Effects of blood pathological changes before TAI on pregnancy of dairy cows with anestrus and estrus

ABSTRACT The objective of this study was to investigate the influence of plasma pathological changes before timed artificial insemination (TAI) on pregnancy of cows. The contents of estrogen (E2), progesterone (P4), glucose (Glu), selenium (Se), brain-derived neurotrophic factor (BDNF), and histamine (HIS) in plasma of 48 Holstein cows were measured before TAI. According to the estrus detection, the cows were divided into estrus (E) and anestrus (A) groups. After pregnancy testing at 28 d after TAI, two groups of E and A were divided into positive pregnancy of E group (EP+), negative pregnancy of E group (EP-), positive pregnancy of A group (AP+), and negative pregnancy of A group (AP-). The contents of E2, P4, Glu, Se, BDNF and hIS significantly differed among the four groups (P&lt;0.01). The ROC analysis was used to determine the risk of negative pregnancy test (-) after TAI was increased when plasma E2 was less than 46.45 pmol/L in cows before TAI. The changes in E2, P4,hIS, Glu, and BDNF in the blood of natural estrus and natural anestrus cows affected the pregnancy after TAI. the level of E2 in plasma may be used to assess the risk of negative pregnancy after TAI.摘要 本研究旨在探讨定时人工授精（TAI）前血浆病理变化对奶牛妊娠结局的影响。研究于定时人工授精前，检测了48头荷斯坦奶牛血浆中的雌激素（E2）、孕酮（P4）、葡萄糖（Glu）、硒（Se）、脑源性神经营养因子（BDNF）及组胺（HIS）水平。根据发情检测结果，将受试奶牛划分为发情组（E组）与乏情组（A组）；于定时人工授精后28 d开展妊娠检测后，进一步将E组与A组分别分为发情妊娠阳性组（EP+）、发情妊娠阴性组（EP-）、乏情妊娠阳性组（AP+）及乏情妊娠阴性组（AP-）。四组受试奶牛的E2、P4、Glu、Se、BDNF及HIS水平均存在极显著组间差异（P<0.01）。通过ROC分析发现，奶牛在定时人工授精前血浆E2水平低于46.45 pmol/L时，其定时人工授精后妊娠检测呈阴性的风险显著升高。自然发情与自然乏情奶牛血液中E2、P4、HIS、Glu及BDNF的水平变化，会对定时人工授精后的妊娠结局产生影响；血浆E2水平可用于评估定时人工授精后妊娠阴性的风险。