Assessment of Welfare in Broiler Production and Possible Use of Environmental Enrichment

Transcription

1 Assessment of Welfare in Broiler Production and Possible Use of Environmental Enrichment Werner Bessei University of Hohenheim, Stuttgart-Hohenheim Germany

2 Welfare definitions developed concomitantly with the wealth of the human society Absence of physical damages and diseases Absence of physiological disturbancies Absence of psychological disturbancies Absence of adverse feelings Experience of positive feelings

3 Definitions and Indicators of welfare Definitions Indicators Absence of physical damages and diseases Absence of physiological disturbancies Absence of psychological disturbancies Absence of adversive feelings Experience of positive feelings Growth, livability, reproduction, mobility (gait) Metabolic disorders, stress hormones Apathy, excitement, stereotyped behaviours Fear Playing, dust bathing, positive social interactions

4 Indicators and Inputs Growth, livability, reproduction, mobility (gait) Metabolic disorders, stress hormones Apathy, excitement, behavioural stereotypies Fear, avoidance, crowding Indicators Playing, dust bathing, positive social interactions Inputs Feed, water, shelter, vet. care Light, temperature, ventilation, Space, litter, Frequent contacts to humans Enrichment objects or structures

5 Environmental criteria Stocking density Temperature Litter conditions Air quality (Ventilation rate; regulation and reliability) Light (Intensity, distribution; frequency, spectral characteristics) Feeder space Drinker space Distance between feeders and drinkers Enrichment devices /structural elements

6 Low density (20 kg/m²)

7 High stocking density (40 kg/m²)

8 Influence of stocking density on body weight development in 6-weeks old broilers under good and poor ventilation rate (after Grashorn und Kutritz, 1991) Body weight (g) a a b a ab c 1800 l m e l m e gutes Klima schlechtes Klima l = 38.1 kg/m m = 45.1 kg/m e = 50.4 kg/m Tierschutz Broiler

9 Feed conversion rate Mortality (%) The influence of stocking density on mortality and feed conversion (after Shanawany, 1988) ,9 1,8 1, Stocking density (kg/m 2 )

10 Influence of stocking density of locomotor activity of broilers from 1 to 5 weeks of age (Bessei, 1992) Walking % T/m2 25 T/m2 30 T/m Age (weeks)

11 The influence of stocking density (birds/m²) on scratching behaviour from 1 to 5 weeks of age (Bessei, 1992) Scratching % 2 20B/ m² 25B/ m² 30B/ m² 1,5 1 0,5 0 Age/Weeks

12 Deformation of tibia bones Tierschutz Broiler

13 Activity is important for the Skeleton development

14 Effect of distance between feeder and drinker (Reiter 1996) 2 Meter 12 Meter Live weight g 2022,0 2014,2 Culled for leg disorders % distal angulation tibia Corticalis thickness mm 3,2 a 2,7 b 6,4 a 5,3 b 0,4 b 0,9 a

15 The influence of stocking density on temperature at different sites of the broiler house (Reiter und Bessei, 2000) Hight over litter (cm) ,8 C 21,8 C 22,3 C 20 21,6 C 21,3 C 22,5 C 0 21,6 C 23,3 C 26,1 C -5 23,3 C 26,9 C 31,3 C 19,4 30,0 40,2 Stocking density (kg/m 2 )

16 Aereas of heat dissipation in broilers (picture M. Gerken) Thermal image of conventional broiler (Infrared thermography) Tierschutz Broiler

17 Footpad dermatitis Tierschutz Broiler

18 Litter moisture and FPD in turkeys (Wu and Hocking, 2011)

19 Light-related issues Duration of light Quasi constant light (23 hrs) Intermittent lighting programmes Step-down step-up programmes Light intensity (20 lux?) Light colour (daylight?) Light frequency Natural light?

20 Lighting programme for broilers (Report on broilers, 2000) Light duration N5 N4 N3 N1 S Age (days) Tierschutz Broiler

21 The effect of daylength on eye weight in broilers of 35 and 48 days of age (Schwean-Lardner,and Classen, 2011)

22 The effect of daylength on live weight in broilers of 38/39 days of age (Schwean-Lardner,and Classen, 2011)

23 The effect of daylength on feed conversion rate in broilers of 38/39 days of age (Schwean-Lardner,and Classen, 2011)

24 Methods of environmental enrichment in broilers Lighting programmes Toys Hay or straw baskets Perches, raised platforms (ramps) Free range/winter garden Sequential feeding Scattering of pellets or grains Pecking blocks

25 Frequency (number per 10 min) Influence of age scattered pelleted feed on walking behaviour of broilers (Jordan et al., 2011) Treatment: 2,0 Control Wheat Scatter 1,5 1,0 0,5 0,0 05:00 05:30 06:00 06:30 07:00 Time (hour)

26 (photos Vilomix) Pecking Blocks

27 Perches as enrichment element increase the incidence of breast blisters Breast blisters scores from 1, left, 2 central, 3 right (Lorenz, 2010)

28 Sales over feed cost in 6 weeks old broilers (after Shanawany, 1988) Sales over feed cost ( /m 2 ) Stocking density (kg/m 2 ) Tierschutz Broiler

29 Conclusions The perception of welfare in general has changed in human society concomitantly with its wealth. The requirements for housing and care have been changed accordingly. Welfare-friendly production systems should not only fulfill not only avoid Physical and physiological damages but also grant positive experience. The main animal-oriented welfare issues in commercial broiler production are Low level of activity, leg problems including poor gait and footpad dermatitis, metabolic diseases (SDS, Ascitis), mortality. On the environmental side high stocking density, poor litter quality, lack of structure and extended light periods, are directly or indirectly related to the above welfare problems. The direct effect of stocking density on welfare is generally overestimated. However, stocking density may affect welfare indirectly through wet litter, development of high litter temperature and poor climatic conditions. Quasi-continuous lighting programmes leed to increased eye-balls and reduce the bird`s activity. Extended periods of darkness (6 hours) not only increase the locomotor acticity but also allow high productvity and avoid eye enlargement.

30 Conclusions II Quasi-continuous lighting programmes lead to increased eye-balls and reduce the bird`s activity. Extended periods of darkness (6 hours) not only increase the locomotor acticity but also allow high productvity and avoid eye enlargement. Environmental enrichment is expected to increase the activity of the birds And to reduce metabolic disorders and leg problems. In addition it should Stimulate the expression of natural behaviours and positive feelings. There exist A great variety of objects and methods of enrichment for chickens. To be effective in fast growing broilers the methods of enrichment need to be related to feeding behaviour. Bales of straw and pecking blocks may be Usefull and easily applied under commercial conditions.