Abstract：
Estrus identification is one of the common issues in buffaloes because of their short estrus duration and silent estrus problem. Hence, specific biomarkers facilitating in identifying the estrus stage would be helpful to buffalo farmers and researchers. In our previous studies, taurine, a non-protein amino acid that helps in the secretion of reproductive hormones such as GnRH, was found to be associated with postpartum anestrus in buffaloes. Therefore, the present study was conducted to explore the level of taurine in serum during different stages of the oestrous cycle in healthy cyclic buffaloes. Blood samples were collected from healthy cyclic buffaloes (n = 4), and taurine was estimated at the estrus (0th day), proestrus (-2nd day), metestrus (3rd day) and diestrus (+10th day) stages using TLC method. The days of the oestrous cycle were determined by ultrasonography and observation of behavioural signs by trained professionals. The results revealed that taurine was consistently present in the serum. However, the highest concentration of taurine was observed at the proestrus (0.20 ± 0.03 mg/mL) stage, which was greater (p < .05) than metestrus (0.10 ± 0.05 mg/mL) and diestrus (0.13 ± 0.03 mg/mL) stages, but comparable with the estrus stage. These results were also validated in the simulated population datasets of population size 6 to 10,000. Further, ROC curve analysis for the large simulated population indicated the efficiency of taurine to distinguish proestrus from metestrus and diestrus stages at a lower cutoff value of <0.1643 mg/mL with 60% sensitivity and specificity. Therefore, the present study concludes that serum taurine concentration could help in detecting proestrus stage of buffalo estrous cycle.
摘要：
由于水牛发情时间短，发情困难，发情识别是水牛的常见问题之一。因此，有助于确定发情期的特定生物标志物将对水牛农民和研究人员有所帮助。在我们之前的研究中,牛磺酸,一种非蛋白质氨基酸，有助于分泌生殖激素，如GnRH，被发现与水牛的产后发情期有关。因此,本研究旨在探讨健康水牛在动情周期不同阶段血清中牛磺酸的水平。从健康的环状水牛（n=4）收集血液样本，牛磺酸估计在发情期（第0天），发情期（-第2天），动情期（第3天）和动情期（第10天）阶段使用TLC方法。通过超声检查确定发情周期的天数，并由训练有素的专业人员观察行为体征。结果显示牛磺酸始终存在于血清中。然而,在发情期观察到牛磺酸的最高浓度（0.20±0.03mg/mL），（p<0.05）大于动情期（0.10±0.05mg/mL）和动情期（0.13±0.03mg/mL）阶段，但与发情期相当。这些结果也在人口规模6至10,000的模拟人口数据集中得到了验证。Further,大模拟群体的ROC曲线分析表明，牛磺酸在<0.1643mg/mL的较低临界值下区分发情期和发情期的效率，敏感性和特异性为60％。因此,本研究的结论是，血清牛磺酸浓度有助于检测水牛发情周期的发情期。
