2.4.2. Blood sampling
Blood samples were drawn from the coccygeal vessels for
PAG analysis. Six hours after collection, the samples were
centrifuged (1500g, 10 min; Biofuge 22R, HeraeusSepatech
GmbH, Osterode, Germany), and the serum was removed
and divided into two aliquots. One was stored at 4 °C and
analyzed within three days, and the second was stored at
20 °C and later delivered via dry ice to the laboratory of
the Physiology of Animal Reproduction department of the
University of Liège for quantitative PAG analysis.