Agricultural intensification in the Sahel – The ladder approach

Agricultural intensification in the Sahel can be described as climbing a ladder. The capital, labour, management and institutional requirements increase when farmers climb the ladder, but the potential gains are also higher. The first step on this ladder are agricultural practices without any financial outlay but with increasing labour demand, such as organic fertilizer use, seed priming, water harvesting and harvesting grains at physiological maturity to improve fodder quality. The next step on the ladder is the use of micro-fertilising, popularly known as microdose, at the rate of 0.3 g NPK fertilizer per pocket in sorghum and millet. The following step is the development of improved crop/livestock systems characterized by use of higher rates of mineral fertilisers and manure, increasing cowpea density and improved animal fattening. The last step presented on the ladder is the development of more commercially orientated agriculture characterized by development of cash crops, milk production and/or agroforestry systems. Evidences from the field support the observation that farmers intensify their production in a sequential manner similar to the way described in this paper. The technologies presented can facilitate agricultural intensification by reducing the risks and minimising the cost in agricultural production.     

Disposition of sulfonamides in food-producing animals: pharmacokinetics of sulfamerazine in ewe lambs

Date from plasma and urine samples from four ewe lambs were analyzed after administration of sulfamerazine as single IV and oral doses. A two-compartment pharmacokinetic model was developed to describe the disposition of sulfamerazine. The drug was eliminated, primarily by renal excretion of (i) unchanged sulfamerazine and metabolism to an acetyl metabolite, (ii) polar conjugates, and (iii) a third metabolite. The biological half-life of the drug was 6.6 hours. The average value of the absorption rate constant was 0.433 hour-1 (half-life 1.60 hours). Sulfarmerazine was relatively completely absorbed (approx 81% of dose) after oral administration in solution.