Growth Rate in Three Gallinaceous Species Fed Diets Imbalanced in Calcium, Phosphorus, and Protein

Abstract

Three gallinaceous species, the Ring-necked pheasant (Phasianus colchicus), Red-legged partridge (Alectoris gracea), and chicken fryer (Gallus gallus domesticus) were fed diets containing either 15, 20, or 28% protein, 1 or 3% calcium, and .3 or .6% available phosphorus from hatch through 3 weeks of age.Chicks of all species grew poorly on diets containing 3% calcium and .3% available phosphorus, especially at the higher levels of dietary protein (20 and 28%). When fed diets containing .6% available phosphorus and 15% protein, pheasants and chickens had the same rate of growth from hatch through 3 weeks of age, irrespective of the level of dietary calcium.Feed conversion for groups of birds fed diets containing 1% calcium and .6% available phosphorus at all levels of protein was superior to that from birds fed diets containing similar levels of phosphorus and protein but containing 3% calcium.The higher level of dietary calcium (3%) in rations low in available phosphorus (.3%) caused leg paralysis in many birds of all species after 2 weeks of experiment at the higher levels of protein (20 and 28%). The incidence of leg weakness and mortality, after 3 weeks of experiment, was highest in pheasants followed by chickens and partridge.Irrespective of dietary protein, bone ash values for birds fed diets low in available phosphorus (.3%) and calcium (1%) were significantly (P<.01) higher than that for birds fed diets containing similar levels of protein and phosphorus but higher levels of calcium (3%). Bone ash values obtained for pheasants were consistently lower than those for chickens and partridge, especially when the dietary calcium level was 1%.Diets high in calcium (3%) and low in available phosphorus (.3%) can cause poor growth, severe paralysis, and high mortality if mistakenly fed to chicks of gallinaceous birds, especially pheasants, and result in major economic losses.