Appleby, 1984 – Factors Affecting Floor Laying By Domestic Hens: A Review

All intensive systems of management for domestic hens, except battery cages, involve the collection of eggs from nest boxes. Eggs laid on the floor, instead of in the nest boxes provided, are a major economic problem in breeding flocks housed on deep litter, and in laying flocks in alternatives to batteries. Many floor eggs are broken, and this may encourage egg eating. Those collected are often dirty, which reduces hatchability (Hodgetts, 1981) or saleability. Furthermore, control of floor laying and collection of floor eggs are labour intensive. The problem of floor laying is not just a product of modern intensive husbandry
methods: it was described early in this century by Pearl (Pearl, 1909; Pearl and Surface, 1909) and Turpin (1918). However, the proportion of floor eggs seems to be particularly unpredictable in intensive systems. Several studies have been prompted by increased floor laying occurring on a farm, with no obviously relevant differences in conditions from other farms (Perry et al., 1971a, b; McGibbon, 1976; Hearn, 1981). Perry etaf. reported 30% floor eggs, which is not unusual. Similarly, variation may occur between pens within a single experiment. Dorminey et al. (1970) found 3.5 to 22.9% floor eggs in pens differing only in light intensity, and floor laying was not systematically related to light. This variability suggests that important causal factors of floor laying are being widely overlooked. In this paper, studies of factors affecting the proportion of eggs laid on the floor by domestic hens will be reviewed. It must be emphasized, however, that there have been few properly conducted, statistically acceptable experiments on this subject.