The Effect of Different Concentrations of Safflower Seed on Laying Hen`s Performance, Yolk and Blood Cholesterol and Immune System

Ninety-six 26-wk-old white leghorn layers (w-36 variety) were fed commercial diets containing 0, 4, 7 and 10% safflower seed (SS) and the diets were iso-caloric and iso-nitrogenous. Hens randomly assigned to 4 treatment diets, with 3 replicates and 8 layers in each replicate. The experiment was conducted over a period of 12 wk in order to study the effects of feeding safflower seed on hen performance (egg production, egg weight, egg mass, feed intake, feed conversion ratio (FCR) and weight gain) and egg quality parameters (Hough unit score, yolk color index, yolk index, egg shape, shell weight, shell thickness and density). The yolk of eggs extracted and cholesterol content were determined in each period. Blood samples were collected in non-heparinsed tubes from six hens in each treatment by puncturing the bronchial vein in end of experiment and serum was collected after 8-10 hrs as per standard procedures and was stored for subsequent analysis. Hen performance and egg quality parameters were not significantly (p>0.05) different among treatments except in specific gravity and body weights. The lowest specific gravity observed in 10% SS (1.0806) and the highest gain weight was in 4% SS (140g) treatment. However the lowest Hough unit and shell thickness observed in 10% SS but the different among treatments were not statistically significant. The mean yolk cholesterol content, blood cholesterol and antibody titter against ND and IBD were not significantly (p<0.05) different among treatments but the lowest yolk and blood cholesterol observed in 10 % SS.