Spiro/ina was isolated (rom EI-Khadra lake Wadi EI-Nalroun, Beheira. Egy~t. The alga was identirled as Spiro/ina p/aten:sis. The isolated algae were cultivated onl a
large-scale in 8 basin constructed near the lake. The dry biomass analysis show,d
that the algae biomass contains as high as 60 % crude. protein. 5 % fats, 20 Vo
carbohydrates. 7 % minerals and 5 % moisture. Unwashed biomass was found 10 be
toxic to mice. while mice Injected with washed biomass suspension still healthy
survived. Spiru/ina dry biomass added to the diet of Rahmany male sheep in the rate
of 50glKg signifICantly increased Ca, P. Mg and Cu concentrations in the blood serum
of the animals. The treatment atso reduced the period to puberty and sexual maturity
to 69 % of that of control animals. Addition of Spiro/Ina to the diet significantly
increased semen volume. semen mass activity and number of sperms in unite
volume. The effect of Sp < /em>iro/ina biomass andlor cnude extract on dominant rumen
bacteria (13 isolates) was studied.