title: Characterisation of the Whole Blood mRNA Transcriptome in Holstein-Friesian and Jersey Calves in Response to Gradual Weaning.
abstract: Weaning of dairy calves is an early life husbandry management practice which involves the changeover from a liquid to a solid feed based diet. The objectives of the study were to use RNA-seq technology to examine the effect of (i) breed and (ii) gradual weaning, on the whole blood mRNA transcriptome of artificially reared Holstein-Friesian and Jersey calves. The calves were gradually weaned over 14 days (day (d) -13 to d 0) and mRNA transcription was examined one day before gradual weaning was initiated (d -14), one day after weaning (d 1), and 8 days after weaning (d 8). On d -14, 550 genes were differentially expressed between Holstein-Friesian and Jersey calves, while there were 490 differentially expressed genes (DEG) identified on d 1, and 411 DEG detected eight days after weaning (P < 0.05; FDR < 0.1). No genes were differentially expressed within breed, in response to gradual weaning (P > 0.05). The pathways, gene ontology terms, and biological functions consistently over-represented among the DEG between Holstein-Friesian and Jersey were associated with the immune response and immune cell signalling, specifically chemotaxis. Decreased transcription of several cytokines, chemokines, immunoglobulin-like genes, phagocytosis-promoting receptors and g-protein coupled receptors suggests decreased monocyte, natural killer cell, and T lymphocyte, chemotaxis and activation in Jersey compared to Holstein-Friesian calves. Knowledge of breed-specific immune responses could facilitate health management practices better tailored towards specific disease sensitivities of Holstein-Friesian and Jersey calves. Gradual weaning did not compromise the welfare of artificially-reared dairy calves, evidenced by the lack of alterations in the expression of any genes in response to gradual weaning.
authors.affiliation: Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc, Dunsany, Co. Meath, Ireland.|University College Dublin, School of Agriculture Food Science and Veterinary Medicine, Dublin, Belfield, Dublin, 4, Ireland.
authors.forename: D
authors.identifier: http://orcid.org/0000-0002-4784-8354
authors.initials: D
authors.lastname: Johnston
authors.affiliation: Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc, Dunsany, Co. Meath, Ireland.
authors.forename: B
authors.initials: B
authors.lastname: Earley
authors.affiliation: Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc, Dunsany, Co. Meath, Ireland.
authors.forename: P
authors.initials: P
authors.lastname: Cormican
authors.affiliation: Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc, Dunsany, Co. Meath, Ireland.
authors.forename: D A
authors.initials: DA
authors.lastname: Kenny
authors.affiliation: Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc, Dunsany, Co. Meath, Ireland.
authors.forename: M S
authors.initials: MS
authors.lastname: McCabe
authors.affiliation: University College Dublin, School of Agriculture Food Science and Veterinary Medicine, Dublin, Belfield, Dublin, 4, Ireland.
authors.forename: A K
authors.initials: AK
authors.lastname: Kelly
authors.affiliation: Livestock Systems Research Department, Animal & Grassland Research and Innovation Centre, Teagasc, Dunsany, Co. Meath, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: McGee
authors.affiliation: Animal and Bioscience Research Department, Animal & Grassland Research and Innovation Centre, Teagasc, Dunsany, Co. Meath, Ireland.
authors.forename: S M
authors.initials: SM
authors.lastname: Waters
mesh_terms: D000818:Animals; D002417:Cattle; D018925:Chemokines / Q000235:genetics / Q000378:metabolism; D002633:Chemotaxis; D016000:Cluster Analysis; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D009391:Nephelometry and Turbidimetry; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D017423:Sequence Analysis, RNA; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D013997:Time Factors; D059467:Transcriptome; D015854:Up-Regulation; D014886:Weaning
chemical_list: D018925:Chemokines; D016207:Cytokines; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D012313:RNA