This study was carried out to investigate the effect of large particles (zinc Zn or selenium SE) or nano-Zn and nano-Se particles as feed supplement in lambs rations on feed intake, degradability, growth performance and some blood parameters. Twenty five growing lambs aging about 5-6 months with average body weight of 24.5kg, were used. Lambs were divided into five similar groups and fed randomly on one of the following rations. The first group received the basal ration, composed of concentrate feed mixture (CFM) to cover 50% of protein and energy allowances recommended by NRC (1989) and clover hay (CH) without feed additives which served as the control group (R1). The other tested groups were randomly fed the control ration supplemented with 10 mg large particles zinc (L-Zn), 0.04 mg large particles selenium (L-Se), 5 mg nano particles zinc (N-Zn) and 0.02 mg nano particles selenium (N-Se) / kg CFM for rations R2,R3, R4 and R5, respectively. Two canulated sheep were used to measure in sacco disappearance of DM, OM and CP of tested rations. Results showed that N-Zn & N-Se particles groups improved DM, OM and CP degradability compared with control group. But there were no significant differences among large particles groups and control group. Ration contained N-Zn had a significant effect on DM intake, but there were no significant differences among the large particles zinc (L-Zn) or selenium (L-Se) groups and control group among DMI. On the meantime, results showed that R4 & R5 groups increased (P<0.05) average daily gain and total weight gain compared to the control group. Also, feed conversation as DMI/ kg gain for R4 & R5 groups were improved by 16.93 and 18.25%, as compared with control group. Feed cost /kg gain was decreased for R4 and R5 groups as compared with control group. Serum total protein and albumin for R4 was increased compared with control group. While no significant differences between control group and other groups were found among AST and ALT values. In conclusion, large size particles of Zn or Se could be replaced with smaller amount of nano particles Zn or Se without any side effects on the animal performance.

The present study aimed to determine the effects of using different levels of papaya leaves (PL) and papaya leaves extract (PLE) on productive performance, some blood constituents, oxidative enzyme status, carcass traits, immune response, digestibility coefficients and economic efficiency of weaned New Zealand White rabbits (NZW). Eighty four weaned New Zealand White rabbits (NZW) aged 35 days and weighed 564g ± 3.40 were distributed randomly into seven groups (12 each). The experimental diets contained different levels of papaya leaves and papaya leaves extract (0.0 controls (C), 1, 2 and 3% papaya leaves or papaya leaves extract, respectively. The experiment was lasted for 8 weeks. The obtained results indicated that: The final live body weight, total weight gain and performance index were significantly (P<0.05) improved in the treated groups. Digestibility coefficient and nutritive values were significantly improved for rabbits fed diet contained PL and PLE compared to those fed the control diet. There were significant increases detected for plasma total protein, albumin and globulin while blood plasma cholesterol, LDL and total lipids were significantly decreased by increasing PL and PLE inclusion level compared to control groups. Liver function as AST and ALT activity were not affected by dietary supplementation. Moreover the concentrations of IgG and IgM of rabbits were higher for rabbit supplemented with PL and PLE than the control group. GPx, SOD and CAT were significantly improved by dietary PL and PLE. The best economic efficiency had been recorded with rabbits fed 3% PLE inclusion followed by rabbits received 2% and 1% treatment of PLE, respectively. It is concluded that supplemental papaya leaves extract at the rate of 3 % of the diet improved feed conversion ratio, nutrients digestibility, immunity, and economic efficiency of the NZW rabbits.