ABUNDANCE OF SERUM BETA-miR-2285u MICRORNAs SUGGESTED ENHANCED RUMEN HEALTH OF GOATS FED FORAGE AND HIGH-GRAIN BASED DIETS.

Résumé

The knowledge on how diets influences metabolic disorders in farm animals through modification in the activity and functions of microRNAs is essential. microRNAs are small non-coding RNAs that regulate post transcriptional gene expression, which could serve as biomarkers for several metabolic conditions. Sub-acute

ruminal acidosis (SARA), a metabolic disorder characterized by rumen inflammations as a result of low ruminal pH and the accumulation of volatile fatty acids, is linked to feeding of grains or starch-rich diets. This study evaluated the suitability of miRNAs as potential biomarkers in goat for the diagnosis of SARA, employing next generation sequencing technology for comprehensive identification of miRNAs in plasma and leucocytes. Six bucks were fed a control diet of 100% forage and subsequently, modulated to a 70% high-grain diet. 421 and 523 miRNAs were recorded for plasma and leucocytes, respectively. Bta-miR-2285u, bta-miR-30b-3p and bta miR-1271 were differentially expressed between diets. Thus, they were chosen as potential SARA biomarker candidates and further analyzed by RT- qPCR in more bucks. Bta-miR-30-3p, a rumen specific miRNA that can detect short term ruminal imbalances was highly expressed in plasma of goats. Hence, abundance of serum bta miR-30-3p could serve as effective biomarker for rumen health. Further analysis on mechanism involved may be explored.