Stress-induced oviposition delays in laying hens: Duration and consequences for eggshell quality

Abstract

1. As part of a programme investigating the causation of pecking damage in fowls, this experiment tested a proposal that birds may receive more feather pecks when their plumage colour contrasts with floor litter colour, because litter particles on plumage (as a consequence of dustbathing) may then have greater stimulus value. 2. Groups consisting of 7 light- and 7 dark-coloured bantams were reared from 1 to 11 weeks of age in pens with either wood shavings (light coloured, n=6) or peat (dark coloured, n=6) floor litter. 3. Feather loss from pecking commenced in the 3rd week of life and increased thereafter, but observed pecking damage scores were not consistent with the hypothesis being tested. 4. Despite many more pecks at birds being seen (over 10 weeks) in the wood shavings groups' (661 at particles on plumage, 1795 not at particles) than in peat groups (205, 787), there was no effect of litter substrate on pecking damage. The only evidence supporting the proposal was the finding that, in groups on wood shavings, significantly more pecks at particles on plumage were directed from light coloured birds towards dark ones, than from light to light, dark to light, or dark to dark. 5. Feather eating was confirmed from the presence of feather material in 2% to 15% of faecal droppings collected from each group at 11 weeks, but these proportions were not correlated with pecking damage scores. 6. The results imply that only some feather pecks/pulls were damaging and only some eaten feathers were pulled from other birds.

Comparison of the welfare of layer hens in 4 housing systems in the UK

“…They were provided with full verbal and written instructions on how to complete the forms and a set of photographic scales for standardising scores of variables such as feather damage. Under conditions of stress, hens sometimes delay laying eggs which results in additional calcium carbonate being deposited on the egg shell or egg shell deformations (Hughes et al, 1986;Mills et al, 1987;Reynard and Savory, 1999). In addition, if the hen's vent prolapses or is torn due to laying an overly large egg, this can sometimes result in blood stains being visible on the shells.…”

Some aspects of chicken behavior and welfare

“…Zupan et al (2008a) observed that layers that do not have access to suitable nest sites may present an elaborate sequence of nest seeking and building behaviors one hour before lay, with apparent frustration signs, such as excessive locomotion and exploratory activities (Cooper & Appleby, 1996), as well as a special vocalization, called gackel-call (Zimmerman et al, 2000). In addition, frustration may be physiologically expressed by egg retention in the eggshell gland (Hughes et al, 1986), resulting in an extra calcium layer on the eggshell (Reynard & Savory, 1999). According to Keeling (2004), these signs indicate that the hen's welfare was compromised by the lack of a suitable nest.…”

Interaction between oviposition time, age, and environmental temperature and egg quality traits in laying hens and broiler breeders

“…The negative effect of higher temperature on time of oviposition in laying hens could be considered as an environmental stressor which, according to Hughes et al (1986) and Reynard and Savory (1999), can delay oviposition. Also Yoshida et al (2011) suggested a possible effect of heat stress on ovarian function and consequently egg production in laying hens.…”