unstable egg production curve in laying hens

curve graph graphic model typical production laying flock commercial hens scientific diagram egg weight lower upper ages percentage productive layer brown isa hy line loghman standard peak performance hd hh eggmass factors affecting diseases newcastle disease infectious bronchitis poultry chicken vaccination feed quality avian influenza virus mycoplasma mg bacteria coryza eds syndrome 76 concept conceptual molt diet dietary protein lpai hpai pathogenic genetic potential strain pullet