High levels of contact dermatitis and decreased mobility in broiler breeders, but neither have a relationship with floor eggs

Abstract

Contact dermatitis, both on the foot pads and hocks, is a well-known health issue in broilers. Less is known about contact dermatitis in broiler breeders, however, although they have many risk factors for developing leg health problems in common with broilers. This study aimed to describe the prevalence and severity of contact dermatitis during the production cycle in 5 lines of broiler breeders, investigate possible causes of contact dermatitis, and study its relationship with gait, egg production, and floor egg percentage. Five commercially available genetic lines of broiler breeders were housed in 21 pens of 550 females and 50 males from 20 to 60 wk of age. Every 10 wk litter quality, leg health measurements (foot pad dermatitis, hock burn, and gait) and body weight were assessed of 50 random hens per pen. Total number of eggs, number of eggs laid outside the nest (floor eggs), and mortality were recorded daily per pen. Prevalence of foot pad dermatitis, hock burn, and gait problems increased with age. Litter quality started to decrease at 50 wk of age. Prevalence of foot pad dermatitis was affected by litter quality, whereas genetic line had little effect. One genetic line was more prone to developing hock burns, though generally the prevalence of hock burn (13%) was much lower than that of foot pad dermatitis (74%). The percentage of broiler breeders with gait problems increased up to 24% with age, but this was not related to the prevalence of contact dermatitis. The lines differed in body weight from 32 wk of age onwards, and a higher body weight was related to lower egg production and higher cumulative mortality. The percentage of floor eggs was not related to leg health parameters or genetic line. Broiler breeders thus have similar leg health problems as broilers, but these problems are not related to the percentage of floor eggs, suggesting that other factors are involved in the undesirable behavior of floor laying.

Welfare of broilers on farm

“…Providing aerial perches enables females to avoid unwanted sexual behaviour from the males to a certain extent (Gebhardt‐Henrich et al., 2020 ) and would be feasible in furnished cages. Besides perches, raised slats (van den Oever et al., 2020a ), part‐time separation between the sexes (van Emous, 2010 ), or cover panels can reduce forced copulations and overmating (Leone and Estévez, 2008 ).…”

“…Studies have reported unhealed navels and enlarged yolk sacs to be the abnormalities most frequently registered during chick quality assessment of both on-farm and hatchery-hatched chicks, but with a higher prevalence in chicks hatched on-farm (van de Ven et al, 2012;Jessen et al, 2021b). For example, Jessen et al (2021b) reported unhealed navels to occur in 8.2% of the chicks hatched on-farm, whereas the prevalence was 5.3% for the hatchery-hatched chicks.…”

“…However, none of the studies comparing on-farm and hatchery-hatched chicks reported an increased mortality in the formercontrarily all of them found either a lower or similar first week and total mortality in the chicks hatched on-farm compared to hatchery-hatched chicks (van de Ven et al, 2012;Jessen et al, 2021b). Some studies have reported no or limited evidence of a relationship between chick quality assessments and performance or mortality (Willemsen et al, 2008;van de Ven et al, 2012).…”

“…Chicks that are classified as second-grade typically fall into the following categories: 1) they are unable to stand straight up, 2) they show visible signs of suboptimal incubation conditions, e.g. red hocks or unhealed navels, or 3) they show deformities (van de Ven et al, 2012).…”

Characterization of Escherichia coli and other bacteria isolated from condemned broilers at a Danish abattoir

“…Cellulitis usually develops from initial skin scratches, which allow entry of bacteria into the subcutaneous tissue where they subsequently proliferate and cause infection ( Jeffrey et al, 2004 ; Bernd et al, 2020 ). However, as carcasses with cellulitis in the current study were free from scratches, the development of cellulitis may be attributed to other predisposing factors, i.e., wet irritated skin in combination with stress, genetic factors, nutritional deficiency, population density, litter quality, and breeders’ and hatchery hygiene ( Dziva and Stevens, 2008 ; Allain et al, 2009 ; Kabir, 2009 ; Poulsen et al, 2018 ; Alfifi et al, 2020 ; Iannetti et al, 2020 ; van den Oever et al, 2020 ). A recent investigation of management factors associated with cellulitis reported that measures to reduce stress in broiler flocks reduced the risk of cellulitis ( Bernd et al, 2020 ).…”