Effects of L-carnitine and iron diet supplementations on growth performance, carcass characteristics and blood metabolites in fattening pigs

The aim of this study was to evaluate the effect of dietary L-carnitine supplementation either with or without extra Fe supplementation from Fe-amino acid (Fe-AA) complex on body weight gain, feed conversion, carcass characteristics and blood metabolite concentrations in fattening pigs. The study was carried out with 75 fatteners (30.100 kg body weight), divided into three groups, of 25 pigs each. The control group was given a basal diet that contained 85 mg/kg of Fe from premix. A L-carnitine group was given a basal diet supplemented with 100 mg/kg of L-carnitine, and a L-carnitine+Fe group was given a basal diet supplemented with 100 mg/kg of L-carnitine and 60 mg/kg of Fe from a Fe-AA complex. The supplement of L-carnitine to the diets did not have any effects on the growth performance and carcass traits. The L-carnitine supplement decreased the concentration of triglycerides (p.0.05), cholesterol (p .0.05) and low-density lipoproteins (p .0.01) in the blood serum of pigs, while it increased (p.0.01) the concentration of high-density lipoproteins. The combination of L-carnitine+Fe increased the growth performance of growing pigs (p .0.05) and the lean percentage and fatless ham weight in carcass and also increased (p .0.05) the Fe content in the blood serum and the longissimus dorsi muscle of pigs. The results suggest the more effective outcomes can be reached when L-carnitine+Fe rather than only L-carnitine is used in diets.