Dietary zinc-chitosan nanoparticles addition influences on growth performance, apparent total tract digestibility, carcass indices, and immune function in weaned rabbits.

The aim of this study was to study the effect of zinc oxide-chitosan nanoparticles (Zn-CNPs) on growth performance, plasma constituents, carcass indices, and immune function in rabbit diets. Eighty weaned V-line males rabbits at 5 weeks of age were divided into four dietary groups of control diet; 50 Zn-CNPs; 75 Zn-CNPs;100 Zn-CNPs. Supplementation of Zn-CNPs did not affect final live body weight and average daily weight gain. 100 ppm Zn-CNPs recorded (p < 0.05) higher digestibility of DM, OM, CP, EE, and NFE. Dietary groups of 75 and 100 ppm were higher (p < 0.05) in DCP, TDN (%), and DE (kcal/kg). Zn-CNPs supplementation was higher (p < 0.05) in hot carcass and spleen weights %. The addition of Zn-CNPs in diets promoted dressing%. Significant increases (p < 0.05) in plasma total protein and albumin levels for 75 and 100 Zn-CNPs. Zn-CNPs decreased (p < 0.05) glucose, total cholesterol, LDL concentrations and increased (p < 0.05) plasma zinc levels, IgG, IgM. Plasma HDL level increased (p < 0.05) with 75 and 100 ppm Zn-CNPs. In conclusion, Zn-CNPs supplementations can use safely as a zinc source in rabbits diets without any detrimental effects on growth performance, plasma constituents, and carcass indices. Moreover, 50, 75, and 100 ppm Zn-CNPs enhanced the immune functions.

Ozone formation in the greater Cairo area.

Ozone formation in the greater Cairo area was studied in 1990 in a 3-week measurement period performed at three sites (Shoubra El-Kheima, Mokattam Hill, Helwan), covering a north-south direction of 27 km, and in 1991, from the beginning of April until the end of October, by measurement of the seasonal variation of ozone at one site at El-Kobba. The sinusoidal shape in the diurnal volume fraction plots with peak values of 120 ppb and daily mean value of 50 ppb throughout the year indicate a substantial contribution of photochemistry to the ozone content of the atmosphere. Ozone is produced predominantly over the industrial area in the north and in the centre of Cairo and transported southward by the prevailing northerly winds. Contrary to many urban areas in Europe and in North America, fairly high average ozone levels of 40 ppb are observed during the night throughout the spring and the summer. This may imply that health hazards and crop damage are higher in the greater Cairo area than in Central Europe.