effect of mashhad power plant ca-waste and diet phosphorus level on performance and bone strength of broiler chickens

an experiment was conducted to evaluate the effect of replacing dietary limestone with mashhad power plant calcium-waste in combination with available phosphorus level on growth performance, tibial strength and blood alkaline phosphatase activity in broiler chickens. three hundred and eighty four male broiler chickens were used in a complete randomized design experiment with a 4×2 factorial arrangement of treatments and four replicates of 12 birds each. limestone was replaced with ca-waste source at the rate of 0, 33.3, 66.6 and 100% in combination with two levels of available phosphorus (80% and 100% of ross recommended) in the starter, grower and finisher diets during 1- 42 days of age.tibia ash, ca and p percentage (only treatments contain 100% ross recommended phosphorus) and sera alkaline phosphatase activity of chicks, were measured at 21 days of age. one bird from each replicate was weighed, slaughtered and carcass weight and carcass cuts were weighed on 42 days of age. experimental diets were formulated to be isoenergetic and isonitrogenous with similar nutrients with the exception of total phosphorus.the results showed that the dietary limestone can be replaced up to 100% by mashhad power plant ca-waste source without any significant effect on body weight, serum alkaline phosphatase, carcass weight and cuts, tibia ash, calcium and total phosphorus. also feed conversion ratio was significantly influenced by diet phosphorous levels during grows period.