Testing of the palatability of Thymus vulgaris L. and Origanum vulgare L. as flavouring feed additive for weaner pigs on the basis of a choice experiment

The objective of the study at hand was to investigate within the framework of a pilot project the preference of weaner pigs for either an ad libitum standard feed with thyme or oregano herb as flavouring additive or an ad libitum standard feed without any herbal additive. Thyme or oregano herbs or a combination of both were offered in two different concentrations each (1% and 0.1%) as additive (experimental diets) in standard diet in comparison to the latter without herbal additive (control diet) free of choice. The dosage of the two herbs in terms of total essential oil(s) in the feeds used in the study was 0.02% or 0.002% (v/w), which was equivalent to 1% or 0.1% herbs in the mixture, respectively. A Latin square according to Williams (1949) was used with 6 groups in order to record possible differences in feed intake. All experimental diets aside from that mixed with 0.1% thyme herb were, in comparison to the control diet, significantly less ingested. Where the weanling was given the choice, it did not choose feed with any flavouring additive. Further studies aimed at assessing the use of herbs as aroma additive in the form of a choice experiment are recommended.