Behaviour, welfare, and tibia traits of fast- and slow-growing chickens reared in intensive and free range systems

Abstract

The behaviour, welfare, and tibia characteristics of fast- and slow-growing chickens were evaluated in free-range and intensive production systems. A total of 720 birds of three strains were subjected to these systems after 21 days of rearing under the same intensive environment. Each treatment was replicated six times with 20 birds in each replicate. Data were collected for welfare aspects, including feather condition, footpad, hock joint and tonic immobility, behavioural features, especially feeding or foraging, sitting, walking, scratching, pecking and dust-bathing, and tibia characteristics, including weight, length, width, medullary canal diameter and robusticity index (4 - 8 weeks). Production system had significant effects on all welfare and behaviour aspects of the birds. However, tibia characteristics were not influenced by production system, except for medullary canal diameter. The strains differed significantly in welfare, tibia characteristics and behaviour. For example, the slow-growing strains had better feather condition, footpad and hock joint scores. Significant interactions of strain and production system were noted for all characteristics. It was recommended that Rhode Island Red chickens could be raised under either production system without compromising their welfare or causing adverse effects on leg health.

Comparison of carcass condemnation causes in two broiler hybrids differing in growth rates

“…However, several studies concluded that genetic factors enabling a fast growth rate might negatively affect broiler health and behaviour and, thus, welfare 4 . For instance, studies performed under experimental conditions have reported that fast growth in broilers is a risk factor for high mortality 2,5 , poor adaptive immune system function 6 , increased prevalence of metabolic disorders 7 and skeletal disorders leading to gait abnormalities and lameness 8 , lower activity levels 5,9,10 , higher scores for foot pad lesions and hock burns 5,10 and poor feather condition 10 .Consumer concern for animal welfare has resulted in the development of a market segment using broilers with slower growth rates 11 . Indeed, an increasing proportion of slower growing broilers is used in European broiler production; e.g.…”

How effective are the seasons and different applications in semi-intensive broiler rearing in terms of welfare?

“…(2021) reported that 8-week-old FR broilers showed a much longer TI duration than indoor-raised chickens. On the other hand, according toGhayas et al (2021) andMutibvu et al (2017) fear response was less (TI duration was shorter) in FR group than intensive system. We can say that the ndings are contradictory again.…”

Mortality risk on farm and during transport: a comparison of 2 broiler hybrids with different growth rates

“…Indeed, recent studies under experimental conditions indicated that genetic selection for fast growth is an important risk factor for mortality in broiler chickens ( Havenstein et al, 2003 ; Dixon, 2020 ). In addition, previous studies found associations between fast growth and adaptive immune system function ( Cheema et al, 2003 ), metabolic function ( Lubritz et al, 1995 ), lameness ( Kestin et al, 2001 ), and feather condition ( Ghayas et al, 2021 ). Studies comparing mortality between hybrids of different growth rates are scarce; however, 2 observational studies reported lower mortality during the first week and during the entire production period for slower growing broilers ( Rayner et al, 2020 ; Baxter et al, 2021 ).…”