title: Characterisation of the main drivers of intra- and inter- breed variability in the plasma metabolome of dogs.
abstract: BACKGROUND
  Dog breeds are a consequence of artificial selection for specific attributes. These closed genetic populations have metabolic and physiological characteristics that may be revealed by metabolomic analysis.
  
  
  OBJECTIVE
  To identify and characterise the drivers of metabolic differences in the fasted plasma metabolome and then determine metabolites differentiating breeds.
  
  
  METHODS
  Fasted plasma samples were collected from dogs maintained under two environmental conditions (controlled and client-owned at home). The former (n = 33) consisted of three breeds (Labrador Retriever, Cocker Spaniel and Miniature Schnauzer) fed a single diet batch, the latter (n = 96), client-owned dogs consisted of 9 breeds (Beagle, Chihuahua, Cocker Spaniel, Dachshund, Golden Retriever, Greyhound, German Shepherd, Labrador Retriever and Maltese) consuming various diets under differing feeding regimens. Triplicate samples were taken from Beagle (n = 10) and Labrador Retriever (n = 9) over 3 months. Non-targeted metabolite fingerprinting was performed using flow infusion electrospray-ionization mass spectrometry which was coupled with multivariate data analysis. Metadata factors including age, gender, sexual status, weight, diet and breed were investigated.
  
  
  RESULTS
  Breed differences were identified in the plasma metabolome of dogs housed in a controlled environment. Triplicate samples from two breeds identified intra-individual variability, yet breed separation was still observed. The main drivers of variance in dogs maintained in the home environment were associated with breed and gender. Furthermore, metabolite signals were identified that discriminated between Labrador Retriever and Cocker Spaniels in both environments.
  
  
  CONCLUSIONS
  Metabolite fingerprinting of plasma samples can be used to investigate breed differences in client-owned dogs, despite added variance of diet, sexual status and environment.
authors.affiliation: Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3DA UK.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Lloyd
authors.affiliation: Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3DA UK.
authors.forename: Manfred
authors.initials: M
authors.lastname: Beckmann
authors.affiliation: Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3DA UK.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Tailliart
authors.affiliation: School of Environmental and Rural Science, University of New England, Armidale, NSW 2351 Australia.
authors.forename: Wendy Y
authors.initials: WY
authors.lastname: Brown
authors.affiliation: Institute of Biological Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, SY23 3DA UK.
authors.forename: John
authors.initials: J
authors.lastname: Draper
authors.affiliation: WALTHAM Centre for Pet Nutrition, Freeby Lane, Waltham-on-the-Wolds, Melton Mowbray, Leicestershire, LE14 4RT UK.
authors.forename: David
authors.initials: D
authors.lastname: Allaway
keywords: Inter-breed variability; Intra-breed variability; Metabolite fingerprinting; Metabolomics; Multivariate data analysis; Plasma