Yolk fatty acid composition and cholesterol content in response to level and form of dietary flaxseed

The effect of the level and form of dietary flaxseed on the fatty acid composition and cholesterol content of hen egg has been investigated. Dietary flaxseed notably altered yolk fatty acid composition by increasing total polyunsaturated fatty acids while decreasing monounsaturated fatty acids. a-linolenic acid was linearly increased in response to levels of ground flaxseed, but whole flaxseed resulted in reduced a-linolenic acid availability for yolk deposition. Similar deposition profiles were exhibited by docosapentaenoic and docosahexaenoic acids. These alterations in yolk composition resulted in n-6 to n-3 fatty acid ratio values as low as 2.92 and 1.94 for 5 and 10% ground flaxseed and 2.49 for 10% whole flaxseed feeding, respectively. Dietary flaxseed had no effect on the cholesterol level of eggs, which showed a mean;value of 188 mg/egg or 1247 mg/100 g of yolk.