532 research outputs found
Subchronic dietary exposure of rats to cadmium alters the metabolism of metals essential to bone health
Cadmium (Cd) was recently identified as a risk factor for osteoporosis. Skeletal damage may be the critical effect of low-level long-term exposure to Cd in the general population exposed via food, but the mechanisms behind this are not clearly understood.We investigated the effects of dietary Cd exposure on metals involved in bone turnover. Female rats received a Cd-supplemented diet (0, 10, 50, or 200 CdCl2 mg/kg diet) for 13 weeks. Cd and essential metals stored in the liver were measured by ICP-MS multianalysis. Mineral content of the livers was modified according to Cd level : iron, magnesium and selenium decreased while copper, zinc and manganese increased with increasing Cd levels. Iron was the most strikingly affected metal, falling to one-fifth of control values at high dietary Cd exposure. In this dosage group, selenium decreased to 36% of mean control concentrations while zinc increased to 168%. This mineral imbalance, especially depleted iron stores, can contribute, at least in part, to the Cd-associated risk of osteoporosis. The association between iron metabolism and Cd exposure should be investigated in humans, as Cd and low iron stores could act synergistically as risk factors for osteoporosis
Can species richness be maintained in logged endemic Acacia Heterophylla forests (Reunion Island, Indian Ocean) ?
It is assumed that forests can serve multiple uses, including wood production and maintenance of high biodiversity level. We tested this hypothesis by studying eradication methods of invasive plants currently implemented in exploited endemic Acacia heterophylla forests located in a tropical highland forest region on the island of Réunion. We also compared species richness in logged (over time) and natural forests. Our results show that all individuals of the widespread alien invasive plant Rubus alceifolius were generated from cuttings. We quantifi ed the high growth capability of this species by comparing with those of Acacia heterophylla along with Rubus apetalus var. apetalus, a close non-invasive congener. The substantial multiplicative and vegetative growth ability of R. alceifolius enabled it to form monospecific patches in only 2.5 years. The species richness of the exploited Acacia heterophylla forest was thus very affected. Although the species richness increased over time after logging, the extent of the resulting richness was not as great as that in natural forests which, moreover, included numerous exotic plants. The authors assess the impact of highly disturbing logging operations and, based on the results of the comparisons, are very pessimistic about the possibility of maintaining species richness in logged forests. Nevertheless, the results indicate that the situation is not beyond hope and an eradication program specifi cally tailored to this kind of forest is proposed if exploitation will stop
Effect of seeders and tillage equipment on vertical distribution of oilseed rape stubble
International audienceWhen the spreading of a disease depends on the proportion of infected residues remaining at soil surface it is of crucial importance to analyse the effects of tillage practices on the vertical distribution of stubble. This is the case with phoma stem canker (blackleg), whose epidemics are initiated in autumn, by air-borne ascospores released from stubble located at the soil surface. We compared initial vertical distribution of oilseed rape residues to those observed after sowing and various tillage operations (rotary harrowing, stubble disking, chiselling and mouldboard ploughing). Almost 20% of the initially buried residue was brought back to soil surface with seeding. Rotary harrow brought 40% of the residue buried in the 0-10 cm layer up to the surface and left unburied about 70% of surface residue. Stubble disking appeared to be more efficient for residue burial than chiselling. Mouldboard plough was the only tool that buried all residues. A simple model was developed that predicted burial and return to the soil surface of potentially infected residues as a function of tillage practices used after harvest. Simulation of different tillage sequences showed that the order in which tools were used also affected location of residues. Our results highlighted the importance of tillage in the cultural control of phoma stem canker and will contribute to the definition of integrated pest management strategies for oilseed rape
Optical Excitation of Nuclear Spin Coherence in Tm3+:YAG
A thulium-doped crystal is experimentally shown to be an excellent candidate
for broadband quantum storage in a solid-state medium. For the first time,
nuclear spin coherence is optically excited, detected and characterized in such
a crystal. The lifetime of the spin coherence -- the potential storage entity
-- is measured by means of Raman echo to be about 300 s over a wide range
of ground state splittings. This flexibility, attractive for broadband
operation, and well fitted to existing quantum sources, results from the simple
hyperfine structure, contrasting with Pr- and Eu- doped crystals
Milk digestion in the young rabbit: methodology and first results
[EN] This study aims to determine the digestibility of milk by the young rabbit (21-25 d old), taking into account the increment of digesta content and urine excretion. Nineteen litters of 9 young rabbits 21 to 25 d old were used: 12 litters (S group) fed exclusively with milk using controlled suckling, and 7 litters (Control group) with free suckling and access to the pelleted feed of the doe. The faecal digestibility of milk dry matter (DM) was measured between 21 and 25 d of age, for S litters housed from 15 d of age in a metabolism cage separately from their mother. Between 21 and 25 d, the milk intake, faeces and urine excretion were controlled daily, and the mean increment in digesta content was measured by comparing digesta weight of the whole tract at 21 and 25 d of age (one kit per litter). The increment in digesta content from 21 to 25 d averaged 77% (+8.5 g), sourcing mainly from stomach and caecum contents increase (+57 and +120% respectively). The mean increase for the dry content of the gut (from 21 to 25 d) was 1.75 g DM/kit, and was considered as non-digested to calculate the digestibility coefficient of the milk. The milk intake averaged 30 g/d/kit (7.9 g DM/d kit). No faecal excretion was recorded between 21 and 25 d. From the milk intake and increment in digesta content, the corrected digestibility of the milk dry matter reached 94% (minimum=92.9%, maximum=95.6%). The daily urine excretion averaged 5.1 mL/kit, corresponding to 1.2 g DM/kit. Therefore, the corrected DM retention coefficient of the milk was 79.5%. The quantity of nitrogen excreted in urine was low (0.06 g/d kits), thus the corrected nitrogen retention coefficient for milk reached 82% and the nitrogen retained (corrected) reached 0.44 g/d kit. Accordingly, the amount in metabolisable protein for the milk was 90 g/kg (fresh). The corrected energy retention coefficient was estimated to 95.8%, for a crude energy concentration estimated at 28.14 MJ/kg DM for the milk. Thus, the energy retained (corrected) reached 223 kJ/d kit and the content in metabolisable energy for the milk was 26.94 MJ/kg DM.The authors thank INRA PHASE division for the financial support. The authors would also like to thank the technicians involved in the experiment at the INRA UE PECTOUL (Patrick Aymard, Jacques De Dapper & Jean De Dapper) and in the GenPhySE laboratory (Véronique Tartié).Gidenne, TN.; Bannelier, C.; Gallois, M.; Segura, M.; Lambrecht, V. (2018). Milk digestion in the young rabbit: methodology and first results. World Rabbit Science. 26(4):269-276. doi:10.4995/wrs.2018.10061SWORD269276264Alstin F., Nilsson M. 1990. The Soxtec®hydrolysis system improves the official methods for determining total fat content. Ind. Alim. Agric., 107: 1271-1274.Carabaño R., Piquer J., Menoyo D., Badiola I. 2010. The digestive system of the rabbit, In: De Blas C., Wiseman J. (Eds.), Nutrition of the rabbit, CABI; Wallingford; UK, pp. 1-18. https://doi.org/10.1079/9781845936693.0001EGRAN. 2001. Technical note: Attempts to harmonise chemical analyses of feeds and faeces, for rabbit feed evaluation. World Rabbit Sci., 9: 57-64. https://doi.org/10.4995/wrs.2001.446Gallois M., Gidenne T., Fortun-Lamote F., Le Hueron-Luron I., Lallès J.P. 2005. An early stimulation of solid feed intake slightly influences the morphological gut maturation in the rabbit. Reprod. Nutr. Develop., 45: 109-122. https://doi.org/10.1017/S1751731108001730Gallois M., Fortun-Lamothe L., Michelan A., Gidenne T. 2008. Adaptability of the digestive function according to age at weaning in the rabbit: II. Effect on nutrient digestion in the small intestine and in the whole digestive tract. Animal, 2: 536-547. https://doi.org/10.1017/S1751731108001730Gidenne T., Debray L., Fortun-Lamothe L., Le Huerou-Luron I. 2007. Maturation of the intestinal digestion and of microbial activity in the young rabbit: Impact of the dietary fibre:starch ratio. Comp. Bioch. Physiol. - Part A: Molecular & Integrative Physiology, 148: 834-844. https://doi.org/10.1016/j.cbpa.2007.08.025Gidenne T., Lebas F., Savietto D., Dorchies P., Duperray J., Davoust C., Fortun-Lamothe L. 2015. Nutrition et alimentation, In: Gidenne T. (Ed.), Le lapin. De la biologie à l'élevage, Quae éditions, pp. 152-196.Lebas, F. 1971. Composition chimique du lait de lapine évolution au cours de la traite et en fonction du stade de lactation. Ann. Zootech., 20: 185-191. https://doi.org/10.1051/animres:19710205Maertens L., Lebas F., Szendrő Zs. 2006. Rabbit milk: a review of quantity, quality and non-dietary affecting factors. World Rabbit Sci., 14: 205-203. https://doi.org/10.4995/wrs.2006.565Orengo J., Gidenne T. 2007. Feeding behaviour and caecotrophy in the young rabbit before weaning: An approach by analysing the digestive contents. App. Anim. Behav. Sci., 102: 106-118. https://doi.org/10.1016/j.applanim.2006.03.010Parigi Bini R., Cesselli P. 1976. Estimate of energy excreted in urine by growing rabbits. In: 1st World Rabbit Congress, Dijon, France, Comm. 20, 6.Parigi Bini R., Xiccato G., Cinetto M., Dalle Zotte A. 1991. Digestive efficiency and energy and protein retention in suckling and weanling rabbits. Zootec. Nutr. Anim., 17: 167-180.Savietto D., Cervera C., Blas E., Baselga M., Larsen T., Friggens N.C., Pascual J.J. 2014. Environmental sensitivity differs between rabbit lines selected for reproductive intensity and longevity. Animal, 7: 1969-1977. https://doi.org/10.1017/S175173111300178XUbilla E., Rebollar P.G., Pazo D., Esquifino A., Alvariño J.M.R. 2000. Effects of doe-litter separation on endocrinological and productivity variables in lactating rabbits. Livest. Prod. Sci., 67: 67-74. https://doi.org/10.1016/S0301-6226(00)00196-2Udert K.M., Larsen T.A., Biebow M., Gujer W.P. 2003. Urea hydrolysis and precipitation dynamics in a urinecollecting system. Water Res., 37: 2571-2582. https://doi.org/10.1016/S0043-1354(03)00065-4Zhang Y.K., Cui H.X., Sun D.F., Liu L.H., Xu X.R. 2018. Effects of doe-litter separation on intestinal bacteria, immune response and morphology of suckling rabbits. World Rabbit Sci., 26: 71-79. https://doi.org/10.4995/wrs.2018.591
Optical Excitation of Nuclear Spin Coherence in Tm3+:YAG
A thulium-doped crystal is experimentally shown to be an excellent candidate
for broadband quantum storage in a solid-state medium. For the first time,
nuclear spin coherence is optically excited, detected and characterized in such
a crystal. The lifetime of the spin coherence -- the potential storage entity
-- is measured by means of Raman echo to be about 300 s over a wide range
of ground state splittings. This flexibility, attractive for broadband
operation, and well fitted to existing quantum sources, results from the simple
hyperfine structure, contrasting with Pr- and Eu- doped crystals
Use of dehydrated sainfoin (Onobrychis viciifolia) in rabbit feeding. 2 - Effects of a high dietary incorporation on performance and health of does and growing rabbits, under a sub-optimal breeding commercial environment
[EN] The effects of a high dietary (26%) incorporation of dehydrated sainfoin (DS) (Perly cultivar) on the performance and health of reproductive does and growing rabbits were analysed in a sub-optimal professional breeding environment (presenting previous coccidiosis), and over two non-consecutive reproductive cycles (2 replicates). Performance and health of does and growing rabbits were compared for 2 groups of 194 does and associated litters, when fed isonutritive feeds containing either 0 or 26% DS (DS0 and DS26 groups). Dietary DS incorporation had no effect on doe live weight, fertility rate, mortality, culling rate and doe coccidia excretion levels (P>0.05). In replicate 1, kit growth before weaning was similar among the two groups, but was 12% lower for the DS26 group in the 2nd replicate (significant interaction). Similarly, a significant interaction was detected between the effect of the diet and the replicate for the mortality rate of kits before weaning, i.e. a higher mortality was detected for DS26 (3.3 vs. 1.8%) in replicate 1, while in replicate 2 it was lower (2.1 vs. 4.4%). After weaning, the post-weaning growth rate was improved by 4% (P=0.02) for the DS26 group, while the mortality rate decreased (7.1 vs. 4.5%, P<0.001). Coccidia excretions of growing rabbits were not affected by dietary sainfoin or by replicates. A high incorporation of DS (26%) should be recommended after weaning to improve the performance of growing rabbits without impact on reproducing does.Arrivé-Bellanné, Multifolia and ANRT funding this project and the doctoral programme (ANRT, CIFRE Programme)Gayrard, C.; Bretaudeau, A.; Gombault, P.; Hoste, H.; Gidenne, TN. (2024). Use of dehydrated sainfoin (Onobrychis viciifolia) in rabbit feeding. 2 - Effects of a high dietary incorporation on performance and health of does and growing rabbits, under a sub-optimal breeding commercial environment. World Rabbit Science. 32(1):11-20. https://doi.org/10.4995/wrs.2024.19848112032
Spatial analysis of within-vineyard grapevine sensitivity to solar irradiance patterns. A case study using Pinot noir in a complex terrain
Communication orale, texte intégralWe analyze how the patterns of the solar irradiance affect the growth of Pinot noir grapevines at stand-scale over a hilly terrain bounded by a coniferous forest. Results show that the patterns of irradiance deficit are the primary driving force of the growth. Linear trends display good correlation between the total deficit of irradiance, and the developed growth index (R2 up to 0.96 ). This result also suggests the impact of low minimum temperature due to cold air drainage and stagnation. Results lead to propose a model able to capture at stand-scale 90% of the whole spatial variability of the growth. The model accounts for the diffuse component of the deficit of irradiance and the squared temperature anomalies. Combining such models through the use of GIS enables to better understand the driving mechanisms of grapevine growth over complex terrain, towards a better management of the “terroir” potential whithin climate change
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