Selenium (Se) is an essential trace element that has a large number of biological functions for broilers. However, the absorption kinetics of Se from sodium selenite in the small intestine of broilers remains unclear. Therefore, two experiments were conducted with 28-d-old commercial male broilers to study the kinetics of Se absorption in ligated small intestinal segments. In experiment 1, the Se absorption in duodenal, jejunal, and ileal segments at different post-perfusion time points (0, 20, 40, 60, 80, 100 and 120 min) were compared. In experiment 2, a kinetic study of Se absorption was conducted with the duodenal, jejunal, and ileal loops perfused with solutions containing 0, 0.0375, 0.075, 0.15, 0.30, or 0.60 μg mL⁻¹ of Se as sodium selenite, and Se contents in perfusates were determined at 100 min after perfusion. The results from experiment 1 showed that the Se absorption increased in an asymptotic response (P<0.0001) to post-perfusion time within 120 min in all the small intestinal segments, but increased linearly (P<0.0001) at less than 100 min after perfusion in duodenal and ileal segments, while more than 96.0% of the maximum Se absorption occurred at 100 min after perfusion in each small intestinal segment. In experiment 2, there was no difference (P>0.05) in the Se absorption rate among different ligated small intestinal segments perfused with solutions containing 0.0375–0.15 μg mL⁻¹ of Se, however, the Se absorption rate was higher (P<0.05) in the jejunum than that in the duodenum perfused with solutions containing 0.30–0.60 μg mL⁻¹ of Se. The kinetic curves of Se absorption demonstrated that the Se absorption was a saturated carrier-mediated process in the duodenum, and the maximum absorption rate was 1 271 pg min⁻¹ cm⁻¹; whereas the Se absorptions were a non-saturated diffusion process in the jejunum and ileum, and the diffusive constants were 2 107 and 1 777 cm² min⁻¹, respectively. The results from the present study indicate that the jejunum is the main Se absorption site, and the Se absorption is a saturated carrier-mediated process in the duodenum, but a non-saturated diffusion process in the jejunum and ileum of broilers.

硒（Se）是一种必需的微量元素，对肉鸡具有大量的生物学功能。然而，在肉鸡小肠中亚硒酸钠对硒的吸收动力学尚不清楚。因此，对28日龄的商业雄性肉鸡进行了两个实验，以研究结扎的小肠段中硒的吸收动力学。在实验1中，比较了在灌注后不同时间点（0、20、40、60、80、100和120分钟）十二指肠，空肠和回肠段的硒吸收。在实验2中，用十二指肠，空肠和回肠loop灌注含有0、0.0375、0.075、0.15、0.30或0.60μgmL ^-1的溶液进行了Se吸收的动力学研究。硒作为亚硒酸钠，在灌流后100分钟测定灌流液中的硒含量。实验1的结果表明，在所有小肠段内，Se的吸收在120分钟内对灌注后时间呈渐近响应（P <0.0001），但在灌注后不到100 min线性增加（P <0.0001）。在十二指肠和回肠段，在每个小肠段灌注后100分钟，最大硒吸收量的96.0％以上。在实验2中，灌注0.0375–0.15μgmL ^-1的Se溶液的不同结扎小肠段的Se吸收率没有差异（P > 0.05），但是Se吸收率更高（空肠中的P <0.05）比十二指肠中灌注的含0.30–0.60μgmL ^-1 Se的溶液要高。硒的吸收动力学曲线表明，十二指肠中硒的吸收是一个饱和的载体介导过程，最大吸收速率为1271 pg·min ^-1 cm ^-1。而Se吸收是在空肠和回肠中的非饱和扩散过程，扩散常数分别为2 107和1 777 cm ² min ^-1， 分别。本研究的结果表明，空肠是硒的主要吸收部位，硒的吸收是十二指肠中饱和的载体介导的过程，而在肉鸡的空肠和回肠中是非饱和的扩散过程。