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International audience; Botulism type C was suspected in a 46-year old man after consumption of sick poultry from a flock where botulism type C was confirmed. The patient developed characteristic signs of botulism, but investigation of biological samples did not confirm the presence of Clostridium botulinum or botulinum toxin. Despite having classical botulism symptoms, the man recovered very quickly. This raises the question of botulism transmission to humans by ingestion of contaminated poultry.

Bluetongue virus (BTV) and epizootic haemorrhagic disease virus (EHDV) in deer have already been isolated in Reunion Island and have caused more or less severe clinical signs in cattle (EHDV) or in sheep (BTV), as observed in 2003. In January 2009, cattle in Reunion Island showed clinical signs suggesting infection by one or the other of these arboviral diseases. A study was set up to determine the etiology of the disease. Analysis by reverse transcriptase-polymerase chain reaction (RT-PCR) performed on blood samples from 116 cattle from different districts of the island detected the presence of the EHDV genome in 106 samples and, in 5 of them, the simultaneous occurrence of BTV and EHDV. One strain of EHDV (7 isolates) and one of BTV were isolated in embryonated eggs and a BHK-21 cell culture. Group and subgroup primer-pairs were designed on the segment 2 sequences available in GenBank to identify and type the EHDV strains. Phylogenetic analysis of the genomic segment 2 (encoding the VP2 serotype-specific protein) of the isolates confirmed the serotypes of these two orbiviruses as BTV-2 and EHDV-6 and allowed them to be compared with previously isolated strains.

International audience; The use of urinary cortisol (UC) as an additional tool to evaluate sows welfare was assessed in two experiments. In a preliminary methodological experiment, the kinetics of cortisol excretion in urine was studied during an Adreno Cortico Trophic Hormone (ACTH) challenge test in 10 pregnant sows. In a second experiment, 96 primiparous sows of an experimental unit were assigned to two different housing systems: 48 animals were housed in individual pens (IP) and 48 animals in collective pens (CP) with 6 animals per pen. UC was measured at the beginning and at the end of pregnancy and compared with other welfare indicators such as behaviour or skin damage. In both experiments, UC was measured using a high pressure liquid chromatography assay. In experiment 1, UC was constant on the day before injection of ACTH, with no variations related to circadian rhythm. It began to rise 2 h after the injection, peaked between 2 to 5 h after then returned to the basal concentration on the day after the injection. In experiment 2, UC concentrations were not different between CP- and IP-housed sows but they were higher in sows exhibiting the less stereotypies in comparison with sows exhibiting the most stereotypies. The results of this study suggest that UC is a good indicator of acute stress, more convenient than plasma cortisol measurement since it is a non-invasive method avoiding restraint or catheterisation of sows. They also suggest that UC could also give additional information on the assessment of chronic stress and improve the evaluation of animal welfare if used in conjunction with other welfare indicators.; Le cortisol urinaire comme critère d'évaluation supplémentaire du bien-être de la truie gravide dans deux systèmes de logement. L'intérêt du cortisol urinaire (CU) comme critère d'évaluation du bien-être des truies a été testé dans deux expériences. Dans une première expérience méthodologique, la cinétique d'excrétion du CU dans les urines de dix truies gravides a été mesurée suite à un test à l'hormone adrénocorticotrope (ACTH). Dans une deuxième expérience, 96 truies primipares d'une station expérimentale ont été réparties, pendant la gestation, dans deux systèmes de logement : 48 truies en stalles individuelles (SI) et 48 autres en cases collectives (CC) de 6 animaux. Leur CU a été mesuré en début et fin de gestation puis comparé aux autres critères d'évaluation du bien-être comme le comportement ou les blessures cutanées. Dans chacune des expériences, le CU a été dosé par une méthode de chromatographie liquide haute pression (HPLC). Dans la première expérience, aucun rythme circadien du CU n'a été observé le jour précédant le test à l'ACTH. Le CU a commencé à augmenter deux heures après l'injection d'ACTH, atteint un pic entre 2 et 5 h après puis est revenu à un taux de base le lendemain. Dans la deuxième expérience, le CU des truies logées en SI n'était pas différent de celui des truies logées en CC, mais le CU des truies exprimant le moins de stéréotypies était plus élevé que celui des truies en exprimant le plus. Le résultat de cette étude suggère que le dosage du CU est un bon indicateur de stress aigu, plus facile à mettre en pratique car il n'impose ni prise de sang ni cathétérisation des animaux. D'autre part, le CU est un critère supplémentaire dans l'évaluation du stress chronique et permet d'améliorer l'appréciation du bien-être animal lorsqu'il est associé à d'autres indicateurs.

The possibility of improving the welfare of fattening rabbits by rearing them in pens instead of cages was investigated. Time budgets, locomotion, ear lesions, breaking strength of the femur and productivity were compared in fattening rabbits kept at the same stocking density (15 rabbits m−2) either in standard cages of 0.4m2(6 animals) or in pens of 1.6m2(24 animals). Behavioural observations, performed by video recording at 6 and 9 weeks of age, indicated that the frequency of rabbits walking over one another was higher in cages than in pens at 9 weeks of age. Although the time spent in locomotion did not differ significantly, the number of consecutive hops performed by animals was clearly increased in pens at 6 weeks and tended to be higher at 9 weeks. In pens (without a ceiling), rabbits were observed ‘keeping watch’ with a characteristic fully upright posture; this was not possible for rabbits in cages (with ceilings at 30cm).Ear lesions were more frequent in caged rabbits than in penned; this might be due to the caged rabbits walking on one another, due to the lack of space to perform locomotory behaviour. Weight, diameter and breaking strength of femur tended to increase in rabbits kept in pens. In penned rabbits, body and carcase weight were significantly reduced (by 2.0% and 3.4% respectively) when compared with caged ones. However, overall, the use of wire-floor pens of 1.6m2, housing 24 animals, was considered to be beneficial to fattening rabbits’ welfare when compared to standard-sized cages holding 6 animals.

1. In order to reduce injurious pecking, the influence of environmental enrichment on pecking and perching behaviour was studied in young male and female turkeys. 2. Two different types of enrichment and a control treatment (TO) were tested: T1, metal objects and straw; T2, similar to T1 + wood perches. Birds were housed in 36 m2 pens at a light intensity of 5 lux with 4 replicates per treatment in a 2x3 factorial design. 3. Pecking at objects and perching behaviour were observed weekly. Behaviour was video recorded at weeks 5 and 10. Birds were examined daily for the occurrence of injuries. At the end of the rearing period, an ACTH challenge was performed and H/L ratio was measured. 4. Objects were regularly pecked at. Perching was more common in females, peaked at week 5 (10% to 13% of birds perched) and declined to 0% by week 10. Aggressive pecking was more frequently observed in males in T0 than in T1 or T2 at week 10. Wing (in males and females), tail and head (in males) injuries were more common in T0 than in T1 or T2. T1 and T2 were similar Response to ACTH challenge and H/L ratio were not consistently influenced by treatments. 5. It is concluded that metal objects and straw reduced injurious pecking in young female and male turkeys by redirecting, pecking activity.

1. Perching behaviour of Ross broiler chickens was studied in order to increase the available space at the floor level. Pens (36 m2) were equipped with wooden perches mounted 20 and 33 cm above the litter (5 cm perch length per bird). 2. The influences of stocking density (22 vs 11 birds/m2, experiment 1) and of a 10 min artificial dusk (17 birds/m2, experiment 2) were tested in a 2x2 factorial design (n=4 by treatment) including control pens without perches. In experiment 3, perching behaviour between 2 different group sizes (1020 vs 4590 birds, 17 birds/m2, no replicates) was compared. 3. The percentage of perching birds (PPB) was assessed by scan sampling observations during the 20 to 22 h light period (8 observations per d, 5 d a week, from week 3). In experiment 2, infra-red video recording was performed at the time lights were dimmed and during the dark period. In experiment 1, carcase lesions were noted. In experiment 2, tibia breaking strength of frequently perching birds was compared with controls. Birds were weighed before slaughter and food conversion was calculated. 4. PPB increased with age and density (P0.01) and was highest at the 22 birds/m2 density during week 6 (mean=10.6%, maximum=13.5%). PPB was not influenced by a 10-min artificial dusk. In experiment 3, PPB was slightly lower during weeks 5 and 6 in the large group size compared to the small group size (6.8% vs 7.9% respectively in week 6). 5. Prevalence of carcase lesions and tibia breaking strengths were unrelated to perch usage. Final body-weights were not influenced by the presence of perches except at the 22 birds/m2 density where males were slightly heavier in the control pens compared with males in pens equipped with perches (2096 g vs 2051 g, P=0.015). Food conversion was independent of the presence of perches.

The aim of the present study was to evaluate the optimum starch-fibre content of manufactured dry feed for veal calves. In three identical barns (B1, B2, B3), 126 calves were assigned to seven groups fed the same milk replacer. In each barn there was a control group (C1, C2, and C3), fed only the all-liquid diet, and one (or two in B3) group(s) receiving additional pellets (P1, P2, P3, and P4). Pellets differed by their composition; their starch and NDF characteristics were as follows: 48.0–26.2% (P1); 32.6–43.4% (P2); 25.0–52.2% (P3); and 1.8–78.2% (P4), respectively (in % of dry matter). Health, characteristics of the rumen, performance, and ruminating behaviour were compared between treatments. In calves having access to solid feed, the weight of reticulo-rumen increased by 23–46% compared to controls (p

1. The effect of stocking density on welfare traits of turkeys was studied in 2 experiments. In each experiment 2,633 sexed BUT turkey poults were assigned to 3 rooms, 135 m2 with 1 treatment per room. Because of the large flock size (675,878 and 1080 birds in T1, T2 and T3 respectively) treatments were not replicated 2. Floor space allowances varied according to treatment; for the males: 24 dm2, 18.5 dm2 and 15 dm2 until week 12 and 40 dm2, 31 dm2 and 25 dm2 from week 12; for the females: 16 dm2, 12.3 dm2 and 10 dm2. 2. The scan sampling method in experiment 1 and the focal sampling method in experiment 2 were used to record behaviour at week 6, 9, 12 (males and females), and 16 (males). Birds' ethogram was divided into 7 mutually exclusive behaviours: standing/walking, resting, feeding, drinking, pecking at the environment, pecking at another bird, and preening. Position changes in the pen and the frequency of disturbances of resting birds by other birds were recorded in experiment 2. 3. Gait was assessed at week 12 (females) and week 16 (males). Prevalence of lesions, breast (males), hip and foot (males and females), were recorded at slaughter. Birds were weighed at week 12 (males and females) and week 16 (males). 4. Stocking density had little influence on behaviour except on the frequency of disturbances of resting birds by other birds, which tended to be more frequent at the highest density. 5. Gait deteriorated as stocking density increased. Hip and foot lesions were more frequent at the highest density. Bodyweight decreased significantly with decreasing floor space. 6. The results suggest that turkey welfare was poorer at the highest density than at the 2 lower stocking densities.

Points that raise animal welfare concerns in the turkey broiler production chain are reviewed. Genetic selection of fast growing strains has increased locomotory problems and made natural mating im...

The main aim of the study was to determine to what extent young rabbits kept on wire-floor cages would be attracted by straw bedding and how would access to straw modify their behaviour, health and performance. A total of 384 hybrid commercial breed rabbits (Hycol®) were assigned to 16 pens of 1.6 m2 (15 rabbits/m2). Eight pens used as controls had an all-wire floor, while in eight other pens, rabbits could choose between a wire floor or a deep litter topped up once a week and completely replaced once during the course of the 40-day-long study. Behaviour was recorded by video camera between 7 and 10 weeks of age through 24 h observations consisting of 24 sequences of 1 min every 60 min. Reactions to a new environment were compared between both treatments through the use of an open-field test. Parasitism was monitored from faeces and growth performance analysed. Time budgets showed resting, 60%; grooming, 19%; and feeding, 19–20%; were poorly influenced either at 7 or 10 weeks of age by type of floor. The most unexpected result was the low attraction of straw. Rabbits in the littered pens spent most of their time on the wire (89% at 7 weeks and 77% at 10 weeks; P

A homologous vaccine against peste des petits ruminants (PPR) was investigated in northern Cameroon. The vaccine strain was the attenuated PPRV 75/1 strain. The cost-effectiveness of the vaccine was studied by vaccinating flocks of small ruminants kept in their traditional environment. After 1 year, the mortality rates of the flocks were compared with those of a control group. The results demonstrated that the mortality rates were significantly decreased in the vaccinated flocks. The annual benefit for the herder was estimated to be about 13 400 FCFA (about US$ 22) for a flock of 45 animals.

The aim of the study was to compare different behavioural, physiological and performance traits in three groups of veal calves fed either a routine all-liquid diet with milk replacer (GO) or the same diet supplemented with a total of 10kg (G10) or 25kg (G25) of pelleted straw and cereals. Each of the three feeding programmes involved 21 male Friesian calves kept in individual crates for 20 weeks (from 1 to 21 weeks of age). Oral activities, haematological variables, ruminai characteristics, health and performance were all investigated. In calves supplied with dry feed, there was no evidence of ruminating behaviour; and chewing, regarded as a non-nutritive oral activity, was clearly reduced. The incidence of tongue playing and manipulating objects was not influenced by additional pellets.Haemoglobin concentrations were higher in G25 than in other groups as a result of the extra iron supplied in the pellets. Other blood variables were unchanged. In G10 and G25 changes in rumen characteristics were clearly demonstrated by the following observations: i) the weight of reticulo-rumens increased by 11 and 35 per cent, respectively; ii) small papillae (virtually non-existent in calves fed an all-liquid diet) were present, and there was a darkening of the mucosa; and iii) there was a marked reduction in the number of hairballs, resulting from a continuous elimination of ingested hair by ruminai motility. In G25, carcase weight was significantly (P < 0.05) increased by 6.5 per cent compared with controls and no detrimental effects such as bloating or abomasal ulceration were observed when dry feed was added. Supplying calves with straw-cereal pellets was considered positive for the physiological aspects of welfare in veal calves. However, other diet compositions capable of inducing rumination behaviour should also be investigated.

A mixed vaccine against peste des petits ruminants (PPR) and capripox infection was investigated in northern Cameroon. The vaccine strains were the attenuated PPRV 75/1 strain for PPR and the RM 65 strain for Capripox disease. 25 goats were vaccinated with different doses of the vaccine to study the seroconversion. In another experiment, 20 goats were vaccinated and then challenged with wild virulent strains of PPR and goat pox. The measure of the seroconversion as well as the challenge experiments demonstrated that PPR valence was effective at least till the 10 0.8 tissue culture infective dose 50. However, the capripox valence appeared not to be protective despite the apparition of neutralising antibodies. The economical benefits of using a low dose of vaccine against PPR are discussed. Further studies with new vaccinal strains of capripox viruses are recommended before investigating clinical field trials.

A survey was conducted in north and far-north provinces of Cameroon to determine the risk factors responsible for the appearance of clinical signs in small ruminants. Eight flocks, with a total of 141 animals, were visited weekly for 21 months by field agents who noted the appearance of individual clinical signs. The animals were weighed monthly and their faeces were collected for coproscopic examination. At the same time, their sera were tested against the following microbes: Mycoplasma mycoides subsp. mycoides LC, M. capricolum subsp. capricolum subsp. nove, M. agalactiae, M. capricolum subsp. capripneumoniae , Capripoxvirus and peste des petits ruminants (PPR) virus. The independent variables were province, season, species, sex, age class, presence of external parasites, infestation level by intestinal parasites and seroconversions. The survey emphasized the influence of species and season on nasal discharges (more frequent for sheep and in the cold dry season). The prevalence of contagious agalactia syndrome was higher for animals more than one year old and during the cold dry season; furthermore, it was strongly correlated with mycoplasma seroconversion. The seroconversion against PPR was concomitant with that against Capripoxvirus. Slow growth was associated with strongylosis infestation, the presence of external parasites and the PPR-Capripoxvirus seroconversion. Considering the high cost of vermifuges and insecticides, only a vaccination campaign appears to be suitable. Long-term control measures against parasitical diseases should focus on livestock practices. Hence, it is recommended to compare the productivity of flocks vaccinated with a mixed PPR-Capripoxvirus vaccine, and reared under different livestock conditions.

Mycoplasma mycoides subsp. mycoides LC and Mycoplasma ovipneumoniae were isolated for the first time from a goat in northern Cameroon. Experimental inoculation with M. mycoides subsp. mycoides LC induced death in two inoculated goats with pneumonic, arthritic and mastitic symptoms, whilst Mycoplasma ovipneumoniae was not pathogenic despite its multiplication in the upper respiratory tract (nasal sinuses). Following a single inoculation in a goat with both isolates, the course of the disease was not significantly modified. Mycoplasmaemia and the presence of mycoplasma in the milk were investigated. Necropsy observations of infected animals included areas of pulmonary hepatization with macroscopic thickening of the interlobular septa in one goat, and invasion of the lung by numerous small abscesses with no macroscopic thickening of the interlobular septa in the other animal. In both cases, white fibrinous plaques were present in the thoracic cavity but no pleural fluid was observed. It is recommended to pay particular attention to the diagnosis of M. mycoides subsp. mycoides LC infection in an area where contagious bovine pleuropneumonia is endemic and contagious caprine pleuropneumonia is threatening.

Eight hundred and ninety zebus from the north and far-north provinces of Cameroon were tested with two tuberculin assays to estimate the effect of infection by atypical mycobacteria on tuberculosis diagnosis in the region. Six hundred and seven of these animals were tested simultaneously against brucellosis with a delayed hypersensitivity test to brucellin (DHTB) and three standard serological assays as a comparison of the two classes of tests. The results demonstrated that only one quarter of the animals which were designated as tuberculous by the single tuberculin test were considered tuberculous by the comparative tuberculin test (CTT). For 34% of the CTT-reactive animals, borderline reactions were obtained and the results of the tests were uncertain. With regard to brucellosis, the relative sensitivity of the DHTB was 33%; the relative specificity was 96%. The limitation of the delayed hypersensitivity and serological methods are discussed. The most sensitive diagnostic procedure is a combination of both tests, where subjects are scored as positive if they are positive to either or both tests. The DHTB presents the advantage of requiring neither laboratory facilities nor animal identification.

A prospective cohort study was conducted in the Brittany region to identify the risk factors related to foot-pad dermatitis (considered an indicator of animal well-being) in chicken and turkey broilers reared under commercial conditions. Factors related to the shed, equipment, litter management and stocking density were recorded; the dependent variable was the prevalence of lesions observed on the slaughterhouse chain. Lesions were scored from 0 (no lesion) to 3 (severe lesion). Our survey lasted from May 1999 to October 2000. Fifty flocks of chicken broilers (15 farms), 27 flocks of female turkey broilers (21 farms) and 41 flocks of male turkey broilers (27 farms) were surveyed. In chicken broilers, 10% of flocks were of high quality (80% of birds with score 0) and this was related to the use of concrete floors with a thin layer of wood shavings. In turkey broilers, 48% of female and 46% of male flocks were of bad quality (>10% of birds with score 3). A poor fan ventilation system ( 3 /h/kg) was a significant risk factor. Turkey flocks of high quality were not observed. Stocking density had no influence on the prevalence of foot-pad dermatitis. We concluded that it is possible under high commercial stocking densities to have flocks with a low prevalence of foot-pad dermatitis in chicken broilers, whereas it is not in turkey broilers. Hence in chicken broilers, implementing a monitoring system based on the observation of foot-pad dermatitis prevalence at slaughter appears to be more appropriate than to legislate stocking density. In turkey broilers, it would probably be necessary either to reduce the stocking density drastically or to investigate new systems of floor drainage.

Resume Malgre les progres techniques de la transfusion sanguine, le choc septique transfusionnel a Yersinia enterocolitica est encore rapporte. Une bacteriemie asymptomatique chez le porteur sain lors d'un don de sang est actuellement le mecanisme de contamination admis par tous les auteurs. Nous rapportons un nouveau cas qui s'accorde parfaitement avec les donnees de la litterature. L'evolution du choc chez le receveur a ete fatale et l'enquete, non concluante, menee aupres du donneur en parfaite sante, ne nous a pas permis d'avancer en matiere de prevention de cette complication transfusionnelle greffee d'une lourde mortalite.

In order to investigate the influence of stocking density on broiler welfare, 17,616 Ross chickens were assigned to three different treatments: T1, T2 and T3 with a final stocking density of 27, 35 and 43 kg/m2, respectively (corresponding to an initial density of 12, 16 and 20 birds/m2). Animal welfare was assessed by measuring behavioural, physiological and productivity traits. Behavioural observations included the disturbance frequency of resting birds by other birds, the duration of the lying bouts and the standing/lying ratio. The heterophil/lymphocyte ratios were assessed from blood collected before departure to the slaughterhouse. Main productivity traits were the final live weight and carcass degradation due to foot and pad dermatitis and breast blisters. Most of the observed parameters were adversely affected by the highest density (P0.05). Between T1 and T2, some traits tended to demonstrate that a better degree of bird welfare existed in T1 (higher standing/lying postures ratio and final live weight, lower frequency of pododermatitis and hock lesions; P0.05) whereas other traits showed no differences (frequency of disturbances by other birds during resting, heterophil/lymphocyte ratio). In conclusion, a stocking density of 43 kg/m2 seemed to induce poor bird welfare whereas it was not clearly demonstrated that 27 kg/m2 was better than 35 kg/m2.

International audience

A survey was conducted in North and Far-North provinces of Cameroon with the aim of determining the aetiology of small ruminants herds mortality. Eight herds, 141 animals, were submitted to a weekly visit during 21 months. The emergence of individual clinical signs was noted by a field agent. Monthly, the animals were weighed and their feces were collected for coproscopic examination. At the same time, their serums were tested against the following microbes: Mycoplasma mycoides subspecies mycoides LC, M. capricolum subspecies capricolum subspecies nove, M. agalactiae, M. capricolum subspecies capripneumoniae, a Capripoxvirus and peste des petits ruminants (PPR) virus. The independent variables were province, season, species, sex, age class, climatical data, infestation level by intestinal parasites and seroconversions. At the individual level, the main results were the preponderant influence of species and season on runny nose (more frequent for sheep and in the cold dry season), of age and mycoplasmas seroconversion on contagious agalaxia syndrome and of PPR-Capripoxvirus seroconversion on slow growth. At the herd level, PPR-Capripoxvirus seroconversions explained a fraction of the observed mortalities. It is recommended to develop the field vaccination of the herds with a mixed PPR-Capripoxvirus vaccine.

Quatre-vingt onze autopsies de petits ruminants atteints de troubles pulmonaires ont permis l'isolement des souches de Mycoplasma (M.) suivantes : M. mycoides subsp. mycoides LC, M. ovipneumoniae, M. agalactiae, M. sp. type 2D et M. arginini. Onze souches de Pasteurella multocida (sérotypes A1, A3, A5, A7 et D2) et 11 souches de Pasteurella haemolytica (sérotypes 1, 2, 3, 6, 7, 8 et 9) ont été isolées. Les autres germes bactériens isolés étaient Corynebacterium pseudotuberculosis, Actinomyces pyogenes, Staphylococcus sp., Streptococcus sp., Bacillus sp. et Mycobacterium sp. Des antibiogrammes ont été réalisés sur 32 souches de Pasteurelles, de Corynebacterium pseudotuberculosis et d'Actinomyces pyogenes. Quatre-vingt huit pour cent des souches étaient sensibles à la pénicilline G et à l'oxytétracycline, 84 p. 100 au chloramphénicol. 50 p. 100 des souches n'étaient pas sensibles à la spiramycine et 47 p. 100 à la streptomycine. Une souche de Capripoxvirus a été isolée sur des ovins. L'infection par le virus de la peste des petits ruminants (PPR) a été mise en évidence par la technique d'ELISA-capture sur des échantillons de poumon. Deux enquêtes sérologiques, une sur la pleuropneumonie contagieuse caprine (898 caprins) et une sur la PPR (902 ovins et caprins), ont été conduites dans les provinces du Nord et de l'Extrême-Nord. Aucun anticorps ne fut détecté contre la pleuropneumonie contagieuse caprine. Sur les animaux de l'échantillon, la prévalence de la PPR s'est révélée être de 64 + ou - 7 p. 100 dans la province de l'Extrême-Nord et de 14 + ou - 3 p. 100 dans la province du Nord. Au niveau des mesures de lutte, la diversité antigénique des souches de Pasteurelles isolées tend à rendre difficilement applicable une vaccination contre la pasteurellose des petits ruminants. La PPR apparaît endémique surtout dans la province de l'Extrême-Nord et l'efficacité d'une campagne de vaccination doit être mesurée en milieu réel.

Pour une meilleure connaissance des systèmes et de la productivité de l'élevage bovin, un suivi zootechnique de 36 élevages comportant près de 2 800 bovins a été mis en place à partir de 1989 en milieu paysan dans les provinces du Nord et de l'Extrême-Nord du Cameroun. Les animaux ont été identifiés par bouclage et par l'établissement d'une fiche signalétique. Les événements d'ordre démographique, zootechnique, sanitaire et économique concernant les animaux, les troupeaux ou les éleveurs ont été enregistrés à chaque visite mensuelle. Les principaux systèmes d'élevage de la région ont été identifiés, nomades, semi-sédentaires et sédentaires. La taille moyenne des troupeaux est de 52 têtes. Les races de la région sont essentiellement des zébus avec une prédominance des zébus Akou (39 %), Goudali (28 %), Mbororo (18 %) et Arabes Choa (11 %). L'âge moyen au premier vêlage est de 53 mois et l'intervalle de l'intervêlage de 18,5 mois. Le taux de fertilité apparent est de 53,7 % en moyenne et le taux de fécondité de 52,1 %. Le quotient de mortalité des veaux est très variable, 11,4 % en moyenne; le taux de mortalité des adultes est de 2,3 %. Une amélioration de la productivité globale a été obtenue avec la complémentation alimentaire des troupeaux en saison sèche. Les principales causes de mortalité du bétail et des propositions de plans de prophylaxie sont aussi abordées. Enfin, les contraintes actuelles ainsi que les orientations futures possibles de la recherche et du développement de l'élevage bovin dans la région sont présentées.

Four herds of zebus from northern Cameroon totalling 136 animals were vaccinated subcutaneously with the following doses of Brucella abortus strain 19: 5 x 10(9) colony-forming units (CFU), 10(9) CFU, 5 x 10(8) CFU and 10(7) CFU. Twenty-eight days after vaccination, the following seroconversion rates were observed respectively: 97.4, 96.2 84.2 and 73.3%. Of the 52 animals which could be tested subsequently including 39 over one year old on the vaccination day, only one showed antibodies 6 months after vaccination. The cost price of the strain 19 vaccine produced at the Boklé National Veterinary Laboratory was estimated to be 65 F CFA at the 10(9) CFU dose and 1,740 F CFA at the 5 x 10(10) CFU dose usually recommended. The use of the Buck 19 strain in the medical prophylaxis of bovine brucellosis in northern Cameroon is discussed.

Quatre troupeaux de zébus du nord-Cameroun, comprenant en tout 136 animaux, ont été vaccinés par voie sous-cutanée avec les doses suivantes de la souche B19 : 5 x 10 puissance 9 unités formant colonies (UFC), 10 puissance 9 UFC, 5 x 10 puissance 8 UFC et 10 puissance 7 UFC. Vingt-huit jours après la vaccination, les taux de séroconversion ont été respectivement les suivants : 97,4, 96,2, 84,2 et 73,3 %. Sur les 52 animaux, dont 39 âgés de plus d'un an le jour de la vaccination, ayant pu faire l'objet d'un contrôle sérologique ultérieur, 1 seul présentait des anticorps 6 mois après la vaccination. A la dose de 10 puissance 9 UFC, le coût de revient du vaccin B19 produit au Laboratoire national vétérinaire de Boklé est de 65 F CFA la dose ; à la dose habituellement préconisée de 5x10 puissance 10 UFC, il est de 1740 F CFA. Les différentes perspectives d'utilisation de la souche B19 dans la prophylaxie médicale contre la brucellose bovine au nord-Cameroun sont discutées.

Studies of gastro-intestinal parasites of zebu calves were carried out in traditional herds in Northern Cameroon through monthly faecal analysis in 17 herds for a period of two years. Toxocarosis appeared to be the most important parasitic infection in the North province where its prevalence reached 58% in calves aged 0-6 months; 60% of the infested calves passed large numbers of eggs at least once. Samples revealing high egg counts were more frequent in the dry season. Deworming calves aged one month with a cheap anthelmintic against Toxocara is likely to be economically profitable in the North. Seventy-five and a half per cent of the calves 0-12 months old were infested with Strongyloides; high counts of Strongyloides eggs were registered at least once for 31% of these calves. As for toxocarosis, calves seemed to be more often and more heavily infested with Strongyloides in the North than in the Far North province. Strongyloidosis was apparently of low clinical importance, with the rare clinical manifestations accompanied by toxocarosis. The importance of digestive tract strongylosis was difficult to evaluate. Every steer was affected at one stage of its life in a similar manner in the two provinces; 6.8% of samples showed high egg counts and 35% of the steers aged over six months passed large numbers of eggs at least once. These results did not permit a priori recommendation of a systematic deworming programme against strongyles; instead, several less intensive deworming programmes have to be tested in order to determine their economic profitability. Coccidia were found in 77.4% of calves aged 0-12 months, with heavier and more frequent infections in the North. However, infections of high intensity were generally rare. Trichuris, Moniezia, Fasciola and paramphistomes were rarely found. Concerning nematodosis, curative treatments and cost-profit studies of deworming programmes should be aimed at toxocarosis in calves aged 0-3 months in the North, and strongylosis in steers aged 6-12 months, in both provinces.

For the first time in Cameroon, a strain of Pasteurella multocida serotype B6 was isolated from a haemorrhagic septicaemia outbreak in Zebu cattle in the area of Maga (Far Northern Province). Through the mouse protection test, evidence was given that there was no cross protection between this strain and the strain of Pasteurella multocida serotype E6 which is used as an inactivated vaccine in Cameroon. Hence, it is recommended to use a combined vaccine including both serotypes for the Central and West African countries.

Une enquête technico-économique sur l'embouche ovine en période de Tabaski a été réalisée à Garoua en mai et juin 1992. Les principaux objectifs de l'enquête étaient : - l'identification des pratiques d'élevage et des circuits de commercialisation, - la caractérisation des rations sur le plan qualitatif et quantitatif, -l'appréciation des résultats zootechniques et économiques de l'embouche pratiquée. Il existe plusieurs catégories d'emboucheurs (commerçants, particuliers, éleveurs). La ration type se compose de fourrage (graminée et/ou ligneux) et de sous-produits (sorgho, son et tourteau de coton essentiellement). L'analyse bromatologique des intrants alimentaires les plus fréquemment utilisés a été faite et a permis d'estimer leur valeur nutritive. Les résultats zootechniques sont très hétérogènes. Il y a une différence significative du G.M.Q. entre les deux races étudiées (Poulfouli et Oudah), et une corrélation négative entre le G.M.Q. et la durée du séjour des béliers chez l'éleveur. Sur le plan économique on constate que le coût moyen quotidien de la ration est variable et élevé (188 F. CFA). On enregistre des résultats financiers négatifs chez la majorité des emboucheurs