Reproduction and adaptation characteristics in D’man sheep

D’man breed (D) is found in the oasis of the subsaharian regions of Morocco and reared usually in sedentary type of management with small flocks (< 10 ewes). Preliminary field surveys showed that D is early maturing, prolific and aseasonal. Hence, a multidisciplinary research programme on D was started in 1974. This paper reports the findings of these studies and describes the approach used to (1) characterize and evaluate the performances of D in field and station, (2) study the physiological mechanism involved in its peculiar reproduction and production, (3) study the genetic basis of reproduction parameters, and (4) evaluate use of D in crossbreeding schemes to improve the productivity of other Moroccoan breeds. Results show that D is one of the rare breeds that is simultaneously early maturing, highly prolific and completely aseasonal. However, studies on water turnover and nitrogen recycling show that D is not well adapted to hot climate and poor nutrition. Its reproduction parameters are relatively independent of photoperiod and related to a low sensitivity to negative oestrogen feedback. D male is characterized by high libido and can be used for synchronizing oestruses through the »ram effect». Crossbreeding experiments with non-prolific sheep confirm the heritability of reproductive parameters. However, the genetic basis for these is not yet well known

Changes in endogenous urea recycling and the handling of renal urea in pregnant and lactating Sardi sheep kept on a constant feeding level

Je nach Standpunkt wird das „lange“ 19. Jahrhundert (1815-1914) als Zeitalter eines stabilen Friedens gesehen – oder aber als eine Epoche vieler kleinerer Kriege, durch die Afrika und Asien der europäischen Hegemonie unterworfen wurden. So oder so sahen sich die europäischen Staatsführer aber in den Jahrzehnten vor 1914 zunehmend gezwungen, ihre Eroberungspolitik gegenüber einer Kritik zu rechtfertigen, die den Krieg grundsätzlich in Frage stellte. Dies war besonders einer wachsenden Friedens..

Water movements after an intraruminal water load in pregnant and lactating Sardi sheep

International audienc

Changes in endogenous urea recycling and the handling of renal urea in pregnant and lactating Sardi sheep kept on a constant feeding level

International audienc

Reproduction and adaptation characteristics in DŽman sheep

vokkirjasto Aj-

Evaluation of a New Generation of Coated Fertilizers to Reduce the Leaching of Mineral Nutrients and Greenhouse Gas (N2O) Emissions

The increased use of fertilizers in agriculture and forest and horticulture nurseries contributes to the pollution of water resources and greenhouse gas emissions. The objective of this study is to evaluate a new generation of fertilizers coated with new biodegradable polymers in terms of physical quality, release kinetics, and their effect on reducing nitrate leaching and N2O emissions and compare them to uncoated fertilizers (Urea, monoammonium phosphate (MAP), and KCl) having the same mineral nutrient concentration. In a peat-based substrate, the release of mineral nutrients was similar in both types of fertilizer. Two hours after application, Urea released 34% more urea than Biodrix N, the difference disappearing after one day. The leaching of cumulative ammonium nitrogen after 20 days was reduced by 40% and 26% respectively by Aminaex and Biodrix N compared to Urea. In a peat-based substrate containing 30% (v/v) of compost, the cumulative nitrate leaching was reduced by 54% by Biodrix N and by 41% by Aminaex compared to Urea. The highest average N2O flux was observed on the first day for Urea, whereas for Aminaex and Biodrix N, N2O emissions increased on the third day, reaching a peak of efflux on day 10. A 10-day delay of the N2O efflux emissions and a longer period of emissions were observed in treatments containing Aminaex and Biodrix N compared to Urea. Cumulative N2O efflux was 142, 154, and 171 mg m−2, respectively, for Urea, Aminaex, and Biodrix N over a 20-day period. These new biodegradable polymer-coated nitrogen fertilizers can reduce mineral nutrient leaching in the event of heavy rainfall and lower maximum N2O emissions in comparison with conventional nitrogen sources