Performance comparison of two commercial layer strains

Compare performance traits of two strains of laying hens in the commercial condition. Data from 5 flocks of Hy-line (W-36) strain and 3 flocks of Lohmann lite (LSL) strain between the years 2002-2008 was used. All flocks reared in similar conditions in a caged layer farm. Mean egg Production (%)، egg weight (g)، mortality (%) and feed intake (g/d) were recorded daily in the above mentioned period. Other criteria (feed conversion، peak egg production…) were calculated from recorded variables. In order to better comparison، data were analyzed in three phases: phase 1 (22-40 week)، phase 2 (40-60 week) and phase 3 (60-76 week). Also، the first 20 weeks of post-molt performance were compared. Mean egg production (%) and egg mass output (g/h/d) was higher in LSL strain than W-36 strain (P<0. 01) in all of the above mentioned phases except phase3 with no significant difference. Mortality rate، generally، was lower (P<0. 05) in W-36 than LSL strain. Feed intake was lower in W-36 compared to LSL (P<0. 01). The strain had no significant effect on feed conversion ratio. In conclusion، the results showed that Lohmann lite (LSL) strain was superior in the performance traits to Hy-line (W-36) hens.