Gary Allee Symposium
Gary Allee Symposium
Pre-weaning piglet mortality (PWM) is a substantial economic loss and a welfare concern. It is not a new issue; however, there is evidence that levels are increasing in US herds. Genetic improvements in prolificacy have been accompanied with lower average piglet birth weights, increased within-litter variation in birth weight, and an increasing proportion of low birth weight piglets. Low birth weight is a major pre-disposing factor for PWM. In a survey involving over 11,000 piglets (average birth weight 1.44 ± 0.390 kg), PWM for piglets weighing 1.5 kg was 44, 15, and 8%, respectively. However, the percentage of total mortality from these 3 weight groupings was 35, 42, and 23%, respectively. This suggests that efforts to reduce PWM should mainly focus on lightest 50% of piglets in a population. The major causes and timing of PWM have not changed over time. Crushing and starvation are predominant; the majority of losses occur in the first few days after birth. A substantial proportion of dead piglets have empty stomachs. Pre-weaning mortality is multifactorial in origin; reducing levels requires attention to all factors, starting with farrowing accommodation design and basic facility hygiene programs. Minimizing piglet body temperature decline after birth, and encouraging early colostrum and milk intake are critical. Strategies to reduce competition between piglets for access to the udder and/or supplementary feeding programs are important. Cross-fostering is central to maximizing piglet survival; however, there is a dearth of research-based information to use to design the optimum strategy. The potential influence of gestation nutrition on PWM requires clarification. Pre-weaning mortality is strongly influenced by the people managing the farrowing facilities; developing approaches for early identification of at risk pigs would have benefit. Ultimately, minimizing PWM requires systems-based approaches involving all components from genetic selection for survival through to facility and animal management practices.