Behaviour and stress in three breeds of laying hens kept in the same environment

Abstract

<jats:p>The aim of the study was to determine whether birds of different breeds, with different preferences for environmental elements and kept in identical conditions, would exhibit different behaviour and stress levels. The research material consisted of 50 laying hens of the Green-legged partridge (Zk), Polbar (Pb), and Leghorn (Lg) breeds. The birds were provided with identical environmental conditions. They were kept on litter in separate boxes, with 25 individuals of one breed per box, in the same building. An open field test was used in determining the behaviour of the birds. Levels of cortisol in serum and corticosterone in feathers were evaluated, and haematological and biochemical analyses of blood were performed. Leghorns proved to be a highly excitable and active breed whose needs cannot be fully satisfied in the standard conditions of large farms. Based on a differential leukocyte count, their hyperactivity was associated with increased stress. The Green-legged partridge exhibited the lowest stress levels. Birds kept in the same environmental conditions were found to differ significantly in the level of stress, probably because of differences in their behavioural needs and the possibilities of satisfying them. To reduce stress levels and improve the welfare of hens, it is necessary to verify their preferences first. Stress indicators are elevated in highly excitable birds, and the conditions on large farms are not conducive to meeting their behavioural needs.&#x0D; Keywords: behavioural test, blood indices, corticosterone, laying hens</jats:p>

The Effect of the Type of Non-Caged Housing System, Genotype and Age on the Behaviour of Laying Hens

“…The greater interest of the native-bred hens (Green-legged Partridge) in using the run compared with commercial breeds (Hy-Line Brown) can be associated with a better adaptation of native breeds to local, changing and even extreme environmental conditions. The lower interest of the Hy-Line Brown hens in the run can result from a higher level of fear and stress in commercial hens [ 37 ].…”

“…Birds of different breeds vary greatly in terms of stress levels, despite the same environmental conditions. The lowest levels of stress indicators were found in the Green-legged Partridge hens, indicating their behavioural needs were best met by that environment [ 37 ]. According to [ 36 ], long-term selection to improve the productive characteristics of laying hens intended for cage breeding was carried out in stable environmental conditions, in contrast to non-cage systems, where birds live in more variable environmental conditions and could interact in various ways.…”

“…Native breeds are characterised by good immunity and capability of adapting to the environmental conditions [ 35 ], while commercial hybrids, for many generations, have been selected for high productivity within controlled environmental conditions [ 36 ]. Studies on behaviour and stress in three breeds of laying hens kept in the same environment have shown that compared to Polbar hens and the commercial strain Leghorn, Green-legged partridge hens exhibited the lowest stress levels, which may indicate that their behavioural needs were best met in free-range conditions [ 37 ].…”

Characterization of Table Eggs-Producing Organic Farms in Mazowieckie Voivodeship

“…The Greenlegged Partridge chickens' eggs have a higher content of yolk and better ratio of n-6/n-3 fatty acids in comparison to other breeds, in addition to low cholesterol content [Trziszka et al 2004]. They also exhibit lower stress levels when compared to Polbar and Leghorn breeds kept in similar conditions [Rozempolska-Rucińska et al 2020]. This combination of desired traits contributed to their popularity.…”

The Use of Artificial Intelligence in Assessing Affective States in Livestock

“…Such indirect measures include hormonal assessments, physiological measures, facial expression, brain activity, thermal imaging, vocalisations and movement (30). In multiple farm animal species (cattle, sheep, goats, horses, pigs, poultry), emotional valency has been associated with particular vocalisations (31)(32)(33)(34)(35)(36)(37), changes in nasal temperature (38) or eye temperature (39-41), cortisol levels (39,(42)(43)(44), heart rate and heart rate variability (40,(45)(46)(47)(48)(49), respiration rate (50) but also facial expression and the (change in) position of the ears and tail (31,43,46,(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62). See Table 1 for a collection of studies that tested these measures and how they relate to emotional valence.…”