High rumen degradable starch decreased goat milk fat via trans-10, cis-12 conjugated linoleic acid-mediated downregulation of lipogenesis genes, particularly, INSIG1.

摘要: Starch is an important substance that supplies energy to ruminants. To provide sufficient for high-yielding dairy ruminants, they are typically fed starch-enriched diets. However, diets have been proven increase the risk of milk fat depression (MFD) in cows. The starch present ruminant could be divided into rumen-degradable (RDS) and rumen escaped (RES) according their different degradation sites (rumen or intestine). Goats cows sensitivities MFD. Data regarding potential roles RDS synthesis mammary tissue goats regulating occurrence MFD limited. Eighteen Guanzhong (day milk = 185 ± 12 d) with similar parity, weight, yield were selected randomly assigned one three groups (n = 6), which LRDS diet (Low RDS = 20.52%), MRDS (Medium RDS = 22.15%), HRDS (High RDS = 24.88%) 5 weeks. Compared group, contents significantly decreased. yields short-, medium- long-chain fatty acids decreased group. Furthermore, increased ruminal B. fibrisolvens Pseudobutyrivibrio abundances trans-10, cis-12 conjugated linoleic acid (CLA) trans-10 C18:1 fluid. A multiomics study revealed affected lipid metabolism down-regulation ACSS2, MVD, AGPS, SCD5, FADS2, CERCAM, SC5D, HSD17B7, HSD17B12, ATM, TP53RK, GDF1 LOC102177400. Remarkably, significant decrease INSIG1, whose expression was depressed by CLA, reduce activity SREBP and, consequently, downregulate downstream gene SREBF1. HRDS-induced goat resulted from downregulation genes involved lipogenesis, particularly, INSIG1. Specifically, even though total content concentrate-to-fiber ratio same as those high-RDS diet, low medium did not cause lactating goats.