Detection of antibiotics residues in meat of reformed and marketed laying hens in southern Benin

The presence in meat products of antibiotic residues is of toxicological risks for the consumer. In order to protect consumers through the safety of meat from reformed and marketed laying hens, a qualitative study was conducted in southern Benin. The study was conducted in twenty laying hen farms in Abomey-Calavi, Ouidah and Porto Novo towns. The survey identified antibiotics used by farmers. In each farm, five reformed chickens ready to be marketed were randomly selected. On each bird, the sternum and right thigh were collected and analyzed by the microbiological method of four plates at the Laboratory. Results showed that farmers use eight families of antibiotics: aminoglycosides, diaminopyridines, macrolides, polypeptides, quinolones second and third generation, sulfonamides and tetracyclines. Residues of tetracyclines and aminoglycosides were found only in Abomey-Calavi town with respective proportions of 25.71 ± 10.14% and 21.41± 9.93% while residues of macrolides were observed in three localities which are Abomey-Calavi, Ouidah and Porto Novo, with respective rates of 65.71 ± 9.92%, 46 ± 15.5% and 20 ± 8.36%. From the above results, we recommend to veterinarians the efficient use of antibiotics and to poultry farmers the respect of withdrawal period.Keywords: Antibiotics residues, laying hens, sternum, thigh, Beni

Introgression of a major QTL from an inferior into a superior population using genomic selection

<p>Abstract</p> <p>Background</p> <p>Selection schemes aiming at introgressing genetic material from a donor into a recipient line may be performed by backcross-breeding programs combined with selection to preserve the favourable characteristics of the donor population. This stochastic simulation study investigated whether genomic selection can be effective in preserving a major quantitative trait locus (QTL) allele from a donor line during the backcrossing phase.</p> <p>Methods</p> <p>In a simulation study, two fish populations were generated: a recipient line selected for a production trait and a donor line characterized by an enhanced level of disease resistance. Both traits were polygenic, but one major QTL affecting disease resistance was segregating only within the donor line. Backcrossing was combined with three types of selection (for total merit index) among the crossbred individuals: classical selection, genomic selection using genome-wide dense marker maps, and gene-assisted genomic selection. It was assumed that production could be observed directly on the selection candidates, while disease resistance had to be inferred from tested sibs of the selection candidates.</p> <p>Results</p> <p>Classical selection was inefficient in preserving the target QTL through the backcrossing phase. In contrast, genomic selection (without specific knowledge of the target QTL) was usually effective in preserving the target QTL, and had higher genetic response to selection, especially for disease resistance. Compared with pure genomic selection, gene-assisted selection had an advantage with respect to disease resistance (28–40% increase in genetic gain) and acted as an extra precaution against loss of the target QTL. However, for total merit index the advantage of gene-assisted genomic selection over genomic selection was lower (4–5% increase in genetic gain).</p> <p>Conclusion</p> <p>Substantial differences between introgression programs using classical and genomic selection were observed, and the former was generally inferior with respect to both genetic gain and the ability to preserve the target QTL. Combining genomic selection with gene-assisted selection for the target QTL acted as an extra precaution against loss of the target QTL and gave additional genetic gain for disease resistance. However, the effect on total merit index was limited.</p

Carriere de reproduction des aulacodes (thryonomys swinderianus) mâles d’elevage en Station

Dans le cadre de l’intensification de l’aulacodiculture au Bénin, des donnéestechniques fiables pour maîtriser les aptitudes à la reproduction des animaux ont été recherchées. L’étude de la carrière de reproduction des aulacodes d’élevage mâles à la station a montré que les cas d’infertilité seraient en partie liés à l’âge du géniteur, à l’accouplement, à l’effectif des femelles accouplées et à l’intervalle de réutilisation. En outre, les performances reproductrices des mâles en général et celles des jeunes en particulier, augmentent en fonction du nombre d’accouplements. Le temps utile correspondant à l’âge moyen minimal (8 - 18 mois) pour la réalisation d’un accouplement fécond est au plus de 14 jour