The magnitude and nature of changes in performance of the chicken
2000
Horn, P. | Suto, Z.
The authors summarize the magnitude and nature of the improvement of production traits in layers and broilers based on the results of international strain comparisons conducted in Hungary and other European countries. Layer hibrids showed an annual improvement exceeding 2 eggs/hen in the last two decades. Brown egg layers improved more rapidly in feed efficiency compared to leghorns (-0,6 kg feed/egg kg for the browns, -0,5 kg/egg kg for leghorns), mainly due to improved egg production and reduced body weight. Today layers start to lay 15-20 days earlier than 20 years ago.
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