Characterisation of the Whole Blood mRNA Transcriptome in Holstein-Friesian and Jersey Calves in Response to Gradual Weaning

• Published in: PloS one Vol. 11; no. 8; p. e0159707
• Main Authors: Johnston, D, Earley, B, Cormican, P, Kenny, D A, McCabe, M S, Kelly, A K, McGee, M, Waters, S M
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.08.2016; Public Library of Science (PLoS)
• Subjects: Analysis; Animal husbandry; Animals; Beef; Biology and Life Sciences; Blood; Calves; Calves (Cattle); Cattle; Cell activation; Chemokines; Chemokines - genetics; Chemokines - metabolism; Chemotaxis; Cluster Analysis; Cytokines; Cytokines - genetics; Cytokines - metabolism; Disease control; Down-Regulation; E coli; Eimeria; Escherichia coli; Female; Food science; Gene expression; Genes; Genomics; Grasslands; Health aspects; Hematology; Hermosilla; Immune response; Immune system; Infections; Knowledge representation; Lymphatic system; Lymphocytes T; Medicine and Health Sciences; Messenger RNA; Monocytes; Natural killer cells; Nephelometry and Turbidimetry; Neutrophils; Parasitology; Phagocytosis; Receptors; Receptors, G-Protein-Coupled - genetics; Receptors, G-Protein-Coupled - metabolism; Ribonucleic acid; RNA; RNA - chemistry; RNA - metabolism; RNA, Messenger - chemistry; RNA, Messenger - metabolism; Sequence Analysis, RNA; Signal transduction; Signaling; Staphylococcus aureus; Stress response; T-Lymphocytes - immunology; T-Lymphocytes - metabolism; Time Factors; Transcription; Transcription (Genetics); Transcriptome; Tuberculosis; Up-Regulation; Veterinary medicine; Weaning
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0159707

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.