Investigations on adaptation to high temperatures by Angora rabbits Schlolaut W. in

Baselga M. (ed.), Marai I.F.M. (ed.).

Rabbit production in hot climates Zaragoza : CIHEAM

Cahiers Options Méditerranéennes; n. 8 1994

pages 453-460

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--- Schlolaut W. In vestigation s on adaptation to h igh temperatu res by An gora rabbits. In : Baselga M. (ed.), Marai I.F.M. (ed.). Rabbit production in hot climates. Zaragoza : CIHEAM, 1994. p. 453-460 (Cahiers Options Méditerranéennes; n. 8)

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Schlolaut, Homberg, Ger'many Introduction:

High environmental temperatures reduce performance in rabbits WiLh norrrlnl hair. This effect is .increased by the stronger insulation of Angora rabbits' wool-fleece, Main cause reduced .performance found in animals with longer t'he increasing

difficulty regulating body-tenlperuture, Angora rabbits .try solve this problem by reducing their feed-intake.(Figure). This.

lowers weight-gain and wool-yield . which both depend upon supply of nutrients (Table However.performnnce health otherwise reduced as well by physiological stress caused by regulation

body-temperature before. and after shearing. Semen-quality declines and embryonic mortality rises with increasing length. of the wool-fleece (Brockhuusen et 1 9 7 9 )

.

this stress caused shearing or cpilation can reduced by higher environmental temperatures. Hereby optimal temperattire

v a r i e s between 2 6 and 2 8 centigrades (Vcrrnorel et

temperatures are lower within the first f e w days a-fter wool- harvest, feed-intake will increase and furthermore fat-reserves have to be mobilized in order to provide the necessary energy for keeping up body-temperature. This results in changes metabolism lowering body-temperature within .this period

which l e a d further complications

.

Insulation-capacity of the wool-fleece dependa o n length and thickness OP and, above all, on

intervals. Therefore we investigated to what extend several para- meters' of performance can be influenced by shortening 'the shearing-interval.

Wool-yie1.d (Table 2 )

experiments we compared intervals days with and cil days respectively. Environment-temperature varied between 18 and " C

.

each experiment mule ungoru rabbits received pelleted

f e e d containing 1 0 , s energy 1641

.protein (with 0 , 8 5 % methionirl und cystin) libitum.

)

o f t h e

~

) 9

( 2 ) t t r r w s tittrus w i t h i r l t o r v u l s 3 woolcs.

.

3%.

ape i n f l u e n c e d

.

A t

9 . T h e

( 7 0 ' , 4 % )

per kg

angora-wool under subtropical conditions concgrning economy feeding.

The present results point too the possibility reducing the negative influence high temperatures on reproduction noraml-hairod rubbits by shearing the brooding-animala before sualnwr. Their hair does not again up the next moulting

full , A triul alight show short-huired rubbits have a higher .heat-tolerance than normal-haired rabbits.

The influence this is depending from the highness

temperature and its daily chang'es, Therefore this assumption is, not contrary to the findings of Finzi al. ( 1 9 9 2 ) . Who doesn't found an influece of shearing sperm volume and quality at normal haired males, But the environment temperatures in -this

experiment. changed only from hours with 2 2 to ₅ hours!. eit

30 seems the with the higher temperature wal

to.short, to have influence this parameters.

. Angora, rabbits there negative due

shortening of shearing-intervals, namely shorter and more labour. Still one should take into consideration that price-

differences between grades have declined.

Summary:

Higher ambient temperatures' commplicate regulation body -tem- perature rabbits .more. than normal-haired

The resulting lower feed-intake is followed slower'weight-gain groying animals and reduction wool-yield. Furthermore ,the heat-stress will impair semen-quality and the embryos' surviving chances

The experitnents reported showed that shortening

shearing-intervals resulted increased wool-yield and gain of weight, in improved feed conversion-rate and parameters

r o p r o d u c t i o n . Tho arc

Investigations the influence shearing of normal- Baired rabbits in summertime with regard to improve the parameters reproduction are suggested

.

B r o c k h a u s e n ; P.., P a u f l e r , S., S c h l o l a u t ,

U n t e r s u c h u n g e n a u f . S p e r m a q u a l j t ä t s p a r a m e t e r b e i m A n g o r a k a n i n c h e n . Z O c h t u n g s . k u n d e 5 1 , 234

-

B r o c k h a u s e n , P . , P a u f l e r , S . , M i c h e l m a n n , H . W . , S c h l o l a u t , W . U n t e r s u c h u n g e n d e s E i n f l u s s e s der W o l l a n g e u n d d e r S c h u r f r e q u e n z a u f F r u c h t b a r k e i t s k r i t e r i e n b e i m w e i b l i c h e n A n g o r a k a n i n c h e n .

Z ü c h t u n g s k u n d e 3 2 5

F i n z i , A . , P . , K u s m i n s k i , G. ( 1 9 9 2 ) : E f f e c t o f S h e a r i n g o n R a b b i t B u c k s P e r f o r m a n c e s i n h o t A n l b i o n d C o n d i t i o n s .

P r o c . WASA C o n g r . C o r v a l l i s

S c h l o l a u t , W . The A n g o r a R a b b i t . G T Z E s c h b o r n

S t e p h a n , E . , S c h l o l a u t ,

N.,-

A r b . T o g . V e t . G e s . , C e l l e .

V e r m o r e l , V e r n e t , J . , D o n n a t , J . , T h b b a u l t , R . C . ( 1 9 8 8 ) ~ T h e r m o r e g u l a t i o n d u l a p i n A n g o r a , a p r d s 1 ' Q p i ~ a g e .

C u n i c u l t u r e ' , 8 3 , 249.

-

.

l l

winter

Table l

4

/

Top1 Grade (> 6 cm long) Feed intake Water intake Feed per kg wool

Schlolaut, (1979).

116 1

1 1 o5

1 o9 1

With r i s i n g temperatures, there i s a corresponding drop i n wool yield and h i i intake. Since the reduction in feed intake exceeds that of .the wool, yield, feed conversion improves a t higher temperatures.

T a b ' l e 2

INFLUENCE OF SHORTENED S H E A R I N G INTERVALS ON WOOL. Y I E L D AND FEED C O N V E R S I O N OF A N G O R A R A B B I T S

S h e a r i n g d a y s i n t e r v a l .9 1 70 6 1

W o o l y i e l d .

/

11 II r e l a t i v e 200 113 ,123

F e l t

?

9 170 1 7 9

F e e d i n t a k e / d a y " 188

F e e d l . k g 6 9 , 1 5 6 4 , 4 1 6 2 , 8 6

II 'I r e l a t i v e * % 100 -91

. S h o r t e n i n g s h e a r i n g i n t e r v a l i n c r e a s e t h e . t h a n . f e e d i n t a k e . T h e r e f o r e f e e d c o n v e r s i o n i m p r o v e d .

J a b l e . 3

E F F E C T . O F ^SHEARING INTERVALS AND

R A f 3 6 I T S . ( 9 . . t o 1 8 . week o f a g e = 9 weeks)

9 weeks 3 weeks A d v a n t a g e s . ( + ) ,

( 9 )

3-w.eek ' s h e a r i n g .

L i v p w e i g h t g a i n

Feed, i n t a k e k g 8 . 7 2 6 , O l

1 , 6 8

5 , 8 6

-+

-.

+

T h e f l e e c e m a k e s i t

A

. .

i n t a k e . For t h e same o f a d u l t

a t h i g h t e m p e r a t u r e s , e s p e c i a l l y

. i n

tropic

#