Saccharomyces cerevisiae fermentation products reduce bacterial endotoxin concentrations and inflammation during grain-based subacute ruminal acidosis in lactating dairy cows

Abstract

Subacute ruminal acidosis (SARA) is a metabolic disorder in dairy cows that is associated with dysbiosis of rumen and hindgut microbiomes, translocation of immunogenic compounds from the gut lumen into blood circulation, and systemic inflammatory response. In this study we hypothesized that Saccharomyces cerevisiae fermentation products (SCFP) attenuate the increases in ruminal and peripheral bacterial endotoxin concentrations and the inflammation resulting from repeated induction of SARA. Lactating Holstein dairy cows (parity 2 and 3+, n = 32) were fed diets with or without SCFP (all from Diamond V) and subjected to 2 episodes of SARA challenges. Cows received a basal total mixed ration (TMR) containing 34% neutral detergent fiber and 18.6% starch, dry matter (DM) basis. Treatments were randomly assigned to control (basal TMR and 140 g/d of ground corn with no SCFP) or 1 of 3 SCFP treatments: basal TMR and 14 g/d Original XPC (SCFPa), 19 g/d NutriTek (SCFPb-1×), or 38 g/d NutriTek (SCFPb-2×) mixed with 126, 121, or 102 g/d of ground corn, respectively. Treatments were implemented from 4 wk before until 12 wk after parturition. During wk 5 (SARA1) and wk 8 of lactation (SARA2), grain-based SARA challenges were conducted by gradually replacing 20% of DM of the basal TMR over 3 d with pellets containing 50% wheat and 50% barley. Ruminal fluid, fecal, and blood samples were collected weekly during Pre-SARA1 (wk 4, as baseline), Post-SARA1 (wk 7), and Post-SARA2 (wk 10 for blood and wk 12 for rumen and fecal parameters) stages, and twice a week during the challenges SARA1 and SARA2. Rumen papillae samples were taken only during Pre-SARA1 and Post-SARA2. We measured the concentrations of free lipopolysaccharides (LPS) in the rumen fluid and feces; free LPS and lipoteichoic acid (LTA) endotoxins in peripheral plasma; interleukin (IL)-1β and IL-6 in peripheral serum; acute-phase proteins, serum amyloid A (SAA), and LPS-binding protein in peripheral plasma; haptoglobin (Hp) in peripheral serum; and myeloperoxidase (MPO) in rumen papillae. Induction of SARA episodes increased free LPS concentrations in rumen fluid and tended to increase LTA in peripheral plasma. The SARA episodes increased concentration of circulating SAA and tended to increase that of IL-1β compared with Pre-SARA1. Induction of SARA did not affect the concentrations of circulating IL-6, Hp, and MPO. The SCFP supplementation reduced plasma concentrations of LTA and SAA and serum concentration of IL-1β compared with control. Additionally, SCFPb-2× tended to reduce ruminal LPS in second-parity cows compared with control. Overall, SCFP supplementation appeared to stabilize the rumen environment and reduce proinflammatory status, hence attenuating adverse digestive and inflammatory responses associated with SARA episodes.

Effects of high-grain diet feeding on fatty acid profiles in milk, blood, muscle, and adipose tissue, and transcriptional expression of lipid-related genes in muscle and adipose tissue of dairy cows

“…The causes of this result are probably the decreased lipolysis and ruminal biohydrogenation of dietary fatty acids under the low ruminal pH [47] or the insu cient supply of endogenous fatty acids from liver and adipose tissue [48,49] . Previous studies have shown that grainbased SARA increases ruminal and peripheral bacterial endotoxin concentrations [50] . Zebeli Q et al [51] found that ruminal endotoxin concentration was negatively correlated with plasma TCHO concentration.…”

Effect of an Immunomodulatory Feed Additive in Mitigating the Stress Responses in Lactating Dairy Cows to a High Concentrate Diet Challenge

“…These differences on CORT recorded levels could be related with the high variability of this parameter and low sampling frequency applied in this research. Moreover, it is proposed that the functional metabolites, organic acids, vitamins, and antioxidants present in the yeast cells’ wall, one of the active ingredients in OMNG, may either be used as nutrients by the rumen and gut microbiota or act as signaling molecules affecting interactions between microbes and the immunological response [ 77 ].…”

Invited review: Effect of subacute ruminal acidosis on gut health of dairy cows

“…Also, Kent-Dennis et al ( 2020) observed that a short-term SARA challenge reduced the expression of several genes related to inflammatory responses, suggesting that SARA reduced this response. In addition, Guo et al (2022) observed that moderate grain-induced SARA did not increase the concentration of myeloperoxidase in rumen papillae, which suggests that these papillae were not inflamed. Hence, the acute phase response observed during SARA may be partially due to an inflammatory response in the reticulo-ruminal epithelium.…”

“…This translocation causes local inflammation and the passage of these toxins to the portal circulation and into the peripheral circulation, which can cause systemic inflammation. This inflammation is innate and consists of moderate changes in the concentrations of proinflammatory cytokines and moderate changes in the concentrations of acute phase proteins in blood, including increases in the concentrations of SAA, Hp, and LBP in peripheral blood (Zebeli and Metzler-Zebeli, 2012;Li et al, 2016;Guo et al, 2022). The moderate nature of this immune response may be due to the relatively low immunogenicity of ruminal LPS compared with LPS from pathogenic bacteria, such as E. coli (Plaizier et al, 2012(Plaizier et al, , 2018.…”