Food efficiency in pure strains and hybrids of laying hens analysed in a diallel cross - III. Direct, heterosis and maternal effects on food consumption and adjusted food consumption.

Direct effect, maternal effect and heterosis on food consumption and food c onsumption adjusted for live weight, egg production and weight gain is anal ysed in a 4 x 4 diallel cross including 576 laying hens. Heterosis is divid ed into average-, strain- and specific heterosis and residual reciprocal ef fect. Significant differences were found between strains in direct genetic effect on food consumption and adjusted food consumption. There was a signi ficant maternal effect on food consumption, but not on adjusted food consum ption. Average heterosis was positive and significantly different from zero in both food consumption and adjusted food consumption. Some strains showe d significant differences in strain heterosis. Specific heterosis and resid ual reciprocal effect have small effect on both food consumption and adjust ed food consumption.