Objective: The objective of this experiment was to investigate the effects of fat-soluble vitamin injection on plasma and tissue vitamin status in nursery pigs.Methods: A total of 16 pigs (initial body weight: 7.15±1.1 kg) were allotted to 2 treatments at d 7 post-weaning. Pigs were fed a corn-soybean meal-based basal diet with no supplemental vitamin A and i.m. injected with 300,000 IU of retinyl palmitate, 900 IU of d-α-tocopherol and 30,000 IU of vitamin D₃ with control pigs having no vitamin injection. Blood (d 0, 3, 7, and 14 post-injection) and tissue samples (liver, brain, heart, lung, and muscle; d 7 and 14 post-injection) were collected from pigs. Retinyl palmitate, retinol, and α-tocopherol concentrations were analyzed in plasma and tissues, while plasma was assayed for 25-hydroxycholecalciferol (25-OHD₃).Results: Plasma retinol and 25-OHD₃ concentrations increased by the vitamin injection from d 3 to 14 post-injection (p<0.05) whereas plasma retinyl palmitate was detected only in the vitamin treatment at d 3 and 7 post-injection (115.51 and 4.97 μg/mL, respectively). Liver retinol, retinyl palmitate, and retinol+retinyl palmitate concentrations increased by retinyl palmitate injection at d 7 and 14 post-injection (p<0.05) whereas those were not detected in the other tissues. The d-α-tocopherol injection increased α-tocopherol concentrations in plasma at d 3 and 7 post-injection (p<0.05) and in liver, heart (p<0.10), and muscle (p<0.05) at d 7 post-injection.Conclusion: Fat-soluble vitamin injection increased plasma status of α-tocopherol, retinol, retinyl palmitate and 25-OHD₃. As plasma levels decreased post-injection, vitamin A level in liver and vitamin E level in muscle, heart and liver increased. The α-tocopherol found in plasma after injection was distributed to various tissues but retinyl palmitate only to the liver.

An experiment was conducted to investigate distribution of injected fat-soluble vitamins in plasma and tissue of nursery pigs. A total of 16 pigs were allotted to 2 treatments at d 7 post-weaning and fed a corn-soybean meal-based diet with no supplemental vitamin A. Treatments were control (no vitamins) and intramuscular injection with 3 mL VITAL E-A+D (STUARTPRODUCTS, Inc.) containing retinyl palmitate (RP; 300,000 IU), d-α-tocopherol (900 IU), and vitamin D3 (30,000 IU). All pigs were bled at d 0, 3, 7, and 14 post-injection and tissue samples were collected at d 7 and 14 post-injection (3 pigs/treatment). Data were analyzed by MIXED procedure of SAS. Plasma 25-hydroxycholecalciferol (3.44 vs. 71.00 ng/mL at d 3 post-injection) and retinol (0.09 vs. 0.18 µg/mL at d 3 post-injection) concentrations increased from d 3 to 14 post-injection (P < 0.05). Plasma RP was detected only in the vitamin treatment at d 3 and 7 post-injection (115.51 and 4.97 µg/mL, respectively). Liver retinol (0.63 vs. 19.10 µg/g at d 7 post-injection) and RP (43.33 vs. 199.13 µg/g at d 7 post-injection) concentrations increased at d 7 and 14 post-injection (P < 0.05) whereas those were not detected in the other tissues. The α-tocopherol concentrations increased in plasma (P < 0.05) at d 3 (0.99 vs. 17.14 µg/mL) and 7 post-injection and in liver (4.30 vs. 11.17 µg/g; P < 0.10), heart (4.60 vs. 24.80 µg/g; P < 0.10), and muscle (3.07 vs. 8.30 µg/g; P < 0.05) at d 7 post-injection. In conclusion, fat-soluble vitamin injection to nursery pigs increased plasma and liver status of α-tocopherol, retinol, and RP, and plasma 25-hydroxycholecalciferol concentrations. The α-tocopherol found in plasma post-injection was distributed to various tissues but RP only to the liver. Although plasma levels decreased post-injection, levels in liver increased for vitamins A and E, and vitamin E status was increased in all other tissues except brain.