Development of an assay for the determination of dietary apparent ileal nitrogen and amino acid digestibilities in the meat chicken : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Animal Science at Massey University

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DEVELOPMENT OF AN ASSAY FOR TilE DETERMINATION OF DIETARY APPARENT ILEAL NITROGEN AND AMINO ACID DIGESTIBILITIES IN 1BE 1v1EAT CHICKEN

A T H E S I S P RE S ENTED IN PARTIAL FULFih�NT OF THE REQUI REMENTS FOR THE D EGREE OF

· MAS T E R OF AGRI CULTUR�L SCIENCE IN ANI�.L S C I ENCE AT MAS SEY UNIVERS I TY

KEE HOR YAP 1 9 9 1

Massey University library Palmerston North

Turitea

ABSTRACT

B i o l o g i c a l pr ocedures which qua n t i f y p ro t e i n b e ne f i c i a l l y i n f l ue nc e e f f i c i e n c y o f n u t r i e n t

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value a re expe cted t o p rov i s i on i n d i e t a ry f o rmu l at i ons f o r t h e l ivestock indu s t ry . Thi s thesis p rovides a review o f t w o widely empl oyed qua nt i t a t i ve a s s e s sment s , " D i ge s t i b i l i t y" and

" Ava i l ab i l i t y " and in the expe rime n t a l s e c t i o n ^· de scribes a s e r i e s o f expe r i me n t s unde rt a ke n on me a t c h i c ken t o re fine a s s a y p r o cedures involved i n t he det e rmination of p r o t e i n and amino acid appa rent i l e a l dige s t i b i l i t y v a l ue s .

Five experiment s w e r e undert a ke n .

( l a ) A c omp a r i s on o f two feeding p r o c e dures w i t h three die t s di f fe ring i n part i c l e s i z e with a view t o evaluating t he e f fe c t of f eeding behaviour on t h e f i nal compo s i t ion of the test die t i n the c rop . ( l b ) D e t e rmin a t i o n of c rop r e s idue c ompos i t i o n a s s o c i ated w i t h time

f o l l ow i ng feeding with two f e eding p r ocedures and two die t s di f fe ring in p a r t i c l e size .

( 2 ) A compari s on o f the e f fe c t s o f two s l aught e r procedu r e s and two f l u s hi ng s o luti ons on i l e a l N dige s t ib i l i t y o f mea t and bone meal . ( 3 ) A compa r i s o n o f the e f fect o f t ime o f s l aughter f o l l ow i ng f e eding

on i l e a l N values of two di e t s . ( 4 )

(5)

D e t e rminat i on of t he e f fect o f length o f i l e um on i le a l N dige s t i bi l i ty values of two diet s .

D e t e rminat i on of the e f fe c t o f dige s t i b i l i t i e s of two diet s .

age on i l e a l N and AA

I n l a there w a s c l e a r evidence t h a t b i rd e a t i ng behav i o u r and p a rt i c l e s i ze o f the t e s t d i e t influenced c rop c ontent p roport i o n s o f a numb e r o f c ri t e r i a , mo re notably ch romium a n d n i t rogen . F o r coarse p a rt i cl e die t s a n intubation feedi n g procedure produced a c l o s e r mat c h o f mat e r i a l i n t h e c rop with t h a t o f t h e unt ouched d i e t t h a n a f ree a c c e s s prov i s ion o f food p r o cedure .

I n lb t h e re s ul t s o f t h e st udy we r e i n c o n c l u s ive and n o s a t i s f a c t o ry c a u s e f o r i n c o n s i s t e n c i e s t h a t dev e l op e d b e t w e e n t r e a tme n t s c o u l d b e found .

ll

In 2 , two s l augh t e r procedures , eutha n a s i a by s o di um pen t oba rb i t o n e and a sphyxi ation by c a rbon dioxide , resul ted in s i gn i f i c a n t l y di f fe rent

(P<O. 0 5 ) appa rent ileal nit rogen ( N ) dige st ib i l i t y . D i f f e re n c e s b e t w e e n f l u s h i n g s o l u ti o n s , di s t i l l ed w a t e r a n d phys i o l og i c a l s a l i n e w e r e s ma l l and not s igni f i cant (P<O.OS).

I n 3 , f o r two d i e t t ype s , N and dry mat t e r ( DM ) dige s t ib i l i t i e s were r e l a t i ve l y c on s t a nt ove r s ampl i ng t ime s of 2 t o 5 hou r s f o l l ow i ng t h e s t a r t o f f e e di n g . I l e a l dige s t a s amp l e d qu a n t i t i e s t e n d e d t o b e g re a t e s t a t t h e 4 h o u r sampl ing i n t e rval .

In 4 , di f f e rences in N and OM dige s t i bi l i t i e s o f dige s t a s ample s drawn f rom s e c t i ons of t he i l e um up to 30 cm i n l e ng t h as me a s u re d f rom the i l e o - c ae c a l j un c t i on were generally sma l l and n o n s i gni f i c an t .

In 5, b i rd age had no signi f icant e f f e c t on N and OM dige s t i b i l i t i e s .

T h e main c o n c l u s i o n s dr awn were t hat i n t ub a t i on bet t e r r e t a i ne d the i n t e g r i t y of f o o d r e a c h i n g t h e c r o p . S o d i u m p e n t o b a r b i t o n e w a s a p r ef e rab l e met h o d o f slaught er . I le a l l ength s ampl ed n eeded t o b e kept a s s h o rt as c o n s i s t a n t w i t h p r o v i d i n g a de qu a t e s amp l e ma t e ri a l a n d l a rge s t s ample s i z e s were obtainable a r ound 4 h o u r s f o l l ow i n g t h e s t a rt o f f eeding .

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ACKNOWLEDGEMENT

I am v e ry g r a t e f u l t o my s up e r v i s o r s , M r R . D . K i ng a n d D r P . J . Mo ugha n , f o r t h e i r g u i d a n c e , p a t i e n c e a nd a s s i s t ance t h roughout t h e c o u r s e o f t h i s s tudy . I would l i ke t o expre s s my sincere grati t ude t o D r W . C . S mi t h f o r h i s knowledgeable cont ribution in both the planning and condu c t o f t h i s w o rk .

I would l i ke t o expre s s my appre c i a t i o n t o Mi s s R . A . Wat s o n and Mr D . A . Hami l t on f o r t h e i r a s s i s t ance i n ni t roge n , ch romi um, neutral det e rgent f i b r e and a c i d det e rgent fibre analys i s a nd Mr S . H . Voon for h i s a s s i st an c e i n amin o a c i d determi n a t i on s . Spe c i a l t hanks a r e a l s o due t o Mr D . V . T homa s f o r h i s p r a c t i c a l a s s i s t ance with the c on du c t o f expe riments and i n f e e d preparat ion .

I w o u l d like t o a c k n o w l edge t h e gene r o u s f i n a n c i a l s uppo rt -f o r t h i s s t udy o f G o o dman F i e l d e r Wat t i e Ag ri -produ c t s Limi t e d . I w o u l d al s o l i ke t o exp re s s m y g r a t i t u de t o t h e p a t r o n s o f t h e N e w Z e a l a n d P ou l t ry I ndus t ri e s B u r s a ry a n d the Les Batkin Bur s a ry o f whi ch I was the recipient .

F i n a l l y , the a u t h o r thanks a l l h i s f riends and fami ly f o r t he i r supp o r t and encou ragement du r i ng t h e s e years o f graduate study .

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TABLE OF CONTENTS

P a ae ABSTRACT ^{. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .l} ACKNOWLEDGEMENTS . . . ' . . . i i i TABLE S O F CONTENTS . . . iv L I S T O F TABLES . . . vii L I S T OF F I GURES . . . ix L I S T OF ABBREVIAT I ONS . . . x i i

REVI EW O F LI TERA TURE CHAP T E R 1

1 I N T RODUC T I ON ^{. . .} . ^{. . . . . . . . . . . . . . . . . . .}. ^{. . .} . ^{. . . . . . . . . . . . . ..} . ^. . ^. . . ^{. . .} . ^{. . .}1 1 . 1 Anat omy o f t he D i ge s t i ve T ract ^{. . . . . . . . . . . . . . . . .} .^{. . . .} . ^. . ^. . ^{. . . . . . . . .}7 1 . 2 S e c re t i ons o f t he D ige s t ive T ra c t ^{. . . . . . . . . . . . . . . . .} . . . ^{. . .} . ^{. . . . .} . ^{. .} . 9 1 . 3 Abs o rption f rom t he Diges tive T ra c t ^{. . . . . . .. . . . . . .} . ^{. . . . . . .} . ^{. . . .} . ^{. .}1 1

CHAP T E R 2

2 D I GE S T I B I L I TY ^{. . . . . . . . . . . . . . . . . . . . .} . ^{. . . . . . .} .^. . ^{. . . . . .} . ^{. . .} . ^. . . ^. . ^{. . . .} . ^. 1 3 2 . 1 D i rect P rocedures ^{. . . . . . .} . ^{. . .} . : . . . 1 4 2 . 2 Methods I nvolving T o t a l Collec t i on o r Exc ret a Sampl ing ^{. . . . . . . . . . .}1 4 2 . 2 . 1 Total Col l e c t i on Assay P rocedure . . . . . . . . .. . . . . . . . . . . . . . . . . .1 6 2 . 2 . l a F r ee - a c c e s s Methods ^{. .} . ^. . ^{. . . . . . . . . .. .} . ^{. . . . . . . . . . . . . . .}1 6 2 . 2 . lb I nt uba t i on ^{. . .} . ^{. . . .} . ^{. . . . . . . . . . . . . . . .. . .} . ^{. . . . . . . .} . . . ^{. .}1 7

2 . 2 .le Rapi d As s ay ^{. . . . . .} . ^{. . . . . . . . . . . .} . ^{. .}. ^{. . . . . . . .} . ^{. . . . . . . . .}1 8 2 . 2 . 2 Exc ret a S ampling P rocedures -- I ndi c a t o rs and Markers ^{. . . . . .}1 9 2 . 2 . 3 Endogenous Correction . ^{. . . . . . . . . . .} . ^{. . . .} . ^{. . . . . . . . . .} . ^{. . . . . . . . .}2 0 2 . 3 I leal Col l e c t i o n Met hods ^{. . . . . . . .} . ^{. .} . ^{. . . . . .} . ^{. . . .}. ^{. . . . . . . . . . .} . ^{. . . . .}2 3

2 . 3 . 1 I le a l S l augh t e r A s s ays ^{. . .} . ^{. . . . . .} . . ^{. . . . . . . . . . . . . . . . . . . . . . . .} . 2 4 2^.3^.la The E f fect o f P a s s age Rate . . . 2 6 2^.3^.lb The E f fect of I ndi c a t o r s ^{. .} . . . 2 9 2^.3^.lc The E f fe c t o f D i f fe rent S l a ugh t e r Methods . . . 3 0 2^.3 .ld The E f fe c t o f D i ge s t a Removal . . . 3 1 2 . 3 . 2 I leal Cannu l a t i o n ^{. . . . . . . . . . . . . . . .. . .} . ^{. . . . . . . . . . . . . . . . .} . ^{. . .} . 3 1 2 . 4 S t udies w i t h C o l o s t omi zed B i rds ^. . ^{. . . .} . ^{. . . . .} . ^{. . . . . . . . . . . . . . . . . . . . .}3 2

V

2 . 5 The E f fect o f t he I nt e s t i nal Mi c r o f l o ra upon Amino A c i d

Exc re t i on . . . . . . . . . . .. . . . . . .. . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . .34

2 . 5 . 1 S tudie s w i t h Caecectomi s ed B i rds . . . 3 5 2 . 5 . 2 S tudies w i t h Ge rm- f ree Bi rds ^{. . . . . . . .} . ^{. . . . . . . . . . . . . . .} . ^. . ^{. .} . . 37

2 . 6 The I nf luence o f Mi s cell aneous Va r i a b l e s on D i ge s ti b i l i ty . . . 3 8 2 . 6 . 1 Level o f P rotein ^{. . . .} .^. . . . ^{. . .} . ^{. .} . ^{. . . . . . . . . . .} . ^{. . . .} . ^. . ^. . ^{. . . . . .}38 2 . 6 . 2 Age and Temperature . . . 3 9 2 . 7 I ndirect P rocedures . . . 3 9 2 . 7 . 1 Enzyrnati c A s s ays . . . 3 9

CHAPT E R 3

3 AVAI LAB I L I TY . . . 4 3 3 . 1 D i rect P rocedures . . . 4 6 3 . 1 . 1 Growth A s s ays . . . 4 ₆ 3 . 1 . 2 P la sma }\mina Acid A s s ays . . . 4 8 3 . 2 I ndi rect P rocedu res . . . 4 9 3 . 2 . 1 Mic robi o l o g i c a l A s s ays . . . 4 9 3 . 2 . l a Streot omvces zvmogenes ^{. . . .} . ^{. . .} . ^. . ^{. .} . ^{. . .} . ^{. . . . .} . . . . . . . 50

3 . 2 . lb Tet r ahymena pvri f o rm i s . . . 51

3 . 2 . 2 Chemi cal A s s a y s . . . 5 1 3 . 2 . 2 a FDNB . . . 5 1 3 . 2 . 2 b D-me t h y l i sourea . . . 5 3 3 . 2 . 2 c Dye -bi nding P rocedu re . . . 5 4

CHAP T E R 4

4 EXPERIMENTAL . . . 5 5 4 . 1 Expe riment l a and lb

4 . 1 . 1 Objec t ive . . . 5 5

4 . 1 . 2 Mat e r i a l s a n d Methods . . . 5 6 4 . 1 . 3 Sampl i ng and Analytical P ro cedur e . . . . . . · . . . . . . . . . . . . . . . . . . . .62 4 . 1 . 4 S t a t i s t i c a l Ana ly s i s . . . 6 3

4 . 1 . 5 Res ul t s ( l a ) . . . 6 3 4 . 1 . 6 Di scus s i on ( l a ) . . . 6 9 4 . 1 . 7 Results ( lb ) . . . 7 0

4 . 1 . 8 D i s c u s s i o n ( lb ) . . . 7 8

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4 . 2 Expe riment 2

4 . 2 . 1 Ob j ective ^. . ^{. . . . . . . .. . . .} . . ^{. . .} . ^{. . . . . . .} . . . ^{. . . . . . . . . . . . . . .} . . ^{. . .}8 0 4 . 2 . 2 Ma t e ri a l s and Methods ^{. .. .} .^{. . . . . . . . . .. . . . . .} . ^{. . . . . . . . . . . . . . . .}8 0 4 . 2 . 3 Chemi c a l Ana l y s i s ^{. . . . . . . . . . . . . . .}. ^. . . ^{. . . . . .} . . ^{. . . . . . . . . . . . . . .}8 2 4 . 2 . 4 S t a t i s t i c a l Ana lys i s ^{. . . . . . . . . . . . . . . . . . . . . . . .} . ^{. . . . . . . . . . . . . .}8 2 4 . 2 . 5 Res ul t s ^{. . . . . .} . ^{. . . .. . . . . . . . . . . . .. .} . ^{. . .. . . . . . .} . ^{. . . .} . . . ^{. . . . .} . ^. 8 2 4 . 2 . 6 D i s c u s s i o n ^{. . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .} . ^{. . . . . .} . ^. 8 4 4 . 3 Exp e riment 3

4 . 3 . 1 Obje c t ive ^{. . . . . . ..} . ^{. .} . ^{. . . . . . . . . . . . . . .} . . ^{. .} . ^{. . . . . . .} . ^. . ^{. . . . . . . .}8 6 4 . 3 . 2 Mat e r i a l s and Methods ^{. .} . ^{. . . . .. .} . ^{. . . . . . . . . . . . . .} . ^{. . . . . . . . . .} . ^. 8 7 4 . 3 . 3 Re sul t s ^{. . . . . . . .} .^{. . . . .. . . . . . . . . .. . . . . .} . ^{. . . . . . .} . ^{. . . . . . . . . . . .} . 8 8 4 . 3 . 4 D i s c u s s i o n ^{. . . . . . . . .. . . .. . . . .. .} . ^{. .} . ^{. . . . . . . .} . ^{. .} . ^{. . . . .} . ^{. . . . . . .}9 4 4 . 4 Expe riment 4

4 . 4 . 1 Objective ^{. . . . . .. .. . . . . . . .} . ^{. . . .. . . . . . . . . . . . . .} . ^{. . . . . . . . . .} . ^{. .} . 9 5 4 . 4 . 2 Mat e r i a l s and Methods ^{. . . . . .}. ^{. . . . . .} . ^{. . . . . . . . . . . .} . ^{. .} . ^{. . . . . . . .}9 5 4 . 4 . 3 Resul t s . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . .9 7 4 . 4 . 4 D i s cu s s i o n ^{. . . . . .. .. . . . .. . . . . .. . .} . ^{. . . . . . .} . ^{. .. . .} . ^{. . . . . . . . . . .}1 0 2 4 . 5 E xpe riment 5

4 . 5 . 1 Objective ^{. . . . . . . . .. . . . . . . .} . ^.. ^{. . . . . . . . . .. . . . . . . .} . . ^{. . .} . ^{. . . . .}1 0 4 4 . 5 . 2 Mat e r i a l s and Methods . ^{. . . . . . . .. . . . . . . . . . . . . . . .} . . ^{. . . . . . . . . .}1 0 4 4 . 5 ^. 3 Re s u 1 t s . . . . . 1 0 6 4 . 5 . 4 D i s cu s s i on ^{. . . . . . . . ..} . ^{. . . . . . . .. . . . . . . . .} . ^{. . . .. .} . ^{. . . . . . . .} . ^{. . .}1 1 3

CHAP T E R 5

5 SUMMARY AND CONCLUS I ON S ^{. . . . . . .. .} . ^{.. . . . . . . . . . .} . ^{. . .} . ^{. . .} . . ^{. . . . . . ..} . ^{. .} 1 1 5

B I BL I OGRAP HY ^{. . . . . . . . . . . . . .. . . . . . .. . . . . . . .} . ^. . ^{. . . .} . ^. . ^{. . . .} . ^{. . . . . . . . . . . .}1 1 8

APP END I X . . . .. . . . . . . . . . . . .. . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 4 7

vii

LIST OF TABLES

T a b l e

l Ab s o l u t e and rel ative lengths o f various part s o f t h e

dig e s t ive t ract o f the chi cken a t t w o age s . . . 2 8

2 I ng redient and nut rient compo s i t i on ( g/ k g a i r dry ) o f t h e

l e a s t - c o s t s t a r t e r b r o i l e r di et . . . 5 9

3 I ng r edient compo s i t i o n ( g / kg a i r dry ) of the expe riment a l

di e t s . . . 6 1

4 T h e percent age o f C r , N, NDF and ADF o f c rop s ampl e s ( dry ma t t e r b a s i s ) and. related N, NDF and ADF to Cr r a t i o s o f t re a tmen t s receiving t he comme r c i a l diet b y f eeding met h o d

and c o r re sponding values f o r t h e t e s t diet . . . 6 5

5 T h e percent age o f C r , N, NDF and ADF o f c rop s ampl e s ( dry mat t e r b a s i s and related N, NDF and ADF to Cr r a t i o s o f t re a tmen t s receiving the MBM di et by feeding method and

c o rr e s ponding values for t h e t e s t di et . . . 6 6

6 T h e percent age o f C r , N , NDF and ADF o f c rop samp l e s ( dry mat t e r ba s i s and related N , NDF and

t re a tmen t s receiving t he wheat diet by

ADF to Cr r a t i o s o f feeding method and

c o r re sponding values for the t e s t di et . . . 67

7 Crop f eed a s a percent age o f the feed received ( ea t e n ) f o r

3 di e t s a c r o s s 2 feeding met hods at t ime o f s laugh t e r . . . 6 8

8 T h e pe rcentage o f C r , N , NDF and ADF in the MBM based d i e t ( dry mat t e r ba s i s ) as sampled f rom b i rd c rops according t o feeding t reatment and time t o s l aught e r f o l l owing s t a rt o f

f ee di n g ( n= 6 ) . . . 7 3

9 Rat i o of N : C r , NDF : C r and ADF : C r in the MBM based diet ( dry mat t e r bas i s ) a s s ampled f rom bi rd c rops acco rding to f e eding t reatmen t and t ime t o s l augh t e r f o l l owing s t a rt of

Vll2..

feeding ( n= 6 ) . . . , . . . 7 4

1 0 The percent age o f C r , N , NDF and ADF i n t h e wheat ba sed di e t ( dry mat t e r b a s i s ) a s sampled f r om bi rd c rops a c c o rding t o f e e d i ng t reatment and t ime to s l a ught e r

f o l l owing s t a rt o f f eeding ( n= 6 ) . . . 7 5

1 1 Rat i o o f N : C r , NDF : Cr and ADF : Cr i n t he wheat based diet ( dry mat t e r b a s i s ) as s ampled f rom bi rd c r ops according to feeding t reatmen t and t ime t o s l aughte r f o l lowing s t a rt of

feedi ng ( n= 6 ) ^{. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .}7 6

1 2 C rop feed a s a pe rcent age of the feed rece ived ( eaten ) f o r 2 die t s a c r o s s 2 f e e di ng p rocedu res at di fferent sl aughte r

i n te rv a l s f o l l ow i n g i n i t i a l feeding t ime . . . 7 7

1 3 The e f fe c t o f di f fe rent s l aught e r procedu res and f l u shing

s o l u t ions on appa r e n t i l e a l N diges t ib i l i t y . . . 8 3

1 4 The e ff e c t o f t h e t ime o f s l a ught e r f o l l owing the s t a rt o f feedi ng on N dige s t ib i l i t y a n d dige s t a weigh f o r 3 5 days

o l d meat chickens fed the MBM diet . . . 9 0

1 5 The e ff e c t o f t he t ime o f s l aught e r f o l l owing t he s t a rt o f feeding on p e r c e n t age o f N a nd C r i n digest a ( dry mat t e r

b a s i s ) f o r MBM mea l d i e t . . . 9 0

1 6 The e f f e c t o f t h e t ime o f s l augh t e r f o l lowing the s t a rt o f feeding o n N dige s t ib i l i t y and dige s t a weigh for 3 6 day s

o l d mea t c h i c k e n s f e d t h e wheat di et . --- 9 1

17 The e f fect o f the t ime of slaughL e r f o l l owing the s t a rt o f feeding on percent age o f N a n d C r in dige s t a ( dry mat t e r

ba s i s ) f o r wheat diet ^{. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .}91

18 The e f fe c t o f s amp ling length digesLib i l i t y and dige s t a we i ght c�ickens fed a MBM t e s t di et

o f i leum on f o r 3 5 days

N and DM o l d me at

19 The e f f e c t o f s ampl ing length of i leum on N and Cr p ropo r t i on in t h e dige s t a f o r 35 days o l d me at chi c kens fed

... 98

a meat and bone mea l t est di et ^{. . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . .} 98

2 0 The e f fe c t o f s a mp ling length o f i l eum on N and DM dige s t ibil i ty and dige s t a weight f o r 35 days o l d me at

chi ckens fed a whe a t t e st di et . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . ..99

21 The e f f e c t o f s ampl ing length o f i l eum on N and Cr p ropo rti on in t h e dige s t a f o r 35 day s o l d meat c h i c ken fed

a wheat t e s t di et ^{. . . . . .. . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .}99

2 2 I ngredient and nut rient compos i t i o n ( g / kg a i r dry ) o f the

b r o i l e r g r owe r diet ^{. . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .. . ..}108

2 3 The t reat ment N dige s t i b i l i t y , DM dige s t ibility , di ge s t a weight , length o f il eum and body weight i n t hree d i f f e rent

ages o f bi rds f o r the MBM based diet ^{. . . . . . . . . . . . . .. . . . . . . . . . . . . .}109

2 4 The t reatment N dige s t ib i l i t y , DM dige s ti bil i ty , dige s t a w e i ght , length o f i leum and body weigh t in three di f f e rent

2 5

a ges o f b i rds f o r t he whe at based di et ^{. . . . . . . . . . . .. . . . . . . . . . . . . .}110

Ami no a c i d c ompo s i t ion dige s t i b i l i t y of t h e MBM

and appa rent i le al amino acid based di et a s me a sured in 42 days

o l d me at c h i c kens ^{. . . . . . . . . . .. . .. . . . . . . . . . . . .} . . . . . . . . . . . . . . . . .111

26 Amino a c i d compo s i t i on and appa renL i l e al amino a c i d dige s t i b i l i t y o f t h e wheat based d i e t a s mea s u red in 42 days

o l d me at chickens ^{. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . .}1 1 2

LIS T OF FIGURES

F iaure

1 The e f fect o f the t ime o f s l aughte r f o l l owing t he s t art o f feeding o n percent age o f N and C r in dige s t a (dry mat t e r

Zl

ba s i s ) for MEM diet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2

2 The e f fect o f the t i me o f s l aught e r fol l ow i ng t he s t art o f feeding o n percent age o f N and C r in dige s t a (dry mat t e r

b a s i s ) f o r wheat diet ^{. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .}9 3

3 The effect of s ampl i ng length o f i l e um on N and C r propo rt ion i n the dige s t a f o r 3 5 days o l d mea t chicken fed

a MEM test diet ^{. . . . . . . . . . . . . . . . . .\ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .} 1 00

4 The e ffect o f s amp l i ng length of i le um on N and Cr prop o rtion in the digesta for 3 5 days o l d mea t chicken fed

a wheat test diet ^{. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. . . . .. . . . . . . . . .}1 0 1

AA ( s )

AAlill

ADF

!>-.ME

BV co2 C r2 o 3 DM FA FDNB I L S D MBM N ND F NP R NPU

PER

P FAA P RC TAAD TME

LIST OF ABBREVIATIONS

Amin o acid ( s )

Appa rent amino acid dige s t i b i l i t y A c i d detergent fibre

Apparent met abol i z able ene rgy Bi ological value

Ca rbon di oxide Chromi c oxide D ry mat t e r F ree a c c e s s

1 - fluo ro-2 , 4 -di nit robenzene I ntubat ion

Least s igni f i c ant di f ference Meat and bone mea l

Nit rogen

Neu t ral det e rgent fibre Net protein retention Net protein ut ili zation

Protein e f f i c i ency ratio P l a sma free amino acid P o ul t ry Re s e a rch Centre

T rue amino acid digestibility T rue metaboli zable ene rgy

xii