L'élevage des grands camélidés. Analyse des initiatives réalisées en France

National audienceThe rearing of big camelids is a margin farming activity, developped by some farmers as diversification. These animals (dromedaries and camels) are adapted to desertic areas, climatic stress, draught and under-nutrition. From this point of view, they have developped physiological mecanisms for this adaptation. Their reproduction performances are low (fecondity rate, viability of the calves), but their production performances (growth, meet and milk production) are not negligeable in spite of the constraints from their original middle. One year study on 65 she-camels belonging to 9 farmers in France has allowed to observe that blood parameters as albumin (36.4 ± 4.7 g/l), total globulin (32.7 ± 5.1 g/l) total protein (69.2 ± 6.1 g/l), urea (30.0 ± 14.8 mg/100 ml), glucose (111 ± 12.2 mg/100 ml), free fat acid (0.15 ± 0.15 mmole/l), GLDH (5.8 ± 10.8UI/l), GGT (10.1 ± 5.8UI/l), GOT (48.1 ± 14.3UI/l), calcium (10.2 ± 6.5 mg/100 ml), magnesium (2.6 ± 0.3 mg/100 ml), copper (65.4 ± 20.2 μg/100 ml), zinc (34.6 ± 7.8 μg/100 ml) and ceruloplasmin (41.4 ± 2.6 UO) are similar to the observed values in desertic areas, but with higher standart-deviation due to the high variability of the feeding systems. The season, the feeding supplementation (particularly mineral) and health status have a significant effect on the metabolic profiles of the she-camels. The winter season and the excess of nitrogen supplementation are risk factors for the stillbirth and mortality of calves which overpass 40 % in our study.L’élevage des grands camélidés représente une activité d’élevage marginale, développée par quelques individus dans le cadre de la diversification. Ces animaux (dromadaires et chameaux) sont adaptés aux régions désertiques, au stress climatique, à la sécheresse et à la sous-nutrition. Ils présentent à ce titre tout un ensemble de mécanismes physiologiques témoignant de cette adaptation. Leurs performances de reproduction sont faibles (taux de fécondité, viabilité des jeunes), mais leurs performances de production (croissance, production de viande, production laitière) non négligeables compte tenu des contraintes de leur milieu d’origine. Dans le contexte des pays tempérés comme la France, ils sont confrontés à des conditions climatiques et alimentaires fort différentes de leur aire d’origine. Un suivi pendant une année de 65 chamelles appartenant à 9 éleveurs a permis de constater que les paramètres sanguins tels que l’albumine (36,4 ± 4,7g/l), globuline totale (32,7 ± 5,1 g/l), protéines totales (69,2 ± 6,1 g/l), urée (30,0 ± 14,8 mg/100 ml), glucose (111,0 ± 12,2 mg/100 ml), AGL (0,15 ± 0,15 mmole/l), GLDH (5,8 ± 10,8 UI/l), GGT (10,1 ± 5,8 UI/l), GOT (48,1 ± 14,3 UI/l), calcium (10,2 ± 6,5 mg/100 ml), magnésium (2,6 ± 0,3 mg/100 ml), cuivre (65,4 ± 20,2 μg/100 ml), zinc (34,6 ± 7,8 μg/100 ml) et céruloplasmine (41,4 ± 2,6 UO) présentent des valeurs comparables à celles observées en zones désertiques, mais avec des écart-types généralement plus importants du fait de la grande variété des systèmes alimentaires proposés. La saison, la complémentation alimentaire (en particulier minérale) et le statut sanitaire ont un effet significatif sur le profil métabolique des chamelles. La saison hivernale et l’excès de complémentation azotée représentent des facteurs de risque à ne pas négliger en particulier pour la mortalité des jeunes qui dépasse 40 % dans notre échantillon d’étude

Micro-dosage automatisé sur analyseur à transfert de l'azote alpha-aminé circulant.

An automated method for the determination of plasma free amino groups is described. The analysis is performed on a discrete computerized analyzer after plasma deproteinization using trichloracetic acid. The method is based on the formation of a complex between terminal NH2 radicals and 2,4,6-trinitrobenzene sulfonate (TNBS). The method is accurate (coefficient of variation = 2%), linear over a range of 0.2-7 mM/l and requires small analytic volumes; it also correlates well in the bovine with results from standard liquid chromatography (r = 0.953). With this method a single operator can determine free amino group contents of 50 samples per h

Relation comparée entre les concentrations plasmatiques en cuivre/zinc et l'activité de la superoxyde dismutase chez le dromadaire et la vache

2 tables 3 graph.International audienceOn an experimental farm, five camels and five cows were fed with a similar basal diet over a 6-month period. They received an oral trace element supplement for 3 months (days 22-112). This supplement contained zinc and copper sulphate, and corresponded to twice the daily requirement generally recommended for cows. Plasma zinc and copper concentrations were significantly lower in camels (44 micrograms/100 mL for copper and 38 micrograms/100 mL for zinc) than in cows (106 and 83 micrograms/100 mL, respectively). The supplementation had no effect on the plasma zinc concentration in the camels in spite of the low observed values. The mean erythrocyte SOD activity was also significantly higher in the cows (2,404 +/- 211 IU/100 gHb) than in the camels (1,720 +/- 312 IU/100 gHb). In both species, no correlation was found between copper plasma concentration and erythrocyte SOD activity. In cows, a positive relationship was observed between plasma zinc concentration and SOD activity (r = 0.396). In contrast, a negative relationship was found in camels (r = -0.369). These results are discussed in relation to the physiological peculiarities of the camel

Development of a New Oligonucleotide Array To Identify Staphylococcal Strains at Species Level

The genus Staphylococcus is made up of 36 validated species which contain strains that are pathogenic, saprophytic, or used as starter cultures for the food industry. An oligonucleotide array targeting the manganese-dependent superoxide dismutase (sodA) gene was developed to overcome the drawbacks of the conventional methods of identification. Divergences of the sodA gene were used to design oligonucleotide probes, and we showed that each of the 36 species had a characteristic pattern of hybridization. To evaluate the array, we analyzed 38 clinical and 38 food or food plant Staphylococcus isolates identified by the phenotype-based system VITEK 2 (bioMérieux). This commercial kit failed to identify 8 (21%) of the clinical isolates and 32 (84%) of the food and food plant isolates. In contrast, the oligonucleotide array we designed provided an accurate and rapid method for the identification of staphylococcal strains, isolated from clinical, environmental, or food samples, at species level

Biodiversity of indigenous staphylococci of naturally fermented dry sausages and manufacturing environments of small-scale processing units

The staphylococcal community of the environments of nine French small-scale processing units and their naturally fermented meat products was identified by analyzing 676 isolates Fifteen species were accurately identified using Validated molecular methods The three prevalent species were Staphylococcus equorum (58 4%). Staphylococcus saprophyticus (15 7%) and Staphylococcus xylosus (9 3%) S equorum was isolated in all the processing units in similar proportion in meat and environmental samples S saprophyticus Was also Isolated in all the processing units with a higher percentage in environmental samples S xylosus was present sporadically in the processing units and its prevalence was higher in meat samples The genetic diversity of the strains within the three species isolated from One processing unit was studied by PFGE and revealed a high diversity for S equorum and S saprophyticus both in the environment and the meat isolates The genetic diversity remained high through the manufacturing steps A small percentage of the strains of the two Species shale the two ecological niches These results highlight that some strains, probably Introduced by the meat, will persist in the manufacturing environment, while other strains are more adapted to the meat products

Comparative effects of selenium supplementation on the plasma selenium concentration and erythrocyte glutathione peroxidase activity in cattle and camels

International audienceAt an experimental farm, five camels and five cows were each given a similar basal diet for 6 months. They received oral trace element supplementation for 3 months (day 22 to 112) which included zinc, copper, selenium, manganese, iodine and cobalt and corresponded to twice the daily requirement generally recommended for cows. Plasma selenium concentrations were significantly lower in the camels (20 (s.e. 2) mg/l) compared with the cows (33 (s.e. 2) mu g/l). The mineral supplementation induced a large increase in the plasma selenium concentration in the camels which reached 200 (s.e. 35) mu g/l. In the cows, the increase was much smaller and did not go beyond 65 (s.e. 8) mu g/l. Before supplementation the red blood cell glutathione peroxidase activity was similar in the camel and the cow varying between 4000 and 6000 IU per 100 g haemoglobin. In both species, this activity increased with mineral supplementation and remained very high even when mineral supplementation was stopped. The results suggested that selenium metabolism in camels is different from that in the cow

Comment dépister les déséquilibres biologiques et les troubles de santé chez la vache laitière dans le cadre d'études écopathologiques ?

National audienceThe methods of detection of health and biological imbalances in the dairy cow, which can be performed in ecopathological studies, are presented. Mastitis, metritis, liver disorders, nutritional imbalances, reproductive disorders, stress, specific diseases and non-specific inflammations are reviewed. The possible future evolutions are analyzed

Determination of plasma non-esterified fatty acids in herbivores and man : a comparison of values obtained by manual or automatic chromatographic, titrimetric, colorimetric and enzymatic methods

National audienceNon-esterified fatty acid (NEFA) contents were determined (1) in cow, goat, mare and human plasmas or sera and (2) in bovine serum albumin solutions by thin-layer and gas-liquid chromatographic methods which were compared with 6 chemical methods of determination and 2 enzymatic methods (manual and automatic). The chemical methods combined two extraction techniques (isopropanol-heptane and silicic acid-diisopropyl ether) and three determination methods (titrimetry and colorimetry using either phenol red or copper soaps). Correlations between the nine various methods were high, but in some cases regression lines were different from the bissector and species-dependent. The putative occurrence of interfering compounds or the possible effect of between-species differences in NEFA composition have been discussed. The choice of a fast method depends primarily on practical considerations, but the need to standardize each method for a given species has been stressed. Automatic enzymatic assay seemed to be suitable for routine analyses