Abstracts of the 18th French Rabbit Days
Nantes, France , 27-28 May 2019

The 18th edition of the French Rabbit Days (Journées de la Recherche Cunicole) was organized by the association CUNICULTURE, in association with INRA (Institut National de la Recherche Agronomique) and ASFC (French Branch of the WRSA), in Nantes, during one and a half days 27-28 May 2019. A total of 32 peer reviewed communications, including 3 synthesis, were orally presented to about 90 attendants. The 2 most relevant subjects were 1/ studies on and possibilities of control of the viral haemorrhagic disease caused by the new RHDV2, and 2/ control of digestive disorders, particularly coccidiosis, with nonchemical feed additives or diet formulation. One part of the communications was also devoted to the efforts made for the promotion of rabbit meat in France and to the comportment of consumers in relation with rabbit meat. The full texts of the communications, in French, are available as E-book (156 pages - 7400 Ko). Click here to have the access to this E-book. In addition, French summaries + french full texts + oral presentations (in French also) are available in the www.cuniculture.info website , click here for a free access.

English abstracts of the 32 communications are presented below. for each section


Pathology & Hygiene

Carcass & Meat valorisation


Reproduction & Management

Nutrition & Feeding


Legendre H., Goby J.P., Le Stum J., Hoste H., Cabaret J., Gidenne T., 2019. Gastrointestinal parasitism of organic pasture raised growing rabbits according to age, season and type of pasture. Part 1/ Nematodes. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 9-12.
INRA , GenPhySE, 31326 Castanet Tolosan, France - thierry.gidenne@inra.fr

Abstract : Our trial aimed to study the gastro-intestinal parasitism in pasture raised rabbits, during 3 seasons: winter 2014/2015, summer 2015 and spring 2016. For every season, at weaning 30 rabbits were housed in movable cages on two pastures: sainfoin and tall fescue. Nematodes eggs were counted on a weekly basis in feces. At slaughter (100 d old), the digestive tract was sampled to count the number of nematodes. The type of pasture (fescue vs sainfoin) had no effect on egg excretion or on nematodes prevalence and intensity. Spring 2016 was characterised by a high prevalence of Trichostrongylus sp. (93% of rabbits). A negative correlation between the intensity of infection by Trichostrongylus sp. and daily gain was observed, but without discarding other factors, like the season . These first results suggest to increase the pasture rotation time over the 2 months requested by current organic rabbit farming regulation in France.

Legendre H., Goby J.P., Le Stum J., Hoste H., Cabaret J., Gidenne T., 2019. Gastrointestinal parasitism of organic pasture raised growing rabbits according to age, season and type of pasture. Part 2/ Coccidia. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 13-16..
INRA , GenPhySE, 31326 Castanet Tolosan, France - thierry.gidenne@inra.fr

Abstract : Our trial aimed to study the gastro-intestinal parasitism in pasture raised rabbits: this second part is dedicated to coccidia. Coccidia oocysts were counted weekly in feces, and identified to species, at weaning, 55, 69, 83 and 97 days of age. At slaughter (100 d old) the liver was examined. The type of pasture (fescue vs sainfoin) did not affect the oocysts excretion (all species). Compared to other seasons, in spring 2016, there was a 50% increase in the total excretion of oocysts, particularly in sainfoin pasture (6.5 M.OoPG) where the rotation times was shorter. E. intestinalis was not identified, contrary to E. flavescens during summer and spring 2016. During spring 2016, the number of oocysts of E. flavescens excreted on the pasture of tall fescue was 72% higher compared to the pasture of sainfoin (11,682 and 6,796 OoPG; P<0,05). No diarrhoea was observed during the trial, neither intestinal macro-lesions in the slaughtered rabbits. However, 64% of the livers presented white nodules due to E. stiedae, without a significant effect of the pasture type, or of the season. The mean excretion of E. flavescens may explain a part of the lower daily weight gain (-5 g/d) observed, whatever the pasture type, at spring 2016 compared to the two other seasons.

Maziz-Bettahar S., Aissi M., Ain Baziz H., Saddek Bachene M., Safia Zenia S.. 2019. Prevalence of coccidia infection of rabbits in three regions of Algeria. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 17-20.
Institut des Sciences Vétérinaires, Université Blida1, Algeria - samabe72@yahoo.fr

Abstract : A total of 40 rabbit farms located in three regions of Algeria, namely Médéa, Tizi Ouzou and Djelfa have allowed to evaluate the prevalence and intensity of rabbit coccidiosis. The species of coccidia have also been identified. 273 fecal samples were collected from weaned rabbits aged between 40 and 50 days. The search for coccidia was carried out by a quantitative and qualitative method. For all the farms surveyed, we recorded a prevalence of 90% (80.7- 99.3%). The classification of the farms according to their parasite load allowed us to show that more than one third of the prospected farms have an oocysts excretion between 10 000 and 50 000 oocysts per gramme (OPG) and almost a quarter excrete more than 50 000 OPG. The rest of the farms (32.5%) had an excretion of less than 5 000 OPG. Excretion levels by region show that the region of Tizi Ouzou ranks first with 79% of farms with a parasitic load greater than 10 000 OPG compared to the region of Médéa and Djelfa. Eight species of Eimeria have been identified, E. magna is the dominant species before E. media and E. irresidua (P<0.001).. The species weakly encountered are E. perforans, E. stiedae, E. coecicola, E. piriformis and E. intestinalis . The results obtained show that hygiene measures and the use of anticoccidial drugs in farms are insufficient.

Atkinson A., Le Roux J.F, Prigent A.P., Colin M., 2019. Effect of a polyherbal mixture of Sugar Cane and of Acacia concinna on the oocystal excretion and the zootechnical performances of the growing - fattening rabbit in poor sanitary. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 21-24.
Nuproxa, 3 Rue Jean Rostand, 22 440 Ploufragan, France - copri@wanadoo.fr

Abstract : At weaning (34 d) 299 rabbits were split between 2 dietary treatments, one diet contained 1 kg/ton of Peptasan, a poly herbal mixture of sugar cane and of Acacia concinna and control diets was without chemical or natural substances aiming to control Eimeria development. Collects of droppings were carried out twice during the growth at 50 and 70 days of age; the mortality and weight were measured. The test took place in a deteriorated sanitary context with mortality higher than the one generally observed in this rabbitry. The total oocyst excretion and particularly of the pathogenic Eimerias (Eimeria magna and Eimeria media) decreased at 50 days of age, particularly for Eimeria media. The differences were lower at 70 days of age. The oocysts excretion of Eimeria perforans was little affected by Peptasan. With respect to the totality of oocyst excretion, the percentage of Eimeria media decreased a lot with the Peptasan treatment while that of Eimeria magna was modified little and that of Eimeria perforans increased. Peptasan decreased highly significantly the mortality in growing - fattening rabbits, particularly between 34 and 55 days. The growth performance were not significantly modified. Peptasan appears as a natural product enabling to decrease ookyst excretion and mortality in a sanitary deteriorated context.

Huneau-Salaün A.,Boucher S., Fontaine J., Le Normand B., Lopez S., Maurice T. , Nouvel L., Bruchec A., Coton J., Martin G., Le Gall-Reculé G., Le Bouquin S., 2019. Epidemiological studies of RHD outbreaks in French rabbit farms from 2013 to 2017. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 25-28.
ANSES, Laboratoire de Ploufragan-Plouzané-Niort, BP 53, 22440 Ploufragan, France - adeline.huneau@anses.fr

Abstract : Rabbit viral haemorrhagic disease (RHD) is a critical health threat to the French rabbit industry, which adopted a voluntary control plan against this disease in 2018. In this context, Anses and SNGTV carried out two epidemiological studies on RHD cases that occurred between 2013 and 2018 in France. The objectives were to describe the spread of the RHDV2 and to identify breeding factors influencing the occurrence of the disease, in order to guide the prevention measures recommended in the control plan. Analysis of cases in 295 farms between 2013 and 2017 shows that 32% of the farms were infected at least once; the prevalence of the disease increased significantly in 2016-2017 compared to 2013-2015. Farms already affected in 2013-2015 have a higher risk of infection in 2016-2017 than those that remained uninfected until 2015 (Relative Risk 1.7 CI95% [1.1-2.7]).. A Case-control study carried out on 37 outbreaks between 2016 and 2018 and 32 control farms revealed significant variability in biosecurity and decontamination practices between farms. The risk of disease tends to be linked to these practices, but certain structural factors (e.g. manure disposal system, transfer of kits at weaning) could also influence the risk of virus introduction into farms. These results will be further developed using information from the RDV outbreak monitoring system set up in 2018.

Boucher S., Nicolier A., Le Minor O., Mellet R., Le Moullec T., Sigognault-Flochlay A., 2019. Clinical, macro and microscopic lesional aspects following experimental RHD reproduction using a RHDV2 hypervirulent viral strain. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 29-32.
LABOVET Conseil (Réseau Cristal), ZAC de la Buzenière, BP 539, 85505 Les Herbiers cedex - France - s.boucher@labovet.fr

Abstract : The emergence of an hypervirulent strain of RHDV (GI.2-OLM.2017) with a particularly deadly epizootic event was observed in the Pays de Loire region in 2017 . We used that strain for a viral challenge on SPF rabbits 4 and 10 weeks old. The authors observed the clinical and lesional aspects of this form of RHD. The clinic was similar to that previously described with other strains of RHDV2 but mortality was higher (100% on 4 weeks old rabbits and 88.9% on 10 weeks old rabbits). Maximum time of incubation of the disease was 3 days. A large increase in temperature (up to 41.5 ° C) was noted half a day before death but it was followed by hypothermia 7 hours before death. Jaundice was the most frequently observed lesion, followed by signs of ocular haemorrhage and non-constant epistaxis. Disseminated intravascular coagulation, jaundice and congestions of various organs were observed on histological sections

Le Moullec T., Le Minor O., Joudou L., Beilvert F., Morin H., Sigognault Flochlay A., 2019. Rabbit Haemorrhagic Disease: Efficacy of a commercial bivalent vaccine against a recent highly pathogenic RHDV2 strain and study of the virus excretion. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 33-36

Abstract : An increase in the pathogenicity of the circulating strains was recently reported. The objective of this experimental study was to assess the efficacy of a commercial bivalent vaccine against thd recent highly pathogenic GI.2 isolate (2017), and to study the virus spreading in the organs and its excretion by the infected rabbits. Four-weeks and 10-weeks-old SPF rabbits were vaccinated. After 7 days, controls and vaccinated rabbits were challenged and clinically monitored for 14 days. In the control groups, the challenge strain induced a mortality rate of 100% in 4-week-old rabbits and 89% in 10-week-old rabbits. Vaccination significantly prevented all mortality (all vaccinated rabbits were healthy at the end of the chalenge), clinical signs, detection of viral RNA in serum and gross lesions in young and older rabbits. In vaccinated groups, two weeks after challenge, no RNA copies were detected by PCR in the lungs, kidneys and urine. In 10-week-old vaccinated rabbits, no RNA copies were detected in the liver, spleen and faeces, unlike some 4-week-old vaccinated. In older rabbits, we also demonstrated that the vaccine tested significantly protected from detectable RNA shedding via naso-conjunctival and rectal routes. In young rabbits, shedding via naso-conjonctival route was also strongly prevented; transient shedding via the rectal route was detectable eight days post challenge, and reduced thereafter. We concluded that, despite the quick evolution of GI.2 strains, the protection induced by the vaccine remains adequate.

Le Normand B., Chatellier S., Vastel P., Rebours G., Capucci L., 2019. Dosage of RHDV-2 antibodies on does and their kits in relation to the vaccination. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 37-40.
MCVet Conseil, Site VELVET, 47, Bd Leclerc, 35460 St Brice-en-Coglès, France - b.lenormand@reseaucristal.fr

Abstract : Serological monitoring of 30 primiparous does and of 2 of their kits after vaccination against rabbit haemorrhagic viral disease due to RHDV-2 is performed by c-ELISA method and by IgM2 titration on kits. The does were vaccinated with ERAVAC® when they were 10 weeks old, and young rabbits are vaccinated with the same vaccine during this study when they are 45 days old. 3 does out of 30 don't have antibodies 4 months after the first vaccination with ERAVAC®. The increase of geometric average antibodies titers of the does 11 days after vaccination is totally similar to that of their kits 14 days after vaccination. The young rabbits with the best IgM2 titers 2 weeks after vaccination are from does without or with very low antibodies titers 25 days after parturition ; on the contrary, kits without IgM2 are from does with the best geometric average antibodies 25 days after parturition.

Boucher S., Sauvaget S., Lenoir G., Dupont V., Herbert C., 2019. Hysterotomies for the transfer of young rabbits from one breeding house to another without introduction of microbisme. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 41-44.
LABOVET Conseil (Réseau Cristal), BP 539 85505 LES HERBIERS cedex - s.boucher@labovet.fr

Abstract : In order to be able to bring in a new herd without the risk of introducing new pathogens in the midst of an existing herd, it was decided to do hysterotomies, one day before the supposed date of kindling, and to put in adoption kits which have never been in contact with their biological mother, to synchronized adoptive mothers who have kindled in the adoption room. The anaesthesia protocol was provided for premedication with glycopyrronium bromide at a dose of 0.01 mg / kg body weight, diazepam 1 mg / kg body weight, and morphine hydrochloride 2 mg / kg body weight skin. Then, fixed anaesthesia was obtained with alfaxalone at 4mg / kg PV provided intravenously very slowly and then maintained at a rate of 0.1 mg / kg / minute. The hysterotomy was performed using disposable instruments on 84 rabbits with a rabbit survival rate of 82% after the operation. The technique has made it possible the absence of introduction of new pathogens into the breeding rooms despite the introduction of a new herd.

Gohier G., Menini F.X., Bourdillon A., Tetrel P., 2019. Effect of water intake before slaughtering on rabbit carcass yield. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 46-49.
Mixscience, 2/4 Avenue de Ker Lann, 35172 Bruz Cedex, France - charly.gohier@mixscience.eu

Abstract : Two successive sets of measures were conducted to investigate the effect of water availability before slaughtering on rabbit carcass yields. In each of the two series, 200 rabbits were divided into two different groups: water withdrawal 14h before slaughter (R) or full access to water up to 1h before slaughtering (E). A solid feed withdrawal was applied 15h before slaughtering to all rabbits. The slaughter was carried out on the raising site (no transport). Warm and cold carcass weights as well as carcass yields (reference liveweight measured 14h before slaughtering) were significantly lower for R group: slaughter yield of 53.8% vs 54.1% for group E. Water loss during carcass refrigeration varied from one series of measures to another, with an average of 2.4%, but water availability effect was not significant. On average carcass seizure rate was not significantly modified by water restriction : 2.2% on average. This study shows that under the experimental conditions of slaughter, especially with the absence of transport, the possibility for rabbits to drink until 1h before slaughter seems to have a positive effect on the weight and the carcass yield in comparison to a water restriction set up from 14h before slaughter.

Van Lissum M., Delarue J., Lebas F., Prigent A.Y., Caillaud L, Colin M., 2019. The meat of rabbits fed DHA fortified feeds may be an interesting solution to help meet the human needs of this essential fatty acid - a review. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 50-55.
COPRI, 2 Coat Izella, 29830, Ploudalmézeau, France - copri@wanadoo.fr

Abstract : The specific effects of DHA (C22:6 ?3 fatty acid) on human health are well-known and documented, particularly the reduction of cardiovascular risks, of insulin resistance, of diabetes, of obesity, of metabolic syndrome and of age macular degeneration (AMD). Considering these functional properties, health authorities have recommended a DHA intake of 250 mg / day for adults. However, the Omega-3 intake and particularly the DHA one remains insufficient in the majority of Western countries. Actually, the main DHA source in the European food remains the fatty fishes but it is practically impossible to increase their consumption due to the ocean overexploitation and to the frequent contamination of fishes by heavy metals and the POP (Persistent organic pollutants). Our previous publications have proved that it is possible to increase strongly the DHA level in the rabbit meat by incorporation of microalgae as Shizochytrium sp in their feed. This work demonstrates that the consumption of such a rabbit meat with high DHA level contributes to reach the recommendations in term of human DHA intake established by the health authorities, for the healthy populations and for certain populations with clinical risks. This study emphasizes the interest to consume rabbit meat enriched in vegetable DHA to cover the human requirement without increasing the fish resource overexploitation.

Lebas F., 2019. Rabbit recipes searched on Internet. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 56-59.
Cuniculture, 87A chemin de Lasserre, 31450 Corronsac , France - lebas@cuniculture.info

Abstract : A study was conducted to determine the types of rabbit recipes available and searched by web surfers. An analysis was made of the consultation frequency in 2018 of the 122 recipe sheets available on the website www.cuniculture.info. These results were then compared to the types of rabbit recipes available online on the top 10 culinary sites written in French. For this were selected the first 30 recipes proposed by each site. On the website cuniculture.info rabbit recipe sheets were consulted 36 371 times in 2018, or 10.9% of all visits of the year. By far the most popular recipe was the quick recipe (12 min) for rabbit livers fried in a pan with shallots (37.9% of consultations), followed by the barbecue rabbit recipe (10.6%). Of the 10 other Web sites, 85% of recipes are for simmered dishes or more generally long-cooking dishes prepared with rabbit meat. Rapid recipes (<30 min total) represent only 3% of total recipes but, more important, were absent from the top 30 rabbit recipes for 7 sites out of 10. Given the importance of simple and fast recipes viewed in Internet, particularly those with rabbit liver, an effort to promote this type of recipe could help to support the consumption of rabbit meat in France.

Tudela F., Matheron G., Lebas F., 2019. Knights Brotherhood of the "Rabouillère" . 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 60-63.
Confrérie de la Rabouillère, 31290 Vallègue, France.

Abstract : Created in 1997, in the line of history, by rabbit advocates, the Brotherhood of the Order of Knights of the rabouillère brings together those present in 8 countries, who support the rabbit in all its forms. Through promotional, convivial or festive actions, she shares her knowledge and beliefs of this species and its products with the general public and specialists. During the past 13 years (2006-2018) the Brotherhood has participated or organized 124 public events to promote the rabbit in France or abroad .

Blasco A., Martínez-Alvaro M., Zubiri-Gaitán A., Hernández P., 2019. Metagenomic answer to selection of intramuscular lipids in the rabbit. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 65-68.
ICTA. Universitat Politècnica de València. Valencia 46022. Spain - ablasco@dca.upv.es

Abstract : A metagenomic analysis of 2 rabbit lines divergently selected for intramuscular fat (GA and GB) was performed. Caecal content samples from 40 rabbits belonging to each line were analysed. After analysing the quality of the sequences obtained, 6,230 genes were identified from the metagenomic samples. The undetected genes in 25% of the samples were removed, eventually leaving 4,540 genes. Considering that they are composition data, they were transformed using the log-quotient centred method. PLS-DA (Latent Projection, Discriminant Analysis) analysis was performed to identify genes related to the discrimination of high and low intramuscular fat lines. After the first PLS-DA analysis, "VIP" genes with a VIP> 1 were selected, leaving 105 genes capable of discriminating individuals belonging to each line, with cross-validation Q2 = 0.92. These microbial genes encode proteins involved in different metabolic pathways, the most important pathways being related to energy metabolism (18 genes). The analysis was repeated for these 18 genes, obtaining cross-validation with Q2 = 0.52. Two genes involved in methane metabolism, beta subunit of malate-CoA ligase (K14067) and dihydroxyacetone kinase (K00863), had the highest VIP value, showing a relevant relation with intramuscular fat. The GA line showed a greater abundance of genes involved in specific carbohydrate pathways such as mannose and fructose, L-rhamnose isomerase (K01813), P = 0.99, and dihydroxyacetone kinase (K00863), P = 0.82. In the low intramuscular fat line (GB), other genes such as D-sedoheptulose 7-phosphate isomerase (K03271) and O-antigen ligase (K02847), involved in lipopolysaccharide biosynthesis, were more abundant (P = 0.98 and P = 0.99, respectively).

Herbert C., Suteau M., Lenoir G., 2019. Interest of measuring the residual feed intake in rationed feeding for the improvement of feed efficiency in a Hycole male line. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 69-72.
HYCOLE, route de Villers-Plouich, 59159 MARCOING, France - caroline.herbert@hycole.com

Abstract : A study was conducted on several criteria for optimizing food efficiency: the residual consumption (RC) and the feed conversion ratio (FCR). The objective is to identify one or more criteria for selecting and improving the feed efficiency of animals. The study involved a sample of 393 data from X HYCOLE line males, from May 2017 to January 2019. Food consumption measurements were performed under hourly feeding to match field realities. The measurements were carried out on cages containing two full brothers in order to limit the biases. Statistical analyzes were estimated under software R and genetic parameters under ASReml. Our results showed a heritability of 0.20 ± 0.15 for RC and 0.18 ± 0.13 for FCR, with a strong phenotypic correlation between these two criteria (0.71). RC and FCR have low or medium phenotypic correlations with growth criteria, so they have little influence on animal growth. Genetic parameters analysis does not allow to obtain significant correlations but makes it possible to determine interesting trends for the residual consumption criterion.

Gunia M., Lantier F., Balmisse E., Guitton E., Helloin E., Le Cren D., Lenoir G., Maupin M., Robert R., Riou M., Garreau H. , 2019. RELAPA project (Genomics for rabbit genetic resistance to pasteurellosis): haematological status of susceptible and resistant rabbits. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 73-76.
INRA, GenPhySE, 31326 Castanet Tolosan, France - melanie.gunia@inra.fr

Abstract : Pasteurellosis is the first cause of female mortality in rabbit farms. During the RELAPA project, 953 rabbits were inoculated at 6 weeks of age with a pyogenic strain of Pasteurella multocida (Pm) and were monitored during 14 days. Disease response was very variable among animals, with 7% of resistant animals and 11% of highly susceptible rabbits. A complete blood count was performed 14 days post-inoculation on 574 inoculated and 28 control rabbits. Significant differences in white blood cell, red blood cell, and platelet counts were observed according to the disease resistance score. Susceptible rabbits have a lower red blood cell count, probably due to the haemolytic and hemorrhagic activity of Pm. They also had a higher percentage of monocytes, neutrophils and eosinophils involved in the innate immune and inflammatory responses and, conversely, a lower percentage of lymphocytes (involved in the adaptive immune response) as compared to highly resistant and control rabbits. They seem to be unable to mount an immune response to control the infection. Significant sire effects on several levels of white blood cell populations suggest some genetic variability underlying the haematological response to Pm infection.

Shrestha M., Garreau H., Balmisse E., Bed'hom B., David I., Guitton E., Helloin E., Lenoir G., Maupin M., Robert R., Lantier F., Gunia M., 2019. RELAPA project (genomics for rabbit genetic resistance to pasteurellosis): genetic parameters. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 77-80.
INRA, GenPhySE, 31326 Castanet Tolosan, France - melanie.gunia@inra.fr

Abstract : This study is a first approach to estimate genetic parameters of resistance to Pasteurellosis by experimental infection of a crossbred rabbit population with Pasteurella multocida. Novel disease-related traits were the abscess dissemination score collected post autopsy, a score related to the presence or absence of Pasteurella in the organs from which a composite resistance score was created. For disease-related traits, heritability estimates ranged from 0.09 (±0.05) to 0.16 (±0.06). Highest heritability was estimated for the resistance trait. Results for heritability estimates suggest a contribution of a genetic component in resistance to Pasteurellosis. The genetic correlations between disease resistance and growth traits were high and positive, varying from 0.70 (±0.14) to 0.98 (±0.06).These results support the implementation of a selection against Pasteurellosis in the French breeding programs for meat rabbits using such criteria. Further investigations will be performed using additional disease-related and production traits.

Garreau H., Lantier F., Guitton E., Helies V., Helloin E., Le Cren D., Lenoir G., Maupin M., Robert R., Gunia M., 2019. Relationship between resistance to pasteurellosis in inoculated rabbits and growth and reproduction traits in rabbits raised in commercial farms. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 81-84.
INRA, GenPhySE, 31326 Castanet Tolosan, France - herve.garreau@inra.fr

Abstract : Pasteurellosis is the first cause of female mortality in rabbit farms. The RELAPA project aims at studying the genetic determinism of resistance to pasteurellosis. 955 rabbits produced by 28 sires from 6 commercial lines were inoculated at 6 weeks of age with a pyogenic strain of Pasteurella multocida (Pm) and were monitored during 14 days. These rabbits were scored for resistance to pasteurellosis from 0 to 4, by taking into account post-mortem examinations. The 28 sires produced also 5164 rabbits tested for growth and 884 females with 3568 litters tested for reproduction in commercial farm conditions. Fertility was the only significantly different trait between the offspring of the 14 resistant sires and the offspring of the 14 susceptible sires, with a difference of 7 points in favour of the resistant group. Residual correlations were all low and not significantly different from 0. Genetic correlations between resistance and growth traits were positive but not significantly different from zero (0.32 ± 0.51 for weaning weight and 0.27 ±0.49 for final weight). Genetic correlations between resistance and prolificacy traits were unfavorable but not significantly different from zero (-0.43 ± 0.45. -0.68 ± 0.40. 0.70 ± 0.65 for total number born, number born alive and stillbirth, respectively). These values of genetic correlation are given for information but should be interpreted with caution because of their low accuracy.

Lankri E. , Boudour K. , Aichouni A. , Rechachou F. , Zerrouki-Daoudi N., 2019. Effect of feeding level and rate of protein intake on libido and characteristics of the seed of the male rabbit. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 86-90.
Université Hassiba Benbouali, Chlef, Algeria - e.lankri@univ-chlef.dz

Abstract : 27 male rabbits of the synthetic strain "ITELV 2006", aged from 7.5 to 8 months, were divided into three experimental groups to study the effect of an increase of the dietary protein content (19.7 vs 14.5 %) on the sexual ardor and the characteristics of semen. The lot (A) received ad libitum a standard pelleted feed with 14.5% crude proteins, the lot (B) received only 120 g/day of the same diet. The 3rd lot (C) received a120g/day of the same pelleted feed, the protein level of which being increased up to 19.7% by a daily supplementation with 6.6 g / heat of meat peptone. Daily measurements of intake quantities, as well as weekly measurements of body weight and male libido, were carried out. For each male, two successive ejaculates at 10-minute intervals were collected once a week during 8 weeks. The average daily intake was 132g/d, 115 g/d and 112g/d for the males of lots A, B and C respectively. Body weight gains in 8 weeks were +229, -134 and +59 g for lots A , B and C. . Rabbits responded well to solicitations and had a very high useful collection rate (100%). The mean volume of ejaculates was identical for the 3 lots (0.48ml). A mean concentration of 445×106 spermatozoa per ml of ejaculate (spz/ml) and a mean values of 4.76and 3.15 respectively for mass and individual motility were recorded without significant difference between groups. In the same way, few significant variations were observed, apart from vitality and abnormalities, no difference has been revealed for the ejaculate characteristics between the three groups, however, vitality and percentage of abnormal spz are affected when the males are rationed and without supplementation. It can be deduced from these results that the protein supplementation corrected partly reduction of performance associated with male feeding at 120g/day of standard diet 14.5% proteins

Boudour K., Aichouni A., Lankri E., Zerrouki Daoudi N., 2019. Reproductive performance of rabbit does of the strain "Itelv 2006" according to the artificial kindling-insemination interval - Preliminary results. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 91-94.
Université Hassiba Benbouali, Chlef, Algeria - k.boudour@hotmail.com

Abstract : Sixty primiparous rabbits does of the Itelv-2006 strain, of comparable weight and age (3870 g and 5.7 months on average) were distributed after kindling in three lots of 20, corresponding to an artificial insemination (AI) performed 4 - 7 or 11 days after kindling. The parameters studied were receptivity (color of the vulva) at the time of AI, fertility and prolificacy (total kits born) following this AI. Rabbits inseminated on D4 or D11 post partum were significantly more receptive than those inseminated at D7: 70 and 80% vs. 30% respectively (P = 0.003). Fertility at kindling was similar for lots D4 and D11 (70 and 75%) but significantly lower for lot D7: 60% (P = 0.030). Finally, the lowest prolificacy was observed for group D11: 7.86 total born per litter, vs 8.78 and 9.75 for lots D4 and D11 (P = 0.01). However, a very high stillbirth proportion (47% on average) very probably related to the very unfavorable external conditions at the time of kindling, requires to consider this last result with precautions.

Mouhous A., Benabdelaziz T., Limani C., Kadi S.A., Djellal F., Guermah H., Berchiche M., 2019. Efficiency of state aids in relation to the production performances: case of rabbit farms the region of Tizi-Ouzou, Algeria . 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 95-98.
Faculté des Sciences Biologiques et Sciences Agronomiques, Université Mouloud MammerI de Tizi-Ouzou, Algeria - mouhousazeddine@yahoo.fr

Abstract : The objective of this study was to evaluate the production characteristics of rational rabbit farms and the level of adherence of farmers to the financing mechanisms for the rabbit farms development in the Tizi-Ouzou area. 67 rabbit farms were surveyed for 5 months, in 2017. The results show that 73% of breeders wer between 31 and 55 years old. Women represented only 22% of the surveyed breeders. Rabbit breeding was still a either secondary activity (only 6% considered it as the main activity), practiced mainly by men who are agro-breeders (48%) or extra-agricultural profile (45%). The size of farms was on average 43 females with a variability ranging from 8 to 250 females. The average number of kindlings / year was 6.6 ± 1.1, and the number of rabbits born alive / female was on average 7.0 ± 0.72. The pre-weaning and fattening mortality rates were 8.9 ± 5.9 and 14.3 ± 6.2%, respectively. Sales reach an average of 36.2 ± 9.4 rabbits/female /year with a weight of rabbits of 2.42 kg on average. State aid for the farms at startup have only concerned 42% of respondents, and those for technical assistance have reached 63%. A typology based on the numbers of females showed that the big breeders are the major beneficiaries of State aid. These show the best production performance. In general, livestock productivity varies little according to whether or not they are assisted by the State. However, given these results, it is recommended to further facilitate access to these aids and strengthen the training component in order to improve productivity and a better organization of rabbit breeders.

Gidenne T., 2019. Socio-economic impacts of feed intake restriction strategies for the growing rabbit after weaning - A 10-years retrospective analysis. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 99-106.
INRA, GenPhySE, , 31326 Castanet Tolosan, France - thierry.gidenne@inra.fr

Abstract : The young rabbit, like all young mammals, has to deal with digestive disorders around the weaning period. In breeding, it is desirable to reduce the risk of digestive disorders (diarrhoea) without using drugs, including preventive antibiotic practices. INRA has conducted an ambitious research program in collaboration with ITAVI and the main animal feed companies (federated in a group "GEC"). These works have shown that a good control of the post-weaning feed intake reduces the risk of digestive diseases while improving feed efficiency. In terms of impacts, this lead in both a reduction in the losses of rabbits growing (720000 rabbits saved / year or 30M€ over 2005-2015), a reduction in the use of drugs (-50% antibiotics used against digestive disorders) and by a reduction in food costs (+ 5% of feed efficiency, or 40M€ in savings between 2005-2015). This temporary restriction of the intake after weaning also impacted favourably the environment (- 9% of global warming potential, -11% of eutrophication potentials and -12% of acidification, and -10% occupation of agricultural areas). This practice therefore combines economic, environmental and social benefits

Gidenne T., Roinsard A., Fortun-Lamothe L., Goby J.P., Savietto D., Cormouls M., 2019. A technical referencing database for organic rabbit farming in France: first results. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 107-110.
INRA, GenPhySE, , 31326 Castanet Tolosan, France - thierry.gidenne@inra.fr

Abstract : A first simplified technical referencing system (RTS) was created based from 6 organic rabbit farms with data collected over 3 years of production (2015 to 2017) for the maternity unit (movable cages on pasture or individual pens, average herd = 33 females). The productive lifespan of a female was, on average over one year, and can reach 2 years (variability of 75%). Female mortality averaged 21% over the period. With 5 mating, 3 litters per female/year (60% fertility rate) were obtained, for a total of 25 live kits and 19 weanlings (26% mortality before weaning). Thus, from the technical data calculated in our study, the income of a full-time organic rabbit farmer could potentially be around 26.3k€. This first RTS will be extended to a larger number of breeders, with the deployment of a smartphone application (GAELA) managing the rabbit farm, and synchronized to a database.

Lebas F., 2019. Iodine requirements of rabbits : deficiency, excess and recommendations - A review. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 112-118.
Cuniculture, 87 A Chemin de Lasserre , 31450 Corronsac, France - lebas@cuniculture.info

Abstract : Until the 2010s, the authors of nutrition reviews considered that there was no published scientific paper able to quantify the rabbit's needs for iodine. Recent publications with progressive iodine additions make it possible to set the minimum requirement for growing rabbits at 0.7-0.9 mg of iodine per kg of finished feed. For lactating does, the value of 0.9 mg I / kg is proposed and 0.4 mg I / kg covers the iodine requirements of adult rabbits at rest or of pregnant does. The upper safety limit beyond which performance begins to be degraded is 2.0 to 2.5 mg I/ kg of feed, well below the legal maximum of 10 mg / kg applicable in Europe to rabbit feeds. This review provides the average iodine content of some 40 common raw materials used in rabbit feeding. Their content generally varies between 0.05 and 0.10 mg iodine / kg, values quite insufficient to cover the needs, and thus requiring iodine supplementation. However some raw materials such as molasses, calcium carbonate, fish meal or oyster shells have significantly higher levels of iodine: 1 to 10 mg / kg. Special attention should be given to the iodine content of the finished feeds when using algae among the raw materials of the feed. Indeed their content may vary from 1 mg / kg to 10 g / kg of dry matter (1%) in the case of laminaria. Finally, it is recalled that raw sea salt (not artificially iodized) contains very small amounts of iodine (<2 or <0.7 mg / kg of salt according to the authors), which are notoriously insufficient to cover rabbit iodine requirements.

Legendre H., Gidenne T., Hartmeyer P. , Goby J.P., Jurjanz S., 2019. Dry matter digestibility of grazed sainfoin and tall fescue, and estimation of soil intake, in the organic pastured growing rabbits : first results. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 119-123.
INRA, GenPhySE, , 31326 Castanet Tolosan, France - thierry.gidenne@inra.fr

Abstract : The development of organic rabbits production at pasture is limited by lacks in technical references, particularly about real grazed forage intake and digestibility. Moreover, to measure digestion at pasture we must know the intake of soil (minerals), the latter could eventually contain some pollutants. Therefore, after weaning (43 d) 30 growing rabbits have been allotted in two groups and housed in movable cages on two types of pasture: one with 70% of sainfoin (Onobrychis viciifolia) and the other with 100% tall fescue (Festuca arundinacea). Each cage contained 3 animals, with a shelter of 0.4 m² and a pasture surface of 1.2 m² and was moved every day A pelleted commercial feed was distributed daily at a level of 60 g/rabbit, and was totally consumed. Daily grass intake was calculated by difference between offered and residual grass (cut over 3 cm). The in situ digestibility of the forage + pellets mixture was estimated after total collection of faeces left on the soil for 2 x 4 days. Soil intake has been estimated with an internal marker (acid insoluble ash), from its concentrations in soil, pasture, feed and faeces, as well as dry matter digestibility (DMd). The DMd of pelleted feed, both vegetation types and their mixtures were also determined with metabolism cages (as a control). The DMd of tall fescue varied from 37 to 43% respectively for a measure at pasture or in indoor, whereas the DMd of sainfoin varied only by 1 unit (65.5 to 66.6 resp.). The rabbit's growth was 25% higher on the "sainfoin" pasture, while the total DM intake (pellets+grass) was similar to that of the group "fescue" (55 vs 56 g/j/lap.), but the protein intake was 25% higher for the "sainfoin" group. Soil intake was lower (P<0.05) on tall fescue meadow (1.3% of total DM intake or 1.9 g/d) in comparison to sainfoin (3.0% of total DM intake or 4.2 g/d). The smaller soil intake on pasture of tall fescue could be due to the better soil cover by grass forming a buffer between animals and soil, in comparison to the sparser sainfoin cover

Malabous A., Robert D.., Barotin.L., Prigent A.Y., Van Lissum M. , Colin M., 2019. Influence of metabolites issued from 2 strains of Lactobacillus on the performances of reproduction and of growth of the rabbit. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 124-127.
COPRI Sarl, Coat Izella N°2, 29830 - Ploudalmézeau, France - copri@wanadoo.fr

Abstract : One hundred sixty does in a first reproduction cycle and one hundred seventeen in a second one are split between 2 treatments, a control one and the other one with a feed containing 1,3 kg / ton of Métalac, a product of fermentation of 2 strains of lactobacillus, Lactobacillus farciminis CNCM-I-3699 and Lactobacillus rhamnosus CNCM-I-3698 gathering simultaneously the metabolites and the microorganisms. The test consists to study the reproduction performances of these does and the results on growing - fattening performance of their offspring's which receive a unique feed between weaning and slaughter (70 d.). Even with an higher prolificacy for the control group, the better homogeneity of the "2 days olds rabbits" in the Métalac group has enabled to the breeder to get a lower initial elimination rate for this group than for the control ones. Consequently, the number of weaned rabbits / litter is very highly significantly higher for the Metalac treatment (+0,15 /litter). The mortalities before weaning were not modified. Simultaneously, the weights at weaning of the rabbits and of the litters are heavier (respectively +30 grams and + 406 grams) with the Metalac. Concerning the growing - fattening period, the Metalac distribution to the does before weaning failed to modify the mortality and the growth of their offspring's. However, the 70 days weight remains higher (+ 19 grams). The feed intakes and feed conversion ratio were not modify. The slaughter yields was improved by+0, 8 point for rabbits which received the Métalac before weaning.

Zemzmi J., Rodenas L., Blas E., Martínez-Paredes E., López-Lujan M.C., Moya J., Najar T., Pascual J.J., 2019. Characterization and evaluation of the prebiotic potential provided by the galactomannan extracted from fenugreek in growing rabbit. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 128-131.
Institute for Animal Science and Technology, University Politécnica de Valencia, Valencia, Spain - zemzmijihed@gmail.com

Abstract : Searching alternatives to antibiotics in the industrial meat rabbit breeding, galactomannans (GM) extracted from fenugreek seeds (Trigonella foenum-graecum) has been proposed as a soluble fiber that may have prebiotic effect. To qualify a soluble fiber as prebiotic, it must satisfy three conditions: non-digestibility by stomach and intestinal enzymes, high fermentability by ceacal bacteria, and selective stimulation of the microbial activity in the hindgut. In this context, the aqueous extraction of galactomannan was made from fenugreek seeds produced in Tunisia. In a first trial to test the non-digestibility and fermentability, the GM and two commercial rabbit's feeds [supplemented with 10% soluble fiber (FS) or lignin (LIG)] were subjected to digestion by pepsin and pancreatin followed by fermentation with a cæcal inoculum. In a second trial, the GM was included in a rabbit diet at three levels (0, 0.25 and 0.5%), and its effect on fibrous fractions digestibility was studied. According to our results, fenugreek GM was characterized by a purity of 69% and a galactose/mannose ratio of 1.06. Most of the ingested GM (83.6%) escapes in vitro digestion by pepsin and pancreatin. GM is fully fermented by cæcal inoculum contributing to a high production of volatile fatty acids (46.10 mmol/L) and a low ammonia nitrogen concentration (27.04 mg/L). GM may improve the digestibility of the fiber fraction especially that of the neutral detergent fiber. In conclusion, GM from fenugreek satisfies two properties to be considered as a prebiotic, however, its effect on rabbit's cæcal microbiota needs to be studied to be qualified as a functional soluble fiber with a prebiotic effect in rabbits.

Colin M., Pavlidis H., Le Ven L., Prigent A.Y., 2019. Effect of products of fermentation from Saccharomyces cerevisiae on viability, growth, and meat composition of growing-finishing rabbits. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 132-136.
COPRI Sarl, Coat Izella N°2, 29830 - Ploudalmézeau, France - copri@wanadoo.fr

Abstract : A total of 1,684 rabbits, 46 days old, were split between 2 treatments, one Control and another one containing 1 kg /ton of a product of fermentation of Saccharomyces cerevisiae, the Diamond V Original XPC. The experimentation was conducted with 2 replications with the objectives to evaluate the effects of Original XPC on mortality, growth, feed intake, feed conversion, and the fatty acid profile of rabbit meat. Globally, Diamond V Original XPC reduces the 40-70 days mortality (-3.7 %), and improves the growth of rabbits (+2.8 g/d). This observed effect is particularly important in the first repetition during which the sanitary status was lower than that normally observed on this test farm. Therefore, Diamond V Original XPC is particularly active in deteriorated sanitary conditions in agreement with the literature to date. Finally after slaughter at 70 days, Diamond V Original XPC significantly increases the deposits of Omega 3 (+ 30 à 50 %), particularly ALA (+ 30 à 40 %) and DHA (+ 25 %) in rabbit meat, which is an important strong point in a strategy of enrichment of animal products in these essential fatty acids.

Minetto A., Guillevic M., Prigent A. Y., Colin M., 2019. Effects of dietary omega 3 fatty acid fortification on the fattening performance and nutritional quality of rabbit meat. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 137-141.
Valorex, La Messayais, 35210 Combourtillé, France - copri@wanadoo.fr

Abstract : The effects of a dietary increase of omega 3 fatty acids on growth performance and meat quality of rabbits were studied in 2 consecutive assays involving 1825 rabbit studied between weaning (35 d.) and slaughter age (69 d.). Three feeds were compared, a control diet with a low level of ?-3 (0.07%), and 2 diets with 0.61% ?-3 provided either by extruded linseed Tradi-lin® (3%) or by raw rapeseed seed (13%). Overall, mortality was significantly reduced by increased levels of omega-3 in the feed (-4,4 points) and this effect was higher with Tradi-lin® compared to rapeseed seeds. This results agrees with literature and previous experimentations. The incorporation of Tradi-lin® is therefore an important part of programs aimed at reduction or total elimination of the use of antibiotics in rabbit production. In the present experiment, the growth rate was a little bit mores reduced (-9%) than in previous results. On the other hand, the nutritional quality of rabbit meat was widely improved by a strong increase of its ?-3 fatty acids content (+115%) and a decrease of the ?-6 / ?-3 (3.5 vs 7.5) and LA / ALA (6.6 v 8.4) ratios, with a higher efficiency for the Tradi-lin® treatment. The analytical characteristics of the meat enable to claim "source of omega 3" and agree with the French " Bleu Blanc Coeur " specification

Paës C., Fortun-Lamothe L., Bebin K., Duperray J., Gohier C., Guené-Grand E., Rebours G., Aymard P., Debrusse A-M., Gidenne T., Combes S., 2019. Quantification of solid feed intake of suckling rabbits and pellets diameter and hardness effects on the dietary preferences. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 142-147.
INRA, GenPhySE, 31320 Castanet-Tolosan, France - sylvie.combes@inra.fr

Abstract : Stimulation of the early feed intake of suckling rabbits represents an avenue of research to improve robustness by promoting a resilient gut microbiota. This study aimed to (i) quantify and characterize early solid intake as of 8 days (8d) with an innovative feeding system (in the nest, 8-17d; outside of the nest in feeders, 15-35d), (ii) to separately determine pellets diameter and hardness effects on their palatability. In the first experiment, four pellets differing by diameters were tested in pairs: 2.0, 3.0, 4.0 and 6.0 mm. In a second experiment, pellets with the same diameter (2.5 or 4.0 mm) were pelletized with three die channel lengths: 10, 12, 14 mm or 18, 20 and 24 mm to obtain different hardness. Pellets of a given diameter were tested in pairs against each other (n=10 litters per treatment). Solid feed intake was observed at the litter level as of 8 days (0.02 ± 0.02 g of DM/rabbit). A total of 1.63 ± 0.76 g of DM/rabbit was ingested in the nest with a high inter-litter variability. The milk intake did not have an effect on the early solid intake (P>0.05). The litter weight at equalization was correlated with the feed intake at 2 weeks of age (0.4?r?0.5; P=0.03). The attractiveness of 2.0-mm-diameter pellets when they were available in the feeders was highlighted (from 61% to 86% of total consumption). Pellet hardness effect on the suckling rabbits dietary preferences still needs to be investigated. The onset of young rabbits' solid intake may be stimulated with easy access and palatable pellets. Better knowledge of suckling rabbits' feeding behaviour is opening the way for new studies on microbiota modulation through diet.

Guené-Grand E., Davoust C., Poisson A., Launay C., 2019. Impact of the access time to the feeder before weaning on the growth performance of rabbits raised in litters of 11 rabbits per multiparous rabbit does. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 148-151.
NEOVIA, Rue de l'église, 02400 Chierry, France - eguene@neovia-group.com

Abstract : The breeding of 11 rabbits per litter is possible on farms where the technicality and the quality of young rabbits at birth is good. The 1st objective is to raise 11 young rabbits per rabbit does to study the growth of young rabbits, and the 2nd is to study the effects of feed restriction applied 8 hours a day during the 10 days before the weaning. 40 rabbits does and their 11 young rabbits were divided into 2 groups; a 1st one were fed ad libitum while the other one had access to the feeder only from 4pm to 8am each day. From weaning to 70d of age, all rabbits received the same feed and had access to the feeder 12h per day. The sanitary condition of this trial was very good in maternity as well as in fattening. There was no effect of feed restriction during the maternity period on the weight of young rabbits (935g vs 929g for ad libitum and restricted groups, p> 0.05) or the feed consumption recorded (712 vs 706 g/d/cage; p>0,05). At 42, 49 and 56 days of age, rabbits from ad libitum group were significantly heavier than rabbits with restricted access to the feeder (between + 3% and + 2.5%, p <0.01). At 63 and 70 days of age, the weights between the 2 groups were similar (p> 0.05). The ADG over the period 35-49 days of age was different depending on the type of access to the feeder (5% variation, p <0.0001). It was not different over the other periods studied. In conclusion, the reduction in access time to the feeder had no impact on the growth performances and health status of the rabbits. Under the conditions of this trial, breeding 11 rabbits per rabbit does allows good zootechnical results, consistent with the standard.

Rebours G., Raffin J., Vastel P., Reys S., 2019. Effect of the dietary ratio between digestible and indigestible fibers on the digestive health and performances of fattening rabbits. 18èmes Journées de la Recherche Cunicole, Nantes 27-28 mai 2019, 152-155.
TECHNA France Nutrition, B.P 10, 44220 Couëron, France - gwenael_rebours@techna.fr

Abstract : In animal nutrition, it is common to distinguish digestible fibres (DF) from indigestible fibres (ID), which both have benefits on rabbits' performances and health. In previous studies, dietary ID are usually represented by the ADF. The aim of this study is to explore further by means of a meta-analysis the influence of the ratio between DF and ID thanks to the DF/ADF ratio on the sanitary status and the performances of fattening rabbits. The database contains 28 diets from 8 trials run in the same experimental centre (3856 rabbits from Hyplus genetic), with a ratio DF/ADF ranging from 0,73 to 1,03. Within each trial, feeds from different selected diets are distributed with the same quantity and have a similar nutritional content (excepted for fibre). During the whole fattening period (32 to 71 days old), there is a significant decrease of the digestive sanitary risk (DSR) (P<0,01), the mortality and the morbidity (P<0,05) when the DF/ADF ratio increases. By breaking down the DSR into different types of pathologies, this beneficial effect is also observed on the Rabbit Epizootic Entheropathy (REE) and on paresis (P<0,05), but not on diarrhoeæ (P=0,27). The influence of the DF/ADF ratio on the DSR is significant throughout the first part of the fattening period (32 to 50 days old): A 2,7 point reduction of in DSR is observed per 0,1 point of DF/ADF. Throughout the second part of the fattening period (50 to 71 days old), this effect is not significant but tends to decrease the RSD by 1,1 point per 0,1 point of DF/ADF (P=0,16). When it comes to performance, the Average Daily Gain (ADG) (P=0,96) and the Feed Conversion Ratio (FCR) (P=0,98) are not influenced by this ratio. These results suggest that the beneficial effect of DF and IF on health status can be optimized when their intake respects a certain balance.