Alterations of endotoxin distribution across different biofluids and relevant inflammatory responses by supplementing L-theanine in dairy cows during heat stress

Abstract

The present trial was performed to reveal the regulatory effects of L-theanine on the levels of lipopolysaccharide (LPS) endotoxin within different biofluids, as well as relevant inflammatory responses of dairy cattle under heat stress conditions. Thirty lactating Chinese Holstein dairy cattle (189 ± 47 days in milk, and 2 ± 1 parities) were allocated in a completely randomized design to each of 3 dietary treatments: the control (CON, 0 g/d per cow L-theanine), the low L-theanine dosage treatment (LL, 16 g/d per cow L-theanine), and the high L-theanine dosage treatment (HL, 32 g/d per cow L-theanine). This trial consisted of 38 d (7 d for adaption and 31 d for data and sample collection), and sample collection for rumen liquid, blood plasma or serum, and milk were conducted on the d 27 and 38, respectively. Dairy cattle were constantly exposed to environmental heat stress during this experiment according to the recorded temperature-humidity index (THI). In the LL treatment, LPS concentration in rumen liquid was higher ( P < 0.05), whilst LPS densities in plasma and milk were lower ( P < 0.05) than those of the CON. Supplementing L-theanine at 2 dosages both significantly lowered ( P < 0.05) the level of interleukin (IL)-1β in the serum. Results of the present study suggested that L-theanine could be a promising additive in reducing the detrimental effects of heat stress on dairy cows, and L-theanine supplementation at 16 g/d per cow is preferred because it reduced the LPS translocation into the peripheral blood and LPS accumulation in the milk, as well as mitigated LPS-induced inflammatory reactions in dairy cows during heat stress. Further studies are necessitated to investigate the underlying mechanisms of L-theanine in LPS alteration and inflammation alleviation.

Dietary Supplementation of Enzymatically Treated Artemisia annua L. Improves Lactation Performance, Alleviates Inflammatory Response of Sows Reared Under Heat Stress, and Promotes Gut Development in Preweaning Offspring

“…In addition, HS injures the barrier of the intestine and induces the increment of endotoxins (i.e., LPS) from bacteria flow across the mesenteric-drained viscera. The transfer of endotoxins to the interior circulation contributes to systemic inflammation (49).…”

Tannic acid reduced apparent protein digestibility and induced oxidative stress and inflammatory response without altering growth performance and ruminal microbiota diversity of Xiangdong black goats

“…Upon the translocation of LPS endotoxin from rumen into the peripheral blood, the secretion of a series of pro-inflammatory cytokines and systemic inflammation would be provoked ( 29 , 53 ). No impact on the LPS level in rumen fluid or plasma by TA addition was illustrated by the present trial.…”

“…For the measurement of lipopolysaccharide (LPS) endotoxin in the rumen fluid and plasma, and relevant inflammatory indicators, methods illustrated by Wang et al ( 26 , 29 ) were adopted. A Roche Cobas automatic biochemistry analyzer (c311, Roche Ltd., Basel, Switzerland) and related specific kits (Roche Ltd., Basel, Switzerland) were employed to determine the biochemical blood characteristics, by referring to the manufacturer's protocols and precedent report ( 30 ).…”

Tannic acid supplementation in the diet of Holstein bulls: Impacts on production performance, physiological and immunological characteristics, and ruminal microbiota

“…The LPS endotoxin released by the gram-negative bacteria can stimulate the production of several pro-inflammatory cytokines and thereby trigger systemic inflammation, when it translocates into the peripheral blood from the digestive tract ( 50 , 51 ). As demonstrated in the current experiment, the density of LPS neither in the rumen fluid nor the plasma was influenced by the addition of TA at different doses.…”