An experiment was designed to investigate the effects of dietary supplementation of various concentrations of nanoselenium (NS) on the growth performance, immune status, antioxidant activity and hematological parameters of ducks. A total of 40 (1 day old) Pekin ducklings were equally divided into groups of 10 ducklings each. The 1st group was considered a control and was fed basal diet ad-libitum without nanoselenium (NS) supplementation; 2nd group (fed basal diet + 0.2 mg NS/kg diet); 3rd group (fed basal diet + 0.4 mg NS/kg diet) and 4th group (fed basal diet + 0.6 mg NS/kg diet). The selenium content of the unsupplemented control diet was 0.09 mg/kg during the starter period (0-2 weeks) and 0.07 mg/kg during the grower-finisher period (2-10 weeks). All feeds were formulated according to NRC (1994) to meet the nutritional needs of growing ducks. The experiment was extended for 10 weeks. Growth performance parameters such as body weight development, weight gain, feed consumption, feed-to-gain ratio, performance index and mortality were recorded. At the end of experiment, three randomly selected ducks from each group were selected to assess immune status, antioxidant activity, and blood biochemical parameters. The results showed that ducks fed on diets supplemented with different levels of nanoselenium had significantly higher body weight and weight gain (P<0.05) and consumed less feed than ducks fed the control diet. The third group had the highest body weight and weight gain and the lowest feed intake, followed by the second and fourth groups respectively. The NS supplemented birds had no mortality throughout the experimental period compared with control group which recorded highest mortality rate (20%). Different levels of NS supplementation improved the feed conversion ratio and performance index, the best values was achieved in 3rd group followed by 2nd and 4th groups, respectively. Addition of NS to duck diets significantly (P˂0.05) increased the serum immunoglobulins (IgA, IgG, IgM), glutathione peroxidase (GPx) and superoxide dismutase (SOD) levels, but decreased the malondialdehyde (MDA) levels compared to control. Concerning blood picture, NS supplementation significantly increased white blood cell and lymphocytic counts (P<0.05). However, no significant differences in other hematological parameters between tested groups. In conclusion, the present study found that supplementing duck diets with nano-selenium improved growth performance parameters, immune status, antioxidant activity, blood picture and 0.2-0.4 mg/kg is considered the optimum nano-Se supplementation level, and the maximum nano-Se supplementation level for ducks should not exceed 0.6 mg/kg.

The present work was carried out to study the effect of different levels of Moringa Oleifera leaf meal (MOLM) content as untraditional feedingstuff constituents on ducks performance, carcass traits, blood biochemical parameters and meat chemical composition. A total of 50 mulard ducklings (two weeks old) were randomly divided into 5 groups of 10 ducklings each. The first group was considered the control group (T1) and was fed ad-libitum on a grower-finisher diets. The remaining four groups (T2, T3, T4 and T5) were fed on diets containing MOLM at levels of 2%, 4%, 6% and 8%, respectively. All diets were formulated to be isocaloric (3000 kcal/kg ME) and isonitrogenous (16% CP) as recommended by NRC (1994) for growing ducks. The experiment was extended for 8 weeks. Growth performance parameters include body weight, weight gain, feed consumption, feed-to-gain ratio, relative growth rate, performance index, protein intake, protein efficiency ratio, energy intake and calorie efficiency ratio were all recorded. At the end of the experiment, three randomly selected ducks were slaughtered to evaluate carcass characteristics, meat chemical composition and blood biochemical parameters. The results showed that ducks fed diets containing 2 and 4% MOLM had higher in body weight and weight gain than ducks fed diets containing 6 and 8% MOLM. Feeding of different levels of MOLM to ducklings had no significant effect on feed consumption. The best feed conversion ratio was recorded in group T3 followed by group T2 compared to other tested groups and control T1. Ducks in group T3 fed on 4% MOLM showed improvements in their relative growth rate (RGR) and performance index (PI) compared to other tested and control groups. There were no significant (P>0.05) differences between the control group and the other tested groups in terms of protein intake and protein efficiency ratio, as well as energy intake and calorie efficiency ratio of ducks. Pre-slaughter weight, eviscerated weight and dressing weight were significantly higher in groups T2, T3, T4 fed (2%, 4%, 6%) MOLM compared to those fed on 8% MOLM and control diets. There were no significant differences in the relative weights of the internal organs (liver, heart, proventriculus, gizzard and spleen). Supplementation of duck diets with MOLM significantly (P<0.05) increased DM, CP, EE of the breast and thigh meat compared to the control group, while ash content was not affected. There were no significant (p<0.05) differences between different experimental groups in hematological pictures, except for WBCs, lymphocytic count, mean corpuscular hemoglobin concentration (MCHC), hematocrit (HCT) and platelets. Inclusion of MOLM in duck diets reduced the serum cholesterol and triglyceride concentrations, while the serum total protein and its fractions (albumin and globulin) were not affected. It was concluded that supplementation of Moringa oleifera leaf meal (MOLM) in duck diets had beneficial effects on the growth performance parameters, meat composition and carcass characteristics, as well as improved the immunity by increasing the number of white blood cells and lymphocytes and reduced serum triglycerides and cholesterol concentrations.