engleski

Influence of use of organic minerals in laying hen diets on productive performance, egg quality and bone strength

One of the most important problems in poultry industry is eggshell quality and it has been estimated that eggs with damaged shells account for 6–10% of all produced eggs, what leads to great economic losses. The other problem observed in alternative egg production is poor bone quality related mainly with keel bone fractures which is one of the greatest welfare problems facing commercial egg production. Compared to inorganic sources, the organic mineral sources are reported to have several advantages, including protection from undesired chemical reactions in the gastrointestinal tract, easy passage through the intact intestine wall, and possibly different absorption, metabolic pathway, and mechanisms. The aim of the present experiment was to study the effect of two sources (inorganic and organic) of trace elements zinc, manganese, copper, iron and Se in the diet for hens on laying performance, eggshell quality and chosen parameters of bones. Experiment was carried out on 30 TETRA – SL Brown laying hens from 35 to 50 weeks, randomly assigned to two experimental treatments. Each treatment contained 15 laying hens, individually caged on wire-mesh floor. All layers were fed the same basal diet contained in 1 kg 52 mg Zn and 30 mg Mn. In experimental treatments basal diet was supplemented with 50 ppm Zn, 75 ppm Mn, 36 ppm Fe, 4 ppm Cu, 0, 15 ppm Se in inorganic forms as ZnO, MnO, FeSO4, CuSO4 and Na2SeO3 resp. (group K), and with 30 ppm Zn, 30 ppm Mn, 5 ppm Cu, 5 ppm Fe, 0, 2 ppm Se in organic forms as proteinate complexes. At the end of the experiment ten hens from each group were sacrificed and the tibias from both legs were prepared – left tibias for determination of ash and the right tibias for mechanical properties in three points bending test were determined. Egg production and egg weight were not affected (P>0.05) by dietary treatments. Dietary treatments in organic forms of microelements improved (P < 0.05) eggshell breaking strength and led to high content of Ca in tibias ash 184.48 in group P related to 179.77 g/kg in group K. Also in group P there was higher (P < 0.05) bone breaking strength relative to group K ; 155.90 vs. 108.66 (N). Obtained results indicate that use of organic complexes could alleviate the negative effect of hen age on eggshell and bone breaking strength.

laying hens ; organic complexes ; laying performance ; eggshell quality ; tibia bones

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