Data of thymol dietary supplementation in quail (Coturnix japonica ): linking bioavailability, effects on egg yolk total fatty acids and performance traits

A bi-factorial design combining the effects of the diet supplied (five levels) and time of sampling (five levels) was established for the variables studied: - Five experimental diets (two controls: the basal diet and the basal diet with vehicle solution; and three thymol doses: 2, 4 and 6.25g/kg of feed). - Five times of sampling (one initial sample point; three sample points along the supplementation period and one at the end of the post-supplementation period). Thymol concentration in egg yolk and droppings was assessed using head-space solid phase microextraction followed by gas chromatography-mass spectrometry (HS-SPME/GC-MS). SPME was performed with a manual holder with 100um polydimethylsiloxane (PDMS) fiber and chromatography analysis was carried out in a Perkin Elmer Clarus® 600 equipped with a PSSI injector and a quadrupole MS detector Yolk lipids were extracted following homogenization in a suitable excess of chloroform/methanol (2:1 v/v) and fatty acids were methylated by transesterification to generate Fatty Acid Methyl Esters (FAMEs). FAMEs of total fatty acids of the yolk were analyzed by gas chromatography mass-spectrometry (GC-MS). Chromatography analysis was carried out in a Perkin Elmer Clarus® 600 equipped with a PSSI injector and a flame ionization detector. Potential histopathological changes in quail liver were assessed by a semi-quantitative method in which the alterations are classified into four major reaction patterns concerning to different functional units of the liver or to the whole organ. The extension and number of each alteration were recorded with a light microscope coupled to a digital camera. Performance traits analyzed included body weight, feed intake, egg laying rate, egg physical characteristics and a general welfare quality assessment. Body weight and feed intake were registered using a balance. Egg weight and percentage of constituents were acquired using an analytical balance. Egg morphometric characteristics were determined by means of a digital caliper (0-150mm/0.01). THY concentration in feed was measured for the three doses by HS-SPME.Finally, a welfare assessment based on observations of physical characteristics was made. Female skin lesions and plumage status were evaluated following a procedure adapted from the protocol developed by the Welfare Quality consortium.