' i ] . , r ' . , i . t I : i I

, , l ' i , . j

- i i ' , : ; L l l ' . . 1 t ' . , - ' ^ , 1 . , ; : : . . . , . , , , i , , j 1 : : , 1 , ! i l : : t , * - - ; . . : ^ t - . . - i . i 1 i

' ' . . , ' : i - , ' : . i t , | ' l j . ' . , : . . , : . . . : . | J , , . | , : ' - '

, i ' ,

Lhr rr lai t ' i - ' l_, hr,ql" lei le,J u i l 'c i- :r ;n i , , 1c'r ni l i nl t l : . . , :i l l . : ' . : r n l ; i ; q a S l i r n S i c . i f i : l l , , r i t r r - n i , i J f i r . r . - r . ! . . - ' ' )

, ' . - . .; i j , : . . " l , J : . p r , '

_ j i : t t _ . : ' r , l : - ; , t , . t ; i . , : : i ' , : i - r - , . ' . . . r

. , : , . . ' i : , , . - i r i l i : . : ; : ; 1 ; , , , i ; r ' , t r : ' , : ' l , i - l , i r r , ' , t )r-! : tr'ii:;-.' ir,.:,.: ,; , ' g , g j 1 1 1 ' . ; i 1 . , i

; ! j l j , ) i : 1 . r . I r " : l i

1 . ,, ' ,

- ' , . I i

1 ' ; L , - i i i ; i ) a l , : i i , , , i l t . : l ; : : , i i . ' i r , i , ; , i , . , , i r r i , : , - r , , . , i , . t i i l ; , i , , r j l r . : l ; j . . i t . : i ) j ; r , , i , - r r i ! / , . 1 : : i : i : i i : . ! : : , , : . : j

- i l t l n e i : ' i t i i . i . ' i ; c l j ' j i : l i , l i . i : 3 l . : , I ' : i l i . i - ! i r 1 l l l | : l : : l

b le i l f : r io r r , ' t l p lo t iuc ts t l t : : t r . i t ' c l r r : , l i i l ace r i c i r : i r l l i r , ; l ; i i l , , . : j , ; * .u r , : : r . , : i l i t c t - r Lh j : r :1 . t . , : r : j ; ; , i r i l . r .

, , . , }

ME for fattening and clearly associated with heat increment. The generation of a high heatincrement could conceivably be additional and indistinguishable from the legitimate enery-y costof maintenance. This can in turn, increase the size of the coefficient associated with Wu /). Theproblem could conceivably be more acute in the tropical regions where ruminants often subsistonly very coarse roughages with none or only limited access to concentrate feeding.

The extent of voluntary exercise is, of course, extremely variable and may considerablyinfluence the amount of nutrients needed for maintenance. According to MevNaRo andLooSLI (1956) for example, cattle and sheep expend about I}Vo more energy when standingthan when lying down. BRoDY (1945) also argues on the basis of dimensional analysis that thelarger^and fatter the animals, the fewer and more sluggish the movements, so that insteadof\,VI U. theenergy expended for voluntary exercise tends to vary with the same power of theweight (Wu tr, as does basal metabolism. The energy requirements of the grazinganimal awaitsdetermination.

The energy requirement for maintenance determined in the studies reported here isapproximately similar to the recommendation suggested by N.R.C. (1966). This would suggestthat the N.R.C. (1966) recommendations for maintenance are applicabie and appropriate forKedah-Kelantan cattle.

Based on the studies reported here, it is relevant to suggest practical recommendationsconcerning the maintenance requirements of adult Kedah-Kelantan cattle in Malaysia. While itis appreciated that the results of the present experiments are specific to cattle in the l ive weightrange 163 to 25 I kg, it is considered appropriate to make recommendations outside this range toaccomodate heavier Kedah-Kelantan cattle. Accordingly , Table 7 presents the maintenancerequirements of adult Kedah-Kelantan cattle in the body weight range 200-500 kg.

TABLE 7. SUGGESTED ENERGY REQUIREMENTS FOR MAINTENANCE OFKEDAH-KELANTAN CATTLE IN MALAYSIA

kg Yp;-sBody weight(ke)

ME-1.(KJ /an imal /day)

D E + +

(KJ/animal/dav )

200300400

500

53.2

7 2 . 1

89.5

105.8

32.7741.4r

55.r2

65.16

:10.45

54.82

68.05

80.45

+ Metabol isable energy+ +Digest ib le energv calculated f rom according to ME = 0.81 x DE (Armstrong, 1964).

It is emphasised that the recommendations, essentially for stall-feeding situations, shouldtherefore be considered minimum. For grazing animals, the requirements wil l obviously behigher and it may be of interest to note in this connection that Rrro, SvnH and ANoeRsoN(1958) found that grazing resulted in a maintenance requirement that was 40Vc greater.thanwhen cows were fed in the barn. Additionally, nothing is known presently about the energy costof l ive weight gain. The magnitude of this added maintenance increment is presently unknown,and is thesubject ofcontinuing research on this type ofcattle.

276

It is relevant to note however in this context that for 'maintenance stabilised' Boran andHereford x Boran cattle in Kenya, steers weighing2T5 kg required 24,49 andT3Vc and450 kgsteers 34, 69 and 977c more daily energy when walked 5, 10 and 15 km/day respectiveltcompared to pen fed animals (LEDGER, 1977). It was also calculated that the energy cost ofmaintaining l ive weight when walking was about 4.184 kJ ME/kg/km walked.

The maintenance requirement estabiished in these stddies is of importance becauseKedah-Kelantan cattle in Malaysia spend a large proportion of their l i fe on maintenance. This isdue to the iow level of nutrit ion that they are exposed to, consistent with such other factors ashigh heat production, higher level of disease, periods of feed shortage and low standards ofmanagement. As a consequence, maintenance metabolism accounts for a greater portion of ananimal's totai metaboiism. This is evident from the much greater response potential theseanimals are capable of (DeveNoRa and LEr., 1975: DEveNnRe and wRN zAHARt.lg77).

These issues have two important consequences on the nutrit ion of these animals. Firstlv,the daily maintenance requirements determined in the present studies should give priorit l ' in thesearch and assessment of suitable feeds and t'eeding systems which would provide formaintenance needs, especiallv in the rural areas. Secondly. and in relation to the first aspecr,there is also a parallel need to evaluate those feeding systems which wil l provide energy anclprotein need above maintenance that is consistent with high production. These aspects need tcrbe also studied in deoth.

ACKNOWLEDGEMENT

The author is indebted to Cik Samivah binti Mohamed Nasir for care of the experimentalanimals and Puan iamiah Mohd. Salleh for technical assistance. Encik Mohd. Shokri undertookthe regression analvsrs

SUMMAR}'

A study is reported on the energy requlrements fo; 'maintenance of adul t Kedah-Kelantan cat t le .Two t r ia ls were conducted involv ing a tota l of l2 bul ls . 3 to 3r . : vears of age and wi th a mean l ive *eight o1191 t t> ?1'7 kg. The techniq ue used was that of adjust ing feecl intake to keep i ive weight constant . wherebrthe dai lv intake f recomes the maintenance requirement. For th is purpose. chopper Napier grass(Pettnt .setunt purpureni cut at about f ive weeks age s 'as usecl . In order to reducc t luctuat ions in l ivewetght , the expermcntai per ioci u 'as maintarned between 22 ta 32 weeks, ancl the mainrenance reuurr t r -ment corrected lor changes in l i t ,e weight .

In both t r ia ls. thc l ive we' i i lh t of the animals was kept fa i r iv consianl and th is is re i lccteci rn a I iveweieht change over the ent i re durat ion of the t r ia ls of oniv -0. t< and + i .1 k-q resoect ivelv. l 'he dn matteri n t ake (DMI ) aspe rcen tage o f hve we i sh t i n t he two t r i a i swe re 1 .89an t j 1 . 46pe rcen r . l n t r r a l i . DMI wassigni f icant lv conelated u, i rh mcan l ive weight ( r - 0.82.1" f ' , ' 0 .05 ) .

I t was tbund that thr ' mean rnaintcnancc requtrement was i ,17.2 kcal NlElkg \ 1) t5 or 6 i -5.9 k. lME /keU l )T j .D ryma t te r rn takewason i vs i sn i f r can t l v co r re l a ted (R :0 .82 .+ ,p , / ( 1 . 0 -5 i r n6nco f t he t r : a i s .Thrs requirement, rs h igher tnan the value of "132.2 kJ/kg ql r r : reported in t rx l ia, bur rs approxrmatelvsimi lar to the recommendat ion I rom the U . S. A. B ased on th ts determinat ion. data are given on a tabie ormaintenance requirements of adul t Kedah- l (e iantan catr le in the body weight range 200 to 50Lr kg for sta l iteeding s i tuat ions. At tent ion ts drawn to thc pauci tv ofdata concernine the grazinc animai and also l ivcweight gain, and possib le reasons for var iat ions in maintenance requirements in re lat ion to ty,pe of feedinqare drscussed. These aspects need fur ther research.

27',i

REFERENCES

AGRICULTURAL RESEARCH CouNCIL (1965). The ntirient requirements oJ'farmllr,,esrock. No.2 Ruminants.264pp.

ARMSTRONG. D.G. (1964). The evaluat ion of dr ied grasses as a source of energy for ruminantlivestock. Agric. Progress, -19.. 1-l.

BRoov. s. (1945). Bioenergetic's ttntl Growrh. New york : Reinholds, 1023 pp.

BRouwER. E. . VeN Es. A. . J .H. and Nt lxRvp. H.J. (1965). Value of ear lv and late cut hays tormaintenance of cows. Prot-. 2nd 51.'mp" Energ.t,met(tbolism, Ettr. Ass. Anint. pror1., No.11, p. 20-5-206.

DEveNDRR" c. (1967). s tudies in the nutr i t ion of the indigenous goat of Malava. I I . Themalntenance requlrement of pen-fed _qoats. Malcl s. ttgric. J.. 16 : g0_97.

DEvENone. C. (197-5) . Studies in the ut i l izat ion of r ice st raw b, , , sheep. I . Opt imal level in thediet. Mulut's. agn(. i.. 50 : 169- 186.

Der"pxona. C. and LEE. T.K.C. (197-5) . Studies on Kedah-Kelantan cat t le . I . Ef fect ofimproved nutr i t ion on growth. MARDI Re.s. Bul l . , - l :6g_ u0.

DEVENoR,q, . c . and \ \ ' , \N ZAHART MOHAMED. (1977). The bod."- composi t ion and carcasscharacter is t ic of Kedah-Kelantan cat t le at d i f ferent ages in the rura l areas. , \ Iu lut . . r . 1sr t ( .J . . 5 l : 8 9 - 1 0 6 .

DnvrsoRR. C. and LEE. K .C.T . (1978) . ThcProc'. Breetling for Rttntinttnt Proti.in the1 39 .

e c o n o n t i c p o t e n t i a l o f K e d a h - K c i a n t a n c a t t l eTntp iL s . Serdans . Sc langor . N la la r s i i r . p . 117

Fi-arr . w.P. . CoppocK. c .E. and MooRp. L.A. and HevrRN. R. \ \ ' . (196.1) . Energv balancein lactat ing non-pregnant cows s iven d i f ferent rat ions of hay tc t pel le ted fora-ecs. prr . , r . 2 i l r lsyntp. Energt',Merubctl i.sttt" Errr. ,.1ss. Artrrtt. pr,rr1. Ntl. i l . p. 131 1,1,i.

F larr . W.P.- MoE. P. \ \ ' . . MuxsoN. A.W. and C'oopen. T. (1969). Energy ut i l izat ion ot h ishproducine c ia i ry cows. VI . Summarv of enersv balance cxper inrents u, i th lactat ins Hotstc i r rcows. Proc.4thSvnrp. E,nergt 'Met t tbol isr t t . F, t r r . A.ss. , \n int" Prod. , No. l l . p .235 l - i l .

GeRRerr . W.N. . Me ien. J .H. and LorcReEx, C.p. ( l9-59) . The comparauve cnersv reLlurre_ments of sheep and cat t le for maintenance. / . Anim. s . i . , 1g : 5 lE--517.

HnssrzLrrvrE. T. . l in lsHro. \ ' . . A\ . {Bt} . s . , MonrNoro. H. . NtASHLiBUCrrr . T. , Aen. l \ i . . HoRr i .S. , Tnxarce. K. . Hal ' teoa. ' I - .

and T 'nxRsut . S. ( 1962). Metabol ism of mat ter and encrgrin cat t le . 3. On the maintenance requi rement of energv and prote in tbr Japanese Blackbreed and Holste in breed cows in Japan. Rul l . l \ iu t . Inst . Agr i t ' . Sc i . . lupur t (G).2] :1 1 4_ _ t - 1 - J i t .

Hur toN . " r ' 8 . ( 1%2) . Tne ma in tenance rcqu i remen tso f NewZea iandda i r vca t t l e . p roc . \ , . 2 .Soc. Anint . Prot ! . , l l : i l -3+.

KI-Eteen. M. ( 19. i7) . Boclv s izc and metabol ic rate. p ln,s io l . Re; . . . 27 ; -5 l l - ,5-11.

273

KNorr, J.C., HoDGSoN, R.E. and Er-r-lNcroN, E.V. (1934). Methods of measuring pastureyields with dairy cattle. Bull. Wash. Agric. Exp. Srn., No. 295.

LEDGER. H.P. (1977). The uti l ization of dietary energy by steers during periods of restrictedfood intake and subsequent alimentation. 2. The comparative energy requirements ofpenned and exercised steers for long term maintenance at constant weight. J. agric. Sci.,C a m b . . 8 8 : 2 7 - 3 3 .

LUITINGH. H.C. (1961). The maintenance requi rements of beef s teers and thei r re lat ionship ofmaintenance needs and tota l fa t tening requi rements. J . Agr ic . Sci . , 56: 389-395.

MARSToN. H.R. (1948). Energy t ransact ions in the sheep. I . The basal heat product ion and heatincrement. Aust. J. Sci. Re.s. (B). / : 93-129.

MevNRno. L.A. and LoosLI. J.K. (1956). Animol Nurrit ion. 1th edn. New York : McGrawHi l l , p . v i i + 484 pp.

MINISTRY of AcRrculruRE. FlsHentps and Fooo (1975). Energy, allowances and feedingsystems for ruminants. Tech. Bul / . No. 33, H.M.S.O.. London, 79 pp.

MtrcnEI- t - . H.H. , HeurLToN. T.S. and HarNEs. W.T. (19,11) . Ci ted b_"- Hurror . - . J .B. (1962).J . l lu t r . . -12 : 541-553.

Mul l tcr . D.N. and KEHAR. N.D. (1959). Energy metabol ism in Indian farm animals. I .Rest ing heat product ion in Kumauni h i l s teers. Indiun J. Vet Sci . , 29 :27 -29.

NRttoNel ResaA.RcH CouNcll- (1966). i iutrient Requirements o.f [)orne.stic Atrirnuls No. 3.Nutr ient Requirements of Dairv cat t le . D.C. : Nat ional Research Counci l .

PATLE. B.R. andMUDGAL. V.D. (197-5) . Nla intenance requi rements for enerqv in crossbredcat t le . Br . J . l lu t r . . - l - l : 127- 139.

Re to . J .T . , Sunn . A .M. and ANDERSoN. M .J . (19 , r8 ) . D i f f e rencc i n t he requ i remen ts f o rmaintenance of dairy cattle between pasture and barn feeding conditions. I 'rot'. Cornt,l ll l u r r . Con f . , p .89 -94 .

RtrznaeN. E.G. and BENEotcr . F.G. (1938). Nurr i t ional Pht 's iobgt 'o f 'At lu l r Rurrr inunt , Ptrb l .'1921, Carnegie Inst . . Washington. U.S.A. , 200 pp.

Swtnr . R.W. (1957). The calor ie value of TDN. J. , l t t i t t r . Sc i . , 16: 7-53-7-56.

TRoWsRIocE . P .F . , MouLToN. C .R . and HATGH. E .V . (191 -5 ) . C i t ed by Lu r r r xc ;u . H .C .(1961). Res. Bul l . M. Agr ic . Exp. St . , No. 18.

WINCHESTER, C.G. (1953). Ci ted by LUITINGH. H.C. (1961). Tech. Bul l . U.S. Depr. .Agdr ' . No.1 0 7 1 .

219