Lipopolysaccharide derived from the rumen down-regulates stearoyl-CoA desaturase 1 expression and alters fatty acid composition in the liver of dairy cows fed a high-concentrate diet

Abstract

BackgroundDairy cows are often fed a high-concentrate diet to meet lactating demands, yet long-term concentrate feeding induces subacute ruminal acidosis (SARA) and leads to a decrease in milk fat. Stearoyl-CoA desaturase1 (SCD1) participates in fatty acid biosynthesis in the liver of lactating ruminants. Here, we conducted this study to investigate the impact of lipopolysaccharide derived from the rumen on SCD1 expression and on fatty acid composition in the liver of dairy cows fed a high-concentrate diet. Eight multiparous mid-lactating Holstein cows (455 ± 28 kg) were randomly assigned into two groups in the experiment and were fed a low-concentrate diet (LC) or high-concentrate diet (HC) for 18 weeks.ResultsThe results showed that the total volatile fatty acids and lactic acid accumulated in the rumen, leading to a decreased rumen pH and elevated lipopolysaccharides (LPSs) in the HC group. The long chain fatty acid profile in the rumen and hepatic vein was remarkably altered in the animals fed the HC diet. The triglyceride (TG), non-esterified fatty acid (NEFA) and total cholesterol (TCH) content in the plasma was significantly decreased, whereas plasma glucose and insulin levels were increased. The expression of SCD1 in the liver was significantly down-regulated in the HC group. In regards to transcriptional regulators, the expression of sterol regulatory element binding transcription factors (SREBF1c, SREBF2) and SREBP cleavage activating protein (SCAP) was down-regulated, while peroxisome proliferator-activated receptor α (PPARα) was up-regulated.ConclusionsThese data indicate that lipopolysaccharide derived from the rumen down-regulates stearoyl-CoA desaturase 1 expression and alters fatty acid composition in the liver of dairy cows fed a high-concentrate diet.

Lipopolysaccharide derived from the digestive tract triggers an inflammatory response in the uterus of mid-lactating dairy cows during SARA

“…The results of ruminal pH fed a high concentrate diet were published previously by Xu et al [33] and he confirmed the presence of SARA by measuring the ruminal pH at different time intervals. In this study, consuming a high-concentrate diet (HC group) for 18 weeks resulted in a significant decline in ruminal pH (<5.6) than that in the LC group ( p  < 0.05) and lasted for more than three hours [2].…”

“…Conclusively, LPS activates TLR4-NF-κB signalling. Together with the existing study and the previous reports [33, 37], the protein expressions of NF-κB (p65) and p-p65 were magnified in the HC group.…”

“…To evaluate the inflammatory response in cow uterus and to explore the molecular mechanism triggered by high concentrate diet, SARA was confirmed by measuring the pH of the rumen. Xu et al [33] also confirmed the presence of SARA by measuring the ruminal pH at different time intervals. In our study, the low rumen pH (>5.6) lasted for 223 min and high concentrations of LPS were observed in the rumen fluid and peripheral blood.…”

Dietary regulation of Ucp2 and Ucp3 expressions in white adipose tissues of beef cattle

“…The production of long-chain fatty acids that activate Pparγ may have been enhanced in cattle fed the concentrate or vitamin A-deficient diet. The dietary roughage to concentrate ratio affected the fatty acid composition in bovine WAT; plasma concentration of long-chain fatty acid was generally decreased by feeding high concentrate diet in cattle, but the concentrations of C22:0 and C22:1 were increased (Xu et al 2015). Furthermore, the vitamin A status may affect the fatty acid profile in the intramuscular fat of beef cattle by modulating Δ 9 -desaturase activity potentially (Smith et al 2009).…”

Buffering Agent Induced Lactose Content Increases via Growth Hormone-Mediated Activation of Gluconeogenesis in Lactating Goats

“…In the dairy industry, it is currently common practice to feed a high-concentrate (HC) diet to lactating cows or goats to meet their energy requirements to support high milk production. However, long-term high concentrate feeding is harmful to the health of ruminants and leads to a decrease in milk yield [1]. It was reported that feeding of HC diets to lactating cows causes a decline in the rumen pH if organic acids, such as volatile fatty acid (VFA) and lactic acid, accumulate in the rumen[2].…”