Livestock Production Science 64 (2000) 29–37www.elsevier.com/ locate / livprodsci

Diet effect on the daily feeding behaviour, frequency andcharacteristics of meals in dairy goats

*´J.A. Abijaoude, P. Morand-Fehr , J. Tessier, Ph. Schmidely, D. SauvantLaboratoire de Nutrition et Alimentation INRA de l’INAPG, 16 rue Claude Bernard, 75231 Paris Cedex 05, France

Abstract

An experiment of 4 3 3 weeks was carried out to analyse intake level and rate, number of meals and chewing activities ofdairy goats. Four pairs of Alpine and Saanen goats in mid lactation were fed ad libitum four complete diets CR, CS, FR andFS in a Latin square design. Forage /concentrate ratio in these diets was low (C 5 30/70) or high (F 5 55/45) and starch,rapidly (R) or slowly (S) degradable in the rumen (barley and maize, respectively). The goats were housed in stalls and fittedwith jaw movement recorders. Intake levels were also recorded over 4 3 48 h. Diets were distributed twice daily. Total dailyintake was significantly higher (P , 0.01) on R diets ( 1 200 g DM/day). Intake rates during main meals were 12.6, 12.2,9.1 and 8.7 g/min, respectively, on CR, CS, FR and FS (P , 0.05). The number of secondary meals decreased with theincrease of forage content. Intake during secondary meals was 0.84, 0.88, 0.83 and 0.70 kg DM/day, respectively, on CR,CS, FR and FS. Chewing during eating and rumination depended on the type of diet (less than 740 min/day on C and morethan 820 min/day on F: P , 0.05). In conclusion, goats seem adapt their feeding behaviour to the kind of diet they receive. 2000 Elsevier Science B.V. All rights reserved.

Keywords: Goat; Feeding behaviour; Meal frequency; Meal characteristics; Forage /concentrate ratio; Starch source

1. Introduction behaviour according to the type of diet they are fed,to avoid digestive disorders. A complete understand-

Feeding behaviour of goats is known on pasture ing of the feeding behaviour requires a thorough(Fedele et al., 1993) and rangelands (Bourbouze, study of its three main components: eating, ruminat-1980; Narjisse, 1991) better than in stalls (Morand- ing and idling. This has been widely done in sheepFehr et al., 1991). A detailed knowledge of dairy and cows and we propose a similar study on stall-goat feeding behaviour in stalls is important, on one housed dairy goats.hand, to improve their level of intake, which is the Daily feed intake can be described in terms ofmain factor limiting milk production, and on the number of meals consumed per day, length and sizeother hand, to establish whether goats can adapt their of meals and also rate of eating during meals.

Rumination can be characterized by the number andduration of periods and also by the number of*Corresponding author. Tel.: 133-144-0817-57; fax: 133-144-boluses.0818-53.

E-mail address: morand@inapg.inra.fr (P. Morand-Fehr) In general goats, like sheep and cows, eat during

0301-6226/00/$ – see front matter 2000 Elsevier Science B.V. All rights reserved.PI I : S0301-6226( 00 )00173-1

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two long periods per day called main (M) meals levels resulted in increased eating and ruminationseparated by several smaller meals called secondary times in cows. In goats, chewing time (min/g DM ?

0.75(Sc) meals. This occurs even with only one dis- kgW ) decreased as the level of intake increasedtribution of feeds per day to pen-fed ruminants (Santini et al., 1992).(Dulphy et al., 1990). Geoffroy (1974) with goats De Boever et al. (1990) reported that ruminatingand sheep fed forage and silage diets, and Baumont time per unit of feed changes relatively a little up toet al. (1997) with sheep fed different kinds of a concentrate level of approximately 50% in the dietforages, found that daily intake is mainly determined of cows, but strongly increases with higher per-by the quantities ingested during the two M meals centages.but Morand-Fehr et al. (1991) suggested that the Our objectives were to determine the effects ofnumber of Sc meals is the most important factor forage /concentrate ratio and type of starch on theexplaining intake differences between goats fed the feeding behaviour and chewing activities of stall-same forage diets. housed dairy goats in mid lactation using four

Intake rate was found to be responsible for most of experimental diets.the difference in daily intake and intake in M mealsof sheep fed various types of hay (Baumont et al.,1997). Gill and Romney (1994) found a positive 2. Materials and methodscorrelation between intake rate at the beginning of Mmeals and daily intake in goats. Eight multiparous Alpine and Saanen dairy goats

With a decreasing forage /concentrate ratio, eating in mid lactation (140 days postpartum, weighingtime per unit of feed initially declines rapidly in 65.8610.9 kg with a mean milk yield at start of trialcows, but this trend slows down and can even of 2.260.6 kg/day) were used for a 12-week experi-reverse for diets which are exclusively made of ment. The eight goats, fitted with ruminal cannulae,

´concentrates (Bines and Davey, 1970; Remond, were housed individually in 2 3 1 m shaded pens1972). For proportions of concentrates under 40%, with wooden floors. The goats were alloted in pairs.Dulphy et al. (1996) found that, in dairy cows, All goats had free access to water and to trace-chewing time per unit of feed can be considered as mineralized salt blocks.constant. Bae et al. (1981) showed that increased hay They were offered four complete experimental

Table 1Composition (% DM) and characteristics of the experimental diets offered to dairy goats

Diets

CR CS FR FS

Lucerne hay 15 15 27.5 27.5Dehydrated lucerne 15 15 27.5 27.5Pressed beet pulp silage 35 35 10 10Barley 26 0 26 0Maize 0 26 0 26Soybean meal 8 8 8 8Minerals 1 1 1 1

Dry matter (%) 45.5 45.0 45.2 46.2Total crude protein (g /kg DM) 160 154 179 173Organic matter (g /kg DM) 923 922 918 918NDF (g/kg DM) 404 383 411 404ADF (g/kg DM) 215 205 235 235ADL (g/kg DM) 24 24 35 35

Organic matter digestibility (%) 74.1 74.8 68.0 65.8

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diets CR, CS, FR and FS (Table 1) which differed in ory. It is fixed on a U-shaped plastic base fastenedforage /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 carriedof barley and maize were rolled. Water was added to the device only during the period of tests but thethe high forage diets in order to have approximately basal part, the harness and the halter around the headthe 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 werealways 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 otherthe four diets for a period of 3 weeks. These diets goats in metabolic crates in the same experimentalwere 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-hin the morning will be called day (D) meals and the intervals for analysis. The general model of analysisones after the second distribution, in the evening and contained effects of diet (a , 3 dF), animal (b , 7i j

night will be called evening (E) meals. dF), period (x , 3 dF)k

As there is no uniform determination of the end ofmeals, we fixed the end of M meals when a non- Y 5 m 1 a 1 b 1 x 1 Eijk i j k ijkingestion period of at least 20 min began. This valuecorresponded to the first smallest idling period where Y 5calculated variable, m 5overall meanijkencountered after diet distribution. Determination of and E 5residual standard deviation used as theijkSc meals limits was a little more difficult. We defined error term. A Day/Evening effect (1 dF) wasas 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 fourexperimental diets for 3 weeks before the onset ofthe experiment. During the first 10 days of eachperiod, the animals were adapted to the daily diet. 3. Results

The behavioural studies took place in the last partof each period and consisted of a series of com- Components, chemical analysis and digestibilitiesputerized 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 amongrecord manger weights and jaw movements continu- diets (around 45%) and so were the NDF values butously 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 FSmovement 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 theelectronic memorizer limited to four entries. The jaw goats (Table 2), significantly more with R than S

0.75movement recording system is composed of a sub- diets and intake did not exceed 95 g/kgW per daymandibular 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 eachelectronic device: APEC (Brun et al., 1984). The goat showed positive correlations between total dailyAPEC transforms air pulses generated by the com- intake and intake during M meals: r50.37 (P,0.05,pression of the pipe whenever the goat opens its n532) and also between total daily intake and intakemouth, to electric signals which are stored in mem- during Sc meals: r50.45 (P,0.05, n532). There

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Table 2Effects of the four experimental diets on intake and meal characteristics in dairy goats

cDiets SEM

CR CS FR FS

Intakea b a bPer day (kg DM/day) 2.2 2.0 2.2 2.0 0.04

0.75 0.75 a b a bPer kgW (g DM/kgW /day) 94.6 89.6 96.2 88.1 1.95Of neutral detergent fibre (kg/day) 0.89 0.79 0.90 0.83 0.06Of acid detergent fibre (kg/day) 0.47 0.42 0.51 0.48 0.05

Main mealsa b a aTotal intake (kg DM/day) 1.36 1.17 1.36 1.36 0.08

b b a aTotal duration (min/day) 108 96 150 156 19a a b bIntake rate (g DM/min) 12.6 12.2 9.1 8.7 0.5

d a ab b bIntake rate 10 (g DM/min) 16.4 13.1 12.6 11.0 1.7dIntake rate 30 (g DM/min) 13.1 11.4 12.7 11.2 1.6

b b a aEating time/unit of feed (min/gDM) 0.08 0.08 0.11 0.11 0.01

Secondary mealsa a ab bNumber /day 6.4 6.0 5.2 4.6 0.6

ab a ab bTotal intake (kg DM/day) 0.84 0.88 0.83 0.70 0.08b b a aTotal duration (min/day) 204 194 328 278 30.8

a a b bIntake rate (g DM/min) 4.1 4.5 2.5 2.5 0.3b b a aEating 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 (r520.67, P, diets. R starch diets were ingested at a slightly higher0.05, n532) 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 mealskinetics varied among diets but the shapes of the when goats were fed CS, resulted from both a lowercurves were similar for each diet after the two intake rate in the first 10 and 30 min of the meal, anddistributions. Sc meals were more determinant in from a shorter meal duration but eating time per unitincreasing 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 dietsdaily intake. It was 0.2 kg DM less when the goats (6.2) than on F diets (4.9) and nonsignificantlywere fed CS (P,0.05). No differences were noticed higher on R than S diets. This resulted in a slightlybetween the other three diets. With the CS diet, goats higher intake in Sc meals when goats ate CR and CStended to reduce the M meal duration but the and a significant difference between CS and FS (0.18differences were significant between C and F diets. kg). The lower total duration of Sc meals on C dietsThe M meals were shorter on C diets but mean was accompanied by a significantly higher intakeintake rates in M meals were significantly lower on F rate in Sc meals. The eating times per unit of C diets

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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 thandiets 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 wasters were noticed among diets only with three significantly different between D and E except forparameters presented in Table 3: intake level corre- FS. The differences (E D) were bigger with C dietssponding to one M meal1all Sc meals before the than with F diets. These differences disappearedfollowing M meal, number of Sc meals and intake in when the results were reported per hour and intake inSc meals. Although nonsignificantly different, all the Sc meals became even higher in D than in E in theother 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 daytime separating the evening distribution from the one length, respectively on CR, CS, FR and FS (Tablein the following morning (15 h vs. 9 h). Intake level 4). Goats spent more time eating than ruminating butwas 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 morewhen the goats were fed CS. But intake per hour chewing per day than CR and CS. This resulted fromwas, on the contrary, significantly higher in D longer eating and ruminating periods when the goatswhatever the diet was. were fed high forage diets.

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Table 3Comparison of the day (D) and evening (E) effect in dairy goats fed four experimental diets (only where significant differences exist)

Diets

CR CS FR FSd a b a bIntake level D 1.04 0.91 1.01 0.96

a a a a(kg DM) E 1.16 1.19 1.09 1.09cSEM 0.06 0.06 0.05 0.04

d a a a aIntake level per hour D 115 102 112 107b b b b(g DM/h) E 77 80 72 72

cSEM 5 5 4 3b a a aNumber of Sc meals D 2.5 2.8 2.4 2.2a a a aE 3.8 3.2 2.8 2.4

cSEM 0.36 0.36 0.29 0.34a a a aNumber of Sc meals /h D 0.28 0.31 0.27 0.25a b b bE 0.25 0.22 0.18 0.16

cSEM 0.03 0.03 0.02 0.03e b b b aI Sc meals D 0.27 0.36 0.35 0.32

a a a a(kg DM) E 0.57 0.52 0.48 0.36cSEM 0.06 0.06 0.06 0.05

e a a a aI Sc meals per hour D 30 40 39 36a a a b(g DM/h) E 38 35 32 24

cSEM 4 4 4 3a 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 4Chewing activities in dairy goats fed four experimental diets

cDiets SEM

CR CS FR FSab b a abChewing, min /day 739 639 896 823 57.3ab b a abEating, min /day 418 350 548 414 41.6ab b ab aRuminating, min /day 321 289 348 409 30.5

d b b a aCTU (min/g DM) 0.34 0.31 0.41 0.40 0.02d b b a abETU (min/g DM) 0.19 0.17 0.25 0.21 0.02d b b ab aRTU (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 tendedand 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.

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4. Discussion and conclusion same intake level of lucerne hay, goats spent moretime eating and less time ruminating than sheep.

Dietary behaviour of stall-housed goats differs a Baumont et al. (1997) found that more than 73%little from that of sheep. Goats generally have a of the total daily intake of sheep fed different hayslower intake rate because they have a more selective occurred in M meals. This was a little higher than infeeding behaviour. Dulphy et al. (1994) found that goats in this experiment and could be due to the dietDM intakes were similar in sheep and goats except composition or to the criteria chosen to determine theon low quality roughages where intakes by goats end of a M meal. The duration of M meals found bywere higher (121%). Daily intakes obtained in this Dulphy et al. (1990) for goats was lower (68 min)experiment were similar to the ones found by than the durations we obtained — probably for theMorand-Fehr et al. (1980) when they offered com- same reasons. Differences in intake resulted fromplete diets to dairy goats, and also to those of Lu differences in meal durations and intake rate.(1987). Mean intake rate in M meals was influenced by

Daily intake differed a little among the four the forage /concentrate ratio as was expected and, atexperimental diets probably because the differences a lesser extent, by the type of starch. This could bebetween NDF contents of these diets were limited due to barley, component of the R diets, which could(Table 1) and the diet components were almost the be more palatable than maize, component of the Ssame. Similar results were obtained by Santini et al. diets and thus more rapidly ingested as observed by

´(1991) in goats fed diets with various forage /con- Abijaoude et al. (1997a). As shown by the results ofcentrate ratios and by McLeod and Smith (1989) in intake rate at 10 and 30 min, the low forage dietssteers fed forages differing in fibre content. This were eaten more rapidly in the beginning of the mealdiffers from the results of Kawas et al. (1991) who and then eating rate declined, while goats ate thefound that DM intake in goats increased with a high forage diets at a constant rate in the first 30decrease in forage /concentrate ratio. min. This is probably due to the lower time needed

Total time spent eating is highly variable, depend- to chew diets rich in concentrate and is confirmed bying on feed quality, type and mode of feeding. With the lower eating and ruminating times obtained.diets composed of lucerne hay and concentrate, The mean number of meals per day (from 6.6 tooffered twice a day, eating generally lasts 4 to 7 h 8.4 according to the diet eaten) was similar to theper day in goats (Morand-Fehr et al., 1991). Our value (8.1) obtained by Geoffroy (1974) in goats andresults showed that eating time varied from 6 to 9 h higher than that (6.0) which he obtained in sheep.on the four experimental diets. Although unitary In our experiment, Sc meals were more numerouseating times differ, in general, more or less between and intake rates in these meals were higher on C thanplant species, Baumont et al. (1997) found that the on F diets. This caused differences among dietstype of hay did not significantly affect the time spent which let us suppose that discrimination betweeneating in sheep. Santini et al. (1992) reported that, in diets and regulation occurred more in Sc meals. CSdairy cows, total chewing times per day were not was the least ingested diet in M meals and the mostsignificantly different with diets containing less than ingested in Sc meals maybe because the goats ate to40% of concentrate. Our analyses showed that optimize the level of intake and limit the risks offeeding higher amounts of forage to dairy goats digestive disorders such as acidosis when diets wereincreased both eating and ruminating times. This is rich in concentrate (Giger-Reverdin and Sauvant,in agreement with the results obtained by Santini et 1991). This is as true as the number of mealsal. (1991) on goats and with those of Dulphy et al. increases especially in the evening and night. So,(1996) who considered that chewing time per unit of goats probably do their best to spread intake through-feed increases when the proportion of concentrates out the day.exceeds 50% of the diet of dairy cows. Compared to The high eating time per unit of feed in Sc mealssheep, goats ate less wheaten hay DM during more can result from the selective behaviour when most oftime and ruminated more (McSweeney and Kennedy, the more palatable feeds of the diet have been eaten1992). Domingue et al. (1991) also found that, at the or also because of the fact that satiated animals are

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less hungry and take more time to choose. This was intake kinetics. This will probably help to clarify thenot the case in M meals because they followed a new relationship between ruminal pH and intake rate,diet distribution. meal number or duration.

The differences (less than 7%) noticed betweenthe eating times per unit of feed obtained with thebalances (Table 2) and with the jaw-movement Referencesrecorders (Table 3) can be due to the small intake

´periods of less than 5 min that we discarded when Abijaoude, J.A., Morand-Fehr, P., Tessier, J., Schmidely, Ph.,Sauvant, D., 1997a. Relation between intake, ingestion rate andanalyzing manually (balances) because they did notalimentary preferences in goats receiving diets with differentsatisfy our fixed conditions while they were kept inforage /concentrate ratios and starch sources. In: Wageningen

the second case. Daily eating results obtained with Pers. 48th Annual Meeting of the European Association forthe jaw movement recorders did not match with the Animal Production, Vienna (Austria), p. 311.

´sum of M meals and Sc meals durations for the same Abijaoude, J.A., Morand-Fehr, P., Tessier, J., 1997b. Effect ofphysiological status and type of diets on the dietary preferencesreason.of goats. In: Wageningen Pers. 48th Annual Meeting of theThe fact that the correlation of intake in Sc mealsEuropean Association for Animal Production, Vienna (Austria),

with daily intake tended to be higher than the one p. 312.with M meals shows that the level of intake could ´ ´Abijaoude, J.A., Morand-Fehr, P., Bechet, G., Brun, J.-P., Tessier,have been more influenced by Sc meals in our case. J., Sauvant, D., 1999. A method to record the feeding be-

haviour of stall-housed dairy goats. Small Rum. Res. 33,This differs from the results of Baumont et al. (1997)213–221.in sheep fed hay ad libitum, but confirms the

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voluntary intake, feeding behaviour and rumen function inRuminants can be characterized by a complexsheep fed three contrasting types of hay. Ann. Zootech. 46,dietary behaviour discriminating feeds according to231–244.

´their palatability. Abijaoude et al. (1997b) have Bines, J.A., Davey, A.W.F., 1970. Voluntary intake, digestion, rateshown that goats possess a strong ability to discrimi- of passage, amount of material in the alimentary tract andnate between two offered feeds, both palatable and behaviour in cows receiving complete diets containing straw

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