Plasma vitamin concentrations are altered by fat-soluble vitamin administration in suckling pigs

Abstract Text: Plasma concentrations of some vitamins are purported to be low in nursing piglets raised in confinement. This experiment was conducted to investigate the effect of fat-soluble vitamin administration by different administration routes on plasma concentration of those vitamins in suckling pigs. A total of 45 pigs from 5 litters were allotted to 3 treatments at birth (3 pigs/treatment within each litter). Treatments were oral and i.m. injection of 400 IU of α-tocopherol, 40,000 IU of retinyl palmitate, and 40,000 IU of vitamin D₃ at d 1 of age with the control treatment that had no vitamin administration. Blood samples were collected at d 0 (initial), 1, 2, 3, 4, 6, 9, 14, and 20 post-administration. Plasma 25-hydroxycholecalciferol (25OHD₃), α-tocopherol, retinyl palmitate, and retinol concentration were analyzed. Growth performance did not differ by vitamin administration. Effects of treatment, day, and day × treatment interaction (P < 0.01) were observed in which plasma concentration increased immediately regardless of administration routes to peak at d 2 (4.0, 155.4, and 235.4 ng/mL) for 25OHD₃ and at d 1 post-administration (3.9, 14.3, and 32.3 ug/mL) for  α-tocopherol for control, oral, and injection, respectively. The injection treatment had greater plasma values than the oral treatment. Plasma retinyl palmitate concentration increased only with the injection treatment and peaked at d 1 post-administration (0.13, 0.44, and 3.10 ug/mL for control, oral, and injection, respectively). Plasma α-tocopherol and retinyl palmitate concentration in the oral and injection treatments decreased from the peak plasma values to be similar with the values in the control treatment at d 9 and 3 post-administration, respectively. Plasma 25OHD₃ concentration in the oral and injection treatments was maintained greater than that in the control treatment until d 20 post-administration. These results demonstrate that plasma status of 25OHD₃, α-tocopherol, and retinyl palmitate are changed after administration to newborn pigs, and that the change of plasma profiles of these vitamins is different between types of vitamins administered and between administration routes. The injection administration is more efficient to enhance plasma 25OHD₃ level until weaning than the oral administration. 

Keywords: fat-soluble vitamin administration, plasma vitamin concentration, suckling pigs