Table 1 : Chemical composition (g / kg) of, organic matter (OM), Neutral Detergent Fibre (NDF), Acid Detergent Fibre (ADF) and crude protein (CP) of the diets given in lambs growth trial. The diets D90, D70, D60 and D50 were composed of fresh Digitaria decumbens grass at 14, 28, 42 and 56 days of age of regrowth respectively.

Digitaria decumbens OM CP NDF ADF ADL PDIN / UF *

Age of regrowth (d)

14 927 107.7 749 372 31 90

28 907 75.2 718 352 35 70

42 919 62.6 775 400 44 60

56 926 46.9 738 375 32 50

______________________________________________________________________________________

*The diet D90, D70, D60 and D50 were formulated to provide 4 protein / energy ratios of 90, 70, 60 and 50PDI / UF level of contents in the diet respectively.

Table 2. Chemical composition (g / kg) of, organic matter (OM), Neutral Detergent Fibre (NDF), Acid Detergent Fibre (ADF) and crude protein (CP) of the diets given in rams digestion trial. The diets D120, D110, D90 and D60 were composed of fresh Digitaria decumbens grass at 14, 28, 42 and 56 days of age of regrowth respectively.

Digitaria decumbens OM CP NDF ADF ADL PDIN / UF*

Age of regrowth (d)

14 856.2 147.8 711.1 347.5 58.7 120

28 871.3 120.5 721.6 346.6 56.8 110

42 859.1 119.8 716.0 350.1 42.2 90

56 924.5 57.1 713.1 354.5 39.7 60

______________________________________________________________________________________

*The diet D120, D110, D90 and D60 were formulated to provide 4 protein / energy ratios of 120, 110, 90and 60 PDIN / UF level of contents in the diet respectively.

Table 3. Effect of defaunation on intake, growth and feed conversion efficiency of lambs consuming diets composed of fresh Digitaria decumbens grass harvested at 14, 28, 42 and 56 days of age of regrowth. The diets were formulated to provide 4 protein / energy ratios (PDIN / UF) of 90, 70, 60 and 50 on diet D90 (14 days of regrowth), D70 (28 days of regrowth), D60 (42 days of regrowth) and D50 (56 days of regrowth) respectively.

D90 D70 D60 D50 Significance________ _______ _______ ________F D F D F D F D S.E.M. Def. Diet Def.Diet

DM intake 71.8 75.5 73.4 79.5 62.4 61.2 51.6 49.2 2.2 *** **

(g / kg LW 0.75

)

Energy intake 0.57 0.57 0.58 0.60 0.50 0.48 0.38 0.36 0.02 ***

(UF / d.)

Nitrogen intake 53.0 49.3 39.8 39.3 33.0 29.8 21.0 18.2 1.5 ***

(g / d.) (1)

Nitrogen / Energy 92.9 92.9 69.6 69.6 61.7 61.7 47.6 47.6 0.2 ***

Ratio (2)

Growth (g / d.) 73.4 73.2 109.2 87.6 99.6 93.8 25.0 48.4 11.1 *** *

Conversion efficiency of :

Feed (g / g) 8.9 5.9 9.7 8.1 11.9 9.7 27.1 12.3 1.2

Energy (10-3

UF /g) 6.2 4.1 6.7 5.6 8.2 6.6 15.2 7.4 0.8

D : defaunated animals F: faunated animals; Def. : Defaunation effect; (1) PDIN ; (2) PDIN / UF.* P < 0.05 ; ** P < 0.01 ; *** P < 0.001.

D120 D110 D90 D60 Significance________ _______ _______ _______

F D F D F D F D S.E.M. Def. Diet Def.Diet

DM intake 81.6 82.7 78.7 62.0 79.0 58.6 66.1 51.5 3.1 *** *** **

(g / kg LW0.75

)

Total tract digestibility (%)

OM 72.7 68.2 72.4 64.5 64.8 59.7 58.4 59.4 1.3 *** *** **

NDF 80.8 78.8 80.9 75.5 74.9 72.0 69.6 71.2 0.9 ** *** ***

CP 79.3 76.3 74.9 69.8 73.7 72.0 42.1 40.7 2.0 * ***

Rumen digestibility (%)

OM 57.5 58.4 58.2 53.7 50.6 44.9 49.6 47.7 2.3 ***

NDF 74.3 74.0 74.6 69.6 69.3 65.6 62.8 61.3 1.4 * ***

Particle mean retention time

(Hours) 33.9 35.8 55.4 49.0 44.9 61.9 43.1 78.1 6.9 *** ***

D: defaunated animals F: faunated animals Def.: Defaunation effect.* P < 0.05 ; ** P < 0.01 ; *** P < 0.001.

Table 4. Effect of defaunation on dry matter intake and apparent digestibility in the total tract of organic matter (OM), cell wall (NDF) and crude protein (CP) of rams consuming diets composed of fresh Digitaria decumbens grass harvested at 14, 28, 42 and 56 days of age of regrowth. The diets were formulated to provide 4 protein / energy ratios (PDIN / UF) of 120, 110, 90 and 60 on diet D 120 (14 days of regrowth), D110 (28 days of regrowth), D90 (42 days of regrowth) and D60 (56 days of regrowth) respectively.

Table 5 : Effect of defaunation on nitrogen intake, duodenal nitrogen flow, microbial synthesis efficiency, faecal and urinary excretion of rams consuming diets composed of fresh Digitaria decumbens grass harvested at 14, 28, 42 and 56 days of age of regrowth. The diets were formulated to provide 4 protein / energy ratios (PDIN / UF) of 120, 110, 90 and 60 on diet D120 (14 days of regrowth), D110 (28 days of regrowth), D90 (42 days of regrowth) and D60 (56 days of regrowth) respectively.

D120 D110 D90 D60 Significance______ _______ ________ ________

F D F D F D F D S.E.M. Def. Diet Def.Diet

Nitrogen duodenal flow (g / day)

Non ammonia Nitrogen 16.5 18.1 21.0 21.6 19.8 22.1 15.8 18.6 0.9 ** ***

Microbial nitrogen 10.8 10.3 8.3 10.2 12.2 12.5 10.0 10.3 0.6 ***

Faecal nitrogen 6.7 7.3 5.5 7.3 5.9 5.8 5.9 5.5 0.4 ** *** *

(g N / day)

Intestinal digestion 60.2 59.3 68.2 62.2 68.2 76.3 59.3 64.2 3.7

of Nitrogen (%)

Urinary nitrogen 7.8 5.8 8.8 7.4 8.1 7.4 6.3 6.5 0.6 *** *** *

(g N / day)

Microbial synthesis Efficiency

(g MN / kg OMADR) 17.1 16.1 12.8 17.3 20.9 25.9 17.9 19.1 1.5 * ***

(g MN / kg NDFR) 15.7 15.3 12.2 16.0 18.7 22.0 17.6 18.3 1.2 * ***

D: defaunated animals F: faunated animals Def: Defaunation effect.OMADR: OM apparently degraded in the rumen; NDFADR : NDF apparently degraded in the rumen* P < 0.05 ; ** P < 0.01 ; *** P < 0.001.

Table 1 Chemical composition (g / kg) of, organic matter (OM), Neutral Detergent Fibre (NDF), Acid Detergent Fibre (ADF) and crude protein (CP) of the diets. The diets D120, D110, D90 and D60 were composed of fresh Digitaria decumbens grass at 14, 28, 42 and 56 days of age of regrowth respectively.

Digitaria decumbens OM CP NDF ADF ADL PDIN / UF *

Age of regrowth (d)

14 856.2 147.8 711.1 347.5 58.7 120

28 871.3 120.5 721.6 346.6 56.8 110

42 859.1 119.8 716.0 350.1 42.2 90

56 924.5 57.1 713.1 354.5 39.7 60

_______________________________________________________________________

*The diet D120, D110, D90 and D60 were formulated to provide 4 protein / energy ratios of, 120, 110,90and 60 PDIN / UF level of contents in the diet respectively.

Table 2 : Effect of defaunation on some cellulolytic bacteria, in the rumen of rams consuming 4 diets. The diets D120, D110, D90 and D60 were composed of fresh Digitaria decumbens grass at 14, 28, 42 and 56 days of age of regrowth respectively.

Table 3 : Effect of defaunation on enzymatic activity (polysaccharidases) in rumen solid-associated microorganisms, in rams consuming 4 diets. The diets D120, D110, D90 and D60 were composed of fresh Digitaria decumbens grass at 14, 28, 42 and 56 days of age of regrowth respectively.

D120 D60PDIN / UF, F D SEM F D F D S.E.M. Def. Diet DDiet

Total bacteria 94.67 66.84 8.4 102.2 109.3 87.1 24.3 11.8 * *** *Ruminococcus albus (R.a) 1.98 1.80 0.20 2.36 2.59 1.61 1.01 0.29 **Fibrobacter succinogenens (F.s) 1.39 0.81 0.49 1.13 1.18 1.61 0.48 0.60Ruminococcus flavefasciens (R.f) 0.2 N.E. 0.5 NE 1.8 N.E. 0.40Cellulolytic bacteriab 3.4 3.2 0.6 3.0 4.9 3.7 1.5 0.8 *

% Ra 2.25 3.23 0.25 2.28 2.34 2.22 4.13 0.04 * *% Fs 1.32 1.58 0.55 0.99 1.20 1.64 1.97 0.65% Rf 0.02 NE 0.004 NE 0.2 NE% Celluloytic bacteria 3.5 5.3 0.5 2.8 4.5 4.2 6.1 0.7 * *Cellulolytic bacteriab : sum of the three major cellulolytic bacteria in the rumen (Ra, Fs and R. flavefasciens)NE : Non estimated. Def.: Defaunation effect; * P < 0.05 ** P < 0.01 *** P < 0.001

PDIN / UF, D120 D110 D90 D60F D s.e.m. F D F D F D F D s.e.m. Def. Diet DDiet

Item and time after feedingTotal activity (µmol reducing sugar / (gDM*h))

CMCase0h 29.0 13.9 2.6 5.7 0.1 60.4 41.9 44.6 13.0 5.4 0.5 5.2 *** ***3h 24.1 15.8 1.6 4.1 -0.3 57.7 49.2 28.5 14.6 5.9 -0.3 3.2 ** ***

Xylanase0h 231.8 125.7 20 226.9 68.0 205.7 127.6 329.1 256.5 165.4 50.8 39.9 ** **3h 174.3 130.0 11.8 127.1 67.2 156.1 156.5 269.3 247.0 144.8 49.4 24 * ***

Amylase0h 6.4 5.7 2.3 5.0 3.7 6.1 8.8 16.5 10.4 -0.8 -1.2 4.5 *3h 29.5 16.4 4.4 53.1 33.1 29.6 15.7 35.0 17.0 0.3 -0.3 8.7 ***

Specific activity (µmol reducing sugar / (mg protein*h))CMCase

0h 3.7 1.9 0.3 1.2 0.01 7.8 5.6 4.7 1.7 1.0 0.1 0.6 *** ***3h 2.6 1.6 0.3 0.5 -0.02 5.0 4.6 2.8 1.7 2.0 -0.01 3.2 * ***

Xylanase0h 40.6 27.1 3.2 66.9 32.2 25.0 18.8 34.5 36.5 36.1 20.9 62.8 ** **3h 28.3 23.1 2.8 28.1 25.5 13.6 14.9 27.8 29.0 43.6 23.0 5.6 *

Amylase0h 0.8 1.0 0.4 1.0 1.7 0.7 0.9 1.7 1.4 -0.1 -0.2 0.83h 5.1 2.7 0.9 13.1 10.9 3.0 -0.2 3.9 0.5 0.3 -0.3 1.8 ***

Def.: Defaunation effect; D : defaunated animals; F : Faunated animals ; * P < 0.05 ** P < 0.01 *** P < 0.001

Table 4: Effect of defaunation on enzymatic activity (glycosidases) in rumen solid-associated microorganisms, in rams consuming 4 diets. The diets D120, D110, D90 and D60 were composed of fresh Digitaria decumbens grass at 14, 28, 42 and 56 days of age of regrowth respectively.

PDIN / UF, D120 D110 D90 D60 effectF D s.e.m F D F D F D F D s.e.m Def. Diet DDiet

Item and time after feedingTotal activity (µmol p-nitrophenol / (gDM*h))

-D glucosidase0h 67.2 45.2 3.7 55.6 30.1 56.3 52.4 94.1 71.1 62.5 27.2 7.4 *** ***3h 75.3 48.5 3.5 62.9 33.8 73.7 65.4 84.5 70.8 79.9 24.0 7.0 *** ** *

-D xylosidase0h 75.4 67.1 5.2 77.4 49.5 84.4 84.3 88.8 95.9 51.0 38.6 10.3 **3h 65.3 68.1 4.2 60.1 50.5 79.8 89.3 77.0 96.2 44.1 36.3 8.5 ***

-D glucosidase0h 6.1 4.5 0.7 7.7 2.8 4.6 5.9 6.4 7.2 5.6 2.1 1.53h 4.9 5.0 0.3 1.8 1.4 6.4 7.8 7.3 8.1 4.2 2.5 0.6 ***

Specific activity (µmol p-nitrophenol / (mg protein*h))-D glucosidase

0h 11.9 13.9 0.9 17.6 11.8 6.8 10.5 9.6 13.3 13.5 19.9 1.7 ** *3h 13.1 10.6 0.7 14.0 12.7 6.4 6.4 8.6 8.7 23.3 14.6 1.3 * *** *

-D xylosidase0h 14.0 19.9 1.0 24.5 20.9 10.3 15.2 9.3 16.9 11.6 26.6 1.9 *** *** **3h 10.7 14.3 1.2 14.6 17.9 7.0 9.0 7.9 12.1 13.3 18.2 2.3 * **

-D glucosidase0h 1.2 1.4 0.1 2.5 1.4 0.5 1.2 0.5 1.4 1.3 1.7 0.3 * *3h 0.8 1.0 0.1 0.5 0.4 0.6 0.9 0.8 1.1 1.2 1.6 0.2 **

Def.: Defaunation effect; D : defaunated animals; F : Faunated animals ; * P < 0.05 ** P < 0.01 *** P < 0.001

Table 5: Effect of defaunation on in situ dry matter (DM) degradation, and Ammonia (NH3) in the rumen of rams consuming 4 diets. The diets D120, D110, D90 and D60 were composed of fresh Digitaria decumbens grass at 14, 28, 42 and 56 days of age of regrowth respectively.

PDIN / UF, D120 D110 D90 D60 Effect

F D S.E.M F D F D F D F D S.E.M Def. Diet DefDiet

Item and sampling time after feeding

DM in situ degradation (%)

24h 51.2 50.6 0.8 55.7 57.3 50.7 48.5 46.2 43.9 52.2 52.7 1.6 ***

48h 64.1 63.0 0.9 67.4 68.5 66.6 61.2 59.3 58.5 63.2 63.6 1.7 ***

96h 72.1 68.8 1.5 74.2 75.0 73.7 68.8 69.9 60.8 70.7 70.7 2.3 *

24h (Reference)* 52.8 51.9 1.2 55.7 57.7 50.4 48.6 53.6 49.0 51.4 52.1 2.2 *

NH3 (mgN / L)

0h 118.9 100.5 5.0 155.8 147.8 132.4 87.8 149.1 123.6 38.4 42.7 13.8 * ***

3h 151.2 114.8 4.5 199.6 153.0 166.7 115.3 189.5 155.4 48.9 35.5 12.9 *** ***

6h 147.3 117.0 4.5 184.7 146.9 149.8 100.4 199.7 164.7 55.1 55.7 12.7 *** ***

12h 123.8 111.5 3.3 178.1 159.2 123.4 99.8 161.1 155.3 32.6 31.8 9.0 * ***

Mean NH3 135.3 110.9 3.5 179.5 151.7 143.1 100.9 174.9 149.7 43.7 41.5 9.6 *** ***

Def : Defaunation effect; D : defaunated animals F: faunated animals; * P < 0.05 ** P < 0.01 *** P < 0.001*24h (reference) : 14 days of regrowth Digitaria decumbens degradation for 24 hours

Table 6: Effect of defaunation on pH and Volatile Fatty Acids (VFA), in the rumen of rams consuming 4 diets. The diets D120, D110, D90 and D60 were composed of fresh Digitaria decumbens grass at 14, 28, 42 and 56 days of age of regrowth respectively

PDI / UF, D120 D110 D90 D60 Effect

F D s.e.m F D F D F D F D s.e.m. Def. Diet DefDiet

Item and sampling time after feeding

pH

0h 6.65 6.56 0.03 6.69 6.45 6.68 6.49 6.62 6.51 6.62 6.77 0.07 *

3h 6.56 6.50 0.03 6.51 6.40 6.72 6.57 6.48 6.38 6.53 6.66 0.06 **

6h 6.36 6.30 0.04 6.41 6.28 6.32 6.27 6.27 6.11 6.45 6.55 0.07 ***

12h 6.11 6.16 0.04 6.14 6.15 5.81 6.14 6.07 5.87 6.42 6.49 0.08 *** *

Mean pH 6.42 6.38 0.03 6.44 6.32 6.38 6.37 6.36 6.22 6.50 6.62 0.06 ***

Total VFA (mmol / L)

0h 57.7 56.8 1.4 63.6 58.1 60.2 63.2 55.0 56.4 52.0 49.5 2.7 *

3h 57.9 57.9 1.2 62.0 59.3 59.3 62.3 56.7 57.4 53.8 52.4 2.4

6h 59.2 59.4 1.3 63.8 59.5 64.4 62.2 59.9 64.2 48.7 51.8 2.6 ***

12h 65.1 61.6 1.4 64.1 61.4 73.7 63.4 67.2 66.8 55.2 54.7 2.8 ***

Mean total VFA 60.0 58.9 0.9 63.4 59.6 64.4 62.8 59.7 62.1 52.4 52.1 1.8 ***

Molar proportions

Acetate (C2, molar %) 65.7 67.9 0.3 63.3 65.1 67.0 69.9 67.7 70.7 64.9 65.9 0.6 *** ***

Propionate (C3, molar %) 19.4 18.9 0.2 20.8 20.0 19.6 18.6 18.7 18.5 18.4 18.3 0.3 * ***

Butyrate (C4, molar %) 10.3 8.8 0.2 10.7 9.8 9.2 7.9 8.9 6.5 12.3 11.1 0.5 *** ***

Ratios

C2 / C3 3.4 3.6 0.04 3.1 3.3 3.4 3.8 3.6 3.8 3.5 3.6 0.07 ** ***

C2 / C4 6.7 8.4 0.2 6.3 6.9 7.4 9.2 7.7 11.5 5.2 5.9 0.4 *** *** ***

C3 / C4 1.9 2.3 0.04 2.0 2.1 2.2 2.4 2.1 3.0 1.5 1.6 0.1 *** *** ***

(C2+C4) / C3 3.9 4.1 0.04 3.6 3.8 3.9 4.2 4.1 4.2 4.2 4.2 0.9 * ***

Def : Defaunation effect; D : defaunated animals F: faunated animals; * P < 0.05 ** P < 0.01 *** P < 0.001

-1 0 1

-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0.5

Quantité de MS ingérée (MSI%PV).Différence entre défaunés- faunés.

Cro

iss

an

ce (

GM

Q%

PV

) d

iffé

ren

cee

ntr

e d

éfa

un

és

- fa

un

és

Figure 1 : Effets de la défaunation sur la croissance (GMQ, g/j) d’agneaux en fonction de la teneur en azote/énergie (g PDIN/UF) de rations composées de fourrage (Digitaria decumbens) sans concentré, ou avec concentré (mélange de mais et tourteau de soja). Moyennes ajustées des deux études expérimentales.

Figure 2 : Effets de la défaunation sur la croissance (GMQ, g/%PV) en fonction des quantités de MS ingérées (MSI, %PV). Différences entre défaunés-faunés. Comparaison de nos résultas expérimentaux avec ceux de la synthèse bibliographique des données de la litérature .

0

50

100

150

200

250

40 60 80 100 120 140

Ration Four.Ration mixte

Cro

iss

an

ce

(G

MQ

,g/j)

défauné fauné

défauné fauné

PDIN / UF

4003002001000

300

200

100

0

rumen.(NNH3, mg N/L) FaunésConcentration en N ammoniacal dus jus de

de

ru

me

n.(

NN

H3

, mg

N/L

) D

éfa

un

és

Co

nce

ntr

atio

n e

n N

am

mo

nia

cal d

us

jus

Y = X

p<0.000)(n=75, R=0.80, r.s.d. = 34.1,Y= 0.65 X

190

10 20 30 40 50 60 70

10

20

30

40

50

60

70

80

Flux d'azote duodénalFauné (gN/j)

Déf

auné

(g

N/j)

Flu

x d'

azot

e du

odén

al

Y=X

Figure 3 : Effet de la défaunation sur les flux duodénaux d’Azote (non ammoniacal) gN/J. Comparaison entre les points expérimentaux () et les données de la synthèse bibliographique ().

Figure 4 : Effet de la défaunation sur les concentration en ammoniaque du rumen (NNH3). Comparaison des points expérimentaux () avec les données de la synthèse bibliographique()

Y = 3.3 + 1.03X R2 = 96.5 %, n=30 P<0.00

20 30 40 50 60 70

20

30

40

50

60

70

Digestibilité ruminale des fibres(DrNDF, %) Faunés

Dig

es

tibili

té r

um

ina

le d

es

fib

res

(DrN

DF

, %)

Dé

fau

né

s

Y = X

0 100 200

-10

-5

0

Quantités d'azote ingérées ( gN/j)

Exc

rétio

n d

'azo

te u

rin

air

e (

gN

/j).D

iffé

ren

ces

en

tre

dé

fau

né

s -

fau

né

s

Figure 5 : Effet de la défaunation sur l ’excrétion d ’azote urinaire (gN/j) selon les quantités d ’azote ingérées. Différence entre les animaux défaunés–faunés. Comparaison des points expérimentaux () avec les données de la synthèse bibliographique ()

Figure 6 : Effet de la défaunation sur la digestibilité ruminale des fibres (DrNDF). Comparaison des points expérimentaux () avec les données de la synthèse bibliographique()

Y = -0.06 X

n=12, R2 = 0.57, rsd =1.7 , P<0.001

Y = 0.91 X

( n=18 R2 = 0.98, rsd= 6.7, P<0.001)

1 2 3 4 5 6

-20

-10

0

10

20

30

40

Quantités de MS ingérée (MSI%PV)

Te

mp

s d

e r

ete

ntio

n d

es

pa

rtic

ule

s(h

).D

iffé

ren

ces

en

tre

dé

fau

né

s -

fau

né

sFigure 7 : Effet de la défaunation sur le temps de rétention des particules (h) selon les quantités de MS ingérées (MSI%PV). Différence entre les animaux défaunés–faunés. Comparaison des points expérimentaux () avec les données de la synthèse bibliographique()

Figure 8 : Effet de la défaunation sur l’ indice de consommation (MS) selon la croissance (GMQ %PV). Différence entre les animaux défaunés–faunés. Comparaison des points expérimentaux () avec les données de la synthèse bibliographique ().

0.0 0.5 1.0 1.5

-15

-10

-5

0

Gain moyen quotidien (GMQ%PV)

Dif

fére

nce

en

tre

dé

fau

né

s -

fau

né

sIn

dic

e d

e c

on

som

ma

tio

n (

MS

):