Effects of dietary L-carnitine and coenzyme Q₁₀at different supplemental ages on growth performance and some immune response in ascites-susceptible broilers

Effects of dietary L-carnitine and coenzyme Q10 (CoQ10) at different supplemental ages on performance and some immune response were investigated in ascites-susceptible broilers. A 3 x 2 x 2 factorial design was used consisting of L-carnitine supplementation (0, 75, and 100 mg/kg), CoQ10 supplementation (0 and 40 mg/kg) and different supplemental ages (from day 1 on and from day 10 on). A total of 480 one-day-old Arbor Acre male broiler chicks were randomly allocated to 12 groups, every group had five replicates, each with eight birds. The birds were fed a corn-soybean based diet for six weeks. From day 10-21, all the birds were exposed to a low ambient temperature (12-15 degrees C) to increase the susceptibility to ascites. No significant effects were observed on growth performance by L-carnitine, CoQ10 supplementation, and different supplemental ages. Packed cell volume was significantly decreased by L-carnitine supplementation alone, and ascites heart index and ascites mortality were decreased by L-carnitine, CoQ10 supplementation alone, and L-carnitine + CoQ10 supplementation together (p < 0.05). Heart index of broilers was significantly improved by L-carnitine, CoQ10 supplementation alone during 0-3 week. Serum IgG content was improved by L-carnitine supplementation alone (p < 0.05), but lysozyme activity was increased by L-carnitine + CoQ10 supplementation together (p < 0.05). A significant L-carnitine by supplemental age interaction was observed in lysozyme activity. L-carnitine supplementation alone had no effects on the peripheral blood lymphocyte (PBL) proliferation in response to concanavalin A (ConA) and lipopolysaccharide, but supplemental CoQ10 alone and L-carnitine+ CoQ10 together decreased the PBL proliferation in response to ConA (p < 0.05). The present study suggested that L-carnitine + CoQ10 supplementation together had positive effects on some immune response of ascites-susceptible broilers, which might benefit for the reduction of broilers' susceptibility to ascites.