Correlation between dam effects on body weight of dwarf intraline and of normal straincross broiler chickens.

The correlation between dwarf breeder dam differences in transmitted and maternal effects on intraline dwarf and on straincross normal progeny was estimated as .61 +/- .10 when body weight was measured at 50 days in dwarfs and normals and .57 +/- .11 when measuring 50 day weight in normals and 64 day weight in dwarfs. Normal straincross progeny of dwarf dams will therefore not be expected to benefit fully from genetic gains achieved from body weight selection in dwarf flocks. A different response in body weight to increased rearing density was shown in dwarf and normal birds, with the dwarf birds being better able to tolerate crowded conditions.