Influence of Lippia citriodora verbascoside on growth performance, antioxidant status, and serum immunoglobulins content in piglets

Phytogenic feed additives are used in animal feeding to improve livestock performance. The aim of this study was to determine whether a dietary plant extract from Lippia citriodora, standardized for verbascoside, can modify various immunological, oxidative, and biochemical serum parameters in weaned piglets. A total of 144 piglets, half female and half barrows (7.99 ± 1.40 kg BW), were allocated to three dietary treatments with six replicates per treatment (pens of 8 piglets each). Piglets were supplemented with the following levels of plant extract standardized for verbascoside: 0 (CON = control group), 5 (LV = low verbascoside group), or 10 (HV = high verbascoside group) mg/kg of diet for 56 days. Body weight (BW) and feed consumption were recorded at days 0 and 56 to determine the average daily gain and gain : feed. Twelve piglets from each treatment were randomly selected, and blood was collected by anterior vena cava puncture on days 0, 14, and 56 for glucose, triglycerides, cholesterol, urea, and oxidative status, and on days 0 and 56 for IgG and IgA concentrations. The HV group grew more (P < 0.05) than the CON and LV groups. No significant differences were observed for any of the biochemical parameters between the groups; urea, high density lipoprotein cholesterol, total cholesterol, and low density lipoprotein cholesterol increased significantly over time. Reactive oxygen metabolites (ROM) showed significant time, time × treatment, and treatment effects (P < 0.001). Both serum Igs increased (P < 0.005, P < 0.001 for IgG and IgA respectively) over time in all groups; treatment (P < 0.05), and time × treatment (P = 0.056) effects were found for serum IgA concentration. The Lippia citriodora verbascoside positively influenced antioxidant status and IgA content with a tendential effect on growth performance.