Effect of carnitine feed supplementation on biochemical parameters and the relative levels of inflammatory markers in suckling and weaned piglets

The early postnatal period and the weaning period are the most critical stages in the life of piglets, characterized by high mortality rates and the need to identify effective approaches to improve viability. The aim of this study was to determine the effect of dietary carnitine supplementation in suckling piglets on biochemical parameters and the relative levels of inflammatory markers before and after weaning. After farrowing, two groups of crossbred piglets (Yorkshire × Landrace × Duroc) were formed: 188 piglets in the control group and 190 piglets in the experimental group. During the suckling period, starting from the fifth day of life, piglets in both groups were fed a prestarter compound feed. Piglets were weaned at 28 days of age. The experimental group received a feed supplemented with 50 % L-carnitine at a dose of 500 g/t of compound feed. Blood samples were collected from 10 piglets in each group three days before and three days after weaning, prior to morning feeding, from the orbital sinus. The obtained blood serum was frozen and stored at –20 °C until analysis. Biochemical parameters in blood serum were determined using an automatic biochemical analyzer, Miura 200 (Italy), with commercial reagent kits. The relative content of molecular markers in blood serum was determined by Western blot analysis. Carnitine supplementation during the suckling period had a positive effect on liver condition, as evidenced by increased albumin synthesis and decreased levels of biochemical markers of liver damage. In particular, a decrease in ALT activity and, to a lesser extent, AST activity was observed. A higher glucose level under the influence of the supplement was also established, which may result from redistribution of energy substrates with predominance of fatty acid oxidation processes. The effect of carnitine on the relative levels of molecular inflammatory markers was characterized by a decrease in the relative content of pro-inflammatory cytokines and an increase in anti-inflammatory cytokines. These patterns persisted under weaning stress conditions.