Antimicrobial residues in foods of animal origin in Africa: public health risks.

The authors report on the current status of work on residues of veterinary medicinal products and, in particular, antimicrobial residues in foods of animal origin. This review focuses on residues of veterinary antimicrobials, antimicrobials used in livestock production, the concept of residues, and antimicrobial residues in foods of animal origin. Only one antimicrobial substance has been approved in the West African Economic and Monetary Union, compared with 16 substances in Benin and 56 in the European Union.

Improving village poultry's survival rate through community-based poultry health management: evidence from Benin.

Community-based poultry health management (CBM) is a strategy for village poultry improvement based on the installment of "poultry interest groups" in experimental villages. These groups serve as a channel for the dissemination of village poultry improvement technologies. The use of CBM is due to the fact that village poultry farming is practiced in a total or partial scavenging system which gives the impression that all the birds in the village belong to the same flock.

Biphasic survival analysis of trypanotolerance QTL in mice.

A marker-assisted introgression (MAI) experiment was conducted to transfer trypanotolerance quantitative trait loci (QTL) from a donor mouse strain, C57BL/6, into a recipient mouse strain, A/J. The objective was to assess the effect of three previously identified chromosomal regions on mouse chromosomes 1 (MMU1), 5 (MMU5) and 17 (MMU17) in different genetic backgrounds on the survival pattern following infection with Trypanosoma congolense. An exploratory data analysis revealed a biphasic pattern of time to death, with highly distinct early and late mortality phases.

Marker-assisted introgression of trypanotolerance QTL in mice.

A marker-assisted introgression (MAI) experiment was conducted to use genetic markers to transfer each of the three trypanotolerance QTL from a donor mouse strain, C57BL/6, into a recipient mouse strain, A/J. We used a backcross strategy that consisted of selecting two lines, each carrying two of the donor QTL alleles through the backcross (BC) phase. At the fourth BC generation, single-carrier animals were selected for the production of homozygous animal in the intercross phase.

Strategies to optimize marker-assisted introgression of multiple unlinked QTL.

To optimize designs to implement marker-assisted introgression programs aiming to introgress three unlinked quantitative trait loci (QTL), the present paper studies different alternatives versus a traditional backcross or intercross phase. Four alternative backcross strategies appear to be more advantageous by having 50% less genotyping load than a traditional backcross strategy tracking all three QTL at a time through a single line. A multiplication phase following the selection of homozygous animals at the three QTL as an intercross alternative allows doubling of the number of homozygous animals in a mouse model compared with the first intercross generation.

A model for population growth of laboratory animals subjected to marker-assisted introgression: how many animals do we need?

This study provides methods for calculating the mean and variance of the number of animals with the desired genotype in each backcross generation for a marker-assisted introgression experiment. The ultimate goal is to produce animals which are homozygous for the desired loci. The methods have been developed specifically for experiments with inbred lines.