Biochemical analyses
Samples in lithium heparin were centrifuged at 3000 rpm for 10 min on
arrival at the laboratory and the plasma was separated for biochemical
analysis. Plasma was stored frozen at − 24°C until analysis.
Determinations of 13 parameters were made in sampled birds: Albumin
(Bromocresol green method), Globulin (Biuret method), Urea (Urease–GLDH
method), Glucose (GOD-PAP method), Cholesterol (Chol. esterase chol.
oxidase–Trinder method), Calcium (o-cresolphthalein complexone
reaction), Aspartate aminotransferase AST (IFCC technique), creatinine
kinase CK (IFCC technique), Uric acid (Uricase–Trinder method), Lactate
dehydrogenase LDH (Pyruvate–lactate method), Sodium (Indirect ion
selective electrode), and Potassium (Indirect ion selective electrode).
All biochemical analyses were conducted under ILAB 600 (Instrumentation
Laboratory UK, Cheshire, UK) according to manufacturer instructions. For
some samples, there was insufficient sample volume to realize analysis of
all the biochemical metrics. The laboratory’s quality control was to run
daily internal quality control material and to peer review the results
with other laboratories by using two external quality assurance schemes:
the Randox International Quality Assessment Scheme and the American
Veterinary Laboratory Association.