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

• 作者: Zuo Wang Lingmei Zhang Zhicai Li Yuannian Yu Lingyuan Yang Peihua Zhang Weijun Shen Fachun Wan Jianhua He Wenjun Xiao Dasheng Yang Zhiliang Tan Shaoxun Tang
• 来源期刊: 动物营养（英文版）
• 年，卷（期）: 2021,（4）
• 所属期刊栏目: SHORT COMMUNICATION
• 页码范围: 1253-1257
• 页数: 5页
• 语种: 英文

摘要

The present trial was performed to reveal the regulatory effects of L-theanine on the levels of lipo-polysaccharide (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 d in milk,and 2 ± 1 parities) were allocated in a completely randomized design to each of 3 dietary treat-ments: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.