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Effect of Virginiamycin on in Vivo Digestibility Rumen Fermentation and Nitrogen Balance a
a
a
L. O. Fiems , B. G. Cottyn , Ch. V. Boucque , J. M. a
Vanacker & F. X. Buysse
a
a
National Institute for Animal Nutrition, Agricultural Research Centre-Ghent , Melle-Gontrode, Belgium Published online: 08 Sep 2009.
To cite this article: L. O. Fiems , B. G. Cottyn , Ch. V. Boucque , J. M. Vanacker & F. X. Buysse (1990) Effect of Virginiamycin on in Vivo Digestibility Rumen Fermentation and Nitrogen Balance, Archiv für Tierernaehrung, 40:5-6, 483-489, DOI: 10.1080/17450399009421081 To link to this article: http://dx.doi.org/10.1080/17450399009421081
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Arch. Anirn. Kutr., Zerlin 40 (1990) S/G, 483489 XationalInstitute for Animal Nutrition Agricultural Reserrch Centre-Ghent 3Ielle-Gontrode, Belgium
L. 0.FIEXS,B. G.COTTPN,CEI.V. BOUCQUE, J. 11. VANACIKER and P. X. BUYSSE
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Effect of virgiiiinmycin on in vivo digestibility rumen fermentation and nitrogen balance"
1.
Introduction
Runien fernientation yielding more propiorlate and less acetate improves feed efficieiiey in beef cattle (EXSOR et al., 1960; BLASTER, 1962; HUXOATE, 1966; CHALUPA, 1977). Besides a selection of feeds this alteration in runien fermentation can also be induced b y feed additives, like the ionopGores inonensin, lasaloeid and salinomycin, or other antibiotics such as avoparcin (COTTYK et al., 1983; RIcIiTEri et al., 1984; RICKEet al., 1084; MERCIICPI' and BCRGER, 1986). Most of the mentioned feed additives have no effect on organic inatter digestibility, although a reduction of fibre digestibility (COTTYN et al., 19S3) or an iniprovemant of iiitrogen digestibility (PATE~SOX et al., 1983) may occur. However, results of NUPI'TIFERIXSG et al. (1981) and T ~ E N and D JOUAXY (1983) demonstrate that organic matter digestibility is affected by diet type and additive. A dietary effect on runien fermentation mas reported by RICHTER et al. (1981), where the effect of inonensin on the acetate: propionate ratio differed significantly when the diet contained 40 or SO Ol0 sugnrbeet slices. and Virginiamycin is an antibiotic which is iiof so recently discovered ( D E SOXER VAN DIJCK,1955), but it is mostly used in broilers, pigs and calves. Experiments with et al., 1985). I n vitro ruminants are mostly dealing with performallee (I~ARTILOTTI esperiments of VAX NEVELet, al. (1984) revealed an increased propionate proportion in incubations of ruinen fluid with virginismyein. The objectives of the present study mereto determiiie the influeiicc of \-irginianiycin on in vivo digestibility and rumen fermentattion when used i n different types of diets.
2.
Materials and met,hods
Two digestiontrials (Ia n d I I ) have been conducted with 5 wethers each time, t o study the influence of virgininmyein either i n a mixed diet of maize silage and concentrate (Experiment I),or a complete dry feed (Experiment 11). In experiment I diet dry matter consisted of 0.65 silage and 0.35 conccntrate, while in.experiment I1 the complete feed was based on O.GO dried sugarbeet pulp. Virginiamycin mas included a t 0 or 65 ppm in the concentrate (Experiment I) or 0 and 25 ppm in tho eoinplcte diet (ExCommunication X o 764 of t h e Institute
FIESIS/COTTTX et ai., Effect of Virginiamycin on digestibility
484
périment I I ) . S h e e p were fed a t m a i n t e n a n c e level, a n d confined i n d i g e s t i o n cages. After a n a d a p t a t i o n period of 2 0 d a y s faeces were q u a n t i t a t i v e l y collected a n d sampled once a d a y d u r i n g a n experimental period of 1 0 d a y s . At t h e end of t h e digestion t r i a l s samples of r u m e n fluid were t a k e n from 3 fistulated sheep on four consecutive daj^s a t t w o hours after feeding t o determine p H , a m m o n i a
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c o n c e n t r a t i o n a n d volatile f a t t y acids a c c o r d i n g t o COTTYX a n d BOUCQUE ( 1 9 6 8 ) .
I n a t h i r d trial, conducted w i t h growing bulls in a cross over design, t h e effect of virginiamycin w a s investigated on a p p a r e n t digestibility a n d nitrogen balance. T h e bulls, weighing initially 4 5 0 kg, were confined in metabolism cages a n d fed maize silage ad libitum, supplemented with 7 . 5 g concentrate p e r k g liveweight. Virginiamycin was incorporated i n t h e concentrate a t 0 or 6 5 mg per kg. A d a p t a t i o n a n d experimental periods took 5 weeks a n d 1 0 d a y s , respectively. Chemical composition of t h e feeds is shown in T a b l e 1. Table 1 Chemical composition of t h e experimental feeds (g/kg) Dry matter
Crude protein
Petroleum Crude other fibre extract
Nitrogen free extract
Total ash
Dry matter basis Experiment I Maize silage Concentrate —V* Concentrate + V
283 876 877
75 175 177
31 8 8
204 125 123
646 588 594
44 104 98
Experiment I I Complete diet —V Complete diet + V
881 885
147 145
11 10
125 122
624 629
93 94
Experiment I I I Maize silago Concentrate —V Concentrate + V
276 868 874
76 189 187
22 29 29
220 99 101
623 589 592
59 94 91
• Virginiamycin
3.
R e s u l t s a n d discussion
Digestion trials indicated t h a t virginiamycin did n o t affect digestibility of d r y m a t t e r or organic m a t t e r , neither in roughage-based diets ( E x p e r i m e n t I ) n o r in c o m p l e t e diets ( E x p e r i m e n t I I ) . T h e effect w a s similar in sheep ( E x p e r i m e n t I) a n d in bulls (Experiment III). However, crude protein w a s significantly less digestible in e x p e r i m e n t I , b u t t h i s effect was n o t observed in experiment I I , with a complete diet, or in e x p e r i m e n t I I I , with a similar d i e t a s in e x p e r i m e n t I . P r o m in v i t r o experiments of PrVA e t al. ( 1 9 8 6 ) organic m a t t e r d e g r a d a t i o n w a s n o t affected, while crude fibre degradation w a s significantly reduced b y virginiamycin. This finding is n o t in accordance w i t h t h e unaltered c r u d e fibre digestibility i n o u r experiments.
Arch. Anim. Nutr., Berlin 40 (1990) δ/6
485
Table 2 Effect of virginiamycin on digestibility (%, mean ± s t a n d a r d deviation) Dry matter Experiment I Control
75.8 1.7 75.1 ± 1.5
±
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Virginiamycin Experiment I I Control
82.1 1.2 82.5 ± 1.2
Virginiamycin Experiment I I I Control
78.8 1.4 78.1 ± 1.6
±
86.6 1.1 S6.9 + 0.9
Crude protein
69.4 1.3 60.8* ± 5.9
±
Crude fibre
77.4 3.6 78.7 ± 1.8
71.1 3.6 70.6 ± 2.2
±
82.8 1.1 S2.9 + 1.0
±
±
±
±
±
82.6 1.2 81.5 ± 1.4
90.9 0.9 91.6 ± 0.7
71.0 1.4 70.5 ± 2.7
73.5 1.6 73.1 ± 2.8
59.3 1.7 59.1 ± 3.0
79.9 0.4 79.3 ± 2.3
62.4 1.7 62.3 ± 4.4
79.3 1.7 78.7 ± 2.6
±
58.8 2.4 53.3* ± 5.0
Nitrogen free extract
+
+
74.1 2.7 73.7 ± 2.1
Ether extract
±
±
Virginiamycin
Organic matter
±
±
±
±
* Significant effect of virginiamycin (P-=0.05)
Comparing t h e digestibility coefficient s for maize silage d i e t s in experiments I a n d I I I , carried o u t with sheep a n d bulls respectively, t h e a p p a r e n t digestibility of all components, except e t h e r extract, was significantly higher for sheep. AERTS et al. ( 1 9 8 4 ) r e p o r t e d a s o m e w h a t higher digestibility of maize silage b y cows in comparison with sheep, when b o t h species were fed near m a i n t e n a n c e level. COTTYN et al. ( 1 9 8 9 ) found a similar d r y m a t t e r digestibility for sheep a n d bulls w i t h t h r e e of four feeds, b u t p r o t e i n digestibility w a s a l w a y s b e t t e r for s h e e p . Consequently, differences a r e d u e t o feed i n t a k e level: restricted a t maintenance in experiment I vs. a d libitum in expe r i m e n t I I I . T h e declined digestibility w i t h increased i n t a k e is in accordance with t h e r e s u l t s of B I N E S et al. ( 1 9 8 8 ) .
T o t a l volatile f a t t y acid (VTA) p r o d u c t i o n w a s n o t affected b y virginiamycin. I n e x p e r i m e n t I acetic acid significantly increased from 6 1 . 0 molar % for t h e control diet t o 6 5 . 7 m o l a r % for virginiamycin. Propionic acid was only slightly affected, while b u t y r i c acid concentration was significantly reduced b y virginiamycin. Consequently, t h e C / C ratio was significantly increased from 2 . 4 4 t o 3 . 2 9 b y t h e antibiotic. I n expe r i m e n t I I with a complete diet, no iniluence of virginiamycin on VFA concentration was observed, b u t t h e r e was a slight increase of a m m o n i a . F i r s t of all, fermentation p a t t e r n s in experiments I a n d I I were not in agreement. Differences m a y be related t o t h e t y p e of diet, b u t this p h e n o m e n o n is n o t denied or confirmed in t h e l i t e r a t u r e with regard t o virginiamycin in r u m i n a n t s . However, t h e C / C ratio was significantly reduced when 2 0 0 m g monensin daily was supplied t o concentrated feeds containing 4 0 % dried sugarbeet chips, b u t n o t when 8 0 % chips were used (RICHTER et al., 1 9 8 4 ) . W i t h regard t o t h e molar concentration of acetic acid a n d t h e CJG ratio we found a significant interaction between diet t y p e a n d virgi n i a m y c i n ( P < 0 . 0 5 ) . A t r e n d for a diet χ virginiamycin interaction was also observed i n pigs, where feed efficiency during t h e growing period was slightly lower w i t h virgi2
2
3
3
3
Tabic 3
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E f f e c t of v i r g i n i a m y c i n o n r u m e n f e r m e n t a t i o n ( m e a n ± s t a n d a r d d e v i a t i o n ) Total Acotic VI"A acid (mM/100 ml) Experiment I Control
10.48 1.30 9.41 ± 1.27 ±
Virginiamycin îxporimont I I Control
10.18 1.72 9.99 ± 2.01 ±
Virginiamycin
01.0 ± 2.4 05.7* ± 1.2 59.7 1.4 00.0 ± 1.0 ±
Propionic acid
Butyric Valeric acid acid (molar %)
Isoval. acid
Caproic acid
C2/C3
pH
NH3 (mg/100 ml)
22.0 ± 3.0 20.1 ± 1.3
13.9 0.0 11.4* ± 0.8
1.4 ±0.1 1.3 ±0.2
1.3 ±0.4 1.0 ±0.2
0.4 ±0.2 0.5 ±0.1
2.85 ±0.55 3.29* ±0.24
0.19 ±0.28 C.29 ±0.21
n.a.
13.8 1.0 12.1 ± 1.2
2.0 ±0.2 1.8 ±0.5
0.2 ±0.2 0.2 ±0.2
0.1 ±0.1 0.2 ±0.2
2.49 ±0.27 2.34 ±0.14
5.89 0.22 5.79 ±0.15
24.2 2.2 25.7 • ± 1.3 ±
±
±
r
• significant effect of virginiamycin (P ) n.n.: not analysed
Table 4 E f f e c t of v i r g i n i a m y c i n o n n i t r o g e n b a l a n c e of g r o w i n g b u l l s ( E x p e r i m e n t I I I ) Control
Virginiamycin
1399* ± 1 7 4 570 ± 79 377 ± 73
1373 501 403
Ν intako (g/day) Riocal Ν (g/day) Urinary Ν (g/day) Κ rotention g per day % of intako * mean ± standard deviation
452 ± 1 0 7 32.1 ± 4.7
± 04 ± 48 ±136
409 ± 89 30.1 ± 7.8
n.a.
20.0 ± 5.1 20.G ± 3.7
Arch. Anim. Nutr., Berlin 40 (1090) 5/C
niamycin in rapeseed meal based
487
diets, b u t improved in soybean meal
diets
(CASTELL, 1 9 7 7 ) .
F u r t h e r m o r e , t h e effect of virginiamycin in these e x p e r i m e n t s is n o t in accordance with t h e effect of o t h e r antibiotics. Avoparcin, monensin a n d lasalocid reduced acetic a n d increased propionic acid concentrations (COTTYN e t al., 1 9 8 3 ; THTVEND a n d JOUANY, 1 9 8 3 ) .
Finally o u r i n vivo r e s u l t s did n o t correspond w i t h t h e effect of virginiamycin i n vitro, r e p o r t e d b y VAN N E V E L et al. ( 1 9 8 4 ) . I n t h e i r experiments carbohydrate sub s t r a t e was fermented t o w a r d s less acetic acid a n d more propionic acid. T h e j also found a n inhibition of protein degradation a n d ammonia production with a casein substrate, which is obviously n o t in accordance with t h e higher ammonia concentra tion in o u r experiment I I . Nevertheless, t h e y found a higher a m m o n i a p r o d u c t i o n with virginiamycin on t h e carbohydrate s u b s t r a t e t h a n t h e a m o u n t incorporated in growing microbes. According t o VAN N E V E L e t al. ( 1 9 8 4 ) , t h e antibiotic m a y b e toxic for r u m e n protozoa, resulting in d e a t h a n d extensive d e g r a d a t i o n of t h i s microbial fraction with production of ammonia. Molar concentration of V F A in t h e r u m e n fluid of bulls fed maize silage revealed a t r e n d for a higher concentration of acetic acid a n d less propionic acid d u e t o virginiamycin (MABTILOTTX e t al., 1 9 8 5 ) , which is a confirma tion of t h e results in o u r experiment I . However, t o t a l V F A concentration was reduced, a n d this is n o t in a g r e e m e n t with our experiments. Total V F A production was also decieased b y 3 0 m g virginiamycin per k g DM i n a n experiment of SUSMEL e t al. ( 1 9 8 8 ) with t i s t u l a t e d cows receiving a diet of 0 . 5 0 forage a n d 0 . 5 0 concentrate. These a u t h o r s also reported a significant increase of r u m e n p H a n d a m m o n i a concentration. I n a n in vivo trial of PrvA e t a l . ( 1 9 8 6 ) , also w i t h a maize silage d i e t , concentrations of acetic acid decreased a n d propionic acid increased when 2 2 m g virginiamycin p e r k g D M was fed. Consequently, t h e effect of virginiamycin on molar concentrations of r u m i n a i VFA is largely subjected t o variations, with less acetic acid a n d more propionic acid
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T
in e x p e r i m e n t s of VAN N E V E L et al. ( 1 9 8 4 ) a n d P I V A et a l . ( 1 9 8 6 ) , with m o r e acetic
acid a n d less propionic acid in t h e experiments of MAKTILOTTI e t a l . ( 1 9 8 5 ) a n d in our first experiment, a n d with n o effect on acetic a n d propionic acid in our second experi m e n t . I t is n o t clear w h a t mechanism m a y be responsible for t h e s e diverging results. The effect of virginiamycin on t h e nitrogen balance of growing bulls (Experiment I I I ) is shown in Table 4. Virginiamycin d i d n o t affect Ν excretion a n d retention. A t r e n d t o w a r d s a higher nitrogen retention i n sheep was found for lasalocid (RICKE et al., 1 9 8 4 ) a n d salinomycin ( K O B A Y ' A S H I et al., 1 9 8 6 ) . Nitrogen retention w a s even significantly improved b y monensin in l a m b s (JOYNEE e t al., 1 9 7 9 ) . Consequently, virginiamycin does n o t seem t o possess t h e same properties a s other antibiotics, m a i n l y ionophores, with regard t o t h e nitrogen balance. I n conclusion, virginiamycin did n o t affect d r y m a t t e r a n d organic m a t t e r digesti bility, neither in maize silage nor in concentrate diets. A n interaction between diet t y p e a n d virginiamycin w i t h regard t o t h e a c e t a t e : p r o p i o n a t e ratio was found. N i t r o gen balance w a s n o t affected b y virginiamycin. Summary Three experiments were c o n d u c t e d t o investigate t h e effect of virginiamycin. Dige stibility was determined w i t h wethers, fed a diet of 0 . 6 5 maize silage a n d 0 . 3 5 concen34
Arch. Anim. Nutr., 40 (1990) 5/0
FrEMS/COTTYX e t a l . , Effect of V i r g i n i a m y c i n o n d i g e s t i b i l i t y
488
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t r ä t e on a d r y m a t t e r basis ( E x p e r i m e n t I ) or a complete d r y feed (Experiment I I ) a t m a i n t e n a n c e , a n d with growing bulls fed a maize silage diet a d libitum s u p p l e m e n t ed w i t h 7.5 g c o n c e n t r a t e p e r k g live Aveight ( E x p e r i m e n t I I I ) . Virginiamycin was incorporated a t 0 o r 05 p p m i n t h e c o n c e n t r a t e a n d 0 o r 25 p p m in t h e complete d r y feed. No significant effect on d r y or organic m a t t e r digestibility was observed, although digestibilities of protein a n d e t h e r e x t r a c t were reduced b y virginiamycin in experi m e n t s I a n d I I , respectively. R u m e n fermentation was studied in experiments I a n d I I . Virginiamycin increased acetic acid concentration a n d r e d u c e d b u t y r i c acid concentration in experiment I , b u t exerted n o significant effect i n experiment I I . A n interaction b e t A v e e n diet t y p e a n d v i r g i n i a m y c i n Avas found for t h e C / C 2
3
ratio.
Nitrogen balance, measured in experiment I I I , w a s n o t affected b y virginiamycin.
Zusammenfassung L . 0 . F I E M S , B . G . COTTYN, C H . V. BOUCQUE, J . M. VANACKER und F . X . BUYSSE
Einfluß v o n Virginiamycin auf in u n d Stickstoffbilanz
VIAO
Verdaulichkeit, Pansenfermentation
Die W i r k u n g v o n Virginiamycin Avurde in drei Versuchen geprüft. D i e Verdaulichkeit Avurde s o A v o h l a n H a m m e l n , die im Erhaltungsbedarf m i t einer R a t i o n aus 05 % Mais silage u n d 35 % Kraftfutter (auf TS-Basis) (Experiment I) oder m i t einem Allein futter ( E x p e r i m e n t I I ) gefüttert A v u r d e n , als auch a n A v a c h s e n d e n Bullen geprüft, die bis z u r S ä t t i g u n g Maissilage u n d 7,5 g K r a f t f u t t e r p r o k g Lebendmasse erhielten ( E x p e r i m e n t I I I ) . Virginiamycin Avurde i n einer Menge v o n 65 m g p r o k g Kraftfutter u n d 25 m g p r o k g Alleinfutter a n g e A v e n d e t . D i e Verdaulichkeit d e r Trockensubstanz u n d organischen Substanz Avurde nicht signifikant beeinflußt, a b e r die Verdaulichkeit des R o h p r o t e i n s bzvt*. des Rohfettes Avar i m E x p e r i m e n t I bzAV. I I niedriger. I m E x p e r i m e n t I u n d I I Avurde die Pansenfermentation u n t e r s u c h t . Virginiamycin erhöhte die A z e t a t k o n z e n t r a t i o n u n d v e r m i n d e r t e die B u t y r a t k o n z e n t r a t i o n im E x p e r i m e n t I , h a t t e jedoch keinen Einfluß im E x p e r i m e n t I I . E s Avurde eine I n t e r a k t i o n Z A v i s c h e n d e n R a t i o n s t y p e n u n d dem C / C Verhältnis gefunden. Die im E x p e r i m e n t I I I gemessene Stickstoffbilanz Avurde durch Virginiamycin nicht beeinflußt. 2
3
References AERTS,
J . V., J . L.
D E BOEVEB, B .
G. C O T T Y N , D. L.
DE BRABANDER
and
F.
X. B U Y S S E : Anim.
Feed Sei. Technol. 12, 47 (Î984). B I N E S , J . Α., W. H . B R O S T E R , J . D. S U T T O N , V. J . B R O S T E R , D. J . N A P P E R , T. S M I T H and
J.
W.
S I V I T E R : J . agric. Sei., Camb. 110, 249 (1988). B L A X T E R , K. L . : T h e energy metabolism of ruminants. Hutchinson, London, 332 pp. (1962). C A S T E L L , A . G.: Can. J . Anim. Sei. 57, 313 (1977). C H A L U P A , N . : J . Anim. Sei. 46, 585 (1977). C O T T Y N , B . G. and C H . V. B O U C Q U E : J. Agr. Food Chem. 16, 105 (1988). C O T T Y N , B . G., L. O. F I E M S , C H . V. B O U C Q U E , J . V. A E R T S and F . X. B U Y S S E : Z. Tierphysiol., Tierernährg. u. Futterrmttelkde. 49, 277 (1983).
ch. Anim. Nutr., Berlin 40 (1990) 5/G
489
G., L . O . F I E M S , C H . V. B O U C Q U E , F . V A N D E N B R O E K E and F . X . B U Y S S E : J . Anim. Physiol, a. Anim. Nutr. C2, 215 (1989). D E S O M E B , P . , P . V A N D U C K : Anübiot. Chemother, δ, 032 (1955). E N S O K , W . L . , J . C. S H A W and H . F. T E L L E C I I E A : J . Dairy Sei. 42, 189 (1959). HuNGATE, R. E . : The rumen and its microbes. Academic Press, London, 533 pp. (1900). J O Y N E B , A . E . , L . J . B R O W N , T . J . F o c o and R. T . R o s s i : J . Anim. Sei. 4S, 1005 (1979). K o B A Y A s m , Y., M . W A K I T A and S . H O S H I N O : J . Anim. Physiol, a. Anim. Nutr. 56, 90 (1980). M A R T I L O T T I , F . , A . B O R G H E S E , S . T E R R A M O C C I A and F . A N T O N I A Z Z I : A n n . Ist. Sper. Zootec. 18, 43 (1985). M E R C H E N , N . R. and L . L . B E R G E R : J . Anim. Sei. CO, 1338 (1985). M U N T I F E R I N G , R. B . , B . T I I E U R E R and Ύ. H . N O O N : J . Anim. Sei. S3, 1505 (1981). P A T E R S O N , J . Α., B . M . A N D E R S O N , D . K. B O W M A N , R. L . M O R R I S O N and J . E . W I L L I A M S : J . Anim; Sei. 57, 1537 (1983). P I V A , G., F . M A S O E R O and A . P B A N D I N I : Zoot. Nutr. Anim. 12, 453 (1986). R I C H T E R , G., A . H E N N I G , G. F L A C H O W S K Y and H . - J . L Ö H N E R T : Arch. Anim. Nutr. 3 4 , 1 5 7 (1984). R I C K E , S . C , L. L. B E R G E R , P . J . V A N D E R A A R and G. C. F A H E Y : J . Anim. Sei. 58, 194 (1984). S U S M E L , P., B . S T E F A N O N , M . O V A N and E . P I A S E N T I E R : Wiss. Z. W P U . Rostock N - R e i h e 37, 73 (1988). T H I V E N D , P. and J . - P . J O U A N Y : Reprod. Nutr. Develop. 23, 817 (1983). V A N N E V E L , C. J . , D . I . D E M E Y E R and H . K. H E N D E R I C K X : Arch. Anim. Nutr. 34, 149 (19S4).
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COTTYN, B .
Acknowledgements The authors gratefully thank Mrs. N. D E P A E F E and Mrs. M. M A R T E N S for their skilled technical assistance. Virginiamycin was kindly provided by Smith Kline — R. I. T., Brussels. Received 15 September 19S9
Address of authors: L. O . F I E M S , B. G. C O T T Y N , Cn. V . B O U C Q U E , J . M. V A N A C K E R and F . X . B U Y S S E
National Institute for Animal Nutrition Agricultural Research Centre-Ghent Scheideweg 68, 9231 Melle-Gontrode, Belgium
34»
Archiv für Tierernaehrung Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/gaan19
Effect of Virginiamycin on in Vivo Digestibility Rumen Fermentation and Nitrogen Balance a
a
a
L. O. Fiems , B. G. Cottyn , Ch. V. Boucque , J. M. a
Vanacker & F. X. Buysse
a
a
National Institute for Animal Nutrition, Agricultural Research Centre-Ghent , Melle-Gontrode, Belgium Published online: 08 Sep 2009.
To cite this article: L. O. Fiems , B. G. Cottyn , Ch. V. Boucque , J. M. Vanacker & F. X. Buysse (1990) Effect of Virginiamycin on in Vivo Digestibility Rumen Fermentation and Nitrogen Balance, Archiv für Tierernaehrung, 40:5-6, 483-489, DOI: 10.1080/17450399009421081 To link to this article: http://dx.doi.org/10.1080/17450399009421081
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Arch. Anirn. Kutr., Zerlin 40 (1990) S/G, 483489 XationalInstitute for Animal Nutrition Agricultural Reserrch Centre-Ghent 3Ielle-Gontrode, Belgium
L. 0.FIEXS,B. G.COTTPN,CEI.V. BOUCQUE, J. 11. VANACIKER and P. X. BUYSSE
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Effect of virgiiiinmycin on in vivo digestibility rumen fermentation and nitrogen balance"
1.
Introduction
Runien fernientation yielding more propiorlate and less acetate improves feed efficieiiey in beef cattle (EXSOR et al., 1960; BLASTER, 1962; HUXOATE, 1966; CHALUPA, 1977). Besides a selection of feeds this alteration in runien fermentation can also be induced b y feed additives, like the ionopGores inonensin, lasaloeid and salinomycin, or other antibiotics such as avoparcin (COTTYK et al., 1983; RIcIiTEri et al., 1984; RICKEet al., 1084; MERCIICPI' and BCRGER, 1986). Most of the mentioned feed additives have no effect on organic inatter digestibility, although a reduction of fibre digestibility (COTTYN et al., 19S3) or an iniprovemant of iiitrogen digestibility (PATE~SOX et al., 1983) may occur. However, results of NUPI'TIFERIXSG et al. (1981) and T ~ E N and D JOUAXY (1983) demonstrate that organic matter digestibility is affected by diet type and additive. A dietary effect on runien fermentation mas reported by RICHTER et al. (1981), where the effect of inonensin on the acetate: propionate ratio differed significantly when the diet contained 40 or SO Ol0 sugnrbeet slices. and Virginiamycin is an antibiotic which is iiof so recently discovered ( D E SOXER VAN DIJCK,1955), but it is mostly used in broilers, pigs and calves. Experiments with et al., 1985). I n vitro ruminants are mostly dealing with performallee (I~ARTILOTTI esperiments of VAX NEVELet, al. (1984) revealed an increased propionate proportion in incubations of ruinen fluid with virginismyein. The objectives of the present study mereto determiiie the influeiicc of \-irginianiycin on in vivo digestibility and rumen fermentattion when used i n different types of diets.
2.
Materials and met,hods
Two digestiontrials (Ia n d I I ) have been conducted with 5 wethers each time, t o study the influence of virgininmyein either i n a mixed diet of maize silage and concentrate (Experiment I),or a complete dry feed (Experiment 11). In experiment I diet dry matter consisted of 0.65 silage and 0.35 conccntrate, while in.experiment I1 the complete feed was based on O.GO dried sugarbeet pulp. Virginiamycin mas included a t 0 or 65 ppm in the concentrate (Experiment I) or 0 and 25 ppm in tho eoinplcte diet (ExCommunication X o 764 of t h e Institute
FIESIS/COTTTX et ai., Effect of Virginiamycin on digestibility
484
périment I I ) . S h e e p were fed a t m a i n t e n a n c e level, a n d confined i n d i g e s t i o n cages. After a n a d a p t a t i o n period of 2 0 d a y s faeces were q u a n t i t a t i v e l y collected a n d sampled once a d a y d u r i n g a n experimental period of 1 0 d a y s . At t h e end of t h e digestion t r i a l s samples of r u m e n fluid were t a k e n from 3 fistulated sheep on four consecutive daj^s a t t w o hours after feeding t o determine p H , a m m o n i a
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c o n c e n t r a t i o n a n d volatile f a t t y acids a c c o r d i n g t o COTTYX a n d BOUCQUE ( 1 9 6 8 ) .
I n a t h i r d trial, conducted w i t h growing bulls in a cross over design, t h e effect of virginiamycin w a s investigated on a p p a r e n t digestibility a n d nitrogen balance. T h e bulls, weighing initially 4 5 0 kg, were confined in metabolism cages a n d fed maize silage ad libitum, supplemented with 7 . 5 g concentrate p e r k g liveweight. Virginiamycin was incorporated i n t h e concentrate a t 0 or 6 5 mg per kg. A d a p t a t i o n a n d experimental periods took 5 weeks a n d 1 0 d a y s , respectively. Chemical composition of t h e feeds is shown in T a b l e 1. Table 1 Chemical composition of t h e experimental feeds (g/kg) Dry matter
Crude protein
Petroleum Crude other fibre extract
Nitrogen free extract
Total ash
Dry matter basis Experiment I Maize silage Concentrate —V* Concentrate + V
283 876 877
75 175 177
31 8 8
204 125 123
646 588 594
44 104 98
Experiment I I Complete diet —V Complete diet + V
881 885
147 145
11 10
125 122
624 629
93 94
Experiment I I I Maize silago Concentrate —V Concentrate + V
276 868 874
76 189 187
22 29 29
220 99 101
623 589 592
59 94 91
• Virginiamycin
3.
R e s u l t s a n d discussion
Digestion trials indicated t h a t virginiamycin did n o t affect digestibility of d r y m a t t e r or organic m a t t e r , neither in roughage-based diets ( E x p e r i m e n t I ) n o r in c o m p l e t e diets ( E x p e r i m e n t I I ) . T h e effect w a s similar in sheep ( E x p e r i m e n t I) a n d in bulls (Experiment III). However, crude protein w a s significantly less digestible in e x p e r i m e n t I , b u t t h i s effect was n o t observed in experiment I I , with a complete diet, or in e x p e r i m e n t I I I , with a similar d i e t a s in e x p e r i m e n t I . P r o m in v i t r o experiments of PrVA e t al. ( 1 9 8 6 ) organic m a t t e r d e g r a d a t i o n w a s n o t affected, while crude fibre degradation w a s significantly reduced b y virginiamycin. This finding is n o t in accordance w i t h t h e unaltered c r u d e fibre digestibility i n o u r experiments.
Arch. Anim. Nutr., Berlin 40 (1990) δ/6
485
Table 2 Effect of virginiamycin on digestibility (%, mean ± s t a n d a r d deviation) Dry matter Experiment I Control
75.8 1.7 75.1 ± 1.5
±
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Virginiamycin Experiment I I Control
82.1 1.2 82.5 ± 1.2
Virginiamycin Experiment I I I Control
78.8 1.4 78.1 ± 1.6
±
86.6 1.1 S6.9 + 0.9
Crude protein
69.4 1.3 60.8* ± 5.9
±
Crude fibre
77.4 3.6 78.7 ± 1.8
71.1 3.6 70.6 ± 2.2
±
82.8 1.1 S2.9 + 1.0
±
±
±
±
±
82.6 1.2 81.5 ± 1.4
90.9 0.9 91.6 ± 0.7
71.0 1.4 70.5 ± 2.7
73.5 1.6 73.1 ± 2.8
59.3 1.7 59.1 ± 3.0
79.9 0.4 79.3 ± 2.3
62.4 1.7 62.3 ± 4.4
79.3 1.7 78.7 ± 2.6
±
58.8 2.4 53.3* ± 5.0
Nitrogen free extract
+
+
74.1 2.7 73.7 ± 2.1
Ether extract
±
±
Virginiamycin
Organic matter
±
±
±
±
* Significant effect of virginiamycin (P-=0.05)
Comparing t h e digestibility coefficient s for maize silage d i e t s in experiments I a n d I I I , carried o u t with sheep a n d bulls respectively, t h e a p p a r e n t digestibility of all components, except e t h e r extract, was significantly higher for sheep. AERTS et al. ( 1 9 8 4 ) r e p o r t e d a s o m e w h a t higher digestibility of maize silage b y cows in comparison with sheep, when b o t h species were fed near m a i n t e n a n c e level. COTTYN et al. ( 1 9 8 9 ) found a similar d r y m a t t e r digestibility for sheep a n d bulls w i t h t h r e e of four feeds, b u t p r o t e i n digestibility w a s a l w a y s b e t t e r for s h e e p . Consequently, differences a r e d u e t o feed i n t a k e level: restricted a t maintenance in experiment I vs. a d libitum in expe r i m e n t I I I . T h e declined digestibility w i t h increased i n t a k e is in accordance with t h e r e s u l t s of B I N E S et al. ( 1 9 8 8 ) .
T o t a l volatile f a t t y acid (VTA) p r o d u c t i o n w a s n o t affected b y virginiamycin. I n e x p e r i m e n t I acetic acid significantly increased from 6 1 . 0 molar % for t h e control diet t o 6 5 . 7 m o l a r % for virginiamycin. Propionic acid was only slightly affected, while b u t y r i c acid concentration was significantly reduced b y virginiamycin. Consequently, t h e C / C ratio was significantly increased from 2 . 4 4 t o 3 . 2 9 b y t h e antibiotic. I n expe r i m e n t I I with a complete diet, no iniluence of virginiamycin on VFA concentration was observed, b u t t h e r e was a slight increase of a m m o n i a . F i r s t of all, fermentation p a t t e r n s in experiments I a n d I I were not in agreement. Differences m a y be related t o t h e t y p e of diet, b u t this p h e n o m e n o n is n o t denied or confirmed in t h e l i t e r a t u r e with regard t o virginiamycin in r u m i n a n t s . However, t h e C / C ratio was significantly reduced when 2 0 0 m g monensin daily was supplied t o concentrated feeds containing 4 0 % dried sugarbeet chips, b u t n o t when 8 0 % chips were used (RICHTER et al., 1 9 8 4 ) . W i t h regard t o t h e molar concentration of acetic acid a n d t h e CJG ratio we found a significant interaction between diet t y p e a n d virgi n i a m y c i n ( P < 0 . 0 5 ) . A t r e n d for a diet χ virginiamycin interaction was also observed i n pigs, where feed efficiency during t h e growing period was slightly lower w i t h virgi2
2
3
3
3
Tabic 3
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E f f e c t of v i r g i n i a m y c i n o n r u m e n f e r m e n t a t i o n ( m e a n ± s t a n d a r d d e v i a t i o n ) Total Acotic VI"A acid (mM/100 ml) Experiment I Control
10.48 1.30 9.41 ± 1.27 ±
Virginiamycin îxporimont I I Control
10.18 1.72 9.99 ± 2.01 ±
Virginiamycin
01.0 ± 2.4 05.7* ± 1.2 59.7 1.4 00.0 ± 1.0 ±
Propionic acid
Butyric Valeric acid acid (molar %)
Isoval. acid
Caproic acid
C2/C3
pH
NH3 (mg/100 ml)
22.0 ± 3.0 20.1 ± 1.3
13.9 0.0 11.4* ± 0.8
1.4 ±0.1 1.3 ±0.2
1.3 ±0.4 1.0 ±0.2
0.4 ±0.2 0.5 ±0.1
2.85 ±0.55 3.29* ±0.24
0.19 ±0.28 C.29 ±0.21
n.a.
13.8 1.0 12.1 ± 1.2
2.0 ±0.2 1.8 ±0.5
0.2 ±0.2 0.2 ±0.2
0.1 ±0.1 0.2 ±0.2
2.49 ±0.27 2.34 ±0.14
5.89 0.22 5.79 ±0.15
24.2 2.2 25.7 • ± 1.3 ±
±
±
r
• significant effect of virginiamycin (P ) n.n.: not analysed
Table 4 E f f e c t of v i r g i n i a m y c i n o n n i t r o g e n b a l a n c e of g r o w i n g b u l l s ( E x p e r i m e n t I I I ) Control
Virginiamycin
1399* ± 1 7 4 570 ± 79 377 ± 73
1373 501 403
Ν intako (g/day) Riocal Ν (g/day) Urinary Ν (g/day) Κ rotention g per day % of intako * mean ± standard deviation
452 ± 1 0 7 32.1 ± 4.7
± 04 ± 48 ±136
409 ± 89 30.1 ± 7.8
n.a.
20.0 ± 5.1 20.G ± 3.7
Arch. Anim. Nutr., Berlin 40 (1090) 5/C
niamycin in rapeseed meal based
487
diets, b u t improved in soybean meal
diets
(CASTELL, 1 9 7 7 ) .
F u r t h e r m o r e , t h e effect of virginiamycin in these e x p e r i m e n t s is n o t in accordance with t h e effect of o t h e r antibiotics. Avoparcin, monensin a n d lasalocid reduced acetic a n d increased propionic acid concentrations (COTTYN e t al., 1 9 8 3 ; THTVEND a n d JOUANY, 1 9 8 3 ) .
Finally o u r i n vivo r e s u l t s did n o t correspond w i t h t h e effect of virginiamycin i n vitro, r e p o r t e d b y VAN N E V E L et al. ( 1 9 8 4 ) . I n t h e i r experiments carbohydrate sub s t r a t e was fermented t o w a r d s less acetic acid a n d more propionic acid. T h e j also found a n inhibition of protein degradation a n d ammonia production with a casein substrate, which is obviously n o t in accordance with t h e higher ammonia concentra tion in o u r experiment I I . Nevertheless, t h e y found a higher a m m o n i a p r o d u c t i o n with virginiamycin on t h e carbohydrate s u b s t r a t e t h a n t h e a m o u n t incorporated in growing microbes. According t o VAN N E V E L e t al. ( 1 9 8 4 ) , t h e antibiotic m a y b e toxic for r u m e n protozoa, resulting in d e a t h a n d extensive d e g r a d a t i o n of t h i s microbial fraction with production of ammonia. Molar concentration of V F A in t h e r u m e n fluid of bulls fed maize silage revealed a t r e n d for a higher concentration of acetic acid a n d less propionic acid d u e t o virginiamycin (MABTILOTTX e t al., 1 9 8 5 ) , which is a confirma tion of t h e results in o u r experiment I . However, t o t a l V F A concentration was reduced, a n d this is n o t in a g r e e m e n t with our experiments. Total V F A production was also decieased b y 3 0 m g virginiamycin per k g DM i n a n experiment of SUSMEL e t al. ( 1 9 8 8 ) with t i s t u l a t e d cows receiving a diet of 0 . 5 0 forage a n d 0 . 5 0 concentrate. These a u t h o r s also reported a significant increase of r u m e n p H a n d a m m o n i a concentration. I n a n in vivo trial of PrvA e t a l . ( 1 9 8 6 ) , also w i t h a maize silage d i e t , concentrations of acetic acid decreased a n d propionic acid increased when 2 2 m g virginiamycin p e r k g D M was fed. Consequently, t h e effect of virginiamycin on molar concentrations of r u m i n a i VFA is largely subjected t o variations, with less acetic acid a n d more propionic acid
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T
in e x p e r i m e n t s of VAN N E V E L et al. ( 1 9 8 4 ) a n d P I V A et a l . ( 1 9 8 6 ) , with m o r e acetic
acid a n d less propionic acid in t h e experiments of MAKTILOTTI e t a l . ( 1 9 8 5 ) a n d in our first experiment, a n d with n o effect on acetic a n d propionic acid in our second experi m e n t . I t is n o t clear w h a t mechanism m a y be responsible for t h e s e diverging results. The effect of virginiamycin on t h e nitrogen balance of growing bulls (Experiment I I I ) is shown in Table 4. Virginiamycin d i d n o t affect Ν excretion a n d retention. A t r e n d t o w a r d s a higher nitrogen retention i n sheep was found for lasalocid (RICKE et al., 1 9 8 4 ) a n d salinomycin ( K O B A Y ' A S H I et al., 1 9 8 6 ) . Nitrogen retention w a s even significantly improved b y monensin in l a m b s (JOYNEE e t al., 1 9 7 9 ) . Consequently, virginiamycin does n o t seem t o possess t h e same properties a s other antibiotics, m a i n l y ionophores, with regard t o t h e nitrogen balance. I n conclusion, virginiamycin did n o t affect d r y m a t t e r a n d organic m a t t e r digesti bility, neither in maize silage nor in concentrate diets. A n interaction between diet t y p e a n d virginiamycin w i t h regard t o t h e a c e t a t e : p r o p i o n a t e ratio was found. N i t r o gen balance w a s n o t affected b y virginiamycin. Summary Three experiments were c o n d u c t e d t o investigate t h e effect of virginiamycin. Dige stibility was determined w i t h wethers, fed a diet of 0 . 6 5 maize silage a n d 0 . 3 5 concen34
Arch. Anim. Nutr., 40 (1990) 5/0
FrEMS/COTTYX e t a l . , Effect of V i r g i n i a m y c i n o n d i g e s t i b i l i t y
488
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t r ä t e on a d r y m a t t e r basis ( E x p e r i m e n t I ) or a complete d r y feed (Experiment I I ) a t m a i n t e n a n c e , a n d with growing bulls fed a maize silage diet a d libitum s u p p l e m e n t ed w i t h 7.5 g c o n c e n t r a t e p e r k g live Aveight ( E x p e r i m e n t I I I ) . Virginiamycin was incorporated a t 0 o r 05 p p m i n t h e c o n c e n t r a t e a n d 0 o r 25 p p m in t h e complete d r y feed. No significant effect on d r y or organic m a t t e r digestibility was observed, although digestibilities of protein a n d e t h e r e x t r a c t were reduced b y virginiamycin in experi m e n t s I a n d I I , respectively. R u m e n fermentation was studied in experiments I a n d I I . Virginiamycin increased acetic acid concentration a n d r e d u c e d b u t y r i c acid concentration in experiment I , b u t exerted n o significant effect i n experiment I I . A n interaction b e t A v e e n diet t y p e a n d v i r g i n i a m y c i n Avas found for t h e C / C 2
3
ratio.
Nitrogen balance, measured in experiment I I I , w a s n o t affected b y virginiamycin.
Zusammenfassung L . 0 . F I E M S , B . G . COTTYN, C H . V. BOUCQUE, J . M. VANACKER und F . X . BUYSSE
Einfluß v o n Virginiamycin auf in u n d Stickstoffbilanz
VIAO
Verdaulichkeit, Pansenfermentation
Die W i r k u n g v o n Virginiamycin Avurde in drei Versuchen geprüft. D i e Verdaulichkeit Avurde s o A v o h l a n H a m m e l n , die im Erhaltungsbedarf m i t einer R a t i o n aus 05 % Mais silage u n d 35 % Kraftfutter (auf TS-Basis) (Experiment I) oder m i t einem Allein futter ( E x p e r i m e n t I I ) gefüttert A v u r d e n , als auch a n A v a c h s e n d e n Bullen geprüft, die bis z u r S ä t t i g u n g Maissilage u n d 7,5 g K r a f t f u t t e r p r o k g Lebendmasse erhielten ( E x p e r i m e n t I I I ) . Virginiamycin Avurde i n einer Menge v o n 65 m g p r o k g Kraftfutter u n d 25 m g p r o k g Alleinfutter a n g e A v e n d e t . D i e Verdaulichkeit d e r Trockensubstanz u n d organischen Substanz Avurde nicht signifikant beeinflußt, a b e r die Verdaulichkeit des R o h p r o t e i n s bzvt*. des Rohfettes Avar i m E x p e r i m e n t I bzAV. I I niedriger. I m E x p e r i m e n t I u n d I I Avurde die Pansenfermentation u n t e r s u c h t . Virginiamycin erhöhte die A z e t a t k o n z e n t r a t i o n u n d v e r m i n d e r t e die B u t y r a t k o n z e n t r a t i o n im E x p e r i m e n t I , h a t t e jedoch keinen Einfluß im E x p e r i m e n t I I . E s Avurde eine I n t e r a k t i o n Z A v i s c h e n d e n R a t i o n s t y p e n u n d dem C / C Verhältnis gefunden. Die im E x p e r i m e n t I I I gemessene Stickstoffbilanz Avurde durch Virginiamycin nicht beeinflußt. 2
3
References AERTS,
J . V., J . L.
D E BOEVEB, B .
G. C O T T Y N , D. L.
DE BRABANDER
and
F.
X. B U Y S S E : Anim.
Feed Sei. Technol. 12, 47 (Î984). B I N E S , J . Α., W. H . B R O S T E R , J . D. S U T T O N , V. J . B R O S T E R , D. J . N A P P E R , T. S M I T H and
J.
W.
S I V I T E R : J . agric. Sei., Camb. 110, 249 (1988). B L A X T E R , K. L . : T h e energy metabolism of ruminants. Hutchinson, London, 332 pp. (1962). C A S T E L L , A . G.: Can. J . Anim. Sei. 57, 313 (1977). C H A L U P A , N . : J . Anim. Sei. 46, 585 (1977). C O T T Y N , B . G. and C H . V. B O U C Q U E : J. Agr. Food Chem. 16, 105 (1988). C O T T Y N , B . G., L. O. F I E M S , C H . V. B O U C Q U E , J . V. A E R T S and F . X. B U Y S S E : Z. Tierphysiol., Tierernährg. u. Futterrmttelkde. 49, 277 (1983).
ch. Anim. Nutr., Berlin 40 (1990) 5/G
489
G., L . O . F I E M S , C H . V. B O U C Q U E , F . V A N D E N B R O E K E and F . X . B U Y S S E : J . Anim. Physiol, a. Anim. Nutr. C2, 215 (1989). D E S O M E B , P . , P . V A N D U C K : Anübiot. Chemother, δ, 032 (1955). E N S O K , W . L . , J . C. S H A W and H . F. T E L L E C I I E A : J . Dairy Sei. 42, 189 (1959). HuNGATE, R. E . : The rumen and its microbes. Academic Press, London, 533 pp. (1900). J O Y N E B , A . E . , L . J . B R O W N , T . J . F o c o and R. T . R o s s i : J . Anim. Sei. 4S, 1005 (1979). K o B A Y A s m , Y., M . W A K I T A and S . H O S H I N O : J . Anim. Physiol, a. Anim. Nutr. 56, 90 (1980). M A R T I L O T T I , F . , A . B O R G H E S E , S . T E R R A M O C C I A and F . A N T O N I A Z Z I : A n n . Ist. Sper. Zootec. 18, 43 (1985). M E R C H E N , N . R. and L . L . B E R G E R : J . Anim. Sei. CO, 1338 (1985). M U N T I F E R I N G , R. B . , B . T I I E U R E R and Ύ. H . N O O N : J . Anim. Sei. S3, 1505 (1981). P A T E R S O N , J . Α., B . M . A N D E R S O N , D . K. B O W M A N , R. L . M O R R I S O N and J . E . W I L L I A M S : J . Anim; Sei. 57, 1537 (1983). P I V A , G., F . M A S O E R O and A . P B A N D I N I : Zoot. Nutr. Anim. 12, 453 (1986). R I C H T E R , G., A . H E N N I G , G. F L A C H O W S K Y and H . - J . L Ö H N E R T : Arch. Anim. Nutr. 3 4 , 1 5 7 (1984). R I C K E , S . C , L. L. B E R G E R , P . J . V A N D E R A A R and G. C. F A H E Y : J . Anim. Sei. 58, 194 (1984). S U S M E L , P., B . S T E F A N O N , M . O V A N and E . P I A S E N T I E R : Wiss. Z. W P U . Rostock N - R e i h e 37, 73 (1988). T H I V E N D , P. and J . - P . J O U A N Y : Reprod. Nutr. Develop. 23, 817 (1983). V A N N E V E L , C. J . , D . I . D E M E Y E R and H . K. H E N D E R I C K X : Arch. Anim. Nutr. 34, 149 (19S4).
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COTTYN, B .
Acknowledgements The authors gratefully thank Mrs. N. D E P A E F E and Mrs. M. M A R T E N S for their skilled technical assistance. Virginiamycin was kindly provided by Smith Kline — R. I. T., Brussels. Received 15 September 19S9
Address of authors: L. O . F I E M S , B. G. C O T T Y N , Cn. V . B O U C Q U E , J . M. V A N A C K E R and F . X . B U Y S S E
National Institute for Animal Nutrition Agricultural Research Centre-Ghent Scheideweg 68, 9231 Melle-Gontrode, Belgium
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