Effect of Canola Oil and Vitamin C Inclusion into Diets on Laying Performance, Egg Quality and Lipid Peroxidation of Egg in Layer Hens

This study was carried out to determine the influence of canola oil and vitamin c included into ration on performance, egg quality and tbars value of egg yolk in layers. a total of 72 lohmann white laying hens, 40 wks of age, reared at the research and application farm of agricultural faculty of atatürk university, were randomly allocated to four dietary treatments. each treatment group (n= 18) was replicated six times as subgroups, comprising of 3 birds each. experimental groups were composed by adding 0% canola oil and vitamin c (i: control), 4% canola oil (ii), 200 mg vitamin c/kg (iii) and 4% canola oil+200 mg vitamin c /kg (iv) to basal rations. then, the hens were fed with these diets for 12 weeks. diets and water were submitted as ad libitum. at the end of the trial, it was observed that vitamin c (iii) increased egg production (p<0.05) and improved feed efficiency (p<0.01); canola oil (ii) increased egg weight (p<0.01); and the combination of vitamin c and canola oil (iv) significantly decreased the daily feed consumption. also the cracked egg ratios of treatment groups (ii, iii and iv) were lower than that of control group (p<0.01). there is no difference in egg quality parameters such as egg weight, shell stiffness (kg/cm^2), shape index (%), shell thickness (mm), albumen index (%) and ve haugh value amongst groups except for yolk color and yolk index. vitamin c significantly increased yolk color (p<0.01). however, yolk index was affected (p<0.05) by canola oil (ii) and combined (iv) diets. on the other hand, vitamin c added ration (iii) decreased tbars value for 21 days storage, and for 42 days storage as compered with canola oil (ii) added group. as a result, it was determined that canola oil and vitamin c included rations had positive effects on some performance and egg quality parameters. inclusion of vitamin c to ration decreased lipid oxidation and prolonged the shelf life of egg, in case of canola oil having unsaturated fatty acid composition consumed by layers.