EFFECT OF ORGANIC AND INORGANIC SOURCES OF CALCIUM AND PHOSPHORUS ON LAYING HENS PERFORMANCE

Thte'e hundred White Bovans laying hens aged 24 weeks were used, to
evaluate the effects of dietary organic and Inorganic sources of calcium ( Ca ) and
phosphorus (P) on laying performanCe and egg quality. Hens were randomly divided
into tour experimental treatments .. Thus four isocalorlc ( ME ; 2850 kcal (kg) and
isonltrogenous (18 % CP) experimental diets were formulated, having equal Ca ( 40~. )
end available P ( 0.45% ) contentt . . Hens in ( Tr1 ) received 2.6% bone meal (B )
and 8.5% /im6stoM (lS); thosa in (Tr 2) received 2.6% BM and 8.5% eggshell me I
(ESM ); those In (Tr 3) received 1.6% dicaJclum phosphate ( DCP ) and 9.5% LS ; SF
those In (Tr 4) received 1.8% DCP and 9.5% ESM. The experiment was terminated I
torty weeks of age.
The obtained results revealed thaI. layers feed a diet contaning a
comblnstioo of BM as a source of P and lS as a source of ca ( Tr1 ) , attained a
beller performance fer of egg Production, and feed conversion compeared the oth r
treatments . Means of egg weight. feed Intake and Haugh unit were not significan y
affected by the dietary treatments. However, those layers feed a diet contaning a
compination of DCP as a source of P and ESM as a source of Ca ( Tr 4 ) , achiaved
the lowest performance tor egg production • and produced eggs of thinner she Is
compared with nlhe other trealmentes .
The highest values of nutrients dlgeslibdity and reteulion rates of Ca and P
were oblalned with diets of (Tr1) and (Tr 3) , fallowed by Intermedicete values for (Tr
2) ,white that of (T( 4) gave the lowest ones.
Generally . ihe consistent trends of egg production and shell thicltness show d
beneficiat effects of BM: as an organic source of P, and LS: as an inorganic
source of Ca : when being added to laying hen diets, in comparison with DCP a d
ESM.