Increased litter size in pig breeding challenges pig and sow welfare
Subject
Overview of the development in litter size and its consequences for sow and pig welfare
Target audience
Competent Authorities, inspectors and welfare policy workers of the EU Member States
Large litters
Selection for large litters has resulted in sows giving birth to several pigs exceeding the number of functional teats available at the sow’s udder. Pigs develop a stable teat order within 24 h after birth where each pig suckles from and defends a preferred teat. The sow lets down milk in a synchronised pattern with milk let down approximately 1 time per hour with milk accessible for only 15-25 sec. When the number of pigs exceeds the number of functional teats, the nursing-suckling pattern in pigs is disturbed to an extent where interventions are necessary. Interventions include split suckling, cross fostering and use of nurse sows, milk supplement and artificial rearing.
Reduced welfare
Even though interventions are necessary to keep surplus pigs alive, they all come with a price in terms of reduced welfare for both pigs and sows:
Reduced welfare in pigs in hyper prolific litters is due to increased mortality rate, decreased birth weight and viability, increased competition and fighting, impaired internal biosecurity and in many cases lack of space in the farrowing pen.
Reduced welfare in sows is due to high metabolic demands, prolonged farrowing and longer time being crated.
Considering the health and welfare problems related to the suggested mitigation strategies, as well as the lack of trained work force experienced throughout EU, using less prolific sow lines seems important to improve pig and sow welfare in the farrowing unit.
Introphoto: Artificial rearing piglets (©Aarhus University)