Kinetic uv assay

Blood collection from sows (n = 8 for each treatment) was taken by venipuncture of the jugular vein, using 10 mL disposable syringes at day 70, 90, and 110 of gestation, 24 h postpartum, and at day 21 of lactation. All blood samples were enclosed in serum tubes (SST^TMII Advance, BD Vacutainer, Becton Dickinson, Plymouth, UK), as well as ethylenediamine tertaacetic acid (EDTA) tubes (BD Vacutainer K₂E, Becton Dickinson, Plymouth, UK), and centrifuged at 1957× g and 4 °C for 15 min (5810R, Eppendorf, Hamburg, Germany), after clotting at room temperature for 30 min. The upper liquid (serum) of the blood was separated to a microtube (Axygen, Union City, CA, USA) and stored at −20 °C in a freezer, until later analysis. Blood urea nitrogen (BUN; kinetic UV assay, Roche, Mannheim, Germany), total protein (colorimetry, Roche, Mannheim, Germany), creatinine (kinetic colorimetry assay, Roche, Mannheim, Germany), and urea (kinetic UV assay, Roche, Mannheim, Germany) were analyzed by Modular Analytics (Hitachi Ltd., Tokyo, Japan). Plasma amino acid was analyzed by LC–MS/MS (3200 QTRAP, AB SCIEX, Framingham, MA, USA).

In each treatment, six randomly selected pigs of near-average BW were used to collect blood samples on the initial day and at the end of each phase. Blood samples were taken from the jugular vein to measure blood urea nitrogen (BUN), total protein, glucose, and creatinine during the growing and finishing phases. Blood samples were collected in a disposable culture tube and centrifuged for 15 min at 3,000 rpm and 4°C (Eppendorf centrifuge 5810R, Hamburg, Germany). The serum was carefully transferred to 1.5-mL plastic tubes and stored at −20°C for later analysis. BUN (kinetic UV assay; Roche, Mannheim, Germany) and glucose (enzymatic kinetic assay, Roche, Germany) concentrations were analyzed using a blood analyzer. The creatinine and total protein concentrations were measured by kinetic colorimetry assay using a blood analyzer (Modular Analytics, PE; Roche, Germany).

Blood samples were taken from the jugular vein of six randomly selected pigs in each treatment when BW were recorded to measure blood urea nitrogen (BUN), glucose, albumin, and total protein after a 3 hours fasting. All blood samples were collected in serum tubes (SST II Advance, BD Vacutainer, Becton Dickinson, Plymouth, UK). Collected blood samples were centrifuged for 15 min at 3,000 rpm at 4°C (5810R, Eppendorf, Hamburg, Germany). Serum was carefully transferred to 1.5 mL plastic tubes and stored at −20°C until analysis. Total BUN (kinetic UV assay, Roche, Mannheim, Germany), albumin (Cobas 8000, Roche, Germany), and glucose (enzymatic kinetic assay, Roche, Germany) concentrations were analyzed using a blood analyzer. Total protein concentration was measured by a kinetic colorimetry assay using a blood analyzer (Modular Analytics, PE, Roche, Germany).