Forty male Ile-de-France lambs (10 blocks of 4 homologous lambs) were used to study the effects of four feeding systems on muscle fatty acids (FA): raising and finishing on cool-season grasses (G), raising on the same grasses and stall-finishing, indoors, on concentrates and hay, respectively, for 22 (GSS) or 41 days (GSL), and stall-feeding indoors on concentrates and hay during both growing and finishing periods (S). Twenty-four lambs only (6 blocks) were retained for comparison of growth performances, lipid content in the longissimus thoracis muscle (LT) and their FA composition according to treatment. The 16 other lambs (4 blocks) were removed from the comparison, due to a large spread in the growth of the lambs towards the end of the trial. No significant effects of treatment were seen on the rate of growth (221, 228, 243 and 245±SE 8.0g/d, respectively, for G, GSS, GSL and S groups), and the lipid contents of the LT (2.22, 2.16, 2.17 and 2.52±SE 0.11g/100g fresh tissue). Grazing, lowered n−6 PUFA (polyunsaturated fatty acids), and increased n−3 PUFA and C18:2 c9t11 (conjugated linoleic acid cis9, trans11) compared to concentrate feeding. The main effects of grazing were not removed by a short period of finish indoors on concentrate (GSS group), but C20:4 n−6 and C22:6 n−3 contents achieved the lowest contents in this group, with significant differences from the values observed for GSL and S groups (C20:4 n−6) or from the three other groups (C22:6 n−3). After a longer period of finish on concentrate (GSL group), C18:3 n−3 (linolenic acid), C18:2 c9t11 and long chain (LC) n−3 PUFA were brought to the levels observed in the S group. In terms of adequacy for human health, the C18:2 n−6/C18:3 n−3 ratios were favourably low in the four groups (2.6, 3.6, 4.9 and 5.2±SE 0.7, respectively, for G, GSS, GSL and S groups), the level observed in the case of G group being significantly lower than for the three other groups and the level observed for GSS group being significantly lower than for the GSL and S groups.

In mammals, radical oxygen species (ROS) are essential factors of cell replication, differentiation and growth (oxidative signal), notably during gestation, but are also potentially damaging agents. In Women, ROS play a role in remodeling of uterine tissues, implantation of the embryo, settlement of the villi and development of blood vessels characteristic of gestation. The body stores of vitamins and minerals of gestating females are used to keep ROS fluxes at a level corresponding to oxidative signals and to prevent an imbalance between their production and scavenging (oxidative stress), which would be detrimental to the mother and fetus. There is some evidence that, although based on different regulatory mechanisms, most of the effects of ROS reported in humans also occur in pregnant ruminant females, some of which have been actually reported. Many vitamins and trace elements have dual effects in the organism of mammals: (a) they are involved in the control of metabolic pathways or/and gene expression, (b) but most of the time they also display ROS trapping activity or their deficiencies induce high rates of ROS production. Deficiencies induce different disorders of gestation and can be induced by different kinds of stress. An example is given, corresponding to the decreased contents of cobalt of forages, when exposed to sustained heavy rains, so that the supply of vitamins B12 to the organism of the ruminant that grazes them is reduced and failure of gestation is induced. Outdoor exposure of ruminants to adverse climatic conditions by itself can increase the vitamin and trace element requirements. Adaptation of production systems taking into account these interactions between gestation and sources of stress or change of the quality of feeding stuffs as well as further developments of knowledge in that field is necessary to promote sustainable agricultural practices.

In mammals, radical oxygen species (ROS) are essential factors of cell replication, differentiation and growth (oxidative signal), notably during gestation, but are also potentially damaging agents. In Women, ROS play a role in remodeling of uterine tissues, implantation of the embryo, settlement of the villi and development of blood vessels characteristic of gestation. The body stores of vitamins and minerals of gestating females are used to keep ROS fluxes at a level corresponding to oxidative signals and to prevent an imbalance between their production and scavenging (oxidative stress), which would be detrimental to the mother and fetus. There is some evidence that, although based on different regulatory mechanisms, most of the effects of ROS reported in humans also occur in pregnant ruminant females, some of which have been actually reported. Many vitamins and trace elements have dual effects in the organism of mammals: (a) they are involved in the control of metabolic pathways or/and gene expression, (b) but most of the time they also display ROS trapping activity or their deficiencies induce high rates of ROS production. Deficiencies induce different disorders of gestation and can be induced by different kinds of stress. An example is given, corresponding to the decreased contents of cobalt of forages, when exposed to sustained heavy rains, so that the supply of vitamins B12 to the organism of the ruminant that grazes them is reduced and failure of gestation is induced. Outdoor exposure of ruminants to adverse climatic conditions by itself can increase the vitamin and trace element requirements. Adaptation of production systems taking into account these interactions between gestation and sources of stress or change of the quality of feeding stuffs as well as further developments of knowledge in that field is necessary to promote sustainable agricultural practices.

Thirty-two male Ile-de-France lambs were used in a factorial 2×2 design to analyse the effects of feeding systems (grass outdoor, G, or concentrate and hay indoor: stall, S) and of growth rate (low, L, or high, H) on total lipids, triglyceride (TG) and phospholipid (PL) contents and their fatty acid composition in the longissimus thoracis muscle (L.T.). Contents were lower for TG (10.4 vs. 15.8 mg/100 g fresh tissue, P<0.05) and higher for PL (6.4 vs. 5.8 mg/100 g fresh tissue, P <0.05) in grass-fed lambs compared to stall-fed ones. TG of grass fed lambs displayed lower proportions of palmitic acid (C16:0), monounsaturated fatty acids (MUFAs), linoleic acid (C18:2n-6) and other (n-6) polyunsaturated fatty acids (PUFA) and higher proportions of stearic acid (C18:0), linolenic acid (C18:3n-3), cis 9, 11 trans C18:2 and trans monounsaturated fatty acids. In PL of the same lambs only lower MUFA, C18:2n-6 and (n-6) PUFA and higher C18:3n-3, (n-3) PUFA and cis 9, 11 trans C18:2 were observed. Growth rate had no effect on lipid, TG or PL contents of longissimus thoracis. However C18:0 proportions were higher in TG and lower in PL for low growth rate lambs. Low growth rate lambs had also lower cis 9, 11 trans C18:2 in TG. Thus, irrespective of growth rate, the muscle lipids characteristic of grass fed lambs fulfilled the recommended features of human food components much better than that of stall fed lambs, namely for CLA and C18:3n-3. The lower ratios of (n-6) to (n-3) PUFA displayed in grass fed lambs both in TG and in PL were also useful to discriminate all the grass fed lambs from all the stall fed animals.

The aim of the work was to study the relationship between subcutaneous adipose tissue development and the fat firmness score attained in the carcass. For this purpose, 48 Lacaune male lambs were fed a concentrate from 23.5±0.2 to 41.4±0.2 kg live weight (63±0.7to122±3.2 days of age, respectively). After slaughter, the lamb carcasses were classified according to fat firmness (1: very firm to 5: very soft/oily). Subcutaneous adipose cell was measured and their overall distribution determined. Results showed that the adipose cells of the studied lambs exhibited a bimodal distribution, suggesting that a fast postnatal hyperplasic or cell proliferation process had been initiated in the subcutaneous adipocytes. In addition, the size of the small adipocyte peak was inversely correlated with the firmness of the fat (40.5, 37.7 and 30.9% of total adipocytes for groups of lambs with a firmness score of 4–5, 3 and 1–2, respectively). In this way, the average adipocyte cell diameter of the lambs with firmness scores of 4–5 (71.8±0.55 μm) was less than that for the lambs with scores of 3 (73.9±0.46 μm), and in turn, the diameter of this latter group was smaller than that of lambs with scores of 1–2 (77.6±0.59 μm). This work indicates the existence of a relationship between the intensity of the hyperplastic process undergone in the lamb subcutaneous adipose tissue and its fat firmness.

Oxygen radicals are ubiquitous in the life span of mammals. They carry an unbalanced electron to proton ratio, which provides them with a very active affinity towards cell components and a great variety of impacts on oxido-reductive processes, which are required by living organisms for their development. They are continuously formed and originate, in particular, when electrons escape from the respiratory chain and combine with oxygen. Various stresses increase their flux, destroy radical trapping agents (vitamines, glutathione, etc) and thus increase the animal's requirements of the latter. They also alter cellular structures. Many features of animal functions may then be affected, directly (immediately after stress) or indirectly (progressive and long term exhaustion of the organism) : reduction of sperm function or of female fertillty death of embryos, poor survival of new-borns, low growth rates, carcasses and meats of a lower quality than expected from the lineage of the animals with a lower shelf-life, and reduction of the contents of a series of components required to sustain human health at the best. Great care thus has to be applied to respect a good equilibrium between the attack and defense of the organism.

Les phénomènes radicalaires sont omniprésents dans la vie des animaux domestiques. Les radicaux libres oxygénés en sont à l’origine : leur structure électronique déséquilibrée leur confère une grande réactivité sur les constituants tissulaires qui leur permet d’entrer en jeu dans le contrôle d’une grande variété de réactions d’oxydo-réduction indispensables à la vie et à la croissance. Ils sont formés de façon continue dans l’organisme sain, en particulier par fuite d’électrons à partir de la chaîne respiratoire et au cours de l’élimination des composés tissulaires peroxydés. Les stress de toutes natures augmentent leur flux, épuisent les réserves de l’organisme en composés protecteurs qui les capturent (en particulier les vitamines et le glutathion) et augmentent donc les besoins correspondants des animaux. Pour finir, ils peuvent conduire à l’altération des structures cellulaires. Les conséquences intéressent une grande variété de fonctions animales, de façon directe (immédiatement après une série de chocs) ou indirecte (affaiblissement à long terme de l’organisme). Les attaques radicalaires peuvent ainsi conduire à une diminution du pouvoir fécondant des spermatozoïdes, à une baisse de la fertilité des femelles, à des mortalités embryonnaires et à une baisse de la vitalité des nouveau-nés. Par ailleurs, elles peuvent ralentir la croissance des animaux et conduire à l’obtention de carcasses et de viandes de qualités inférieures au potentiel des animaux. Ces baisses de qualité sont caractérisées par une durée de conservation plus courte et par une diminution de la teneur des tissus en composés intéressants pour la santé de l’homme. Le plus grand soin doit donc être apporté à la conduite des animaux d’élevage, afin de respecter l’équilibre entre l’attaque et la défense de l’organisme des animaux domestiques. Documents à télécharger

The aim of this study was to investigate the effect of substituting wheat and barley by sugar beet pulp on the quality of subcutaneous adipose tissue of intensively reared lambs. Rumen fermentation and methylmalonate plasma concentration, both considered as indicators of lamb metabolism, were also studied. Forty-nine male lambs of the Lacaune dairy breed were fed from 23.6 (+/-4.1) kg to 41.0 (+/-1.9) kg live weight with hay and a pelleted concentrate containing either wheat and barley (80%, group C) or sugar beet pulp (70%, group P). Rumen fluid samples were collected at 0, 1, 2, 4 or 6 hours after the last meal before slaughter from 5 lambs per diet at each time. The plasma concentration of methylmalonate was measured in two samples per lamb collected 12 and 36 d before slaughter. The calculated metabolisable energy intake and average daily gain were not significantly different between group C and P (3.27 Mcal.d(-1) and 309 g.d(-1)). Six hours after the last meal, the rumen concentration of total volatile fatty acids was higher in group C than in group P (186 vs. 137 mmol.L-1, P<0.01) and the acetate/propionate ratio was lower (0.91 vs. 2.07, P<0.01). The average concentration of methylmalonate in plasma was higher in group C than in group P (2.76 vs. 1.92 mmol.L-1, P=0.09). However, the diet had no significant effects on the firmness and colour of subcutaneous adipose tissue; globally, the quality was poor. No relationship between plasma concentration of methylmalonate and fat firmness scores was observed.

Soft and off-coloured subcutaneous adipose tissue can be observed in a variable proportion of intensively reared lamb carcasses. This can result in financial losses for farmers. Introducing sugar beet pulp in the finishing diet has sometimes been recommended since it is thought to improve adipose tissue quality. Compared with cereals, the sugar beet pulp might modify ruminal fermentation and decrease the proportion of propionate produced. Propionate may be used as a primer unit for the synthesis of fatty acids with low melting points which are characteristic of soft adipose tissue. The aim of this study was to verify the effects of sugar beet pulp on performance and carcass quality. Forty-eight male "Lacaune" (milk breed) lambs, weaned at 27 (+/- 4) days were used. They were given hay and a pelleted concentrate composed of either wheat and barley (80 %, group C) or sugar beet pulp (70 %, group P) ad libitum. The firmness and the colour of the adipose tissue were scored 18 hours after slaughter both visually and manually. Growth rate was higher in group P than in group C (377 vs 328 g.d(-1) (P < 0.01), respectively) even though there was no significant difference in the amount of theoretical metabolisable energy ingested between groups (3.34 vs 3.22 Mcal.d(-1)). Plasma concentrations of glucose and beta-hydroxybutyrate were higher in group P than in group C (0.88 vs 0.84 g.L-1 (P < 0.05) and 49 vs 37 mu eq.L-1 (P < 0.01), respectively). P lambs tended to deposit less internal fat than C lambs. However, the firmness and the whiteness of subcutaneous fat was not improved by diet P compared to diet C. More carcasses with soft adipose tissue were observed in P compared to C (P = 0.20); 0 vs 5 carcasses were judged to be firm, 9 vs 8 were judged to be slightly soft, 11 vs 7 were judged to be soft and 4 vs 4 were judged to be very soft and oily, in treatments P and C respectively. ((C) Elsevier / Inra).

Ovine carcass discoloration is caused by heterogeneous phenomena, which as of yet, are incompletely elucidated. In order to refer to well known problems, we also describe, here in, the pathological origin and features of another type of discoloration (brown-yellow carcasses), as well as the characteristics of yellow type discolorations. The types of discolorations on which we focus (brown-red carcasses) are due to a high rate of oxygen radical formation which ensues some risk of slight to marked tissue peroxidation. Meat from these carcasses can develop strong- to off-flavors and may in the worst case be unsuitable for consumers' health within a few days of slaughter. It is therefore necessary to avoid such alterations. Brown-red discoloration can have numerous sources including dietary characteristics or environmental design, although the best known factors are high contents of polyunsaturated fatty acids, deficiencies in vitamin E or in copper, and growth rates which are too high or too low as consequence of intake levels. Apparently, many other sources of discoloration can occur. New investigations are necessary to deal efficiently with those phenomena.

first group was raised outdoors on garrigue (grazing lambs) ; the second group was weaned at 5 weeks of age and was fed hay and a commercial pellet based on barley (indoor-fed lambs). The lambs were slaughtered over a range of bodyweights from 23 to 36 kg. Triglyceride (TG) and phospholipid (PL) concentrations and fatty-acid composition of three muscles (Supra spinatus ; Longissimus dorsi ; Tensor fasciae latae) were determined

1. Close arterial infusion of clenbuterol (0.7 microgram/hr) for a 3 hr period led to decreased protein synthesis and degradation (both P < 0.05) across the hind-limb of sheep. 2. Systemic infusion of the drug (14 micrograms/hr) for a similar period increased blood flow (P < 0.001) through the hind-limb and decreased protein degradation (P < 0.05). 3. Following chronic (7 day) close-arterial infusion of clenbuterol (1.9 micrograms/hr) hind-limb protein synthesis and degradation again declined (P < 0.05) but this was apparently not recovered during 7 days of drug withdrawal. 4. In consequence, during subsequent systemic infusion of the drug (62 micrograms/hr) the lower rates of protein metabolism were not altered significantly, despite improved whole nitrogen retention (+30%, P < 0.01). 5. The results are discussed with reference to the differential actions of beta-agonists on the various tissues of the hind-limb.

Les caractéristiques de couleur et de fermeté de 27 échantillons de tissu adipeux récoltés en abattoir (4 blancs, 4 jaunes, 19 brun-rouge) ont été décrites par différentes méthodes utilisables en abattoir ou en laboratoire (en particulier, la spectrocolorimétrie). Pour certains de ces échantillons, des informations concernant les conditions d’élevage des animaux ont pu être collectées. Les tissus adipeux blancs « de référence » étaient fermes et correspondaient à des agneaux produits essentiellement à l’herbe. Nous y avons trouvé une faible quantité de pigments héminiques, probablement de l’oxyhémoglobine résiduelle après saignée. Les tissus adipeux jaunes étaient colorés par des pigments héminiques, et par des pigments caroténoïdes et/ou de la bilirubine et présentaient des caractéristiques de fermeté assez proches de celles des tissus adipeux blancs. Les origines possibles de ces défauts de coloration sont présentées. Les tissus adipeux brun-rouge provenaient généralement d’animaux ayant reçu des rations riches en concentré. Ces tissus présentaient des défauts de fermeté dus à une diminution de leur teneur en lipides et à une modification de leur composition en acides gras. Le défaut de coloration a pu être attribué 1) à un effet du degré de fermeté du tissu adipeux sur la réflexion de la lumière, 2) à l’accumulation excessive de pigments héminiques. Celle-ci résulte de la fragilisation de la membrane des érythrocytes du fait des caractéristiques de composition en acides gras des phospholipides, 3) aux produits de la peroxydation des acides gras insaturés, elle même stimulée par ces pigments héminiques.

— The effects, according to the age of the animals, of tricaprylin in addition to coconut oil on the digestibility of the constituents of the milk substitutes, on energy and nitrogen balances, and on growth and feed efficiency before weaning were studied in a trial comprising two parts.Two differ- ent diets (C, Ta), containing 160 or 95 g tallow, 90 or 53 g coconut oil, 0 or 50 g tricaprylin, 250 or 269 g protein, 22.2 or 20.8 MJ gross energy per kg dry matter, were prepared.The different protein and energy contents of the 2 diets were due to the flotation of part of the lipids in the case of diet Ta.Part 1 involved 50 male Limousin or Romanov x Limousin preruminant lambs, used in two replicates, each comprising 2 series of energy (obtained by indirect calorimetry) and nitrogen balance at 2 or 5 weeks (first replicate, series 1 and 2), or at 2, 4 or 6 weeks (second replicate, series 3 and 4).Part 2 was a feeding trial involving 51 Limousin and Romanov x Limousin preruminant lambs, used in two replicates.Growth rates and feed efficiency were obtained between 10 and 35 days.The nitrogen digestibility was higher in 5-week-old lambs who were fed diet Ta, or for all the lambs fed diet Ta taken together (P < 0.05).Respective digestibilities of energy and nitrogen in- creased from 95.5 to 98.3% and from 97.0 to 98.3% between the second and the sixth week of age (P < 0.025).A higher protein efficiency (P < 0.05), and a higher level of nitrogen balance (P < 0.005) of the same magnitude at all ages (+14 to +25%) were obtained in lambs who were fed diet Ta.Effi- ciency of ME utilization for energy (k , = 0.72), protein (k p = 0.62), or lipid (k = 0.87) deposition and maintenance requirements (MEm = 411 to 451 KJ kg-1 (W °. d) were not altered by the type of diet.Those results were discussed in relation to the respective effects of tricaprylin, carbohydrates and protein contents of the diet.preruminant lamb -tricaprylin -energy and nitrogen balance Résumé — Effets combinés de la tricapryline, de l'huile de coprah et de la quantité de lipides, de glucides et de protéines sur la digestibilité d'un lait de remplacement offert à l'agneau préruminant et sur les bilans d'azote et d'énergie.Les variations en fonction de l'âge des animaux, des effets de l'addition de tricapryline à des laits de remplacement déjà enrichis en huile de coprah, sur la digestibilité des constituants de la ration, les bilans d'énergie et d'azote, la vitesse de crois- sance et l'efficacité d'utilisation des aliments pour la croissance, ont été étudiés chez l'agneau préruminant, au cours d'une expérience composée de deux parties.Deux aliments (C, Ta) comportant 160 ou 95 g de suif, 90 ou 53 g d'huile de coprah, 0 ou 50 g de tricapryline, 250 ou 269 g de pro-Les différences entre les régimes pourraient être dues à la tricapryline ou à la plus grande teneur en glucides et en protéines de l'aliment Ta.Selon les résultats antérieurs, aucun des 3 facteurs ne peut rendre compte à lui-seul, de l'amplitude inhabituelle des effets observés qui paraît liée à l'interac- tion entre la présence de tricapryline et la plus grande teneur en glucides de l'aliment expérimental.Ces résultats apparaissent intéressants pour la formulation d'aliments mieux adaptés aux potentialités de croissance des jeunes préruminants, et en particulier à la nutrition de l'agneau présentant un faible poids de naissance, suite à une sous-alimentation in utero.agneau préruminant — tricapryline -fixation d'énergie et d azote

— The effects of tricaprylin or coconut oil on the digestibility of milk-substitute constituents, nitrogen balance, growth-rate and feed efficiency before weaning have been studied in 2 successive trials using 12 male Charmois (trial 1) and 20 male Limousin and Romanov x Limousin preruminant lambs (trial 2).In trial 1, 3 different diets (C i , T,a, T,b) containing 230, 161 or 92 g tallow and 0, 69 or 138 g tricaprylin per kg dry matter (DM) were prepared.Digestibility of the milk-substitutes was studied in 2-and 3-week-old lambs, and growth-rate and feed efficiency were studied up to weaning.In trial 2, 3 other diets (C 2 , C0 2 and T 2 ) containing 249, 166 or 166 g tallow, 0, 83 or 0 g coconut oil, and 0, 0 or 93 g tricaprylin per kg DM, were prepared.They were used for digestibility and nitrogen balance determination in 3-and 6-week-old lambs.Growth rates and feed efficiency were obtained between 10 days and weaning.In trial 1, the level of intake was 14 and 29% higher in lambs fed T1 a and Ti b than in lambs fed Ci .Apparent digestibility of the diets was significantly higher (P < 0.05) after tricaprylin substitution for part of the tallow.The extent of the effect increased with the level of tricaprylin (P < 0.025).Mean apparent respective digestibilities of energy and nitrogen were 0.907, 0.947 or 0.971 and 0.924, 0.961 or 0.972, growth rates 195, 265 or 282 g/day (P < 0.05) and feed efficiency 670, 797 or 725 g gain/kg DM intake, respectively with C i , T,a or T!b milk substitutes.In trial 2, tricaprylin intake did not have any effect; coconut oil led to a slight increase in nitrogen digestibility, but only in 6-week-old lambs (from 0.970 to 0.979; P < 0.05).Mean apparent respective digestibilities of energy and nitrogen were 0.967, 0.969 or 0.972 and 0.965, 0.971 or 0.967 respectively for C 2 , C0 2 or T 2 .Coconut oil diet led to a 13 or 19% (P < 0.01) higher nitrogen balance respectively in 3or 6-week-old lambs; tricaprylin resulted in a slight increase of nitrogen balance in 3-week-old lambs (+ 11 %, P < 0.10).Growth-rates and feed efficiency were respectively 179, 211 or 199 g/day and 25.8, 26.7 or 27.0 g gain/MJ GE for C 2 , C0 2 or T 2 .preruminant lamb — tricaprylin -coconut oil Résumé — Effets de la substitution de tricapryline ou d'huile de coprah à une partie du suif dans les aliments d'allaitement offerts à des agneaux préruminants.Les effets de l'incorporation de tricapryline ou d'huile de coprah à des laits de remplacement sur leur utilisation digestive, la fixation d'azote dans les tissus, la vitesse de croissance des agneaux et l'efficacité alimentaire avant sevrage ont été étudiés au cours de 2 études successives mettant en jeu 12 agneaux mâles préruminants de race charmoise (essai 1) et 20 agneaux mâles préruminants de race Limousine ou Romanov x Limousine (essai 2).Dans l'essai 1, 3 régimes différents (C l , T!a, T!b) comportant 230, 161 ou 92 g de suif et 0, 69 ou 138 mg de tricapryline par kg de matière sèche (MS), ont été préparés.La digestibilité de ces laits de remplacement a été mesurée à 2 et à 3 semaines et la croissance des agneaux et l'efficacité alimentaire étudiées jusqu'au moment du sevrage.Dans l'essai 2, 3 autres régimes (C 2 , C0 2 et T2) comportant 249, 166 ou 166 g de suif, 0, 83 ou 0 g d'huile de coprah, et 0, 0 ou 93 g de tricapryline par kg MS, ont été préparés.La digestibilité et le bilan de l'azote ont été mesurés à 3 et à 6 semaines.La vitesse de croissance des agneaux et l'efficacité alimentaire ont été étudiées entre le dixième jour et le moment du sevrage.Dans l'essai 1, les agneaux ont consommé respectivement 12 et 49% de plus avec les aliments T!a et T!b qu'avec l'aliment C l .La digestibilité a augmenté de façon significative avec la quantité de tricapryline substituée à du suif de l'aliment de départ (P < 0,05), elle est passée de 0,907 à 0,947 ou 0,971 pour l'énergie et de 0,924 à 0,961 ou 0,972 pour l'azote, respectivement dans le cas des régimes C l , T!a et T!b.Les vitesses de croissance ont été de 195, 265 ou 282 gljour (P < 0,05) et l'efficacité alimentaire 670, 797 ou 725 g gainlkg MS ingérée.Dans l'essai 2, l'utilisation de tricapryline n'a eu aucun effet significatif sur la digestibilité.L incorporation d'huile de coprah dans les aliments a permis d'accroître légèrement la digestibilité de l'azote, mais seulement en sixième semaine (de 0,970 à 0,979; P < 0,05).La digestibilité apparente moyenne a été de 0,967, 0,969 ou 0,972 pour l'énergie et de 0,965, 0,971 ou 0,967pour l'azote, respectivement avec les régimes C 2 , C0 2 ou T 2 .L aliment contenant l'huile de coprah a conduit à une augmentation de 13 ou de 19% (P < 0,01) de la fixation d'azote dans les tissus, respectivement à 3 ou à 6 semaines.Avec l'aliment contenant la tricapryline la fixation d'azote a légèrement augmenté à 3 semaines (1 i %; P < 0,10).Les vitesses de croissance et l'efficacité alimentaire ont été respectivement de 179, 211 ou 199 gljour et de 25,8, 26,7 ou 27,0 glMJ avec les aliments C 2 , C0 2 ou T 2 .agneau préruminant -tricapryline -huile de coprah