Microtube

Blood collection from sows was performed based on similar BW and BF (n = 6 for each treatment) by venipuncture of the jugular vein using 10 ml disposable syringes at days 35, 70, and 110 of gestation, 24 h postpartum and day 21 of lactation. Blood from suckling piglets (n = 16 for each treatment) was collected from the anterior vena cava using 3 mL disposable syringes 24 h postpartum and 5 mL disposable syringes on day 21 of lactation. All blood samples were collected in serum tubes (SST II Advance; BD Vacutainer, Becton Dickinson, Plymouth, UK) and EDTA tubes (BD Vacutainer K2E; Becton Dickinson, UK) and centrifuged at 3,000 rpm and 4°C for 15 min (5810R; Eppendorf, Hamburg, Germany) after being allowed to clot at room temperature for 30 min. The upper layer (serum) of the blood was separated into a microtube (Axygen, Union City, CA, USA) and stored at −20°C for subsequent analysis. BUN was analyzed using a Cobas 6000 by kinetic/photometric method. Creatinine and total protein were analyzed using a Cobas 6000 by colorimetric method. Urea was analyzed using a Cobas 8000 by enzymatic UVS (UV spectrophotometry method).

Blood of sows (n = 4 for each treatment) was taken by venipuncture of the jugular vein using 10 mL disposable syringes at 24 h postpartum, and on 7 and 21 days of lactation. Blood of suckling piglets (n = 4 for each treatment) was collected from the anterior vena cava using 3 mL disposable syringes at 24 h postpartum and 5 mL disposable syringes on 7 days and 21 days of lactation.
All blood samples were enclosed in serum tubes (SST II Advance, BD Vacutainer; Becton Dickinson, Plymouth, UK) as well as ethylenediamine tetra-acetic acid tubes (BD Vacutainer K2E; Becton Dickinson, UK) and centrifuged at 3,000 rpm 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 into a microtube (Axygen, Union City, CA, USA) and stored at −20°C until later analysis.

Blood samples (n = 6 for each treatment) were collected from the jugular vein of sows using 10 mL disposable syringes at 24 h postpartum and 21 days of lactation. Additionally, blood samples (n = 12) were collected from the anterior vena cava of piglets using 3 mL disposable syringes at 24 h postpartum and 21 days of lactation. The initial values were obtained randomly (n = 4 for sows and piglets) from the experimental animals after completed the experiment arrangement. All blood samples were moved to serum tubes (SSTTMII Advance; BD Vacutainer, Becton Dickinson, Plymouth, UK) and ethylenediaminetetraacetic acid tubes (BD Vacutainer K₂E; Becton Dickinson, UK). Individual samples were centrifuged at 3,000 rpm and 4°C for 15 minutes (Eppendorf centrifuge 5810R; Hamburg, Germany), and the supernatant was separated into a microtube (Axygen, Union City, CA, USA) and stored at −20°C until analysis.