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A CASE FARM STUDY OF H I GH AND LOW SHEEP PERFORMANC E ON SOUTHERN
NORTH I SLAND H ILL C OUNTRY .
D . I . GRAY FEBRUARY 1 9 8 7
A th e s i s pr e sen t e d in par t i a l fulfilment o f t he requir emen t s f o r th e degree of Ma s t er o f Agri cultural Sc i en c e in Farm
Management at Ma s sey Univer sity.
( i )
ACKNOWLEDGEMENTS
I wish to expre s s my c on siderable appr e c i a t i on to Mr A . F . McRa e an d Mr W . J . Parker f or their guidance and a s si s t ance in a l l a spec t s o f thi s study , par t i c u l arly given that th i s wa s a d i f fi c u lt period f o r both supervisor s . I wi sh a l s o t o ap o lo g i s e t o Ali son and Vivienne for the large amount o f f amily t ime thi s s t udy required o f their hu sbands over the l a s t two·year s .
I am very gra t e f u l for th e early guidan c e f r om Pro f e s sor R . J . Town s ley . I am also very grat e f u l for th e a dvi c e and guidan c e provided by Mr E . Rober t s wh ose rath er d r y Welsh humour wa s much appre c i a t ed in th e lower moment s of th e st udy .
My th anks t o Mr K. I . Lowe wi thout who s e a s s i stanc e , my
involvement wi th Tuapaka would not have even tu a t ed and t o the s t a f f at Tuapaka who wi l lingly gave o f th eir t ime and shared th eir exper i en c e . Th i s was an importan t part o f the study in t erms o f c oming to grips wi th th e pra c t i c a l i t i e s o f hill coun try f arming . For their
contributions in th i s area I mu st thank Mr A. H arwood , Mr R. McLaren an d Mr T . Shannon . Many thanks also t o C aro l , Vi cki and Diana for th e wonderful hospi t a l i t y over the l a st five years .
Th i s st udy would not be pos sible wi th out th e dat a c o llected f rom Tuapaka by Mi s s R. Smith , Mr A. Bruere an d Mr M. Dickson . Th o s e th at have experienced the c limate at Tuapaka wi l l understand th e dedi c a t ion
required of thi s j ob .
Numerou s people have a s s i s t ed me in th e c omp letion o f thi s st udy , some dir e c t ly and other s indirec t ly th rough reducing my teach in g l o a d a t k e y t imes . In particular , Mr J . C . L o c kh art , Ms B . W . Hawkin s , Mr B . J . Ri dler , Dr A . Wright , Mr S . T . Morri s , Mr M . Carter and Dr D . G . McC a l l .
Th anks a l s o t o Glenyss Hamlin for her skill and more par t i c u l a r ly her pat i ence in typing thi s st udy .
I owe a large debt t o my f amily for th eir support through wh a t h a s proved a f airly lon g st udy period , but maybe now I c an f i t in the
f i sh ing trips and house renova t i on s that have been put off over the last " f ew" year s .
Finally , thanks t o my f latma t e s Greg , P e t e and e sp e c i a l ly S a l ly who have provided c on t inual support on th e h ome front which h a s b e en much appreciated .
AB STRAC T
Two areas o f research are repor t e d in this s tudy . F i r s t , the c ompari so n between the pro f it ability o f a high performanc e f lock a nd a low per f o rmanc e f l o ck run at a high e r s t o c king r a t e o n Ma s s ey
Univer s i t y ' s Tuapaka hill c ountry uni t . S e c ond , the c ompa r i son between s imple feed budget ing and c omplex s imula t i on mod e l ling as methodo l o g i e s u s ed in th e d e s ign of past o r a l based sys t ems .
Whi l e the higher performanc e f lock i s found t o be marginally more pro f i t a b l e than th e lower performanc e f l o c k , the s impl e ( spreadsh e e t b a s ed ) f e ed budget models u sed f o r the analysis show l i t t le differ ence in the p a t t ern of f eed demand between th e f l ocks . The g r e a t e s t
di f f erenc e s in pro f itabi lity were d u e t o s t ocking r a t e r a ther than p e r f orma nc e . A low s t o cking rate system that allowed l ambs t o be g r own o u t to heavy carcass weigh t s wa s found to be the mo s t pro f i t able sys t em for Tuapaka . A number o f weakne s s e s can be ident i f ied in the s imp le f eed budget ing appro ach however .
The s e inc lude : limited feed t able d a t a on the e f f ec t s o f
d i f f er e nt leve ls o f nu t r i t ion on animal p e r f ormance f o r t h e peri o d s o f pre gnancy and lac t a t i o n ; a l a c k o f feed t able data on t h e relat ionship be tween f e ed int ake and wool produc t i o n , and failure to t ake int o a c c o unt the inter a c t ion be tween past ure c over , past ure growth rat e s , p a s t ure qua lity , animal int ake and subs equent leve l s o f animal
p e r f o rma nc e . These lat t er two weakne s s e s are ana lysed by u s ing spreadsh e e t based s imulation mod e l s in the second part o f th e study .
The r e su l t s o f the se analysis indic a t e that wool product ion i s u nder - e s t imated by the s imple f e ed bud get mo del , par t i c u l ar ly in the c a s e o f th e high performanc e f l o c k . C or r e c t ing thi s increases the pro f i t margin between the two f l o cks , but does not a l t e r the r anki ng s .
Ana lysis o f th e e f f e c t o f int era c t ions betwe en p a s t u r e compo nent s and anima l performance over the period o f lactation shows that the s imple f ee d budget appro ach f a i l s to repr e s ent the true s i t uat ion i n t e rms o f t h e pattern � f past ure growth , animal intakes and subsequent p e r f ormance level s , and that th i s is e s pe c i ally so whe r e pasture c over f a l l s be l ow 1 000 kg DM/HA . Th i s analy s i s sugge s t s tha t the linear r e l a t i o n sh i p s a s sumed in the s imple f eed budget appro a ch d o not h o l d in reali t y .
The c o nc lu s ions f rom thi s s t udy are that a high p e r f o rmanc e , l ow s t o cking r a t e system would be more p r o f i t able than a l ow perf ormanc e , h i gh s t o cking rate system f o r the Tuapaka h i l l country u ni t , but that i t would o f f er lit t le advant age in t erms of better mat chi ng f e ed d ema nd a nd f e ed supply .
( i i i )
Complex simu l a t i on modelling h a s a numb e r o f advan t a g e s over the simple feed budgeting technique . However , the u s e o f th e s e mod e l s � s dependen t on the validat ion of th e mod e l s and the con s t r u c t i on o f mod e l s th at are " u ser- friendly" . The s t u dy iden t ified a n umber o f areas wh ere f ur ther work i s required in the validat ion o f some o f the more complex int er-relat ion ships .
Simple feed budgeting is qu i c k and s i mp l e t o use , and in a gro s s sen se provide s feasible results provided pa s t ure cover levels are main t a ined wi thin c er t ain bound s . The d e f in i t ion of th e upper and lower bounds requires further wo rk , a revi ew of the lit erature suggests they are 1 00 0 and 1 7 00 kg DM/ HA .
Th e use o f spreadsheet techno logy proved highly e f f ec t ive f or the development o f simple f e ed budget mode l s . H owever , the r e were a
number of con s train t s evident when spr e a d sh e e t s were u s e d for the c on s truction o f more c omplex mode l s . The s e in c luded , c apacity , c a l c u lation t ime and limi t a t ion s in t erms o f the avai l ab i l i ty o f mathematical formulae . Wi th further devel opmen t s in thi s t e chn o logy expected , spreadsheet s should prove a u s e f u l t oo l in the developmen t o f more compl ex simu la t i on mode l s .
CHAPTER ONE:
1 . 0 1 . 1
1 . 2 1 . 2 . 1 1 . 2 . 2 1 . 2 . 3 1 . 2 . 4 1 . 3
CHAPTER TWO : 2 . 0 2 . 1 2 . 2 2 . 2 . 1 2 . 3 2 . 3 . 1 2 . 3 . 2 2 . 3 . 3 2 . 4 2 . 4 . 1 2 . 4 . 2 2.4 . 3 2 . 4 . 4 2 . 5 2 . 5 . 1 2 . 5 . 2 2 . 6 2 . 7 2 . 7 . 1 2 . 7 . 2 2 . 7 . 3 2 . 8 2 . 8 . 1
TABLE O F C ONTENTS
I ntroduc t i o n .
Mot iva t i o n f o r t he s t udy .
The physi c a l r e sourc e s and manag ement o f Tuapaka .
Physica l Re sourc e s .
The Tuapaka h i l l f arming sys t em .
The need for a revi se d farming system.
Obj e c t ives o f the s tudy . The s i s o u t l ine .
FEED BUDGET ANALYS I S
C hapter o u t l i ne . I ntrodu c t i o n .
Tuapaka f ee d supply . Pasture qua l i t y . Feed demand .
Ewe feed r equi rement s .
Replac eme nt ewe ho gget f e ed re qui r eme nt s . Sale lamb f e ed re quir eme nt s .
St ock numbers . St ock l o s s e s . Replacement ra t e .
S t ock s a l e s and pur c ha se s . Stock number c a l c u la t i ons . Analysis o f pro f i t abi l i ty . I ncome as sumpt i o ns .
C o s t a s sumpt i o ns .
General f orm o f the mode l . The f eed budg e t mode l . Feed supply .
F eed demand .
Model c a l c ulat i ons . Financ i a l mod e l .
Farm c o s t c al cu l a t i on s .
Page No .
1 1
3 3 9 1 0 1 1 1 1
1 3 1 3 1 4 1 4 1 5 1 5 1 9 2 2 2 2 2 3 2 3 2 3 2 3 2 4 2 4 3 1 3 2 3 3 3 3 3 3 3 3 3 4 3 5
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Page No .
2 . 9 2 . 9 . 1 2 . 9 . 2 2 . 1 0 2 . 1 0 . 1 2 . 1 0 . 2 2 .ll
CHAPTER THREE :
3 . 0
D i s c u s sion o f result s . In troduc t i on .
Feed budget result s . Fin ancial result s .
Betwe en f lock profit abi l i t y c omparison . With in f lock pro f i t ability c omparison . Conc lusion s .
THE LIMITATIONS OF THE FEED BUDGETING TECHN IQU E
Int r oduc t i on .
3 . 1 The relat ion ship between p a s t ure cover and 3 .l.l
3 .l. 2 3 . 2 3 . 3
3 . 4
CHAPTER FOUR : 4 . 0 4 . l 4 .l.l 4 .l. 2 4 .l. 3 4 . 1 . 4 4 .l. 5 4 .l. 6
4 . 2 4 . 2 . 1
past ure gr owth ra t e .
The e f f e c t o f pasture cover on animal in t ake The factors that a f f e c t p a s t ure quali t y . S imu lat ion mode llin g .
Discuss ion o f the appli c abi l i t y of McC a l l ' s mode l .
Summary .
C ONSTRUCTION OF SIMU LATION MODELS
Int r oduc t i on .
The animal sub-mod e l s .
Th e replac ement s t o c k mode l . The sale lamb mode l .
The dry ewe model .
Th e pregn an t ewe mode l s . The lac t at ion mode l .
A c omparison o f s imu l a t i on generated wo o l produc t i on with a c t u a l levels o f woo l pro duc t i on .
The pasture mode l .
The Tuapaka pasture growth model .
The generation o f poten t i a l pasture growth r a t e s .
E f f ec t o f c limatic variabl e s on p a s t u r e growth r a t e s at Tuapaka .
Th e dead mat t er c omponent o f the sward P a sture quality .
3 5 3 5 3 9 4 4 4 4 4 8 5 0
5 1
5 2 5 2 5 3 5 4
5 5 5 6
5 8 5 8 5 8 6 0 6 0 6 2 6 6
7 0 7 1 72
4 . 2 . 2
4 . 3
CHAP TER FIVE :
5 . 0 5 . 1 5 . l . l 5 . l . 2 5 . 2
5 . 2 . l 5 . 2 . 2 5 . 2 . 2 . l 5 . 2 . 2 . 2
5 . 2 . 2 . 3 5 . 2 . 2 . 4
5 . 2 . 2 . 5 5 . 3
CHAPTER SIX : 6 . 0 6 . 1 6 . 2 6 . 3 6 . 4
B I BL IOGRAPHY
The pa s ture model s t ructure .
C ompar i son between a c tual p a s t u r e growth r a t e s and model s imu lated pasture
produc t i on . Summary .
A COMPARI SON OF SIMULATION MODELL ING OUTPUT WITH SIMPLE FEED BUDGETING TECHN I QUES
In trodu c t i on . Wool pr oduct ion . Met hodol o gy .
Re sul t s and d i s cu s s i on .
The in teract ion between pasture parameters and anima l performan c e .
Me thodol o gy .
Resu l t s and d i s c u s s i on . Introduc t i on .
The int e r a c t ion o f p a sture cove r , p a s t ure growth r a t e s , animal intake and s t o c king rat e . The e f fe c t of ewe and lamb in t ake on animal perf orman c e .
The e f f e c t o f sward c ompo sit i on on pas ture quali t y .
Summary and d i s c u s s i on of result s . C onclus ion .
C ONCLUSION C hapt er o u t l in e .
Evalu a t i on o f res earch met hodolo gy . C on c lu s ion s from f ee d budget analys i s . Po ssible areas for f u r t her resear c h . C onclusion .
Page No .
7 8 7 8
8 1 8 1 8 1 8 2
8 5 8 5 8 5 8 5 8 6
9 0 9 6 l OO 1 0 3
1 0 4 1 0 4 1 0 5 1 0 7 1 0 8
1 0 9
1 . 1 1 . 2 1 . 3
( vi i )
FIGURES
Locat ion map .
I deali sed sec t i on acr o s s Tuapaka farm, showing physiographic uni t s .
Tuapaka sheep unit .
2 . 1 The effect o f c ar c a s s we i ght and grading on
Page No .
4
5 8
the net value o f ewe and ram lamb c a r c a s se s . 2 9 4 . 1
4 . 2
The rate o f net dead herbage a c c umul a t i on as a percentage of average green c over versus soil moi sture percen t age at Tuapaka for the period Sept ember to March .
A plot of ac tual ver s u s simulated pa sture growth rat e s ( kg DM/ HA/ DAY ) f or 1 9 8 4 at Tuapaka .
75
79
l . l
2 . 1 2 . 2
2 . 3
2 . 4
2 . 5
2 . 6 2 . 7
2 . 8
2 . 9
2 . 1 0
2 . 1 1
2 . 1 2
2 . 1 3
2 . 1 4
2 . 1 5 2 . 1 6
TABLE S
Page N o
A summary of average mon th ly rain f a l l
data ( mm) f o r Tuapaka from 1 9 7 6 - 1 9 8 5 . 6 Average mon th ly pastur e growth rate s f or
the Tuapaka h i l l un it . 14
Average monthly pasture qua lity values for
hill c ount ry . 1 5
The pregn ancy s t a t u s o f ewe s within f l ocks
ach ievin g l OO% lambing and 1 32 % lambin g . 1 6 The liveweight pro f i l e s for s in g l e , twin and
triplet rearing ewe s ( kg ) . 1 7
The average feed r equiremen t s for ewe s o f diff eren t bearin g rank/ rearing rank
( MJME / EWE / DAY ) . 1 8
The l ambing spread for a h i l l country ewe flock. 1 9 The liveweight pro f i l e s of r eplac ement ewe lambs
for th e l OO% and 1 3 2 % f locks . 1 9 Th e l amb liveweigh t c ompo s i t i on of th e l O O% and
the 1 3 2 % f locks . 2 0
The average feed r equi remen t s for th e replacement stock fr om the l OO% and 1 3 2 % lambin g flo cks . 2 1 The ave rage feed requir ement s for n on-replacement lamb s from the lOO% and 1 3 2 % lambin g f locks . 2 2 The average mon thly wool gr owth rates for the
sale l amb s . 2 5
A summary o f the woo l c l i p and pri c e s for th e
l OO% and 1 3 2 % lambing f l o cks ( kg ) . 2 6 A summary o f the l iveweigh t , c ar c a s s weigh t ,
G . R . fat d epth , gradin g and schedule price of th e lOO% and 1 3 2 % lambing f l o c k ' s sale lambs . A summary o f th e value o f lamb carc a s s e s from the l OO% and 1 3 2 % l ambing f l o c ks .
Cull ewe pr i c e .
A summary o f animal h e a l th c o s t s .
2 7 & 2 8
3 0 3 1 3 2
2 . 1 7
2 . 1 8
2 . 1 9
2 . 2 0
2 . 2 1
2 . 2 2
2 . 2 3
2 . 2 4
2 . 2 5
2 . 2 6
2 . 2 7
2 . 2 8 2 . 2 9
( ix)
Page No .
Average monthly past ure growth rat e s ,
animal requirement s , pasture surplu s / d e f i c i t and pasture c over l evel s f o r the 1 00% flock stocked at 1 0 . 5 SU / HA .
Average monthly pasture gr owth rate s ,
animal requirement s , pas ture surplu s / d e f i c i t and pasture c ove r level s f o r the 100% flo c k s t o c ked at 1 1 . 5 SU/HA .
Average monthly past ure gr owth rates ,
animal requirements , pas ture surplus / d e f i c i t and pasture c over level s f or th e 100% flock s t o c ked at 1 2 . 5 SU/HA .
Average monthly pasture growth rat es ,
animal requi reme nt s , pasture surplus / d e f i c i t and pasture c over level s for the 1 3 2 % fl ock stocked at 9 . 0 SU/HA .
Average monthly pasture growth rat es ,
animal requirement s , pasture surplus / de f ic i t and pasture c over level s for th e 1 3 2 % fl ock stocked at 1 0 . 0 SU/HA .
Average monthly pasture growth rat es ,
animal requir ement s, pasture surplus / d e f i c i t and pasture c over level s for th e 1 3 2 % flo c k stocked at 1 1 . 0 SU / HA .
A c ompari son o f the f e ed requirement s o f single, twin and t r iplet rear ing ewe s .
A c ompari son o f the f e ed requir ement s o f a singl e rearing ewe , with a twin bearing/ single rear ing ewe
3 6
3 6
3 7
3 7
3 8
3 8 4 0
and a tr iplet bearing/ s ingle rearing ewe . 4 1 A c ompa r i s on o f the propor tion o f ewe s that fail t o
rear the number o f l amb s pre sent at b i r th f r om the
100% and 1 3 2 % l ambing flocks . 4 2
A c ompari s on o f hal f monthly f eed requir ement s o f
replacement s t o c k f o r th e 100% and 1 3 2 % flo c k . 4 3 The gros s margin ind i c e s for th e 1 0 0 % a n d 1 3 2 %
flo cks . 4 5
Wool production for the 1 00% and 1 3 2 % flocks . 4 5 The c omponent s o f t o t al sh eep inc ome f or th e 1 00%
and 1 32 % flocks . 4 6
2 . 30
2 . 3 1
2 . 3 2
2 . 3 3
4 . 1 4 . 2 4 . 3 4 . 4 4 . 5
4 . 6
4 . 7 5 . 1
5 . 2
5 . 3
5 . 4
5 . 5
5 . 6
Page No .
The c omponent s o f sheep inc o me f or the lOO% and
1 3 2 % f lo cks . 4 7
A breakdown o f the c ompo nent s o f lamb meat inc ome
for the lOO% and 1 32 % f lo cks . 4 7
Lamb me a t produ c t i o n indic e s f or the lOO% and
1 32 % f lo c ks . 4 8
The proport i o n o f lamb s i n t he diff erent grades for the two f locks at three s t o c king ra t e s . 4 9
The r e p l a c ement s t ock mod e l . 5 9
The dry ewe mod e l . 6 1
The pregnant ewe mode l . 6 3 - 6 5
The l a c t a t ing ewe mo de l . 6 7 - 6 9
A c omp a r i son o f s imulat ion generated woo l
produc t i on and a c t ual wo o l produc tion on Ma s sey
Univer s i ty ' s Tuapaka hi l l u n i t and River side farm. 7 1 Mul t i p l e regr e s s i o n analysi s o f pasture growth
rates and c l imat i c data .
The Tuapaka pasture growth mo d e l .
A c ompar i son o f woo l produ c t i o n ( kg ) generated by simulat i o n wi t h e s t ima t e s u s e d in the simple feed budget a nalys i s .
A c ompari son o f the phys i c a l and financ ial ind i c e s based o n woo l produc t i o n gene r a t e d b y simulation and
7 3 7 6
8 2
the e s t ima t e s u s ed i n the s impl e f eed budge t analys i s . 8 4 The e f f e c t o f s t o c king r a t e a nd i nit i a l pasture
cover on the p a t t ern of p a s t u r e c over achieved ( kg DM/ HA ) .
The e f f e c t of s t ocking r a t e a nd initial pa st ure cover l ev e l s o n f eed supply and feed demand . The propo r t i o n o f t ot a l f e ed s upply produced over the period of lac t a t io n for the three s t ocki ng r a t e opt ions .
The e f f e c t o f t he average l eve l o f green p a s t ure cover ( kg DM/HA ) and p a s t ur e g r owth r a t e s ( P . G.R . ) ( kg DM/HA/DAY ) .
8 6
8 8
8 9
8 9
5 . 7
5 . 8
5 . 9
5 . 1 0 5 . 1 1
5 . 1 2
5 . 1 3
5 . 1 4 5 . 1 5
5 . 1 6
(xi )
Page No .
The effec t o f average green pa s t ure ( kg DM/ HA) and lamb liveweight ( kg ) on ewe and lamb dry ma tter in takes ( kg DM/HD /DAY ) .
A summary of ewe in t ake s ( kg DM/ EWE / DAY ) , ewe liveweight ( kg ) an d ewe liveweight gain ( gm / DAY ) over lac t a t i on .
The ef fec t o f st oc king r a t e and pasture c over leve ls on ewe mi lk produc t i on over lac t a t i on C l / DAY ) .
A summary of ewe in t ake s ( kg DM/ HA/DAY ) and woo l
9 1
9 2
9 3
growth rates ( gm/DAY ) . 9 4
The ef fec t o f s t oc king r a t e and pasture c over leve l s on lamb li vewei ght gain over lac t ation ( gm / Day ) . 9 5 The effec t of en ergy int ake ( MJME / DAY ) on lamb wool produc t ion over lac t a t i on ( gm/HD / DAY ) . 96 The average sward dige s t ibili t y , energy c on t ent and quality of pasture c on s ume d for t he thr e e s t oc kin g rate option s over lac t a t ion .
The effec t of s t oc king r a t e and pasture c over on the perc ent age of green dry ma t t er present .
The effec t o f average green past ure cover l eve ls ( kg DM/HA) on dead ma t t e r accumulat ion r a t e s ( kg DM/ HA/DAY ) .
A summary of the po s i t i on of the three s t oc king r a t e opt ion s at wean ing and a c ompari son o f t he
dif ferenc es again s t the high st oc king r a t e o p t i on , with allowanc es made for the feed c o st o f d i f f erenc e s
9 7 9 8
9 9
in liveweight . 1 0 1
