The impact of a challenge with moderately pathogenic Escherichia coli O128:C6 on the digestive physiology and gut bacterial community of growing rabbits under two feeding programmes was analysed. Upon weaning (28 d old), 180 rabbits were allocated to four groups (9 cages of 5 rabbits per group) for two weeks: group C100 was non-inoculated and fed ad libitum; C70 was non-inoculated and feed intake was limited to 70% of C100; I100 and I70 were inoculated and fed ad libitum or restricted to 70%, respectively. At the age of 31 d (D0), rabbits were orally inoculated with E. coli (2.2×108 colony forming units/rabbit). The effects of inoculation spiked on D4, with a 28% lower growth rate for I100 than for C100. Limited feed intake reinforced the inoculation’s effects on growth: I70 had a 66% lower growth rate than C70. The morbidity rate peaked at 42% between D4 and D7 for inoculated groups, without significant effect of the feed intake level. E. coli concentration peaked on D5/D6 in the caecum of the I100 and I70 groups. Inoculation reduced by 30% (P<0.05) the villus height/crypt depth and villus/crypt area ratios in the ileum, with no significant effect of the intake level. Inoculation was associated with a tenfold increase in serum haptoglobin (P<0.001) for both ad libitum and restricted rabbits. On D5, the inoculation modified the structure of the ileal bacterial community (P<0.05), but not that of the caecum. The feed intake level did not affect either the structure or diversity of the bacterial community, both in the ileum and caecum.

Abstract This chapter discussed the health problems (mainly digestive) linked to the balance of dietary components and the presence of nutrients in excess, mainly in relation to the initial composition of feed ingredients, but also to the feeding strategy. Also highlighted are the feeding strategies (feed quantity and nutritional quality) for the doe and for the growing rabbit. The last section will cover the health consequences of non-nutritional components that are frequently associated with feed ingredients, such as mycotoxins and water quality. The methods for health status assessment that are practical in rabbit breeding were also discussed.

La pathologie représente un poids économique important en élevage rationnel du lapin de chair. En effet, un quart des lapereaux meurent entre la naissance et la vente. Chez les reproductrices, sur trois femelles entrant dans une bande, une meurt avant la 3ème mise bas, une autre est réformée pour cause de performances insuffisantes (infertilité) ou problème sanitaire, une seule assure une production. Deux syndromes principaux sont classiquement identifiés chez le lapin : le syndrome respiratoire qui domine chez les adultes et le syndrome digestif, plus fréquent chez les lapins en croissance. Dans cette synthèse nous ferons le point sur les principales maladies infectieuses pouvant être rencontrées dans les élevages rationnels et sur les recherches développées au cours de ces dernières années concernant les agents étiologiques impliqués.

Les coccidioses constituent l'une des maladies les plus meurtrières chez les lapins. Pour mieux contrôler cette affection, une prophylaxie vaccinale est mise au point. La réussite d'une telle innovation passe par la perception des cuniculteurs. Ainsi, la présente étude a été entreprise afin de déterminer les facteurs favorisant l'adoption par les éleveurs de la vaccination des lapins contre les coccidioses. Les enquêtes menées auprès des cuniculteurs ont révélé que 100% d'entre eux ont une opinion favorable du vaccin. De même, 83,3% des éleveurs ont affirmé que le vaccin était efficace. Par ailleurs, 80% des éleveurs ont déclaré connaître la coccidiose. Parmi ceux-ci, 62,5% avait bien décrit les signes cliniques de la coccidiose. L'étude économique a montré que la vaccination engendre un bénéfice net de 123,2 F CFA par lapin comparativement aux lapins non vaccinés. La vaccination s'avère efficace et est bien appréciée par les utilisateurs. Son adoption contribuera à améliorer les conditions de vie des cuniculteurs.© 2015 International Formulae Group. All rights reserved.Mots clés: Oryctolagus cuniculus, cuniculture, coccidies, prophylaxie, immunisation, adoptionEnglish Title: Socio-economic effects on the rabbit breeders of rabbit's vaccination against intestinal coccidiosis in BeninEnglish AbstractCoccidiosis is recognized as being one of the major serious diseases in rabbit breeding. For a better control of this disease, a vaccination program is set up. The perception of the rabbit breeders determines the success of this innovation. Thus, this study was undertaken in order to determine the factors which favour the adoption of the rabbit vaccination against coccidiosis by the rabbit breeders. Survey performed on rabbit breeding revealed that 100% of the breeders included in the survey thought that vaccine is useful for the control of coccidiosis. An average of 83.3% of breeders has reported that the use of vaccine was effective to control coccidiosis. Likewise among rabbit breeders included in the study, an average of 80% has been reported to know coccidiosis. Among those breeders, an average of 62.6% was reported to know well clinical symptoms of coccidiosis. Economical study carried out on rabbit breeding showed that vaccine involves a net profit of 132.2 F CFA per vaccinated rabbit compared to non vaccinated rabbits. Vaccine turns out to an effective control of coccidiosis in rabbit and was well appreciated by the breeders. Its adoption will help improving rabbit breeders' life.© 2015 International Formulae Group. All rights reserved.Keywords: Oryctolagus cuniculus, rabbit breeding, coccidia, prevention, immunization, adoption

The aetiological agent of epizootic rabbit enteropathy (ERE) is still unknown although a bacterial infection seems the most likely hypothesis. In this study, amplification of the V5 and V6 regions of 16SrDNA from four virulent and two non-virulent caecal samples was performed using a pyrosequencing platform. The virulent samples did not group in the same cluster. The bacterial flora identified was both different and richer than the cultivable bacterial flora. These findings highlight the need for biomolecular techniques to identify the aetiological agent of ERE.

Les coccidioses constituent un problème sanitaire majeur pour l’élevage cunicole. Une vaccination contre cette maladie à l’aide de souches précoces de Eimeria ayant une parfaite innocuité est nécessaire. Pour évaluer cette innocuité, trois lots de 12 lapereaux de 35 + 1 jours ont été inoculés avec des souches précoces de Eimeria magna et Eimeria media provenant des lapins élevés au Bénin. Un mélange à parts égales des deux souches a été constitué. Les animaux du lot 1 ont été inoculés per os avec ce mélange à la dose de 5 x 103 oocystes et ceux du lot 2 ont reçu le même mélange à la dose de 2,5 x 103. Le lot 3 a servi de témoin. Deux semaines après l’inoculation, aucun cas de mortalité et/ou de diarrhée n’a été enregistré ; les témoins ont excrété moins d’oocystes (3,2 x 104 oocystes/g) comparativement aux animaux expérimentaux (P < 0,01) du lot 1 (10,1 x 106 oocystes/g) et du lot 2 (8,8 x 106 oocystes/g), confirmant ainsi une bonne multiplication de ces souches. La chute du GMQ des lots inoculés par rapport à celui des témoins est significative (P < 0,001) mais reste modérée. Il en résulte que ces souches s’avèrent être de bonnes candidates à un vaccin.Keywords: Coccidiose, Eimeria magna, Eimeria media, vaccin, lapin, Bénin

Epizootic rabbit enteropathy is a gastrointestinal disorder of unknown aetiology of farmed rabbits characterised by inanition and mortality. Genomic analyses of virulent and non-virulent samples of inocula were performed using random amplification of polymorphic DNA (RAPD). Differences in bacterial DNA composition were found between inocula, but specific sequences were not linked with field cases of epizootic rabbit enteropathy.

Three groups of twelve 35-day-old rabbits were used for the experiment. Two groups were vaccinated with a mixture of precocious lines of Eimeria magna and Eimeria media originating from corresponding wild strains isolated in Benin. One group benefited of a booster whereas the second one was kept without booster. A third non-vaccinated group was used as control. All groups were challenged per os with an equal mixture of the wild strains of E. magna and E. media at a dose of 104 oocysts per animal. Three weeks after the challenge inoculation, no case of diarrhoea was recorded in the two groups of vaccinated rabbits, as compared to the non-vaccinated rabbits that developed diarrhoea. No mortality was recorded in the three groups. During the patent period, oocyst output of vaccinated rabbits was significantly lower than that of control animals (P<0.01), confirming a good immunogenic characteristic of the precocious lines. No booster effect was noticed for the boost vaccinated group. The daily weigh gain of the two groups of vaccinated rabbits was significantly higher than that of the non-vaccinated rabbits (P<0.05). Consequently the precocious lines of Benin origin turned out to be immunogenic and therefore constitute good potential candidates for vaccine production for this country.

Thirty six 25-day-old suckling rabbits and thirty six 29-day-old rabbits weaned since one day were orally vaccinated with one of the two doses (3.5 x 103 or 3.5 x 104 oocysts) of a precocious line of Eimeria magna. Only the groups vaccinated with the highest dose displayed a vaccine reaction, but without diarrhea or mortality. A vaccination totaly or incompletely protected against disease, assessed by daily growyh rate patterns, according to the dose given and reduced oocyst output 10 to 1000 times, measured between the 4th and the 10th day following the challenge inoculation.

Fifty two coccidia free rabbit does were used in this experiment and 26 of them were immunized by repeated per os inoculations of 104 oocysts of Eimeria magna precocious line during gestation. The oocysts output was completely controlled after the third inoculation and signs of disease were never observed. The serum antibodies (Ab) were titrated by an ELISA method. In the controls, the Ab titers were constantly below the optical density 0,25 at the wave length 405nm. In immunized does, the Ab level began to increase 4 weeks after the first inoculation. Booster inoculations given 7 and 4 days before parturition produced a high increase of Ab level. 26 females received an injection of sporozoites 2 and 17 days after parturition; these injections produced a dramatic increase of the Ab level compared with that of the untreated females. The serum Ab of the weanlings were titrated at 29 and 39 days of age. In all groups, the Ab titers were very low but a slightly higher level was observed in the groups corresponding to the immunized does. The dramatic increase of the Ab titers of the does injected with sporozoites had no effect on the Ab titers of their litters. To test the protection transmitted by the mothers, the weanlings were inoculated with 10 oocysts of the same Eimeria magna precocious line and the oocysts output was measured. The whole excretion of oocysts was identical (6 x 10 oocysts) in all groups, and the decrease in weight gain was identical to that of inoculated controls. We can conclude that the does immunity did not protect the litter against an infection with E.magna.

Using 180 35-day-old SPF rabbits, this study used the effectiveness of bacitracin as a tool for acquiring more information on the various phases of ERE, in particular during the hours following inoculation. Five groups of animals were used, including 3 treatments with Bacivet S(R) (bacitracin) at different times from inoculation, with the standard inoculum TEC3. Three parameters were studied: growth, mortality and stomach noises (borborygmi). A significant fall in growth rate was observed during the first 18 hours following the inoculation in all the inoculated groups, both medicated and not medicated. Treatment with bacitracin eliminated mortality and borborygmi, but not the initial fall in growth rate. Treatment starting 18 hours after inoculation is less effective during the acute phase than the preventive treatment. With a preventive treatment interrupted as soon as 18 hours after inoculation, a delay of several days was observed before the appearance of the disease (fall in growth rate, manifestation of borborygmi) and total mortality was reduced. Very few pathogens can explain this early fall in growth rate. Bacitracin is an antibiotic which offers good control of the disease, and probably of the pathogen but not of the physio-pathological disturbances in the first few hours. The intervention of an exogenic toxin in the first hours of contamination seems likely. Borborygmi are important criteria. The intensity and/or frequency could be used as semi-quantitative criteria to characterize the disease and for the prognosis. In a simultaneous trial, a group was contaminated with the same inoculum, heated for 10 min at 55 degrees C, in order to obtain more information on the type of pathogen involved in the etiology of ERE. This treatment did not modify the virulence of the inoculum.

Digestive troubles are the main cause of morbidity and mortality during growth in rabbit production. The diagnosis of enteritis, which is characterized by diarrhoea, remains difficult to establish. However, identification of sorne specific pathogens may be possible. Coccidia and bacteria, like Escherichia coli (mainly 0103 serogroup) or Clostridium spiroforme are the most frequent pathogens. In adults, respiratory pathology with Pasteurella multocida is predominant, as well as staphylococcal infections.. In these conditions, the rabbit is one of the most important consumers of antibiotics among the domestic animals. The noxious role, particularly of penicillins and of sorne macrolids (clindamycin and lincomycin) is underlined. Otherwise, if sorne antibiotics like tetracyclin can be successfully used against respiratiory disorders, they could be harmful in case of Clostridium spiroforme contamination of rabbits, when used alone. A table at the end of this papar encloses antibiotics to proscribe, to avoid and those that can be used (with brief indications on their dosage).

The aetiology of epizootic rabbit enteropathy (ERE) is still unknown despite ten years of continuous research. A putative bacterial aetiology is the basis of current research. The fractionation of the reference inoculum (TEC4) is a major step towards finding the potential bacterial agent(s). In this study, TEC4 was fractionated by different techniques: centrifugation on discontinuous sucrose gradient, cell adherence and chloroform/ethanol treatment. The different fractions were inoculated into SPF rabbits and analyzed with classical bacteriological techniques. ERE was reproduced with two of the six fractions obtained. Four species never previously cultured from TEC were identified in the process but, to date, none of them seems to be the aetiology of ERE.

INDEX 1 Methods to estimate the health status and to measure the risk of digestive troubles ........ 2 2 Troubles related with major nutrients imbalance............................................................... 2 2.1 Fibre and starch intake ................................................................................................... 3 2.1.1 Consequences of a reduction in the fibre intake ..................................................................3 2.1.2 Effect of the type of cell wall constituents...........................................................................5 2.2 Protein level and quality ................................................................................................ 6 2.3 Lipids ............................................................................................................................. 7 3 Feed intake strategy and digestive pathology of the growing rabbit ................................. 8 4 Troubles associated with dietary compounds present at toxic level .................................. 8 4.1 Minerals and vitamins.................................................................................................... 8 4.2 Mycotoxins .................................................................................................................... 9 5 Water quality and pathology............................................................................................ 10

Soixante-quatre lapins EOPS (exempts d'organismes pathogénes spécifiés), âgés de 4 a 6 semaines ont été répartis en deux lots égaux. L'un (TC), a été traité pendant 3 semaines avec un corticoide, la déxamétasone, à raison de 3 injections de 4 mg/kg, par semaine. L'autre lot (NT), a reçu seulement des injections d'eau physiologique. Aprés 19 jours de traitement, l'ensemble des animaux a été inoculé par voie orale, avec du broyat digestif susceptible d'induire l'Entérocolite Epizootique du Lapin (EEL). Les résultats ont montré qu'avant l'inoculation, la croissance a été fortement réduite dans le lot traité à la déxamétasone: poids vif réduit de 24% par rapport au lot non traité. L'inoculation a entraîné une élévation considérable de la mortalité dans le lot TC: 65,5%, contre 13,8% dans le lot sans corticoide, au cours des 9 jours d'observation ayant suivi l'inoculation. Les lésions caractéristiques de l'EEL ont été retrouvées chez 74% des lapins morts dans le lot TC et chez 100% de ceux du lot NT. La mortalité est apparue un jour plus tôt chez les lapins TC: à J2 post-inoculation, vs J3 pour le lot NT. Dés J1, des lésions spécifiques de l'EEL ont été détectées dans le lot TC. Ce modèle expérimental animal (immunodépression de lapin EOPS) constitue une avancée capitale pour la suite des travaux sur l'EEL.

The etiology of epizootic rabbit enteropathy (ERE) is still unknown despite ten years of continuous research. A putative bacterial etiology is at the basis of current research. The fractionation of the reference inoculum (TEC4) is a major step to find the potential bacterial agent(s). In this study, TEC4 was fractionated with two techniques: centrifugation on discontinuous sucrose gradient then cell adhesion. Two selected fractions were inoculated to SPF rabbits and analyzed with classical bacteriological techniques. ERE was reproduced with both fractions. The 16S rDNA gene was amplified in all fractions and in three negative controls and subsequently analyzed with Restriction Fragment Length Polymorphism (RFLP) and Denaturating Gradient Gel Electrophoresis (DGGE). A difference in bacterial DNA composition was found between virulent and non-virulent fractions which reinforce the potential role of bacteria in the etiology of ERE.

The rabbit, which is herbivorous and monogastric, harbours in distal parts of the gut an active and abundant symbiotic microbiota, which plays a key role in its digestive physiology, both for health and digestive efficiency. In the caeco-colic ecosystem, there are complex interactions among the biotope (i.e. the caecum) and the biocenosis (the microbiota), and its functioning still remains poorly known. This review will first summarise the data concerning the caecal biotope and its physico-chemical characteristics, which were subjected to numerous studies. Our knowledge of the caecal biocenosis, obtained by traditional culture based methods will then be presented, and then those obtained recently using molecular microbiology tools. Lastly, this review will described the effect of some main nutrients and of some feeding strategies on the function of this ecosystem, and the relationships with the digestive health of the young rabbit.