RNA-seq analysis of differential gene expression in jejunal epithelial from Holstein Friesian bulls undergoing diet restriction and compensatory growth

The objective of this study was to examine the effect of dietary restriction and subsequent re-alimentation induced compensatory growth on the global gene expression profile of jejunum epithelial Holstein Friesian bulls (n=40) were assigned to one of two groups: restricted feed allowance (RES; n=20) for 125 days (Period 1) followed by ad libitum access to feed for 55 days (Period 2) or (ii) ad libitum access to feed throughout (ADLIB; n=20). All bulls received the same diet of 70% concentrate 30% grass silage through out the experimental trial,with the amount of feed provided different dependent on each treatment group. At the end ofeach period, 10 animals from each treatment group (RES, ADLIB) were slaughtered, and jejunum epithelial collected from all animals. RNA was extracted and jejununal epithelium gene expression was examined using RNAseq technology on all samles collected (end of Period 1: 10 samples each from ADLIB and RES groups; end of Period 2: 10 samples each from ADLIB and RES groups). Dietary restriction and subsequent re-alimentation were associated with altered expression of genes involved in digestion and metabolism, aswell as cellular protection and detoxification in jejunal epithelia. This information may be exploited in genomic breeding programmes to assist selection of cattle with a greater ability to compensate following a period dietary restriction. Overall design: 40 jejunumal epithelium RNA samples were analysed in total. 10 samples were from jejunum epithelium collected at the end of a period of dietary restriction (d 125; Period 1) and 10 samples were from jejunum epithelium collected after 55 days of compensatory growth (d 55 of re-alimentation, Period 2). In addition, RNA was also anlaysed from 10 samples collected from animals fed ad libitum at the end of both Period 1 and Period 2.

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Keogh K, Kenny DA, Waters SM