The influence of turning on the hatchability of hens' eggs I. The effect of rate of turning on hatchability

Abstract

Eggs were incubated at various frequencies of turning (tilting through 90°) and their hatchability compared with eggs incubated as controls at 24 turns per day evenly distributed throughout the 24 hr. The turning treatments were: 0, once in 2 days, 2, 6, 12, 48, 96, 144, 192 and 480 turns per day. Differences in hatch of fertile eggs between the treated and control eggs at each level of turning were obtained and used to indicate the trend of hatchability in response to varying turning frequency and also the optimum rate of turning. This was observed to be 96 turns per day. Nil or few turns per day gave very poor results and at very high frequencies (up to 480 x ) hatchability decreased only slightly relative to the turning frequency.