EFFECTS OF SUPPLEMENTING LAYING HENS' DIETS WITH VERMICULITE ON MORPHOMETRIC PARAMETERS, CHEMICAL COMPOSITION, FATTY ACID PROFILE AND EGG PRODUCTION

This experiment was designed to study the effects of supplementing laying hens' diets with vermiculite (V) and vermiculite mixed with fishmeal (FM) on productivity, morphometric parameters, chemical composition and fatty acid profile of eggs as well as on some blood plasma indicators of laying hens. Hajseks White birds were randomly divided into 5 groups (20 birds per group) and 24-weeks-old hens were fed for 2 months with: 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 1.5% vermiculite + 3.5% fish meal. In two tested groups of hens fed with V+FM, the productivity of eggs was higher than in the control group. Hens in groups B and C laid 100 eggs more than the control group and group D and E produced about 200 eggs more after feeding with V+FM. A higher content of protein, carbohydrates and energy value of eggs were observed. The average egg weight was the highest in group E, where also the weights of protein, white and yolk of eggs were the highest. Eggs of group C hens had the highest parameters of weight, thickness and density of the shell. The results showed that supplementation of V+F significantly affected the concentration of fatty acids (FA) and the protein content in the yolk and white. Feeding a diet supplemened with minerals and proteins led to an increase in the total fatty acid 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 from groups D and E. The content of protein, WBC, HGT, calcium in blood of hens group fed with combination of V+FM was higher. The observed high mineral nutritional value implicates that a vermiculite additive could be used in the production of high quality poultry products. For the future of the poultry industry, especially in developing countries, this novel knowledge of vermiculite as a feed additive is very important.