Long-term effects of prior diets, dietary transition and pregnancy on adipose gene expression in dairy heifers

Abstract

Adipose tissue is highly involved in whole-body metabolism and is the main site for lipid synthesis, storage and mobilization in ruminants. Therefore, knowledge about adipose tissue responses to different diets is important, especially in growing heifers as the feeding regimes of replacement heifers affect their future success as dairy cows. However, at gene expression level such knowledge is limited. As part of a larger feed trial, adipose tissue biopsies from 24 Norwegian Red heifers were collected at 12 months of age (12MO) and at month seven of gestation (PREG) and analyzed by next-generation mRNA sequencing. Between these two sampling points, all heifers had gone through a successful conception and a feed change from four dietary treatments of high or low energy (HE/LE) and protein (HP/LP) content (treatments LPHE, HPHE, LPLE and HPLE) to a low-energy, low-protein pregnancy feed given to all animals. Gene expression differences between different feed treatments at 12MO are described in an earlier publication from our group. The main objectives of this study were to investigate the long-term effects of diets differing in protein and energy density level on gene expression in adipose tissue of growing replacement dairy heifers. To achieve this, we examined the post-treatment effects between the treatment groups at month seven of gestation; 6 months after the termination of experimental feeding, and the long-term gene expression changes occurring in the adipose tissue between 12MO and PREG. Post-treatment group comparisons showed evidence of long-term effects of dietary treatment on adipose gene expression. Differences between protein treatments were smaller than between energy treatments. Adipose gene expression changes from 12MO to PREG were much larger for the HE than the LE treatments and seemed to mostly be explained by the characteristics of the diet change. 97 genes displayed a unidirectional expression change for all groups from 12MO to PREG, and are considered to be treatment-independent, possibly caused by pregnancy or increased age. This study provides candidate genes and key regulators for further studies on pregnancy preservation (TGFB1, CFD ) and metabolic regulation and efficiency (PI3K, RICTOR, MAP4K4,) in dairy cattle.

Differential gene expression in the Longissimus dorsi of Nguni and Bonsmara bulls finished on low and high energy diets

“…Expression of transcripts of ENSBTAG00000031205 (fold-change = 31.5; FDR P = 2.5 x 10 -5 ) that encode 40S ribosomal protein S4 were likewise affected by the breed by diet interaction. Waerp et al (2019) previously observed transcripts of this gene to be differentially abundant in adipose tissue from dairy heifers at 12 months of age versus when they were seven months pregnant when the heifers were fed a high energy diet but not when a lower energy diet was fed. The ENSBTAG00000049315 (foldchange = -178.5; FDR P = 6.6 x 10 -3 ) was the final transcript affected by the breed by diet interaction.…”

Favored single nucleotide variants identified using whole genome Re-sequencing of Austrian and Chinese cattle breeds

“…For Mongolian cattle, ALDOA was the highest expressed gene with 12,960 FPKM in chorid plexus tissue in the brain. ALDOA is primarily related to glycolytic and energy metabolism ( Wærp et al, 2019 ). TNNT2 identified in Yanbian was highly expressed in heart tissue with 5006 FPKM.…”

“…According to https://bgee.org/?page=gene&gene_id=ENSBTAG00000007075 , this gene was described as a major histocompatibility complex, class I, A-like precursor and has paralogs to BOLA-A and JSP.1 genes. And has an association with feeding efficiency in Norwegian Red heifers where it is upregulated during diet changes from low-protein-high-energy to low-protein-low-energy feed ( Wærp et al, 2019 ). Yet, for GO classification, we considered only genes with official ID names overlooking functions of genes with prefix ENBST names.…”