Resumen de Effects of L-carnitine supplementation to diets with different fat sources and energy levels on fatty acid composition of egg yolk of laying hens
Muzaffer Corduk, Senay Sarica, Eda Calikoglu, Mustafa Kiralan
BACKGROUND: The present study was carried out to determine the effects of feeding diets with two different levels of metabolisable energy (ME) (11.51 or 10.88 MJ ME kg−1 diet) and three different sources of fat (palm oil, sunflower oil or fish oil) with or without supplemental L-carnitine (0 or 500 mg kg−1 diet) on the fatty acid (FA) composition of egg yolk and the passage of n3 polyunsaturated FAs to egg yolk in laying hens. RESULTS: The ∑n3, particularly C22:6n-3, FA contents of egg yolk were significantly reduced by adding of L-carnitine (C2) to different fat sources (P < 0.01). The ratio of n6/n3 was reduced from 53.77 to 17.72 in eggs yolks when ME was lowered in the diet with C2-sunflower oil (SFO) whereas it was enhanced from 2.19 to 9.31 in C2-E2 (low energy) diet with fish oil (FO) (P < 0.001). The diet with E2 or C2 containing FO resulted in a decrease of the C22:5n-3, C22:6n-3 and ∑n3 FA contents of egg yolk (P < 0.001). On the other hand, supplementation of C2 to diets with SFO or palm oil (PO) caused to a decrease in the C22:6n-3 and ∑n3 FA contents of egg yolk (P < 0.01). A significant increase of the ratio of n6/n3 in egg yolk can be seen by feeding with E2 diet by adding of C2 to all fat sources like in E1 (normal energy) diet (P < 0.001). CONCLUSION: Dietary treatments resulted in major changes in FA composition of egg yolk. The supplemental C2 in diet decreased the C22:5n-3, C22:6n-3 and ∑n3FA contents in egg yolk. The use of FO in diets with E2 significantly reduced the passage rate of C22:6n-3 FA to egg yolk. Copyright © 2008 Society of Chemical Industry
