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.

 

This study was conducted to investigate the effect of dietary supplementation with pyrroloquinoline quinone (PQQ) in the form of PQQ disodium (PQQ·Na₂) on the growth performance, carcass traits, meat quality and antioxidative ability of broilers.  A total of 720 one-d-old Arbor Acres male broilers were randomly allocated to 1 of 6 treatments with 8 replicates of 15 birds per replicate in a completely randomized design.  Birds were fed a PQQ·Na₂-unsupplemented corn-soybean meal basal diet (control) or the basal diet supplemented with 0.1, 0.2, 0.3, 0.4 or 0.5 mg PQQ·Na₂ kg^–1 for 42 d.  Compared with the control chicks, the chicks fed the diets supplemented with PQQ·Na₂ had lower (P<0.05) feed:gain (F/G) during the grower phase and drip losses of breast muscles on day 42.  As supplemental PQQ·Na₂ level increased, plasma total antioxidant capacity (T-AOC) on d 42, liver T-AOC on d 21 and heart T-AOC on d 21 and 42 increased linearly (P<0.05), but malondialdehyde concentrations in plasma, liver and heart on d 21 or 42 decreased linearly (P<0.001) or quadratically (P<0.005).  The results from the present study indicate that dietary supplemental PQQ·Na₂ can improve antioxidant ability and meat quality  of broilers, and in general, it is implied that the optimal supplemental PQQ·Na₂ level is 0.1 mg kg^–1 of diet for broilers from 1 to 42 d of age.