Effects of stress during commercial hatching on growth, egg production and feather pecking in laying hens

Abstract

Every year, billions of egg layer chicks around the world are hatched under highly stressful, industrial circumstances. Here, it is investigated how the stressful procedure in the commercial hatchery, including incubation, hatching, processing, and transport affects the chicks with regards to traits relevant for the egg production industry. These traits were compared to those of a control group hatched in a small incubator and handled gently och quietly in a quiet room without any processing and transport. The chicks were weighed at hatch and at eight additional time points: 4 days, 1 week (w), 2 w, 3 w, 5 w, 8 w, 20 w and 25 w of age. Feather pecking was studied at 15 w of age and damages to the feathers and injuries on the comb and wattle were assessed at 25 w of age. From 19 w of age, eggs were collected on three days per week, counted and weighed. Chicks from a commercial hatchery had a lower hatch weight than control chicks (p<0.001). At 20 w of age, the weight of the commercial hatched chicks was still numerically lower, although this did not reach statistical significance. Commercially hatched chicks tended to show more feather pecking behaviour at 15 w of age compared to control chicks (p<0.1), although feather condition at 25 w of age showed the opposite pattern. Regarding production, commercially hatched chickens laid fewer (p<0.05) and smaller (p<0.05) eggs than chicks hatched and handled under calm circumstances. From this experiment, it is concluded that the stressful experience in the commercial hatchery has an overall negative effect on traits relevant for the industry.

Can Early Environmental Enrichment Buffer Stress from Commercial Hatchery Processing in Laying Hens?

“…However, HC-groups were weighed at a later time-point than CC due to transportation delay, hence, the weight difference could at least partly be explained by dehydration. In previous studies, we have found variable effects of hatchery stress on weight development [1,33]. This may, for example, be a result of different ages of the parental flocks [34][35][36][37], something that was not controlled for in our experiments.…”

Uso de probióticos y sus efectos en el bienestar de la gallina ponedora

“…Sabendo que as aves sob condições comerciais criadas em gaiolas ou em alta densidade podem apresentar comportamento anormal, como agressividade, bicagem e até canibalismo, resultante de estresse (Hedlund & Jensen, 2022;Jiang et al, 2022), a manutenção do equilíbrio da microbiota é crucial para a homeostase fisiológica e comportamental, saúde, bem-estar (Jiang et al, 2022) e qualidade dos ovos produzidos (Hedlund & Jensen, 2022). Assim, a suplementação com probióticos torna-se uma ótima opção, pois promove efeitos benéficos à saúde em resposta ao estresse das aves, além de melhorar o processo de adaptação ao ambiente de produção (Jha et al, 2020;Krysiak et al, 2021).…”

Effects of Stocking Rate and Environmental Enrichment on the Ontogeny of Pecking Behavior of Laying Hen Pullets Confined in Aviary Compartments during the First 4 Weeks of Life

“…AP is used to establish a pecking order [ 14 , 15 ]. The possibly of stressful circumstances in a commercial hatchery and housing conditions [ 26 , 27 ] could have facilitated agonistic behavior towards their conspecifics, despite the availability of enough food, which had been spread generously on the chick paper throughout the compartment before the placement of the chicks [ 20 ]. However, the establishment of a pecking order was probably not possible due to the large group size, consisting of over 100 animals, which was too large to enable the individual acquaintanceship of the chicks [ 15 , 16 ].…”

“…The rearing conditions are an important risk factor for the development of SFP in laying hens [ 22 , 23 , 24 , 25 , 26 ]. There is some evidence that the stressful experience in the commercial hatchery has an overall negative effect on the development of pullets [ 27 ]. The combination of not having litter at the age of 1–4 weeks and the absence of daylight at the age of 7–17 weeks was a significant predictor of feather damage during the laying period in organic laying hens according to Bestman et al [ 23 ].…”