Growth performance, immune response, serum metabolites and digestive enzyme activities of Japanese quail fed supplemental L-carnitine

Abstract

The aim of this study was to evaluate the effect of using graded levels of L-carnitine on growth performance, serum metabolites, humoral and cell mediated immune responses and intestinal digestive enzymes activity of Japanese quail chicks. Two hundred forty 7d old Japanese quail chicks were randomly divided into four groups of 60 chicks. The first group was fed on the basal diet (control), while groups 2, 3 and 4 were given the basal diet supplemented with 100, 200 and 400 ppm L-carnitine, respectively. The results showed significant improvement 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 organ weights (bursa and spleen values). Moreover, supplemental L-carnitine with different levels enhanced the humoral and cell mediated immune responses in Japanese quail as evidenced with better antibody titers against Newcastle disease virus and greater wing web swelling in response to PHA-L injection, respectively. The serum level of total proteins, globulin, high density lipoprotein (HDL), triiodothyronine (T3) and thyroxin (T4) was significantly increased for quails fed on diets contained either 200 or 400ppm L-carnitine. But, the concentrations 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, the albumin level didn't significantly affected by dietary L-carnitine supplementation. A significant increase in the activities of amylase, lipase, trypsin and chymotrypsin enzymes was found throughout the small intestine portions with supplemental L-carnitine. It is concluded that, L-carnitine supplementation with 200ppm up to 400ppm was sufficient to enhance the growth performance traits, immune response, thyroid and digestive enzyme activities and antioxidant system in growing Japanese quails. © IDOSI Publications, 2014.