Behavioral expressions and biochemical composition of body exudates are significantly altered in concert with the endocrine status, which are all clear indicators of physiological conditions of animals. In this study, we sought to infer about the reproductive physiological status of Kangayam cattle (Bos indicus) by analyzing behaviors, endocrine pattern, and body exudates and further to discover estrous biomarkers so as to facilitate timely artificial insemination/mating and to aid in aspects of conservation of the species. Therefore, in this study, we followed Kangayam cows through pre-estrous to post-estrous phases to correlate the endocrine dependence of biochemical constituents in urine and cervical mucus and sought to identify estrous biomarkers. Behavioral estrus was confirmed in 10 cows, from which urine samples were collected and subjected to determination of LH, FSH, estrogens, progesterone, proteins, and lipids. Furthermore, urinary fatty acids and proteins were profiled using gas chromatography and SDS-PAGE, respectively. The volatile compounds in the urine and cervical mucus were identified by gas chromatography–mass spectrometry analysis. The data revealed that LH, FSH, and estrogen levels increased significantly in estrous urine compared with nonestrous urine, whereas progesterone status was vice versa (P < 0.05). The lipid content was also significantly higher in estrous urine than in pre- and post-estrous urines (P < 0.05). There were also cyclical variations of volatiles and fatty acid profiles across phases of the estrous cycle. More acidic compounds were present in estrous urine, rendering it more acidic, than in pre- and post-estrous urines. Interestingly, oleic acid, which was present as a fatty acid in estrous and post-estrous urines, appeared to be a volatile in post-estrous urine and estrous cervical mucus. In addition, octanoic and butanoic acids were specific to both estrous urine and cervical mucus, indicating their possible candidature as estrous biomarkers. SDS-PAGE analysis showed pronounced expression of a 98 kDa protein in post-estrous urine, which in matrix-assisted laser desorption ionization-time of flight mass spectrometry was identified as albumin. Our results demonstrate multiple biomarkers in estrous urine and specific volatiles in cervical mucus that offer scope to develop viable estrus detection kits for Kangayam cows.

身体分泌物的行为表达和生化组成与内分泌状态一致发生了显着变化，这都是动物生理状况的明确指标。在这项研究中，我们试图推断袋鼠牛（Bos indicus）的生殖生理状况。），通过分析行为，内分泌模式和身体分泌物，并进一步发现发情的生物标志物，以便及时进行人工授精/交配，并有助于保护物种。因此，在这项研究中，我们跟踪袋鼠奶牛从发情前到发情后的阶段，以关联尿液和宫颈粘液中生化成分的内分泌依赖性，并试图鉴定发情的生物标志物。在10头母牛中确认了行为发情，从中收集了尿液样本并进行了LH，FSH，雌激素，孕酮，蛋白质和脂质的测定。此外，分别使用气相色谱和SDS-PAGE对尿中的脂肪酸和蛋白质进行了分析。尿液和宫颈粘液中的挥发性化合物通过气相色谱-质谱分析法鉴定。反之亦然（P <0.05）。发情尿液中的脂质含量也显着高于发情前后的尿液（P<0.05）。在发情周期的各个阶段，挥发物和脂肪酸的分布也存在周期性变化。与发情前后的尿液相比，发情尿液中存在更多的酸性化合物，使其呈酸性。有趣的是，在发情和发情后尿中以脂肪酸形式存在的油酸似乎在发情后尿液和发情的宫颈粘液中是挥发性的。此外，辛酸和丁酸对发情的尿液和宫颈粘液都具有特异性，表明它们可能作为候选发情的生物标志物。SDS-PAGE分析表明，发情后尿液中有一个98 kDa蛋白的明显表达，在基质辅助激光解吸电离飞行时间质谱中被鉴定为白蛋白。