A BSTRACT In this experiment the effects of supplementing laying hen’s diets with
vermiculite (V) and vermiculite mixed with fishmeal (FM) on productivity,
morphometric parameters, chemical composition and fatty acid profile of eggs, and some blood plasma indicators of laying hens were studied. "Hajseks white" birds
were randomly divided into 5 groups (20 birds per group) and 24 weeks of age hens
were fed 2 months: A-base diet (BD) (control group), B and C-base diet with 3% or
5% vermiculite and D and E-base diet and 1% vermiculite + 2% fish meal or 1%
vermiculite + 3.5% fish meal. In two tested groups of hens fed with vermiculite plus
fishmeal productivity of eggs was higher than control group. Hens groups B and C
laid 100 eggs more than control group and group D and E about 200 eggs more after
feeding with V+FM. A higher content of protein, carbohydrates and energy value of
eggs were observed. Average egg weight was the highest in group E (63.3 g), also
weight of protein, white and yolk of egg. Eggs of hens group C had the highest
parameters of weight, thickness and density of shell. The results showed that
supplementation of V+F significantly affected concentration of the fatty acid (FA),
protein content in the yolk and white. Feeding with supplementing diet in mineral and
protein led to an increase in total fatty acids content and dietary mono (MUFA) and
polyunsaturated fatty acids (PUFA). The level of n-6 FA (especially linoleic and
linolenic acids) was significantly increased in eggs of hens group D and E. The
amount of protein, WBC, HGT, calcium of hens group fed with combination of
V+FM was higher. The high mineral nutritional value gives a perspective of the use
vermiculite additive in the production of high quality poultry products. For future
poultry industry, especially in developing countries, this novel knowledge of
vermiculite as feed additive is very important.