Comparison of Crosses Including a Local Breed or an Experimental Line to a Commercial Control for Egg Production in Morocco

Abstract

The performance of two crosses each including a line of Egyptian origin (Fayoumi x Leghorn and ISA x Mandarah) and a third utilizing an experimental line selected for low feed consumption during the laying phase (ISA x R^-) were compared to those of a brown-egg-type commercial cross (ISA brown). The hens were kept in cages (three per cage) in a laying house equipped with windows and no specific isolation. During two periods, 20 to 35 and 45 to 50 weeks of age, the hens were fed a commercial diet. Only half of each cross were fed that diet from 36 to 44 weeks of age. In all cases, the performance of the two crosses with a local line (Fayoumi x Leghorn and ISA x Mandarah) was lower at all times compared to the other two crosses for egg laying rate, average egg weight and feed efficiency. Differences between the ISA x R^- cross and the commercial Isabrown cross for the same variables were rather small, some in favor of the Isabrown (earlier age at point of lay, average egg weight, laying rate during the first weeks), others in favor of the experimental cross (laying rate after 35 weeks, and overall feed efficiency in spite of a higher body weight). The mortality rate measured at early stages or cumulated over time was always lowest for the ISA x R^- cross, highest for the Isabrown cross, and intermediate for the other two crosses. In conclusion, the ISA x R^- cross was overall the best in the conditions of this trial.