Transcriptomic analysis of acute stress in goats. Transcriptomic analysis of acute stress in goats

Transportation stress causes significant changes in physiological responses in goats; however, studies exploring the transcriptome of stress are very limited. This study was conducted to analyze the transcriptome of stress and meat quality in goats using RNA-seq technology. Fifty-four male Spanish goats (8-mo old; BW = 29.7 ± 2.03 kg) were randomly subjected to one of three treatments (TRT; n = 18 goats / treatment): (i) transported for 180 min, (ii) transported for 30 min, or (iii) held in pens (control). Blood samples were collected before and after treatment for stress hormone, metabolite, and transcriptomic analysis. RNA-Seq technology was used to obtain the transcriptome profiles of blood. Analysis of physiological data using SAS showed that plasma cortisol concentrations were higher (P < 0.01) in 180 min and 30 min groups compared to the control group. A similar effect was noticed in plasma non-esterified fatty acid concentrations. Glucose concentrations were the lowest in the control group, highest in the 180 min group, and intermediate in the 30 min group (P < 0.01, while plasma creatine kinase concentrations were not significantly influenced by TRT. Neutrophil counts were higher (P < 0.01) and lymphocyte counts were lower (P < 0.01) in 180 min group compared to 30 min or control groups. The DESeq2 software identified a total of 430 DEGs for control vs. 30 min comparison, of which 127 genes were upregulated. For 180 min vs. control comparison, 741 DEGs were upregulated. Enrichment analysis of DEGs related to transportation stress through Gene Ontology and KEGG databases revealed that the DEGs related to inflammatory pathways, caspases, and apoptosis such as IL1R2, CASP14, CD14, TLR4, and MAPK14 were highly expressed in the transported group of goats compared to non-transported goats. Stress in goats leads to a sequence of events at cellular and molecular levels that causes inflammation and apoptosis and is also reflected in blood metabolites and leukocyte counts. Overall design: The protocols for this research were approved by the Animal Care and Use Committee at Fort Valley State University prior to beginning of the experiment. A total of fifty-four uncastrated male Spanish goats (8-mo old; BW = 29.7 ± 2.03 kg) were randomly subjected to one of three treatments (TRT; n = 18 goats/treatment): (i) transported for 30 min (approx. 50 km), (ii) transported for 180 min (approx. 200 km), or (iii) held in pens (control), on two different days. A livestock trailer with internal floor dimensions of 4.5 × 1.8 m were used to transport the goats. The ambient temperatures were -3.0 ± 1.0 ºC and 1.0 ± 1.0 ºC on day 1 and 2, respectively. Prior to the experiment, goats were primarily raised on free range pasture with a grain supplement and with ad libitum access to hay and water. Feed was withheld overnight prior to the day of the experiment.