Beschreibung
Calcium is the key element required for bone and eggshell formation in laying hens. Consequently, knowledge regarding the calcium requirements of broiler breeder pullets/hens during rearing period (up to 22 weeks) and laying period (23 to 60 weeks) is of utmost importance. This study showed that 1.0% Ca is adequate for normal bone development in broiler breeder pullets on restricted feed during rearing period. It seems that 2.5% Ca (3.5 - 4.0 Ca g/hen/day) is needed for growth, bone development and good egg quality of broiler breeder hens during the laying phase. From 23 to 35 weeks of age, 1.5% dietary Ca was sufficient to achieve maximum hen day production, egg weight and egg mass. Additionally, from 36 to 60 weeks of age 2.5% Ca is required for maximum hen day production, eggshell weight, egg mass and eggshell quality. Higher Ca retentions were observed for birds consuming 2.5% Ca diet compared to 1.5% Ca. Bone dimensions, mechanical properties, true cortical area and percent bone increased up to 18 weeks of age. The same increase was found from 35 to 60 weeks for the tibia length but not for the tibia width.
Autorenporträt
Dr. John Cassius Moreki holds PhD in Animal Science (with specialization in poultry nutrition) from the University of the Free State in South Africa. John currently lectures poultry and pig sciences to both undergraduates and postgraduates at Botswana College of Agriculture. He has been involved in the poultry industry for over 25 years.
