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Wat is duurzaam fokken? Grenzen aan selectie Prof. em. E. Decuypere 6 november 2013
Motivation in the past: increased animal production and productivity
New signal: “cheap and safe food but not at any cost” concern/threatening by the public: nature of food; food safety? are the new (bio)technologies applicable to man? animal welfare? predominance of economics?
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After World War II • • • •
production efficiency of production stock or herd size, farm dimension specialisation, mechanisation
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Reaction on industrialisation, specialisation and mechanisation From animal-machine Animals as living and sensible beings Utilitarian approach of animal welfare Pathocentrism: animal liberation (1975, P. Singer)
Zoocentrism (T. Regan)
condemnation / rejection of animal husbandry or any instrumental use of animals in its most extreme form
Sustainable animal production = livestock farming with care Principles:
Health and safety of animals and man: one health Customised care: ensuring robustness, dignity and integrity No nuisance from environmental and societal perspective Credible performance (from socio-economic perspective)
“Implementation of concrete measures is a challenge; should be in relation to the different types of animal husbandry practiced in developed and developing countries “ (from Scholten et al.; NJAS 2013)
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What is “careful” livestock farming? • Ethical concept • “Layered” meaning theory of moral circles • Chance or opportunity to reach caring, sustainable farming (Nijland et al. NJAS, 2013)
Layers of increasing inclusivity of care on basis of social and temporal dimensions.
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Selection limits for growth and feed efficiency? Reached because of: • Exhaustion of genetic variability quantitative nor molecular genetics give indication • Unwanted correlated responses associated with continued selection for production efficiency EXAMPLE: unidirectional selection in broiler production
Unwanted responses from selection EXAMPLE: Broilers Feed consumption: 95% slaughter population 5% breeder population
In prolific species poultry, the majo consumed by the generation (95% breeder populatio Therefore, unwa responses are m occur in poultry a in broiler product the unidirectiona
Strong unidirectional selection:
More unwanted responses in broiler production
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Energy intake per unit meat output (MJ/kg)
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Extreme growth
Reproductive efficiency
Incompatibility growth/reproduction more pronounced in • Species with high prolificacy • Multiparous mammalian farm animals
Therefore: Focus selection goals: Slaughter generation
Breeder generation
• Growth • Feed conversion • Carcass quality
• Reproduction parameters
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Further improvements cause dilemmas 3 dilemmas for broiler meat production (apparent since 1980)
1 fast growth and feed conversion VS. changes in lean/fat tissue ratio ponderal and energetic efficiency VS. metabolic disorders 2 of growth and feed conversion ration (FCR) 3
fast growth and extreme lean tissue growth
VS. reproductive effectiveness of the breeder
Dilemma 2: weight vs leg problems in broilers apparently simple and direct link between • selection for increased weight at young age • leg problems (tibia dyschondroplasia, twisted legs, …) BUT not so directly mechanistically evident: next slide
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Dilemma 2: weight vs leg problems in broilers Tibia Dyschondroplasia (TD) and body weight in ad lib fed broilers selected for 4 generations for feed conversion efficiency: for growth upon ad lib feeding: for growth upon restricted feeding:
FC-line GL-line GR-line
Frequency of Dyschondropplasia (TD, %) TD score No TD Light TD
M
Severe TD
No TD Light TD
Body Weight (g)
sex
F
Severe TD
FC
GL
GR
FC
GL
GR
48
11
9
1948
2138
2264
48
60
56
1998
2211
2133
3
28
35
1975
2063
1998
65
32
27
1728
1908
1913
35
61
56
1775
2006
1901
0
7
18
-
1794
1772
D1/2: Link weight – leg problems? Appearance of Selected
Sexe
against twisted legs against twisted legs + for body weight
M
for body weight
against twisted legs against twisted legs + for body weight for body weight
F
Twisted legs (%)
Dyschondroplasia (%)
Body weight
1.5
14.1
1808
2.5
21.3
1941
10.5
41.0
1969
0
5.2
1555
0.2
7.5
1677
3.4
15.4
1708
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D3:Fast and lean growth vs reproduction Domestic poultry: negative relationship between body weight and reproductive efficiency • Selection for growth rate in broiler chickens reduction of the reproductive capacity of parent stocks
• Parent of meat-type poultry genetic potential of fast, efficient growth + reproduction
• Maximize egg and chick production quantitative feed restriction optimum degree and timing still to be elucidated 17
A double broiler breeder paradox Reproductive efficiency
BBP Health and metabolic disturbances
Productivity, resource efficiency
welfare
Animal welfare, and integrity
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Robustness Selective breeding in terms of production + traits related to health and welfare improve “robustness” Robustness = •
production potential
•
resilience to external stresses
•
physiological ability to maintain or re-establish homeostatic state or balance
Robustness • Should be integrated in the breeding goal • Should not be achieved by violation of the integrity ~ “telos” of an animal Notion of integrity is a requirement of robustness (Star et al., 2008)
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Uit ‘De gouden kooi: over het ontstaan van het huisdier’ van A. GAUTIER
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Veranderende houding in de mens-dier relatie •
Verlichting en rationalisme Wetenschap & Technologie Industriële revolutie en stagnatie van de landbouw
•
Vanaf 1880: impact Amerikaans graan crisis in de landbouw, de veeteelt terug belangrijk
•
Voor en vooral nà WO-II: mechanisatie schaalvergroting specialisatie
intensificatie en instrumentalisatie van dieren
Veranderende houding in de mens-dier relatie • • • • •
Dubbeldoeldieren verdwijnen (specialisatie) Minder grondgebonden veehouderij Kennis- en kapitaalsintensief Aan het oog onttrokken, Band met individuele dieren verdwijnt
Kloof tussen producent en consument van dierproducten
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Verscheiden mens-dier relaties Onderscheiding obv bv diergeneeskundige kosten die men bereid is te dragen voor een dier Indeling en definitie van : • • • • • • •
nutsdieren (landbouwhuisdier, proefdier, werkdieren) gezelschapsdieren hulpdieren hobbydieren schadelijke dieren exotische dieren wilde – en jachtdieren
Muskus rat Paard Schaap
Konijn
Merkwaardige gelijkenis met de bestiaria van de Middeleeuwen !
Conclusie Er is een ambigue houding t.o.v. de verschillende gedomesticeerde dieren, ook m.b.t. eugenetica. “all animals are equal…but some are more equal than others” (G. Orwell, Animal Farm)
Ofwel instrumenteel gebruik van dieren binnen de grenzen van hun “welzijn” en/of “integriteit” m.a.w. speciesisme is niet moreel verwerpelijk
Ofwel kunnen zij NIET ten bate van de mens worden gebruikt, en dit voor alle huisdieren inclusief proefdieren, gezelschapsdieren, … (en niet opportunistisch enkel voor nutsdieren) m.a.w. is speciesisme verwerpelijk
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Bedankt voor uw aandacht!
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