Final Project Webinar 22nd of April 2021
Free-ranging profiles of commercial and heritage
meat-purpose chickens, their welfare and gastrointestinal tract
features
Joanna Marchewka et al.
Organic meat purpose chicken production
• Increased public concerns of animal welfare and sustainability in conventional poultry production systems
• Consumers’ interest in meat from poultry reared in low-input systems:
• housing and management aim for optimizing health and welfare of chickens
• In EU organic system birds are provided with ranging areas
Final Project Webinar 22nd of April 2021
Organic meat purpose chickens in Poland
• Poland - the largest EU-27 chicken producer (20% of EU chicken production)
• Poland covers only 0.3% of the EU organic food market value; (6 EURO/year/person spent on organic products in 2020)
• Between 6th and 9th rank in number of certified organic farms in EU (all species) but only 4% of livestock production in Poland is organic
• Organic poultry production marginal in Poland (less than 1% of the total poultry production); Western Europe - above 10%
Gornowicz et al., 2017
FreeBirds: Optimizing the use of the free range as the key to improve organic chicken production
Project aims: • Relation between chickens’ free range use and bird
health, welfare and performance • Smart tools and management strategies
Study aims in Poland 2
stra
ins
of c
hick
ens Focus
Animal welfare
Gastrointestinal tract morphometrics, small intestine
microstructure, amount of pasture and feed ingested
Weather conditions
Range use
Material and methods
Experiment: • Summer 2018
• SASSO C44 and Green-legged Partridge
• 12 pens with outdoor runs • 10 birds/pen
• Data collected from wk. 5 (birds can go outdoors) to wk. 10
• 24/7 video recordings
• birds tagged with a laminated color tag
SASSO and Green-legged Partridge • Sasso is a slow-growing broiler hybrid
• GLP is a dual purpose heritage Polish breed – widely accepted in practice (high quality of meat and eggs)
• Both are well adjusted to outdoor conditions
• Different exterior (colored chicken vs. wild type coloration)
• Not comparable in body weight, size and growth rates
Ranging profiles • Not all broiler chickens in a flock access the outdoor
range when the opportunity is provided
• Campbell et al. (2016) profiled individual laying hens, differing in their ranging profiles
• Profiling attempt has not been performed in meat-purpose chickens
We ranked the birds based on their range use frequency and distributed into 3 ranging profiles:
• outdoor-preferring ranging profile
• moderate-outdoor ranging profile
• indor-preferring ranging profile
Investigation levels
Production system
Genetic strain/breed/hybrid
Flock
Ranging profile
Individual
Call focus: organic and low input systems
SASSO C44 and Green-legged Partridge
Experimental design: pens
Outdoor-preferring Moderate-outdoor Indor-preferring
120 birds in 12 pens
Focus: Animal welfare • Despite consumers’ belief that access to an outdoor range
improves chicken welfare, still little is known if it is true
Genetic strain/breed/hybrid
• Improvements in breast plumage cover, gait scores, cardiovascular function and reduction in weight (i.e. Ross 308)
• Outdoor range use association with the welfare condition in slower-growing broiler chicken genetic strains may vary
Ranging profile
Ranging profiles in hens were strongly associated to coping styles (Campbell et al., 2016)
Coping styles are related to the levels of stress and disease vulnerability (Koolhaas and Van Reenen, 2016)
Welfare condition of birds presenting different ranging profile may vary
•
•
•
Welfare Assessment Scale 0 (optimal condition) to 2 (major deviation from optimal condition): • plumage condition • comb pecking wounds • skin injuries • dirtiness • toe damage • eye pathologies • footpad dermatitis • hock burns
Either 1 (present) or 0 (absent): • respiratory infections • diarrhea
Scale 0 (perfect walking) and 5 (unable to walk) - Welfare Quality gait scoring method
• walking ability
Results: Animal welfare
• Effect of interaction between genetic strain and ranging profile on respiratory infections
• Sasso condition was worse for FPD, plumage condition, comb pecking wounds, dirtiness, and toe damage
• Toe damages were more frequent in indoor-preferring birds, as compared to other ranging profiles
Implications: Animal welfare
• To implement strategies encouraging chickens to use the outdoor area, evidence is needed that outdoor-preferring birds present better or equal welfare as indoor-preferring and moderate-outgoing birds
• Associations between ranging profiles and welfare of investigated genetic strains identified
• Further research to establish the causal relationship between range use and indicators of birds’ welfare needed
Focus: Animal welfare
Focus: Gastrointestinal tract morphometrics, small intestine microstructure, amount of pasture and feed ingested
• Optimal gastrointestinal tract development is important for nutrient absorption and for poultry to resist diseases and assure welfare
• Birds reared with access to the pasture consume material found outdoors
• Is frequency of the outdoor range use associated with the ingested material and the development of birds gut?
Gastrointestinal tract measurements
• The aim of the current study was to investigate:
gastrointestinal small intestine amount of pasture-tract microstructure originating material
morphometrics and feed
• Birds divided into 3 ranging profiles
• Analysis separately for the Sasso and Green-legged Partridge
Results: Gastrointestinal tract morphometrics, small intestine microstructure, amount of pasture and feed ingested
• Villi in terms of their height and area were the lowest for indoor-preferring Sasso, as compared to outdoor-preferring ones
• In the crops of the moderate-indoor Green-legged Partridges there was significantly more pasture matter, as compared to other ranging profiled birds of that breed
• Correlations between the gastrointestinal tract and its content measurements were different for each breed
Implications: Gastrointestinal tract measurements
• The optimal gut development is important for the efficiency of the nutrient absorption and the ability of poultry to resist disease
• The level of the development of the gastrointestinal tract and its content may be considered as potential retrospective indicators of the birds ranging profile
• Links between intestinal microflora vs. gastrointestinal tract measurements vs. behaviour and emotional states still need to be explored
Focus: Weather conditions • Outdoor environmental conditions influence animal
comfort
• Comfort zone related to weather parameters for free-range broilers not investigated yet
Ranging areas: • Long, open spaces with
little shelter
• Shelter, if present, often unavailable to all birds in a flock at once (Stadig et al., 2017)
Focus: Weather conditions
• Outdoor shelters often not protective from all weather parameters
• Single-type shelters don’t fulfil protective role to all birds within the flock, if individuals are sensitive to varying weather conditions
Weather conditions
• Previous studies averaged the breed or treatment group range use
• Weather data collected each minute throughout the whole experiment by an automatic weather station
• Exact matching of an individual bird range access with instantly changing weather parameters
Results: Weather conditions • Associations between weather parameters and range use for 30%
of Green-legged Partridge and Sasso chickens
• Weather explained up to 35% of the range use variability
• Between breeds, range use associations with different weather parameters were identified:
• Negative associations with relative humidity most frequently in Green-legged Partridges
• Positive associations with atmospheric pressure most common in Sasso chickens
• Ranging areas design to accommodate individual preferences/needs, e.g. by including provision of multiple construction and vegetation elements
Conclusions
• Dividing birds into ranging profiles helped to describe associations between their range use and health and welfare more precisely than only by comparing genetic strains
• Evidences found that outdoor-preferring birds present better welfare as indoor-preferring and moderate-outgoing birds
• Indoor-preferring birds require further characterisations
• Gastrointestinal tract health and function parameters were associated to range use frequency
• Birds presented various individual range use reactions under the same weather conditions
• Individualized range use optimization strategies may be required for best production outcomes
Final Project Webinar 22nd of April 2021
Thank you for attention