Dietary thymol in quail: Dose-dependent effects on total fatty acid profile of egg yolk during supplementation and after its discontinuation

FERNANDEZ M. E.; MARIN R. H.; RODRIGUEZ, F.; KEMBRO J. M.; LABAQUE, M. C.

Orlando

Congreso; Poultry Science Association 106th Annual Meeting; 2017

Poultry Science Association

Phytogenic feed additives such as thymol may result in major improvementsin modern intensive poultry production due to their antioxidantproperties and beneficial influence on lipid metabolism, performance,health and welfare issues. However, there are still questions concerningdynamics of their biological action, optimal dosage and period ofsupplementation needed to achieve meaningful effects as well as persistenceof induced changes after discontinuation of supplementation.Herein, we focused on changes induced along 28d of thymol dietarysupplementation in quail egg yolk total fatty acid profile. Furthermore,we evaluated whether those effects remain apparent in the mid-term(21d) after discontinuation of supplementation. Fifty adult female quail(Coturnix japonica) were randomly assigned to 1 of 5 dietary treatmentsas follows: CON (basal diet), VEH (basal diet plus ethanol); THY80,160 and 250 (basal diet supplemented with 2, 4, 6.25g of thymol perkg of supplemented feed, respectively). Eggs were sampled at 0, 7, 14,and 28 d (d) of supplementation and after 21d of treatment discontinuation.Methyl esters of total fatty acids of the yolk (FA) were analyzedby GC-MS. GLMMs and Fisher tests were used to detect differences at P < 0.05. THY80 required 28d of supplementation to reduce theSFA (summation of saturated FA), while THY160 and THY250 onlyneeded 14d for a reduction of similar or greater magnitude, respectively.However, after 21d of cessation of supplementation the aforementionedeffect disappeared in THY80 but not in THY160 and THY250. WhileTHY80 failed to increase PUFA (summation of polyunsaturated FA)along supplementation, THY160 and THY250 increased PUFA by d14 of supplementation and remained increased after 21d of supplementdiscontinuation. FA changes induced by THY along the supplementationperiod are consistent with an improved nutritional quality of eggs.Findings suggest a thymol effect depending on both the dose and durationof the supplementation treatment. Furthermore, the persistence ofthose effects after supplement discontinuation is also consistent with adose-dependent phenomena.