In Pakistan, sorghum (jawar) occupies 4th place with a production of 218.6 thousand tons (Economic survey of Pakistan 2000-200 1) after wheat, maize and rice. Its use is limited in poultry feed because it contains antinutritional factor i.e. tannin, phytic acid (68% of Total phosphorus). The low tannin sorghum varieties can replace maize up to 50%, and sorghum high in tannin can replace maize up to 25% in poultry diet.

While considering different nutrients for broiler feed formulation minerals are also very important. Among minerals phosphorus plays an important role for poultry production. Balancing the phosphorus in compound feed is difficult task because less than one third of the phosphorus in the feedstuffs of plant origin is biologically available to monogastric animals (NRC, 1994). The organic phosphorus exists in the bran of grain, consisting mainly of phytic phosphorus,

Phytase is an enzyme that liberates P from vegetable materials, destroys the antinutritional properties of phytate. Phytase was one of the first enzyme to be described in the literature. As early as 1907 the release of phosphorus from an organic phosphorus containing substrate was described by Suzuki and others (Maga 1982). The enzyme "phytase" is now known to cause the release of phosphate from phytic acid by catalyzing a series of hydrolysis reactions.

Keeping in view the above facts an experiment was conducted to study the effects of phytase on the performance of broiler fed on sorghum- based diets.

Two hundred broiler chicks were purchased from Big Bird Poultry Breeders and divided in to five groups. These groups were further subdivided in four replicates, having ten chicks in each. The chicks were kept in starter batteries for the first four weeks and then shifted to grower batteries till the end of experiment (six week). Five starter and five finisher rations (sorghum based) A, B, C, D, and E were prepared. "A" was control having 0.45 and 0.35% AP in starter and finisher rations respectively. While B, C, D and E supplemented with phytase enzyme (600 FTU/kg of feed) having 0.40, 0.35, 0.30 and 0.25% AP in starter and 0.30, 0.25, 0.20 and 0.15% AP in finisher rations respectively. Light, feed and fresh clean water was provided round the clock.

The parameters studied were weight gain, feed consumed, feed conversion ratio, dressing percentage, mortality, phosphorus availability and economic. The data thus collected was subjected to statistical analysis. The results indicated that the weight gain of chicks fed on rations B and C were comparable to ration A (control). The chicks fed on rations D & E significantly (P
RECOMMENDATION

1. By the use of phytase in poultry feed phosphorus availability could be increased.
2. Use of phytase enzyme is economical.
3. By the use of phytase enzyme 0.1% available phosphorus can be decreased in the broiler ration.