This experiment was conducted to explore the effect of long-term supplementation 25-hydroxyvitamin D3 (25-OHD) as a vitamin (VD3) substitute on performance, bone traits, and egg quality laying hens from 1 day 72 weeks age. In total, 900 one-day-old Lohman pullets were randomly allotted into three dietary groups (three treatments × 15 replicates 20 birds per replicate): VD3 2800 IU/kg; 25-OHD 69...

Osteoporosis, a progressive decrease in mineralized structural bone, causes 20 to 35% of all mortalities in caged White Leghorn hens. Previous research has focused on manipulating the egg laying environment to improve skeletal health, with little research on the pullet. The objective of the current study was to determine the effect of perch access on pullet health, bone mineralization, muscle d...

There is considerable evidence that 7-10 days before a pullet begins to lay a new system of secondary bone is laid down, under the combined influence of androgens and oestrogens, in the marrow cavities of all the bones in the skeleton in which haematopoietic tissue is present (Taylor & Moore, 1956). This medullary bone forms a highly labile reserve of minerals which are mobilized during the cal...

The objective of this study was to investigate the effect of dietary protein levels on pullet development and egg production performance of local hens. One hundred sixty local chicken pullets were used in this study. During the rearing period, the pullets were divided randomly at a density of 16 chicks per cage in rearing pens. During week 1, all birds were fed a starter diet containing 19% cru...

It is frequently recommended that commercial laying pullets are reared on step-down lighting regimens, rather than on constant short photoperiods, to help achieve BW targets during rear and optimal performance in lay. To evaluate the effectiveness of this strategy, Shaver White pullets were maintained on 8-h day lengths or given a step-down lighting regimen from 23 to 8 h over periods of betwee...

the aim of the present study was to compare different periods of feed deprivation (day number of starvation in four physical feed restriction programs) on total immunuglobulins and lymphocytes percentage in pullets and cockerels of broiler breeder. a 4x2 factorial experiment based on a completely random design. 160 pullets and 160 cockerels of broiler breeder. feed intake content weekly was the...

To ensure that laying hens can make full use of the various resources within an aviary barn and develop optimum bone health while minimizing keel fractures, appropriate cognitive development during rearing is critical. Given previous work documenting benefit ramps could be used by to transition between tiers reduced incidence project examined provision period, which birds voluntarily from 10 d ...