Growth Performance, Immune Response, Serum Metabolites and Digestive Enzyme Activities of Japanese Quail Fed Supplemental L-Carnitine

摘要

The aim of this study was to evaluate the effect of using graded levels of L-carnitine on growthperformance, serum metabolites, humoral and cell mediated immune responses and intestinal digestive enzymesactivity of Japanese quail chicks. Two hundred forty 7d old Japanese quail chicks were randomly divided intofour groups of 60 chicks. The first group was fed on the basal diet (control), while groups 2, 3 and 4 were giventhe basal diet supplemented with 100, 200 and 400 ppm L-carnitine, respectively. The results showed significantimprovement in body weight, feed conversion and dressing percent of quails, particularly with the high level(400ppm) followed by those of the mid one (200pm). Similar trend was noted for the relative lymphoid organweights (bursa and spleen values). Moreover, supplemental L-carnitine with different levels enhanced thehumoral and cell mediated immune responses in Japanese quail as evidenced with better antibody titers againstNewcastle disease virus and greater wing web swelling in response to PHA-L injection, respectively. The serumlevel of total proteins, globulin, high density lipoprotein (HDL), triiodothyronine (T3) and thyroxin (T4) wassignificantly increased for quails fed on diets contained either 200 or 400ppm L-carnitine. But, theconcentrations of total lipid, cholesterol, triglycerides, low density lipoprotein (LDL) and malondialdehyde(MDA), which is the primary stable by-product of lipid peroxidation, were reduced. On the other hand, thealbumin level didn’t significantly affected by dietary L-carnitine supplementation. A significant increase in theactivities of amylase, lipase, trypsin and chymotrypsin enzymes was found throughout the small intestineportions with supplemental L-carnitine. It is concluded that, L-carnitine supplementation with 200ppm up to400ppm was sufficient to enhance the growth performance traits, immune response, thyroid and digestiveenzyme activities and antioxidant system in growing Japanese quails.