Milk digestion in the young rabbit: methodology and first results

[EN] This study aims to determine the digestibility of milk by the young rabbit (21-25 d old), taking into account the increment of digesta content and urine excretion. Nineteen litters of 9 young rabbits 21 to 25 d old were used: 12 litters (S group) fed exclusively with milk using controlled suckling, and 7 litters (Control group) with free suckling and access to the pelleted feed of the doe. The faecal digestibility of milk dry matter (DM) was measured between 21 and 25 d of age, for S litters housed from 15 d of age in a metabolism cage separately from their mother. Between 21 and 25 d, the milk intake, faeces and urine excretion were controlled daily, and the mean increment in digesta content was measured by comparing digesta weight of the whole tract at 21 and 25 d of age (one kit per litter). The increment in digesta content from 21 to 25 d averaged 77% (+8.5 g), sourcing mainly from stomach and caecum contents increase (+57 and +120% respectively). The mean increase for the dry content of the gut (from 21 to 25 d) was 1.75 g DM/kit, and was considered as non-digested to calculate the digestibility coefficient of the milk. The milk intake averaged 30 g/d/kit (7.9 g DM/d kit). No faecal excretion was recorded between 21 and 25 d. From the milk intake and increment in digesta content, the corrected digestibility of the milk dry matter reached 94% (minimum=92.9%, maximum=95.6%). The daily urine excretion averaged 5.1 mL/kit, corresponding to 1.2 g DM/kit. Therefore, the corrected DM retention coefficient of the milk was 79.5%. The quantity of nitrogen excreted in urine was low (0.06 g/d kits), thus the corrected nitrogen retention coefficient for milk reached 82% and the nitrogen retained (corrected) reached 0.44 g/d kit. Accordingly, the amount in metabolisable protein for the milk was 90 g/kg (fresh). The corrected energy retention coefficient was estimated to 95.8%, for a crude energy concentration estimated at 28.14 MJ/kg DM for the milk. Thus, the energy retained (corrected) reached 223 kJ/d kit and the content in metabolisable energy for the milk was 26.94 MJ/kg DM.The authors thank INRA PHASE division for the financial support. The authors would also like to thank the technicians involved in the experiment at the INRA UE PECTOUL (Patrick Aymard, Jacques De Dapper & Jean De Dapper) and in the GenPhySE laboratory (Véronique Tartié).Gidenne, TN.; Bannelier, C.; Gallois, M.; Segura, M.; Lambrecht, V. (2018). Milk digestion in the young rabbit: methodology and first results. World Rabbit Science. 26(4):269-276. doi:10.4995/wrs.2018.10061SWORD269276264Alstin F., Nilsson M. 1990. The Soxtec®hydrolysis system improves the official methods for determining total fat content. Ind. Alim. Agric., 107: 1271-1274.Carabaño R., Piquer J., Menoyo D., Badiola I. 2010. The digestive system of the rabbit, In: De Blas C., Wiseman J. (Eds.), Nutrition of the rabbit, CABI; Wallingford; UK, pp. 1-18. https://doi.org/10.1079/9781845936693.0001EGRAN. 2001. Technical note: Attempts to harmonise chemical analyses of feeds and faeces, for rabbit feed evaluation. World Rabbit Sci., 9: 57-64. https://doi.org/10.4995/wrs.2001.446Gallois M., Gidenne T., Fortun-Lamote F., Le Hueron-Luron I., Lallès J.P. 2005. An early stimulation of solid feed intake slightly influences the morphological gut maturation in the rabbit. Reprod. Nutr. Develop., 45: 109-122. https://doi.org/10.1017/S1751731108001730Gallois M., Fortun-Lamothe L., Michelan A., Gidenne T. 2008. Adaptability of the digestive function according to age at weaning in the rabbit: II. Effect on nutrient digestion in the small intestine and in the whole digestive tract. Animal, 2: 536-547. https://doi.org/10.1017/S1751731108001730Gidenne T., Debray L., Fortun-Lamothe L., Le Huerou-Luron I. 2007. Maturation of the intestinal digestion and of microbial activity in the young rabbit: Impact of the dietary fibre:starch ratio. Comp. Bioch. Physiol. - Part A: Molecular & Integrative Physiology, 148: 834-844. https://doi.org/10.1016/j.cbpa.2007.08.025Gidenne T., Lebas F., Savietto D., Dorchies P., Duperray J., Davoust C., Fortun-Lamothe L. 2015. Nutrition et alimentation, In: Gidenne T. (Ed.), Le lapin. De la biologie à l'élevage, Quae éditions, pp. 152-196.Lebas, F. 1971. Composition chimique du lait de lapine évolution au cours de la traite et en fonction du stade de lactation. Ann. Zootech., 20: 185-191. https://doi.org/10.1051/animres:19710205Maertens L., Lebas F., Szendrő Zs. 2006. Rabbit milk: a review of quantity, quality and non-dietary affecting factors. World Rabbit Sci., 14: 205-203. https://doi.org/10.4995/wrs.2006.565Orengo J., Gidenne T. 2007. Feeding behaviour and caecotrophy in the young rabbit before weaning: An approach by analysing the digestive contents. App. Anim. Behav. Sci., 102: 106-118. https://doi.org/10.1016/j.applanim.2006.03.010Parigi Bini R., Cesselli P. 1976. Estimate of energy excreted in urine by growing rabbits. In: 1st World Rabbit Congress, Dijon, France, Comm. 20, 6.Parigi Bini R., Xiccato G., Cinetto M., Dalle Zotte A. 1991. Digestive efficiency and energy and protein retention in suckling and weanling rabbits. Zootec. Nutr. Anim., 17: 167-180.Savietto D., Cervera C., Blas E., Baselga M., Larsen T., Friggens N.C., Pascual J.J. 2014. Environmental sensitivity differs between rabbit lines selected for reproductive intensity and longevity. Animal, 7: 1969-1977. https://doi.org/10.1017/S175173111300178XUbilla E., Rebollar P.G., Pazo D., Esquifino A., Alvariño J.M.R. 2000. Effects of doe-litter separation on endocrinological and productivity variables in lactating rabbits. Livest. Prod. Sci., 67: 67-74. https://doi.org/10.1016/S0301-6226(00)00196-2Udert K.M., Larsen T.A., Biebow M., Gujer W.P. 2003. Urea hydrolysis and precipitation dynamics in a urinecollecting system. Water Res., 37: 2571-2582. https://doi.org/10.1016/S0043-1354(03)00065-4Zhang Y.K., Cui H.X., Sun D.F., Liu L.H., Xu X.R. 2018. Effects of doe-litter separation on intestinal bacteria, immune response and morphology of suckling rabbits. World Rabbit Sci., 26: 71-79. https://doi.org/10.4995/wrs.2018.591

NUTRITIVE VALUE OF SUN-DRIED SULLA (HEDYSARUM FLEXUOSUM) AND ITS EFFECT ON PERFORMANCE AND CARCASS CHARACTERISTICS OF GROWING RABBITS

[EN] The nutritive value and potential use of sundried sulla hay (Hedysarum flexuosum, g/kg as feed: 885 dry matter, 438 neutral detergent fibre (NDF), 337 acid detergent fibre (ADF), 80 acid detergent lignin and 147 crude protein (CP) for growing rabbits was studied by comparing three diets (regression method) containing an increasing inclusion rate of sulla hay (S): 0% (control, S0), 15 % (S15) and 30% (S30) in substitution for control diet (294 g NDF and 179 g CP/ kg). Three groups of 30 rabbits (individually caged) were fed ad libitum the three diets from weaning (35 d, mean weight: 572 ± 93g) to 84 d of age. Faecal digestibility of the diets was measured between 42 and 46 days of age on 10 rabbits per group. The digestible energy (DE) concentration of sulla hay estimated by regression was 8.96±0.57 MJ/kg DM, thus 7% higher than standard alfalfa meal, which would account for its high NDF digestibility (54.9%). Digestibility of crude sulla protein was estimated at 42.8%, corresponding to a digestible crude protein concentration of 71.1±8.9 g/kg DM. Even at a high incorporation rate in the feed (30%), sulla hay did not cause adverse effects on the animal growth (mean 36.0 g/d), feed intake (mean 119 g/d) or health. Feed conversion was better for a moderate rate of sulla inclusion in the diet (about 15%) than for a higher inclusion rate (3.14 vs. 3.36, P < 0.001). Health status and slaughter traits were not affected by the sulla incorporation rate. Sun-dried sulla hay (Hedysarum flexuosum) could thus be considered a good fibre source for the rabbit as a substitute for alfalfa meal.The authors thank Yazid Louchami who placed his rabbitry at our disposal and the assistance he provided us during the follow-up of the experiment, Farid Djellal and Hanachi Zemihi for their assistance in the experimental trial and Muriel Segura for her help in biochemical analyses (INRA, UMR 1289 TANDEM, CastanetTolosan, France). This work was partially financed by the CMEP project (05 MDU 667).Kadi, SA.; Guermah, H.; Bannelier, C.; Berchiche, M.; Gidenne, T. (2011). NUTRITIVE VALUE OF SUN-DRIED SULLA (HEDYSARUM FLEXUOSUM) AND ITS EFFECT ON PERFORMANCE AND CARCASS CHARACTERISTICS OF GROWING RABBITS. World Rabbit Science. 19(3):151-159. doi:10.4995/wrs.2011.848SWORD15115919

Estimation of grass biomass consumed by rabbits housed in movable paddocks

Biomass allowance is a key feature in pasture-based rabbit production systems. It conditions not only the stock density (rabbits/m²) and/or the number of grazing days, it also influences the grazing behaviour of animals. When herbage restriction occurs, pelleted feed and/or cereal intake goes up. Inadequate pasture management may also impair the biomass quantity and quality if overgrazing occurs. To avoid the undesirable effects of overgrazing and better manage pellet and cereal intake, information on both biomass availability and rabbits’ grazing capacity are needed. Here, we present an adaptation of the rising plate meter method (developed for biomass intake measures for ruminants) for use in rabbit. To this end, we designed an experiment where two groups of 12 rabbits each were kept in two different fields: under an apple orchard (AO) or on fallow land (FL). We followed the animals for 5 consecutive weeks (from 45 to 80 d old). Rabbits lived in 25 m² movable paddocks, and every week a new paddock location (called paddock-spot) was made available for them. At each new paddock-spot, we measured the herbage height inside the paddocks and performed samplings of the available biomass (i.e. herbage cut after herbage height measurement) outside the paddocks. From this data we estimated the available biomass inside each paddock-spot by fitting linear regression equations of biomass to herbage height. Overall, rabbits in the AO and FL had access to 1328±65.7 and 1386±58.6 kg of dry matter (DM) per ha, respectively. In every field and paddock-spot, the biomass available was lower than the rabbits’ grazing capacity; overgrazing was the rule. Roughly, and under a restricted herbage allowance, rabbits in the AO ingested 45.2 g DM/d and rabbits in the FL 43.4 g DM/d. In the last week (64 to 80 d old), the biomass intake of rabbits in the AO and AL represented 26.4 and 23.5% of the total DM intake, respectively. These values, however, does not represent the real grazing capacity of growing rabbits. In this study, we provide some advice on the sampling method to obtain reliable biomass estimations and we mention two methods for handling influential observations in linear regression

Diversity and Co-occurrence Pattern Analysis of Cecal Microbiota Establishment at the Onset of Solid Feeding in Young Rabbits

This study aimed to evaluate how the feeding strategy of rabbit kits at the onset of solid feed intake could affect ecological diversity and co-occurrence patterns of the cecal bacterial community. From birth to 18 days of age kits were exclusively milk-fed, and between 18 and 35 days the young rabbits also had access to solid feed. After weaning at (35 days), young rabbits were exclusively fed solid feed. Three experimental feeds were used: a high concentrate diet [H: 10.16 MJ digestible energy (DE)/kg and 15.3% crude protein (CP)], a low concentrate diet (L: 9.33 MJ DE/kg and 14.7% CP) and a reproductive female diet (R: 10.57 MJ DE/kg and 17.3% CP). The rabbit kits (n = 357) were divided into three groups, differing by the diet received during two periods: from 18 to 28 and from 28 to 49 days of age. In the groups LL and HH, rabbit kits were fed L or H diets, respectively, during both periods. Kits in the group RL received feeds R and L from 18 to 28 and 28 to 49 days of age, respectively. Cecal bacterial communities of 10 rabbits per group were carried out at 18, 28, 35, 43 and 49 days of age by MiSeq Illumina sequencing 16S rRNA encoding genes. Between 18 and 28 days of age, solid feed intake was higher in the group RL compared to the other two groups (+24%; P &lt; 0.01). Overall, 13.4% of the OTUs detected were present in the cecal ecosystem from 18 to 49 days old, whereas 17.4% were acquired with the onset of solid feeding and kept from 28 days on. Exclusive milk consumption constrains the bacterial community toward a similar structure but high phylogenetic beta-diversity. Introduction of solid feed induced a sharp change of microbial community structure and decreased phylogenetic diversity. A strong relationship in bacterial community network occurred only from 43 days on. Our feeding strategy at the onset of solid feed ingestion exhibited only a moderate effect on the microbial community structure (P = 0.072), although the LL group seemed to reach faster maturity compared to the two other groups

Influence of the incorporation mode of sugar beet pulp in the finishing diet on the digestive tract and performances of geese reared for foie gras production

The aim of this work was to study the effects of incorporating sugar beet pulp (SBP) into the diet of geese in two feeding systems (complete pelleted feed or loose-mix feeding system) on crop development and performance. A total of 480 1-d-old male geese were divided into three groups whose diet differed from d 56 to 90: a complete pelleted diet containing 50% corn (control diet: AMEn 11.5 MJ/kg; CP 161 g/kg), and no SBP; a complete pelleted diet containing 50% corn and 10% SBP (SBPcp diet: AME(n): 11.5 MJ/kg; CP: 161 g/kg); and a mix in the same feeder (SBPlm diet) of 500 g/kg of protein-rich pellets containing 20% SBP (SBPprp: AME(n): 9.0 MJ/kg; CP: 250 g/kg) and 500 g/kg of whole corn (WC: AME(n): 14.0 MJ/kg; CP: 72 g/kg). Body traits, including crop volume, were measured at d 91. From d 91 to 106, 88 birds/group were overfed with a mixture contain-ing mainly corn and water before slaughter to measure fatty liver performance. Feed intake from d 56 to 90 was higher (+ 10%; P = 0.004) in the SBPcp group than the other two, but at d 90, the body weight (BW) of the birds was higher (+ 7%; P = 0.002) in the SBPlm group than the other two. At d 91, the volume of the crop was greater in the SBPcp group (80.4 mL/kg of BW, P 0.05) between the three groups. In conclusion, the use of sugar beet pulp in the diet of finishing geese helps the adaptation of the digestive tract to the overfeeding period, even in a loose-mix feeding system based on whole corn

Digestion of milk by the young rabbit : first results

This study aims to determine the digestibility of milk by the young rabbit (21-25d old), taking into account the increment of digesta content and urine excretion. Nineteen litters of nine young rabbits of 21 to 25 days old were used: 12 litters fed exclusively with milk using a controlled suckling (CS group), and 7 litters with free suckling and having access to the pelleted feed of the doe (Control group). The faecal digestibility of milk dry matter was measured between 21 and 25d of age, for CS litters housed in a metabolism cage separated from the doe cage from 15 d old. Between 21 and 25d old, milk intake, feces and urine excretion were daily controlled, and themean increment in digesta content was measured by comparing digesta weight of the whole tract at 21 and 25d old (one kit per litter). Between 21 and 25d, the increment in digesta content averaged by 77% (+8.5 g), sourcing mainly from stomach and caecum contents increase (+57% and +120% resp.). The mean increase for the dry content of the gut (DCGi) from 21 to 25d old was 1.73g DM/kit, and was considered as non digested to calculate the corrected digestibility coefficient of the milk. The milk intake averaged 30 g/d/kit (7.9 g DM/d/kit). No faecal excretion was recorded between 21 and 25d. From the milk intake and increment in digesta content, the corrected digestibility of the milk dry matter reached 78% (minimum=72.1%, maximum = 82.5%). The daily urine excretion averaged 5.1 ml/kit, corresponding to 1.2 g DM/kit. Therefore, the corrected DM retention coefficient of the milk was 63.4%. The quantity of nitrogen excreted in urine was low (0.06g/d/kits), thus the corrected nitrogen retention coefficient for milk reached 82%, and the nitrogen retained (corrected) reached 44 g/d/kit. Accordingly the amount in metabolisable protein for the milk was 90 g/kg (fresh). The corrected energy retention coefficient was estimated to 95%, thus the energy retained (corrected) reached 217 kJ/d/kit, and the content in metabolisable energy for the milk was 27.62 kJ/kg (fresh).Este estudo tem como objetivo determinar a digestibilidade do leite de laparos, levando em consideração a acúmulação do conteúdo digestivo e a excreção de urina. Foram utilizadas 19 ninhadas de nove laparos de 21 a 25 dias cada uma: 12 ninhadas foram sobmetidas ao aleitamento restringido sem acesso ao comedouro da coelha (grupo CS) e 7 ninhadas com aleitamento a vontade e livre acesso à raçãoda coelha (grupo controle). A digestibilidade fecal do leite foi medida entre 21 e 25 dias de idade, para as ninhadas CS alojadas em gaiolas de digestibilidade a partir dos 15 dias de idade. Entre 21 e 25 dias de idade, o consumo de leite e a excreção de fezes e urina foram medidos diariamente. No referente ao incremento médio do conteúdo digestivo, este foi medido pela diferença de peso do trato digestivo entre os dias 21 e 25d anos (um laparos por ninhadas). Entre 21 e 25 dias, o incremento médio do conteúdo digestivo foi de 77% (+8,5 g), proveniente principalmente do aumento do conteúdo do estômago e do ceco (+ 57% e +120%, respectivamente). O aumento médio do conteudo intestinal seco (DCGi) entre 21 e 25 dias foi de 1,73g de materia seca (MS)/laparo. Este valor foi considerado não digerido para corrigir o coeficiente de digestibilidade do leite. Em media, a ingestão de leite para cada laparo foi de 30 g / dia (7,9 g de MS/dia). Nenhuma excreção fecal foi recuperada entre 21 e 25 dias. A partir dos dados de consumo de leite e do incremento do conteudo digestivo, a digestibilidade corregida da matéria seca do leite foi de 78% (mínimo = 72,1%, máximo = 82,5%). A excreção media diaria de urina foi de 5,1 ml/laparo, o que corresponde a 1,2 g de MS / laparo. Portanto, o coeficiente corrigido de retenção de MS do leite foi de 63,4%. A quantidade de nitrogênio excretada na urina foi baixa (0,06 g/dia/laparo), resultando em um 3 coeficiente de retenção de nitrogênio de 82%, e uma quantidade de nitrogênio retido (corrigido) de 44 g/dia/laparo. Portanto, a quantidade de proteína metabolizável do leite de coelhas foi de 90 g / kg de leite fresco. O coeficiente corregido de retenção de energia foi estimado em 95%, resultando em uma quantidade diaria de energia retida de 217 kJ/laparo. O conteúdo de energia matabolisada do leite fresco de coelhas foi de 27,62 kJ/kg

Ingestion et digestion de fourrages secs et verts pour le lapin – première approche pour la luzerne et la carotte entière

Cette étude a pour objectif d'estimer le niveau d'ingestion et la digestion pour 2 plantes entières, distribuées seules ou en association : des carottes fraîches entières (fanes incluses), ou de la luzerne soit fraîche "Luzerne" ou sous forme de foin "Foin". Trois essais ont été conduits sur des lapins, entre 7 et 10 semaines d'âge (essai 1) et entre 5 et 7 sem. d'âge (essais 2 & 3), logés en cage individuelle à métabolisme et nourris à volonté en ration simple ou mixte avec ces 3 aliments. Chez des lapins de 8 semaines (essai 1) l'ingéré sec de foin est de 50 g/j par kg de poids métabolique (PM =poids vif 0,75). Chez des lapins âgés de 6 semaines, la consommation de carotte atteint 401 g/j (40% du poids vif), et celle de luzerne fraîche 224g/j, soit un ingéré sec de 73 et 59 g/j respectivement. L'ingéré sec de carotte est similaire à celle du foin de luzerne (70g/j/kg PM). La distribution du foin associé à la carotte (ration mixte) permet de stimuler l'ingestion de foin. La digestibilité de la MS de la carotte et de la luzerne fraîche est de 78% et 72% chez des lapins de 6 semaines, 61% seulement pour le foin. En ration mixte, on n'observe pas d'interaction pour la digestibilité de la MS entre la carotte fraiche et le foin de luzerneThis study aims to estimate the intake level and digestion for 2 whole plants, distributed alone or in combination: fresh whole carrots (leaves included), or alfalfa either fresh or as hay. Three trials were conducted on rabbits, between 7 and 10 weeks of age (trial 1) and between 5 and 7 weeks of age (trials 2 & 3), housed in individual metabolic cages and fed ad libitum with these 3 feeds. In 8-week -old rabbits (trial 1) the dry matter (DM) intake of hay reached 50 g/d per kg of metabolic weight (MW= live weight 0.75). In 6-week -old rabbits, carrot consumption was 401 g/d (40% of live weight) and that of fresh alfalfa was 224g/d, i.e. a dry matter intake of 73 and 59 g/d respectively. DM intake of carrot was similar to that of alfalfa hay (70g/d/kg MW ). The distribution of the hay associated with the carrot (mixed ration) stimulated the intake of hay. The DM digestibility of carrot and fresh alfalfa is 78% and 72% in 6 -week -old rabbits and only 61% for alfalfa hay. No interaction was observed for the DM digestibility of carrot and alfalfa hay when given associated in a mixed ratio

Nutritive value of fresh ash (Fraxinus Angustifolia) leaves for growing rabbits

The nutritive value of Ash (Fraxinus angustifolia) leaves, harvested in autumn was determined (direct method), using ten rabbits (individually caged) weaned at 35d old (mean body weight: 911g) fed ad libitum only fresh Ash leaves during 16 days. Ash leaves composition was: organic matter (OM) 89.3%, crude protein (CP) 14.6%, neutral detergent fibre (NDF) 39.4, acid detergent fibre (ADF) 26.3, acid detergent lignin (ADL) 15.1% on dry matter (DM) basis. The faecal digestibility of the Ashleaves was measured between 48 and 51 days old. The digestibility of OM, CP, NDF and ADF were 74, 67, 59 and 59% respectively. The concentration in digestible energy and digestible protein of the Ash leaves was estimated to 13.59 ± 0.90 MJ and 98 ± 10.4 g/kg DM respectively. The Ash leaves harvested in autumn could be considered as a good source of energy and fibre for growing rabbit. Key words: Ash leaves, Fraxinus angustifolia, nutritive value, autumn, digestibilit

Sainfoin as a replacement of alfalfa : nutritive value and performances in the rabbit

Since the sainfoin (Onobrychis viciifolia) contains high ADF and ADL levels associated with a high level of protein, it could be a good alternative to alfalfa for rabbit feeding. Nowadays dehydrated pelleted sainfoin ‘DpS’ (PERLY variety) is available on the market (Multifolia company). However no informations are available about the nutritive value of DpS when incorporated in a complete balance pelleted diet for the growing rabbit. Thus we studied the effect of substituting 40% of the alfalfa in a control diet (C) with sainfoin (diet S), on digestion and performances of two groups of 16 rabbits housed in metabolic cages (8 cages of 2 per group), and fed freely C or S diets from weaning (28 d) to slaughter (70 d). DpS chemical composition was: crude protein ‘CP’=17.3%, ADF=30.4%, ADL=12.0%. Chemical composition C and S pelleted diets were: CP=15.9 & 16.7% resp., ADF=19.9 & 23.4%. The S diet also differed from C diet by its tannin (1.8% vs 1.0% tannic acid equivalent) and its ADL concentration (8.4 vs 4.3%). A five days fecal collection period (60-64 d old) was performed to calculate the digestibility. Growth rate (28-70 d) was 5% lower in S than in C group (38.2 vs 40.2 g/d; P<0.05), while feed intake was 3% higher for S than for group (121.5 vs 116.5 g/d, P<0.05), as was the feed conversion ratio (3.18 vs 2.90; P<0.01), probably in relation to the higher ADL level for S diet. Protein digestibility was 5 units lower in S compared to C groups (69.6 vs 75.3%; P<0.01), probably associated with the high tannin concentration. Energy digestibility did not differ between S and C diets (mean = 65.4%). Using the substitution method, the digestible energy ‘DE’ content of dehydrated sainfoin pellets, as a raw material, was calculated at 11.21 MJ/kg (40% higher than alfalfa), and digestible proteins content at 110 g/kg (similar to alfalfa). In conclusion, dehydrated pelleted sainfoin constitutes a good alternative to alfalfa, since it supplies energy and protein as well fibres, and particularly lignins essential for the growing rabbit

Valeur nutritive du sainfoin deshydrate, lors d'une forte substitution dans un regime a base de luzerne, dans l'alimentation du lapin en croissance

Le sainfoin (Onobrychis viciifolia, variété PERLY) déshydraté en bouchons "Sdb" contient des niveaux élevés d'ADF et d'ADL associés à un niveau élevé de protéines. Il pourrait donc, comme la luzerne, être une source intéressante de fibres et de protéines végétales en alimentation cunicole, mais sa valeur nutritive pour le lapin est méconnue. L'effet de l'incorporation de 40% de Sdb (aliment SD), dans un aliment témoin granulé à base de luzerne déshydratée (TL) a été étudié sur la digestion, et les performances de 2 groupes de 16 lapins logés dans des cages à métabolisme (8 cages de 2 par groupe), et nourris à volonté avec le régime TL ou SD, depuis le sevrage (32j) jusqu'à 74j. d'âge. La composition chimique de Sdb es t : protéine brute "PB" = 17,3%; ADF = 30,4%; ADL = 12,0%. Les 2 aliments ne sont pas iso-nutritifs, leur analyse chimique est : PB = 15,9 et 16,7% resp. pour TL et SD; ADF = 19,9 et 23,4%. De plus, SD diffère de TL par sa teneur en tanins (1,8% vs1,0% resp.) et en ADL (8,4 vs 4,3%). Une collecte fécale totale (57 à 61 j.) a permis de mesurer la digestibilité. La croissance (32-74d) des lapins du groupe SD est 5% plus faible que celle de TL (38,2 vs 40,2 g/j; P <0,05), tandis que l'ingestion du groupe SD est 3% supérieure à celle de TL (121,5 vs 116,5 g/j; P <0,05), ainsi que l'indice de consommation (3,18 vs 2,90; P <0,01), probablement en relation avec le niveau plus élevé de lignines dans l'aliment SD. La digestibilité des protéines est réduite de 5 unités pour le groupe SD (69,6 vs 75,3%, P <0,01), lien avec la forte concentration en tanins. La digestibilité de l'énergie est similaire entre les régimes SD et TL (moyenne = 65,4%). L'écart de digestibilité entre SD et TL permet de calculer (par différence) la concentration en énergie digestible "ED" du sainfoin déshydraté (Sdb): 2680 kcal d'ED/kg (11,21MJ/kg), et sa teneur en protéines digestibles: 110 g/kg. La valeur énergétique est plus élevée qu’attendu et doit être confirmée. Le sainfoin apparait comme une alternative à la luzerne, comme source d'énergie, de protéines, et de fibres, notamment de ligninesThe dehydrated sainfoin (Sdb, Onobrychis viciifolia, PERLYcultivar) contains high ADF and ADL levels associated with a high level of protein, and could be an alternative to alfalfa for rabbit feeding. Thus we studied the effect of 40% incorporation of Sdb (diet SD) in a control diet (TL, alfalfa based), on digestion and performances of two groups of 16 rabbits housed in metabolic cages (8 cages of 2 per group), and fed freely TL or SD diets from weaning (32d) to 74d old. Sdb chemical composition was: crude protein "CP"=17.3%, ADF=30.4%, ADL=12.0%. Chemical composition of TL and SD diets were: CP=15.9 & 16.7% resp., ADF=19.9 & 23.4%. The SD diet also differed from C diet by its tannin (1.8% vs. 1.0%) and its ADL concentration (8.4 vs. 4.3%). A four days fecal total collection period (57-61d old) allowed to calculate the feeds digestibility. Growth rate (32-74d) was 5% lower in SD than in TL group (38.2 vs 40.2 g/d; P < 0.05), while feed intake was 3% higher for SD than for TL group (121.5 vs 116.5 g/d, P < 0.05), as was the feed conversion ratio (3.18 vs 2.90; P < 0.01), probably in relation to the higher ADL level for S diet. Protein digestibility was 5 units lower in SD compared to TL groups (69.6 vs 75.3%; P < 0.01), probably associated with the high tannin concentration. Energy digestibility did not differ between SD and TL diets (mean= 65.4%). Using the substitution method, the digestible energy "DE" content of dehydrated sainfoin pellets, as a raw material, was calculated at 11.21 MJ DE/kg (2680 kcal/kg), and digestible proteins content at 110 g/kg. The energetic value was higher than expected and must be confirmed. In conclusion, dehydrated sainfoin constituted an alternative to alfalfa, since it supplies energy and protein as well fibres, and particularly lignins essential for the growing rabbi