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SOME E FFECTS OF HOT CLIMAT IC CO NDIT IO NS O N BRAHMAN X FRIE S IAN AND F RIESIAN CALVE S
F E D HIGH AND LOW ROUGHAGE RAT IO NS
A thesis
presented 1n p arti al fulfi lme nt of the requ i rement s fo r t he degree
of
MASTER OF AGRICULTU RAL SCIENCE in
A NI MAL SCIE NC E
at
MASSEY UNIVERSITY
FRA NCIS KING CH IU TIO NG 1 9 7 8
A CKNOWLEDGEME NTS
=========
The autho� i s especially thankful to his
s upervisor Dr . c.w. Holmes , who ha d a s s i st ed e fficiently and wi sely in all a sp e cts of the studi e s . Without whom , thi s thes i s would not have been written.
The autho r i s also extremely thankful to the f o llowi ng p e ople:
Madam Helen Akers for her s chol a r ship in M . Agr . Se .
Mr . P. Sauwa for hi s sincere co-op eration in carryi ng out the experi ment.
Professor D . S . Flux , Pro fessor R . A . Rae
and Mr . A . B . Pleasant s for thei r assistance in exp eriment al des ign and s t at istical
analys es .
Mr . M . L . Ngu yen, Mr . J . Ravens an d
Mrs . R . C . Chri stensen fo r thei r techni c a l assistance in chemi c a l analys es .
Mr. W . J . Lock yer , and Mr . R . S . Mc Clenaghan for thei r gener al a s s istance in running the e xp eriment .
Miss B . P . Sng , Mr . C . C . Chai and Mr . K . S . Tan for thei r v arious a s s i stance�
Mrs . A . F . Barton and the s ecret a r i es of Loke and King Comp a ny, Advo c a t es for thei r eff i c i ent t yp i ng .
Miss Sim Kim Yan and Mi ss King Sie Choo also for thei r e fficient t yp i ng .
CONT E NTS.
Abstr act
A cknowledgements L iRt of t a bl es
L i s t of figures
/
di a gr ams lnt.r oduct ionChapter One - Review of Li�erat ure
(I) VOLU NTARY F EED INTAKE IN CATT L E P . l 3 ( 1 ) CO�TR(1I. OF FE E D INTAKE
1 . 1 Centr al Nervous S.ystem
1 . 2 Signals to regul a t ing system 1 . 2 . 1 ) phys ical s i gnal s
1 . 2 .:? ) met abol i c s i gnals 1 . 2 . 3 ) c orrelation of feed
intake
1 . 2 . 4 ) roles of hormones ( 2 ) FACTOR�; A FFECT I NG F E ED INTAKE
2 . 1 Animal factors 2. 1 . 1 � genet,ic
and wat er
2. 1 . 2 ) others (physiologic al state , gr owth , sex and health) 2 . 2 Fo od fa ctors
2 . 2 . 1) type of diet
2 . 2 . 2 ) others (nutr ient imb alance , -p al at ability and av ail abil ity) 2 . 3 Envir onment al factors
2 . 3 . 1 ) high t emper ature 2 . 3 .2 ) diurnal variations
(
II) VOLU NTARY WATER INTAKE IN CA'l''l' L E P . 45 (1) CO NTROL OF WAT ER BA LANCE1 . 1 Regul at i on of r en al output 1 . 2 Regul ation of water intake
( 2 ) FACTORS A FFECT I NG WAT ER I NTAK E 2 . 1 Animal factors
2 . J. . l ) genetic
2 . 1 . 2 ) others ( physiologi c a l s t at e , a ge , act ivity )
2 . 2 Food factors
2 . 2 . 1 ) type of food 2 . 2 . 2 ) others
2 . 3 Environment al f a ctors 2 . 3 . 1 ) high t emperature 2 . 3 . 2)
2 . 3 . 3 )
water deprivation
free water ad lib in hot environment-
( I I I ) D IGESTIBILITY P . 5 9
( 1 ) Geneti c factors and digestib i l it y (2 ) Food fact ors a n d di gestib ility
2 . 1 . Type of feed 2 . 2 Level of feeding
( 3 ) Heat stress and digestibility ( IV ) GROWTH RATE P . 6 7
(1) Genetic dif ference s in growth rate 1 . 1 � taurus
1 . 2 B. indi c us
1 . 3 Zebu crossbreds 1 . 4 New bree ds
( 2 ) Nutrit ional e ffects on growth rate 2 . 1 Tropi c a l pasture
2 . 2 Feeding rations
( 3 ) Heat stres s and growth rate ( V ) E F F E CTS OF RADIA!;ION P . 87 ( V I ) CO NCLUSIO N P. 91
Chapter Two - MATER IAL S A ND M E THOD S P . 9 3 ( I ) MAIN EXP ERIM E�T P . 9 3
-·
---�---J
I\
( 1 ) Experimental des i gn and l ayout ( 2 ) M at er i a l s
2 . 1 Animals 2 . 2 Diets
2.3 Environmental conditions ( 3 ) Methods and Mana gement
3.1 Rec t al temperature and respiration rate 3 . 2 Diet
3.3 Environment a l conditi ons J. 4 Live-weight
3 . 5 Digest ibility of diet ( 4 ) Chemic a l Aualyses
4.1 Nitrogen analysis 4.2 Energy analys i s
4 . 3 Dry matter determinat ion ( 5) St atistic al Analysis
5. 1 Feed int ake 5.2 Di ge stib ility 5 . 3 Growth rate 5 . 4 wat er int ake
(II) RADIANT HEAT STRESS TRIAL P.l09 (1) Experiment al l ayout
( 2 ) Materi a l s 2 .1 Animals 2 . 2 Diets
2 .3 Environmenta l conditions ( 3 ) Methods and Mana gement
3.1 Respirat ion rate and re ctal temper ature 3 . 2 Diets
3. 3 Envi ronment al conditions Chapter Three - RESULTS
(I) MAIN EXPERIMENT P . ll 7
( 1 ) Respiration rate and rectal t emperature
( 2 ) Fee d Intake
2 . 1 Variation of hay and p e l l et proportions in the ration
2 . 2 Dry matter intake
2 . 3 D i ge stibl e energy intake ( 3 ) Digestibility
3 . 1 Dry matter di gestib i l ity 3 . 2 Gross energy digestibi l ity
3 . 3 Apparent nitr ogen dige stib ility (4 ) Liveweight Gain
( 5 ) Water Intake
( I I) RADIANT H EAT STR E S S TRIAL p . 1 4 3 (1 ) Radi ant Heat Lo ad
( 2 ) Net Exchange s of Radiant Heat
(3 ) Res p iration Rate and Rectal T emperature
( 4 ) Dry Matt er Int a ke ( 5 ) Water Intake
Chapter Four - D ISCUSSIO N
(I) MA I N EXPERIMPKT p . 1 50 ( 1 ) Fee d Intake
( 2 ) Diges tibility (3 ) Liveweight Gain (4 ) Water Intake
( IJ) RA.D IANT H EAT STRESS TRIAL P . 1 6 7 ( 1 ) Radiant Heat Enviror�ent
( 2 ) Res piration Rata and Rectal Temperatur·e ( 3 ) Dry Matter Intake
( 4 ) Water Intake
Chapter Five - CO NCLUSION
Appendic e s R e f er e n c e s
(I) MA IN EXPERIM ENT P . 1 7 1 ( 1 ) Temperature
( 2 ) Diet ( 3 ) Bree d
(4 ) Br e e d x Diet Interact i on
( 5 ) Bre e d x Temperature Interaction ( 6 ) Temperature x Diet Interaction
(7 ) Bree d x Diet x Temperatur e Interactions (II) RADIANT HEAT STRESS TRIAL P . l 73
Tab l e 1 .
T ab l e 2 . Tab l e 3 . T ab l e 4·
T ab l e s.
T ab le 6 . T ab l e 7 . T ab l e 8 .
T ab l e 9 . Tab l e 10 . Tab l e 11 . Tab l e 12 .
T a b l e 1 3 . . ] able 14 • Tab l e 1 5 . Tab l e 1 6 . T ab l e 1 7 . Tab l e 1 8 . Tabl e l9o
List. of Tab l es
Breed comparisont; in growth r at e under sub-tropi c a l or tropical condit ions . P . 7 0
Calving percentages in crossb r e ds in ' Belmont1• P . 7 4 Mai n re cogni z e d crossb r e ds . P . 7 4
Estimated b e e f production from nat ural grassl ands and s own gra s s l ands in the tropics . P . 7 7
The eight t r eatments o f the Main Experiment . P . 9 4 The c omposition of pellets and hay . P . 98
Time of exposure or without exposure t o r adiant heat loa d . P . l 0 9
Age and fasted l ivewei ghts o f calves i n Radiant 'beat stress t r i al . P . lll
Environment a l conditions of r a di an t heat roont . P . ll 3
p. 1:{.8 Mean values o f respir ation r ate and r ectal temperatur e ; Me an values o f dry matter int ake and original
l iveweight . P . l 20
Mea1: values of digestible int ake and original l iveweight . P . l 2 4
Dry matter digestibility . P . l 2 7 Gross energy digestib i li t y . P . l 3 0
Appa rent nitr o gen dige st ibility . P . l 3 1 Liveweight gai n . P . l 3 3
Water int ake . P . l 3 7
Radiallt r.eat fluxes of r adi ant. room . P . 1 43
Net exchanges of ra diant heat b etween the animal and the environment . P . l 4 4
Tab l e 2 0 . Me an val ues of respiration r ate and rectal t emp- e r at ure . P . l 45
Tab l e 2 1 . Dry matter int ake in r adiant heat�stress t r ial . P . l 46 Tab l e 2 2 . Water intake i n radi ant h e at stress trial . P . l 4 9 T ab l e 2 3 . Comparis ons o f voluntary feed intake i n hot and
cool environments . P . l 5 1
Tabl e 2 4 . Di gestibility and level of feeding. P . l5 9
D ia gram 1
Dia gram 2 Diagram 3 D iagram 4 F i gure 1 F igur e 2
Fi gure 3 Fi gure 4
F i gure Sa Figure 6a Fj gure 7 F i gure 8 F i gur e 9
List o f Figures/Diagrams
The energy exchanges b etween an animal and i t s environment. P . 8 8
Experimental layout in Mai n Experiment . P.95
Experimental layout in Radiant heat stress t r ial . P.llO Plan o f radiant lamps layo ut . P.ll5
Probabl e relationships b et ween._ener gy and food intake and contr olling mechanisms. P . l8
Seas onal liveweight changes of cattl e , 1-4 year�
old grazing nat ive pastur e at Katherin e , N.
Austra l ia . P.7 8
Origi nal l ivewe i ght o f experimental animals in Mai n E xperiment . P. 9 7
Room environmental conditi ons i n Radiant heat stres s trial . P . ll2
& 5b Dry matter intake. P . l 2 1 & 1 2 2
& 6b Dige s t ible ene r gy intake . P . l 2 5 & 1 2 6
Dry matter di ge stibility . P . l 2 8 Gross enery dige stib ility. P . l2 9
Apparent nitrogen digestibility. P . l 3 2
Figure lOa, lOb & l O c Livewei ght ga in . P . l 3 4, 1 3 5 & 1 3 8
Figuee l la Figuee 1 2 Fi gure 1 3 F i gw"e 14
& llb Water intake . P . l 3 9 & 1 40
Wat e r intake per unit dry matter intake . P.l 4 2
Dry matter intake i n Rad iant heat stress trial . P . l 4 7 Dry matter intake and wat e r intake i n Radiant
heat s tress ·tr ial. P . 1 48
ABSTRACT
The exp e riment consis ts of two p arts : the Mai n trial a nd Radi ant heat stress tri a l .
1 . Ma in T r i a l . The effects o f temperatur e , breed t yp e , die t types a nd th eir intera cti ons on feed intak e ,
digestibi lit y , liveweight gain ( LWG ) and Water intake w e r e examined in the Main tria l . E ight Friesi an ( F ) and eight Brahman x Friesian ( B F ) c a strated male calves ( 6 months old ) w ere allocated to b e fed on the High r at i on
( pe ll ets ad l i b . + 10% of the total feed dry matter a s hay ) a nd the Low r a ti on ( hay ad lib . + 1 0% of the tota l f e ed dry matter a s pe llets ) , and to be kep t in a hot room ( 34 . 5° C , 4 5% RH ) OR a cool room ( 16 . 9 ° C , 86% RH ) for a
p eri od of 5 9 days . There were ei ght indi vidual t r e atments , with two anim a ls on each treatment.
The calves in the hot room h a d a s igni ficantly lower dry ma tter intake (DMI), diges tible ene rgy intak e (DEI) and LWG tha n thos e i n the c oo l room . The calves f e d on the High ration had a signifi cant l y higher DMI, DEI and LWG tha n those fed o n the L ow r at ion, B F c alves h a d a signi ficantly higher DMI, DEI and LWG t han F c alves when f e d the High r a ti on in both the hot a nd cool rooms , but the two breeds had very similar f eed intakes and LWG when fed the Low rati on.
In the hot room, there was a s l i ght but s ignific ant increase in dry matte r and energy diges t i biliti e s , but not appa r ent ni trogen digesti bility .
The Water intak e w a s s igni fi c a n t l y higher in the hot r o om than in the cool room . The water intake b y B F c alves fed the Hi gh ration w a s signific antly higher than other treatments due to their h igher DMI. The calves fed the High ration had a significantly higher water intake than
those fed on the Low ration in t he hot room and thi s was a l s o mainly a reflec tion of the higher DMI by calves fed the High rati on .
2 . Radia nt Heat Stress Tri a l . The e ffects o f exposu r e t o simula te d sunshine o n f e e d and water i ntak es w e r e
investiga t e d in thi s trial . Six anima ls ( 4 B F, 2 F ) from t h e hot rooms in the Main Tri a l were exp osed to a r a diant h e a t load for 8h dai ly during a period o f two weeks ,
fo l lowed o r p r eceded by a p eri o d of two w eeks in the a bs ence of a ra diant heat l o a d in a hot envi ronm ent
( 30 . 0 - 3 3 . 1° C ) and fed on a hi gh rougha ge di et ( 500g p el l ets + h a y ad li b . ) .
The r e was no s i gnificant reduc tion in DMI or increase in water int ake when the c alves were e xp o s e d t o the r adiant h e a t l o a d in a h ot envi rorun ent .
In b oth the Main and Radiant He at Stress Tri a ls , the rectal t��eratur e as heat stress indicator di d not c o r relate well with the DMI an d LWG of B F and F c alves under heat s tress .
