Animal breeding: a neglected factor in animal welfare Anna Valros Professor of Animal Welfare 17.6.2010 1
Contents Domestication Animal welfare Resource allocation theory Examples of negative side effects of breeding for production Breeding and behaviour Discussion points 17.6.2010 2
Evolution vs domestication 4600 m.yrs. 3600 2600 1600 600 200 0 Earth forms Life begins Mammals evolve 60 m.yrs. 50 40 30 20 10 5 2 0 Horse-like animals Domestication Horse Human 20 000 10 000 8000 6000 4000 2000 0 Dog? Sheep Pig Chicken Cattle Eläinlääketieteellinen tiedekunta / Anna Valros Horse www.helsinki.fi/yliopisto animal breeding 17.6.2010 3
What is domestication? that process by which a population of animals becomes adapted to man and to the captive environment by genetic changes occurring over generations and environmentally induced developmental events reoccurring during each generation (Price, 1984) Eläinlääketieteellinen tiedekunta / Anna Valros www.helsinki.fi/yliopisto 17.6.2010 4
Effects of domestication Reduction of fear Changes in colour Changes in size Changes in fat storage Smaller brain and head, weaker senses Eläinlääketieteellinen tiedekunta / Anna Valros www.helsinki.fi/yliopisto 17.6.2010 5
Domestication and behaviour Behavioural changes slower than physiological changes Changes are mainly quantitavive, not qualitative Eläinlääketieteellinen tiedekunta / Anna Valros www.helsinki.fi/yliopisto 17.6.2010 6
What is animal welfare? Eläinlääketieteellinen tiedekunta / Anna Valros www.helsinki.fi/yliopisto 17.6.2010 7
Health vs welfare Animal health Pathological changes and adaptations to these Animal welfare The balance between the behavioural and physiological needs of an animals and its environment -> The animals perception Eläinlääketieteellinen tiedekunta / Anna Valros Broom, 2009 17.6.2010 8
Animal welfare Very low level of animal welfare Very high level of animal welfare Positive negative situations - 0 + ++ Life not worth living Life worth living Good life Legal minimum? Eläinlääketieteellinen tiedekunta / Anna Valros Broom, 2009 17.6.2010 9
Five freedoms (FAWC, 1993) 1. Freedom from thirst, hunger and malnutrition 2. Freedom from discomfort 3. Freedom form pain, injuries and illness 4. Freedom to express behavioural needs 5. Freedom from fear and anxiety FAWC: Farm Animal Welfare Council 17.6.2010 10
Eläinlääketieteellinen tiedekunta / Anna Valros 17.6.2010 11
eellinen tiedekunta / Anna Valros Hits according to keywords www.sciencedirect.com Search terms Hits Animal welfare (AW) 56 580 AW and behaviour 27 677 AW and transport 10 898 AW and housing 8271 AW and selection 3528 www.helsinki.fi/yliopisto 17.6.2010 12
Resource allocation theory An animal has only a limited amount of resources available When more and more resources are allocated to production, less are available for eg. immune defence, behaviour, coping, stress tolerance (Beilharz, Rauw) Eg. layng hens bred for high production are less active and feed more intensively than Bantham and Jungle fowl (Schutz & Jensen, 2001) Resources can only be increased to a certain limit (eg. feed intake limits nutritional resources) 17.6.2010 13
Examples of negative side effects of breeding 17.6.2010 14
In Denmark 25 000 piglets per day die of hunger Yle 19.5 2010 Mass death of piglets stirs up feelings in Denmark: Greed kills 25 000 per day Uusisuomi 18.5 2010 17.6.2010 15
Piglet mortality Piglets / litter 15 14 13 12 11 10 9 8 7 Total born Born alive Weaned Sold 6 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 Year Evolution of litter size in French sow herds (IFIP-Institut du Porc, National GTTT data bank). Boulot, et al., 2008. 17.6.2010 16
Boulot, et al., 2008 Litter size 9 10-11 12-13 14-15 16 (class) Mean parity 2.6 2.3 2.5 2.6 3.5 Litter N 161 134 245 334 506 No. total 7.2 10.6 12.6 14.5 17.6 born No. born 7.0 10.2 11.9 13.8 16.2 alive No. stillborn 0.3 0.4 0.6 0.7 1.5 Mean BW, kg 1.89 a 1.67 b 1.57 c 1.47 d 1.38 e CV BW, % 14.9 d 17.4 c 20.2 b 21.3 b 23.7 a Distribution in BW classes, % < 1.0 kg 3 e 5 d 8 c 10 b 15 a 1-1.4 kg 8 e 16 d 21 c 29 b 34 a 1.4-1.8 kg 27 c 39 b 43 a 43 a 38 b > 1.8 kg 63 a 40 b 28 c 19d 13 e a,b,c,d,e Within each row, means with no common superscript differ (P < 0.05). 17.6.2010 17
Poultry Broilers and turkeys are the most extreme example of selection for rapid growth and efficient feed conversion ratio - DWG of broilers: 1956: 21 g, 2010: 63 g There is evidence that the selection has caused severe changes in the birds physiology, causing eg. changes in the hypothalamic satiety response (Burkhart et al, 1983) The selection for high growth rate has probably also reduced the immune function in broilers and turkeys as well as increased mortality rates 17.6.2010 18
Broiler breeders Due to huge increases in growth potential, broiler breeders must be severely feed restricted - ad libitum fed broiler breeders had a mortality of 40% by 40 weeks (compared to 6% in restricted (Heck et al 2004) - Over-feeding also leeds to poor fertility (Hocking, 2009) and leg problems (Mench, 2002) - Feed is consumed in about 15 min During rearing, radical feed restriction (25-33%) is necessary to decrease welfare problems - Feeding programs usually include 1-3 no-feed-days per week During the laying phase feed is restricted to 45-80% in females At 39 d a Ross 208 broiler breeder female weighs 615 g and an ad libitum fed broiler female 2,2 kg 17.6.2010 19
Consequences of feed resriction Chronic hunger Aggression around feeding time Abnormal behaviour due to frustration, esp during rearing period Over-drinking (causing need to restrict water availability) Increased redirected and stereotypic pecking Increased pacing Physiological stress responses Elevated plasma cortisol Changes in immunofunction Increased fibre content in feed might have an effect, but it is not very clear - Even though the gut might be fuller, metabolic hunger remains 17.6.2010 20
Broilers Continued genetic selection for fast growth has a negative effect on leg problems, a major part is heritable (Whitehead et al, 2003) A large number of broilers have impaired walking and experience pain and discomfort Slow-growing broiler breeds have better walking ability (Middlekoop et al (2002) European studies show prevalence of leg weakness to be between 0,4 and 32,6% (EFSA, 2010) In a UK study of 51 000 bords, 27,6% scored 3-5 (Knowles et al, 2008) 17.6.2010 21
Broilers cont. Ascites / sudden death syndrome (SDS) are the most common causes of death in healthy flocks Both are caused by a combination of selection for fast growth, feeding and managament There is a genetic correlation between growth and ascites and growth and SDS (Deeb et al 2002, Moghadam et al 2005) High growth is also correlated to lower general activity 17.6.2010 22
Dairy cows The milk yield of dairy cows has increased dramatically during the last 40 years, and is now about 10 times that of beef cattle Both management and genetics have been important, genetics especially after the 1980s Unfavourable genetic correlations between high milk yield and ketosis, mastitis, lameness, fertility problems and reduced oestrus behaviour (Oltenacu and Broom, 2010) 17.6.2010 23
The high production causes metabolic stress: cows can not eat enough to prevent metabolisation of reserves Increased need for nutrients can cause time contstraints (especially in automatic milking systems) and eg. reduced time for resting 17.6.2010 24
Increased size of dairy cows causes welfare problems due to barn buildings becoming too small High producing dairy cows are extremely dependent on proper management and sensitive to disturbances - Problems eg in grazing countries and organic production 17.6.2010 25
Breeding for behavioural traits Should we breed the animal to fit the environment or the other way around? Examples: - we can not anticipate the possible risks - breeding for zombies might decrease suffering, but what about pleasure? And what about animal integrity? -Maternal abilities in sows -Feather pecking in hens -Tail biting in pigs 17.6.2010 26
Social effects By selecting animals on their performance as a group, social effects are accounted for Muir (1996) selected against mortality dur to feather pecking: from 68% in generation 2 to 9 % in generation 6 Ellen et al (2007) slected for egg production and low mortality: 20 vs 30% mortality in the first generation Selection for high social breeding value for growth in pigs altered their aggressive behaviour (de Vries unpublished, see Rodenburg et al 2010) 17.6.2010 27
Discussion points Breeding in optimal conditions: - animals in real life do not get the same resources > risk for welfare problems More information is needed on long-term economical efficiency (eg. milk yield and mastitis) 17.6.2010 28
To conclude Breeding decisions have a major influence on the welfare of production animals A larger focus on health and welfare is needed in breeding programs: Breeding companies have a great responsibility for the future welfare of our production animals. Need for societal discussions on the ethical limits for breeding 17.6.2010 29
Thank you! 17.6.2010 30