# Glucose Injections at Birth, Warmth and Placing at a Nurse Sow Improve the Growth of IUGR Piglets
## Materials and Methods
### Experimental Design  
A total of 88 IUGR piglets were included in the experiment from 37 sows with a parity between 1 and 7. The piglets were visually graded and classified as IUGR piglets based on the modified characteristics from [PERSON] et al. [3] and [PERSON] et al. [7]. The piglets were given a visual score, determining the IUGR piglets by a (1) steep dolphin-like forehead, (2) bulging eyes, (3) hair with no direction of growth. A piglet was defined as IUGR if it had a steep dolphin-like forehead and one other of the characteristics were present; if none of the characteristics were present, the piglets were considered normal and not used in the experiment. A visual score based on the piglets' head shape was chosen, as this has previously been found to be an easier identification method for the farmer than birth weight (see discussion in [14; 15]). At time = -1 h, newborn (approximately between 1-12 h of age) piglets used in the experiment were ear tagged, their sex was recorded, their whole-blood glucose was measured using a glucose monitor (Accu-Chek Aviva Nano, Roche, Basel, Switzerland), a drop of blood was obtained by puncturing the ear vein of each with a syringe (23G x 1-Nr.16, [PERSON], Langeskov, Denmark), rectal temperatures were measured (Apotekets digital thermometer standard, Apotekets, Horsholm, Denmark), BW was recorded (UWE, Bjerringbro Vegte ApS, Bjerringbro, Denmark) and the birth sow's parity and litter size were noted. The experimental IUGR piglets were allocated to one of the four treatments (\(n=22\)) and blocked according to their rectal temperature, measured at \(t=-1\) (ranging from 33 to 39 \({}^{\circ}\)C). The four treatments were (1) Water (WATER; 20 mL 35 \({}^{\circ}\)C warmed water) tube-fed (Unomedical feeding tube, Hatting, Horsens, Denmark); (2) Glucose (GLUC; Glucose Baxter Viaflo, DK Baxter A/S, Allerod, Denmark) (50 mg/mL) injected subcutaneously (\(4\times 1.5\) mL, two in the groin area and two in the neck); (3) Pooled porcine colostrum (COLOS; 20 mL warmed to 35 \({}^{\circ}\)C) tube-fed, previously obtained from other sows around farrowing in the same piggery, and (4) both glucose injected subcutaneously and pooled porcine colostrum tube-fed as described above (GLUC + COLOS). After allocation to one of the four treatments, the piglets were placed in a boarded-off creep area for one hour with a heating lamp (from \(t=-1\) to 0). Treatments were administered three times, at \(t=0\), 3, and 6 h. Rectal temperatures, whole-blood glucose levels, and BWs were measured before each treatment, and at 9, 12, 24, 36, 48 h and at days 7, 14 and 21. The piglets were placed at a nurse sow, with which they stayed for the duration of the trial after the first administration. The nurse sows were selected on the basis of maternal quality; i.e., the number of weaned piglets in the last parity, if they had 14 functional teats and if they had just farrowed (day 0 post-partum). At days 7, 14, and 21 post-partum, glucose levels, rectal temperatures, and BWs were measured and blood samples obtained. The blood samples were collected by holding the piglets in dorsal recumbence, and 6 mL of blood was drawn from the jugular vein using 22-gauge needles into Vacutainer tubes containing EDTA (BD Vacutainer, Franklin Lakes, NJ, USA) and placed on ice until centrifugation. The samples were centrifuged at room temperature for 15 min at 1200\(\times\)\(g\) (CM-6 MT, Elmi, Riga, Latvia), after which, the plasma was transferred to Eppendorf tubes (Sarstedt, Numbrecht, Germany) and immediately frozen at \(-20\)\({}^{\circ}\)C for later analysis of the plasma IGF-1. The plasma IGF-1 concentrations were measured using a porcine IGF-1 ELISA kit (Nordic Biosite, Taeby, Sweden) according to the manufacturer's recommendations. Samples were performed in duplicate and the intra-assay variation was 3.3%. The inter-assay variation was 12.6%. The experimental period lasted from day 0 post-partum until day 21 post-partum, when the piglets were sampled a final time and the experiment ended.