Résumé
A research was conducted to evaluate the effects of combined usage of garlic powder [GP] and cupric sulfate pentahydrate [CS] as two different cholesterol-lowering supplements on blood serum and egg yolk cholesterol concentration in laying hens. A total of one-hundred ninety two 40-wks-old Single Comb White Leghorn [SCWL] laying hens were selected in a completely randomized designed to four diets that included unsupplemental basal diet as control diet [CO], the basal diet supplemented with either 15 g/kg GP, 200 mg/kg CS, or both 15 g/kg GP and 200 mg/kg Cs for a period of 6 weeks. During the experimental period hens performance traits included body weight gain, egg production, egg and yolk weights, egg mass, feed consumption, and feed conversion ratio were recorded. For statistical analysis, data were averaged by replicate for 6 wks period. At the end of the experimental period blood serum and egg yolk samples were collected for cholesterol analysis. Supplementation of GP or CS to the basal diet had no significant [p>0.05] effect on overall performance in laying hens. A decrease in blood serum and egg yolk cholesterol concentration was found [p<0.01] in birds fed GP, CS, and GP/CS diets in comparison with the unsupplemented diet birds [CO diet].Serum cholesterol levels were reduced by feeding GP, CS, or both by about 14,20 and 28% respectively [p<0.01]. Feeding GP or CS decreased egg yolk cholesterol about 6 and 12.5%, respectively [p<0.01], but feeding both GP and CS diet/ supplements had no further beneficial effect on egg yolk cholesterol