Improving Piglet Survival Emma Baxter Susan Jarvis, Sheena Robson, Marianne Farish, Rainer Roehe, Alistair Lawrence, Sandra Edwards 1
Background Total pre-weaning mortality (stillbirths + live-born mortality) = 16-20% ~ 2 million piglets die each year in the UK Economic concern ~ 72-90m potential loss per annum Welfare concern: death can involve chilling/starvation/overlying
What pre-disposes live-born mortality? 3
Events pre-disposing postnatal mortality Low birth weight/viability Litter size Reduced colostrum intake Disease Sub-optimal temperature Lowering of body temperature Chilling Lethargy Starvation Poor maternal behaviour Overlying Physical trauma e.g. savaging DEATH Edwards, 2002 4
Risk factor Low birth weight Total survival (% ) 100 80 60 40 20 0 10 28 53 71 82 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 Birth weight (kg) 88 89 87 85 82 78 5
How can we improve piglet birth weight? Immediate Improve piglet birth weight Optimum nutrition during gestation and lactation Maintaining high feed intake during lactation influences immediate litter growth rate and survival and influences the sow s next litter Long-term Genetic selection strategies Select for optimum weight Select for reduced within-litter weight variability 6
Risk factor Chilling Piglet core body temperature Piglet is the most cold sensitive livestock neonate, born with very little adipose tissue and no brown fat Newborn = 0 minutes Newborn = +1 minutes 7
Temperature profile of newborn Piglet A temperature profile Temperature ( o C) 40 39 38 37 36 35 34 33 32 31 30 19:33:36 19:40:48 19:48:00 19:55:12 Time (24h clock) 8
How can we reduce the risk of chilling? Immediate Improve piglet microclimate (cf. outdoor study) Limit routes of heat loss Long-term 9
Piglet body temperature in different farrowing environments 39 Body temperature ( C) 38.5 38 37.5 Indoor Outdoor 37 0h 2h 24h Time after birth (h) 10
Improve the microclimate Slat temperature Slat and straw temperature 11
How can we reduce the risk of chilling? Immediate Improve piglet microclimate (cf. outdoor study) Limit routes of heat loss Improve piglet birth weight Birth rectal temperature correlates with birth weight Long-term Genetic selection strategies Select for physiological maturity at birth Increased vitality Improve first time behaviours Correlates with body temperature 12
Sucking colostrum increases core body temperature Behavioural landmarks Piglets that are quicker to reach the udder, find a teat and suck are more likely to survive Piglets sucking at udder 13
Risk factor low colostrum intake Colostrum needed for immunity Colostrum available continuously throughout farrowing Colostrum available for 24-30h after farrowing starts Changes to milk after 30h 14
How can we improve piglet behaviour? Immediate Improve micro-climate for piglets (cf. outdoor environment) Behaviour correlates with birth rectal temperature Indirectly via improved maternal behaviour Long-term Genetic selection strategies Selection for placental efficiency less chance of oxygen deprivation Select for physiological maturity at birth Increased vitality Improve first time behaviours 15
Risk factor Poor maternal behaviour Behaviour during farrowing Negative maternal behaviour will influence piglet survival E.g. savaging Savaging is more likely when animals are: Fearful (i.e. gilts) In pain Under stress (e.g. restriction) Evidence that prenatal stress increases the risk that female offspring will savage as mothers (Jarvis et al. 2006) 16
How can we improve maternal behaviour? Immediate Decrease chances of negative maternal behaviour Minimise gestational stress Decrease sow stress particularly during nesting and farrowing Give substrate to allow nesting behaviour Improved farrowing behaviour Minimise heat stress Long-term Genetic selection strategies E.g. Breeding for improved maternal behaviour Promote positive maternal behaviour 17
Can we breed for good maternal behaviour? The GENOMUM project Genetic selection for improved pre-weaning survival of outdoor pigs Two lines HIGH SURVIVAL AVERAGE Achieved a 3% improvement in piglet survival
Can we breed for good maternal behaviour? Crushing behaviour 10 P=0.002 No.of events 8 6 4 2 0 High Survival Genotype Average 19
Conclusion and take-home message The sow, piglets and their environment all interact to influence piglet survival Solutions must focus on immediate (environmental improvements), as well as the long-term (biological improvements via genetic selection programmes) strategies 20
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