´ J
.A. Abijaoude et al. Livestock Production Science 64 2000 29 –37 31
diets CR, CS, FR and FS Table 1 which differed in ory. It is fixed on a U-shaped plastic base fastened
forage concentrate ratio: low C 5 30 70 or high by means of a harness to the back of the goats. With
F 5 55 45, and starch source: rapidly R or slowly this system, the animals are, after a short period of
S degradable in the rumen. Lucerne hay, used in adaptation, able to move easily without being dis-
the diets, was chopped on a 5-cm screen and grains turbed or damaging the device. The animals carried
of barley and maize were rolled. Water was added to the device only during the period of tests but the
the high forage diets in order to have approximately basal part, the harness and the halter around the head
the same DM content in all the experimental diets and muzzle throughout the experiment to eliminate
45. The goats were fed ad libitum refusals problems of adaptation each time recordings were
always exceeded 10 of the distributed diet in a made.
4 3 4 latin square design, every pair receiving one of Digestibility tests were conducted on eight other
the four diets for a period of 3 weeks. These diets goats in metabolic crates in the same experimental
were distributed twice daily at 08:00 and 17:00 h. conditions as those subjected to behavioural record-
Refusals were discarded every morning and evening. ing.
M and Sc meals occurring after the first distribution Jaw movement recordings were divided into 1-h
in the morning will be called day D meals and the intervals for analysis. The general model of analysis
ones after the second distribution, in the evening and contained effects of diet
a , 3 dF, animal b , 7
i j
night will be called evening E meals. dF, period
x , 3 dF
k
As there is no uniform determination of the end of meals, we fixed the end of M meals when a non-
Y 5
m 1 a 1 b 1 x 1 E
ijk i
j k
ijk
ingestion period of at least 20 min began. This value corresponded to the first smallest idling period
where Y 5calculated variable, m 5overall mean
ijk
encountered after diet distribution. Determination of and E 5residual standard deviation used as the
ijk
Sc meals limits was a little more difficult. We defined error term. A Day Evening effect 1 dF was
as Sc meal every intake exceeding 150 g and or 5 occasionally added to this model. Data were ana-
min of time. lyzed using the GLM procedure of SAS 1996.
The goats were offered a mixture of the four experimental diets for 3 weeks before the onset of
the experiment. During the first 10 days of each period, the animals were adapted to the daily diet.
3. Results
The behavioural studies took place in the last part of each period and consisted of a series of com-
Components, chemical analysis and digestibilities puterized data recordings. We have adopted the
of the four experimental diets are presented in Table ´
method described by Abijaoude et al. 1999 to 1. The measured DM contents were similar among
record manger weights and jaw movements continu- diets around 45 and so were the NDF values but
ously for 48 h. Digital balances were fixed under the ADF and ADL were higher in F diets than in C diets.
feed containers of four goats carrying the jaw Consequently, the OM digestibilities of FR and FS
movement recorders in order to determine the intake were lower.
dynamics. Weights were transmitted to an adapted More than 2 kg DM were ingested daily by the
electronic memorizer limited to four entries. The jaw goats Table 2, significantly more with R than S
0.75
movement recording system is composed of a sub- diets and intake did not exceed 95 g kgW
per day mandibular pipe fixed on the inside of the lower
with slight nonsignificant differences among diets. strap of the halter and connected to a portable
Data collected after 4348 h of recording for each electronic device: APEC Brun et al., 1984. The
goat showed positive correlations between total daily APEC transforms air pulses generated by the com-
intake and intake during M meals: r 50.37 P ,0.05, pression of the pipe whenever the goat opens its
n 532 and also between total daily intake and intake mouth, to electric signals which are stored in mem-
during Sc meals: r 50.45 P ,0.05, n 532. There
´ 32
J .A. Abijaoude et al. Livestock Production Science 64 2000 29 –37
Table 2 Effects of the four experimental diets on intake and meal characteristics in dairy goats
c
Diets SEM
CR CS
FR FS
Intake
a b
a b
Per day kg DM day 2.2
2.0 2.2
2.0 0.04
0.75 0.75
a b
a b
Per kgW g DM kgW
day 94.6
89.6 96.2
88.1 1.95
Of neutral detergent fibre kg day 0.89
0.79 0.90
0.83 0.06
Of acid detergent fibre kg day 0.47
0.42 0.51
0.48 0.05
Main meals
a b
a a
Total intake kg DM day 1.36
1.17 1.36
1.36 0.08
b b
a a
Total duration min day 108
96 150
156 19
a a
b b
Intake rate g DM min 12.6
12.2 9.1
8.7 0.5
d a
ab b
b
Intake rate 10 g DM min 16.4
13.1 12.6
11.0 1.7
d
Intake rate 30 g DM min 13.1
11.4 12.7
11.2 1.6
b b
a a
Eating time unit of feed min gDM 0.08
0.08 0.11
0.11 0.01
Secondary meals
a a
ab b
Number day 6.4
6.0 5.2
4.6 0.6
ab a
ab b
Total intake kg DM day 0.84
0.88 0.83
0.70 0.08
b b
a a
Total duration min day 204
194 328
278 30.8
a a
b b
Intake rate g DM min 4.1
4.5 2.5
2.5 0.3
b b
a a
Eating time unit of feed min gDM 0.24
0.22 0.40
0.40 0.06
a
Means without a common superscript horizontally differ significantly P ,0.05.
b
Means without a common superscript horizontally differ significantly P ,0.05.
c
SEM: standard error of the mean.
d
Intake rate 10 30: intake rate at 10 30 min after the beginning of the meal.
was however a negative correlation r 5 20.67, P , diets. R starch diets were ingested at a slightly higher
0.05, n 532 between intake during M and Sc meals. rate than S starch diets regardless of the forage
The animal effect was always significant. concentrate ratio.The differences between diets in
Mean intakes of the four diets during the four intake rate are significant at 10 min but nonsignific-
periods 4348 h are shown in Fig. 1. The two M ant at 30 min Table 2.
meals occurred after the two diet distributions. Intake The significant decrease in intake in M meals
kinetics varied among diets but the shapes of the when goats were fed CS, resulted from both a lower
curves were similar for each diet after the two intake rate in the first 10 and 30 min of the meal, and
distributions. Sc meals were more determinant in from a shorter meal duration but eating time per unit
increasing intake in the case of diets rich in concen- of feed was not different at the same forage concen-
trate, especially at night where intake of high forage trate ratio.
diets was very low. The mean number of Sc meals occurring between
Intake in M meals stood for more than 60 of the the two M meals was greater P ,0.05 on C diets
daily intake. It was 0.2 kg DM less when the goats 6.2 than on F diets 4.9 and nonsignificantly
were fed CS P ,0.05. No differences were noticed higher on R than S diets. This resulted in a slightly
between the other three diets. With the CS diet, goats higher intake in Sc meals when goats ate CR and CS
tended to reduce the M meal duration but the and a significant difference between CS and FS 0.18
differences were significant between C and F diets. kg. The lower total duration of Sc meals on C diets
The M meals were shorter on C diets but mean was accompanied by a significantly higher intake
intake rates in M meals were significantly lower on F rate in Sc meals. The eating times per unit of C diets
´ J
.A. Abijaoude et al. Livestock Production Science 64 2000 29 –37 33
Fig. 1. Mean intake of eight dairy goats fed four experimental diets during 4348 h.
in Sc meals were approximately half than those of F There were significantly more Sc meals in E than
diets richer in forage. in D with CR: 1.3 meals. The number of Sc meals h
Significant differences between D and E parame- was significantly higher in D. Intake in Sc meals was
ters were noticed among diets only with three significantly different between D and E except for
parameters presented in Table 3: intake level corre- FS. The differences E D were bigger with C diets
sponding to one M meal1all Sc meals before the than with F diets. These differences disappeared
following M meal, number of Sc meals and intake in when the results were reported per hour and intake in
Sc meals. Although nonsignificantly different, all the Sc meals became even higher in D than in E in the
other parameters studied were also not evenly shared case of FS.
between D and E undoubtedly because of the longer Daily chewing was 51, 44, 62 and 57 of day
time separating the evening distribution from the one length, respectively on CR, CS, FR and FS Table
in the following morning 15 h vs. 9 h. Intake level 4. Goats spent more time eating than ruminating but
was significantly higher in E than D only with CS showed significant differences according to the diets.
and FS. The maximal difference being 0.28 kg DM FR and FS diets required significantly more
when the goats were fed CS. But intake per hour chewing per day than CR and CS. This resulted from
was, on the contrary, significantly higher in D longer eating and ruminating periods when the goats
whatever the diet was. were fed high forage diets.
´ 34
J .A. Abijaoude et al. Livestock Production Science 64 2000 29 –37
Table 3 Comparison of the day D and evening E effect in dairy goats fed four experimental diets only where significant differences exist
Diets CR
CS FR
FS
d a
b a
b
Intake level D
1.04 0.91
1.01 0.96
a a
a a
kg DM E
1.16 1.19
1.09 1.09
c
SEM 0.06
0.06 0.05
0.04
d a
a a
a
Intake level per hour D
115 102
112 107
b b
b b
g DM h E
77 80
72 72
c
SEM 5
5 4
3
b a
a a
Number of Sc meals D
2.5 2.8
2.4 2.2
a a
a a
E 3.8
3.2 2.8
2.4
c
SEM 0.36
0.36 0.29
0.34
a a
a a
Number of Sc meals h D
0.28 0.31
0.27 0.25
a b
b b
E 0.25
0.22 0.18
0.16
c
SEM 0.03
0.03 0.02
0.03
e b
b b
a
I Sc meals D
0.27 0.36
0.35 0.32
a a
a a
kg DM E
0.57 0.52
0.48 0.36
c
SEM 0.06
0.06 0.06
0.05
e a
a a
a
I Sc meals per hour D
30 40
39 36
a a
a b
g DM h E
38 35
32 24
c
SEM 4
4 4
3
a
Means of D and E in one column without a common superscript differ significantly P ,0.05.
b
Means of D and E in one column without a common superscript differ significantly P ,0.05.
c
SEM: standard error of the mean.
d
Intake level5intake in one main meal1all Sc meals before the following main meal.
e
Intake in secondary meals.
Table 4 Chewing activities in dairy goats fed four experimental diets
c
Diets SEM
CR CS
FR FS
ab b
a ab
Chewing, min day 739
639 896
823 57.3
ab b
a ab
Eating, min day 418
350 548
414 41.6
ab b
ab a
Ruminating, min day 321
289 348
409 30.5
d b
b a
a
CTU min g DM 0.34
0.31 0.41
0.40 0.02
d b
b a
ab
ETU min g DM 0.19
0.17 0.25
0.21 0.02
d b
b ab
a
RTU min g DM 0.15
0.14 0.16
0.20 0.02
a
Means without a common superscript horizontally differ significantly P 0.05.
b
Means without a common superscript horizontally differ significantly P 0.05.
c
SEM, standard error of the mean.
d
CTU: chewing time per unit of feed, ETU: eating time per unit of feed, RTU: ruminating time per unit of feed.
Eating time on diet FR and ruminating time on feed were also higher when goats were fed F diets.
diet FS were significantly longer than on diets CR Chewing and eating times per unit of R diets tended
and CS. to be higher relatively to S diets but ruminating times
Chewing, eating and ruminating times per unit of per unit of feed showed opposite tendencies.
´ J
.A. Abijaoude et al. Livestock Production Science 64 2000 29 –37 35
4. Discussion and conclusion same intake level of lucerne hay, goats spent more
