Les endoparasites des tubes digestifs des moutons de la race Rumbi. Enjeux de développement de l’élevage ovin à Djelfa (Algérie)

Abstract – Parasite examination of sheep of the Rumbi breed is carried out in one of the agricultural zones of the region of Djelfa, that of Rous L'youn. during 6 months using 3 coprological sampling techniques; namely the flotation technique, the Ritchie technique and the Ziehl-Neelsen coloring technique. Following these examinations, 7 species of parasites are identified by the Ritchie technique and 6 by flotation. So, cryptosporidia analyzes are negative and no cryptosporidium species is reported. In terms of species, the six-parasitic species noted by the flotation technique are Toxocara sp., Ascaris sp., Nematodirus sp., Strongyloides sp., Eimiria sp. and Cestoda sp. ind. These same species are found by Ritchie techniques with a 7th one Trichuris ovis.

Keywords : Rumbi breed, endoparasits coprological analyzes, Djelfa, Algeria.

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 La formation endogène de coalitions peut-elle être un remède à la tragédie des communs? Une étude expérimentale

Abstract – The management of commons pools resources raises the problem of their over-exploitation which degenerates in general into their exhaustion. We study the impact of coalition formation in the investment on common pool resource. Our first result from resolution of our model show that social optimum is always in the formation of the biggest coalition, however Nash equilibrium depend on number of player in the game. We choose case in which Nash equilibrium and social optimum coincide. For this example, we demonstrate that in forming the biggest coalition we invest less in CPR and the total payoff is the greatest from all structure. We demonstrate also that comparing to the game without coalition formation (standard case) any structure other then singletons coalitions was an amelioration (less investment and greeter group payoff). We use then experimentation to validate the theoretical results. Over than 100 players participate to the experimentation and was paid according to their decisions. Our first experiment with two treatments (veto & dictator) confirms our theoretical study: players form groups, decrease their investment in CPR and increase their payoff. The dictator treatment was significantly more efficient. The second experiment show that nether we change first group structure, the result is the same. We demonstrate also that decision rules don’t affect final results.

Keywords : CPR, Coalitions, Experiment, Veto & Dictator, decision rules.

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Abstract – An arid zone is characterized as an area of low precipitation, high temperature, and high rate of evaporation. The soil in this zone is characterized by neutral, high salt content, and low organic matter. Therefore its agronomic potential can be easily deteriorated by erosion or over cultivation and consequently amendments are added to enhance physic-chemical properties of soil. This work is a trial to recover soil in El Fja region (Mednine, Tunisia) by adding various amounts of phosphogypsum (PG) a byproduct issued by fertilizers industry. Phosphogypsum-soil mixtures were prepared in pots, with different percentages: 10%, 20%, 30%, 40% and tested under broad bean cultivation (Vicia faba L). Physical and chemical properties of these mixtures were investigated. Water reserve and water retention capacity increased, which led to an augmentation in agricultural yields, its maximum was reached at a percentage of 10% of PG amended.

Keywords : Amendement, arid zone, phosphogypsum (PG), soil.

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Abstract – The aim of the present study was to evaluate resistance to antimicrobial agents of bacteria isolated from mastitis cows, diarrheic and healthy calves, and healthy chickens. Therefore, a total of 679 animals were sampled; milk samples from mastitis cows (n=248), fecal specimens from calves (n=119) and fresh feces from healthy chickens (n=312) to isolate Eschrichia coli strains then evaluate their susceptibility to 17 antimicrobial agents. Escherichia coli were the commonest bacteria isolated from milk of mastitis cows (38%). The carriage rate of E. coli from fecal samples of diarrheic and healthy calves was 86.6% and 88.1% respectively. In poultry, the carriage rate was 90.7%. Resistance to antibiotics was higher in E. coli isolated from chickens then from calves and mastitis cows. The highest prevalence of ESBL producing E. coli was also obtained in feces samples of chickens 14.5% which are considered as a major ESBL reservoir in Tunisia.

Key words: Escherichia coli, mastitis cows, calves, poultry, antibiotics, ESBL, Tunisia.

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Elimination des nitrates contenus dans le lixiviat par adsorption sur un mélange bentonite-chaux et sur une bentonite activée thermiquement chimiquement sous irradiation micro-onde

Abstract – In this work, we studied the possibility of removing the nitrate contained in the leachate of a technical landfill (Boumergued/Algeria) by adsorption on a Maghnia bentonite activated thermally chemically by phosphoric acid and on a bentonite-lime mixture under microwave irradiation. We have Firstly prepared our clay-based adsorbents. As a result, these adsorbents are characterized by different techniques such as X-ray diffraction (XRD). In a second step, we studied the adsorption of nitrate on clay samples, in order to determine the optimum adsorption conditions; we carried several experiments of different pH and different masses. The tests have been realized in synthetic solutions of distilled water. The adsorption results show rapid kinetics at the end of a time which does not exceed 40 min for the activated bentonite, this time decreases to 10 min for the clay-lime mixture with elimination rates equal to 65% for activated bentonite and 98% for clay-lime mixture. 

Keywords : Adsorption, nitrate, activated bentonite, lime, microwave irradiation.

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Gestion de la qualité des eaux d’oued sekkak par le modèle qual2k

Abstract – The quality of water resources is continually deteriorating. This situation is due to the socio-economic development of the different countries. To address this situation and to preserve water resources, strategies for the protection and management of the quality of water resources must be developed.
Mathematical models are a way to describe the relationships between waste loads and water bodies and to describe the concentration of each contaminant. In this respect, water quality models have been used as an important tool in the qualitative management of water resources.
The objective of this work is to model water quality on a part of river Sekkak approximately 32 km (wilaya of Tlemcen northwest of the Algerian territory) using model QUAL2K to assess the water quality, environmental impact of multiple landfills along the river. The spatial simulation of the main descriptors of the water quality of the Sekkak river (dissolved oxygen, biological oxygen demand BOD, ammonium, phosphorus) allowed us to illustrate and estimate several biological phenomena Of self-purification such as biological oxidation of organic pollution estimated at 0.0117mg BOD / L.Km, and nitrification of ammonia nitrogen estimated at 0.082mg NH4 /L.Km.

Keywords : pollution, modélisation, qualitative management, QUAL2K model.

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