This study was aimed to evaluate the effect of mulberry leaf flavonoids (MLF) on oxidative stress, metabolic hormones, and milk production in Murrah buffaloes. Forty multiparous Murrah buffaloes (4 ± 1 lactations) with similar body weight (average 600 ± 50 Kg) and stage of lactation (90 ± 20 d) were randomly selected for this trial. Four treatment groups (10 buffaloes per group) with different doses of MLF included; control (0 g/d), MLF15 (15 g/d), MLF30 (30 g/d), and MLF45 (45 g/d). Buffaloes were fed with total mix ration consisting of grass (Pennisetum purpureum schum), brewery's grain and concentrate mixture for 5 weeks. Meteorological data including ambient temperature and relative humidity were recorded using the online dust monitoring system to calculate temperature-humidity index (THI). After 1 week of the adaptation, milk yield was recorded daily while physiological parameters (respiratory rate, rectal, and body surface temperature), and milk composition were measured weekly. At the end of the trial, blood samples were collected to analyze serum metabolic hormones including estradiol (E2), growth hormone (GH), prolactin (PRL), Tri-iodothyronine (T3), and Thyroxine (T4). Moreover, serum heat shock proteins (HSP), antioxidants enzymes including malondialdehyde (MDA), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and blood biochemical indices were also analyzed. Results revealed a decrease (P = 0.012) in serum MDA level while increasing (P < 0.01) the HSP and serum GHS-Px contents in supplemented buffaloes. Treatment showed a linear and quadratic decrease (p = 0.001) in the serum T-AOC while reducing CAT contents linearly (p = 0.012) as compared to the control. However, no effect of treatment on serum SOD content was observed. Treatment resulted a linear increase (p = 0.001) in serum GH and PRL hormones while increasing serum E2 levels linearly (P < 0.001) and quadratically (P = 0.025). Treatment increased (p = 0.038) the daily milk yield as compared to the control. However, increase (P < 0.05) in serum T3 and T4 contents, fat corrected milk (4%) and milk protein (%) was observed only in MLF45. Moreover, we observed no change in serum biochemical indices except insulin which linearly increased (p = 0.002) in MLF45. Our findings indicated that MLF at 45 g per day is an appropriate level to enhance milk performance and alleviate heat stress in buffaloes.

这项研究旨在评估桑叶类黄酮（MLF）对Murrah水牛的氧化应激，代谢激素和产奶量的影响。该试验随机选择了四十只体重相似（平均600±50 Kg）和泌乳阶段（90±20 d）的Murrah水牛（4±1哺乳期）。四个治疗组（每组10只水牛）包括不同剂量的MLF；对照（0 g / d），MLF15（15 g / d），MLF30（30 g / d）和MLF45（45 g / d）。给水牛喂食由草（紫草狼尾草），啤酒厂的谷物和浓缩混合物，持续5周。使用在线灰尘监测系统记录了包括环境温度和相对湿度在内的气象数据，以计算温度-湿度指数（THI）。适应1周后，每天记录牛奶产量，同时每周测量生理参数（呼吸速率，直肠和体表温度）和牛奶成分。在试验结束时，收集血液样本以分析血清代谢激素，包括雌二醇（E2），生长激素（GH），催乳素（PRL），三碘甲状腺素（T3）和甲状腺素（T4）。此外，血清热激蛋白（HSP），抗氧化酶包括丙二醛（MDA），总抗氧化能力（T-AOC），超氧化物歧化酶（SOD），过氧化氢酶（CAT），并分析了谷胱甘肽过氧化物酶（GSH-Px）和血液生化指标。结果显示减少了（P 血清MDA水平= 0.012），同时增加（P<0.01）补充水牛中的HSP和血清GHS-Px含量。治疗显示线性和二次下降（p = 0.001），同时线性降低CAT含量（p= 0.012）。然而，未观察到治疗对血清SOD含量的影响。治疗导致线性增加（p = 0.001）的血清GH和PRL激素，同时线性增加血清E2水平（P <0.001）和平方（P= 0.025）。治疗增加（p= 0.038）与对照相比的每日牛奶产量。但是，增加（P血清T3和T4含量<0.05），仅在MLF45中观察到脂肪校正乳（4％）和乳蛋白（％）。此外，我们观察到血清生化指标没有变化，除了胰岛素线性增加（p= 0.002）（MLF45）。我们的研究结果表明，每天45 g的MLF是提高牛奶性能和减轻水牛热应激的合适水平。