Genetic variation of phytate phosphorus utilization from hatch to three weeks of age in broiler chicken lines selected for incidence of tibial dyschondroplasia

Abstract

Ability to utilize dietary phytate P was evaluated in 1,387 broiler chicks of 45 sire and 180 dam families, by feeding a corn-soybean base diet supplemented with no inorganic P and a low level of Ca. These chicks were the progeny of high and low incidence of tibial dyschondroplasia (TD) selected divergently for 11 generations and a nonselected control line. Chicks from the control line utilized phytate P better than those from the high or low lines in terms of livability, mortality, and growth performance. Chicks did not differ in mortality and body weight between the high and low lines. Variation in livability and mortality was greater among lines than among families, whereas families accounted for a greater part of variation than lines in body weight. Dams accounted for a slightly larger proportion of variation than sires in traits studied. Genetic selection for improved utilization of dietary phytate P could be effective.