Abstract
The effects of hatch date, location and sex on the body weight and rate of gain in Coturnix coturnix japonica were examined. The data conformed to a mixed model and adjustments were made for the fixed effects of sex, hatch date and location. Adjustment improved the precision of the estimates by reducing the error variances significantly. Rearing equal numbers of birds from each family at different locations made the interactions negligible. Weight gain was greater if illumination intensity up to 35 days was less. Females were not heavier on the 1st day but were heavier on the 14th and 35th days than males. Varience components and genetic parameters were estimated.