Management and nutritional strategies to improve the postnatal performance of light weight pigs

Abstract

During the production period from birth to slaughter there are some pigs that grow markedly slower, despite conditions that seem to support the rapid growth of their contemporaries. This reduction in growth inevitably leads to weight variation within a group and results in system inefficiencies. The aim of this thesis was to identify risk factors involved in poor growth and to develop management and nutritional treatments to enable light pigs to maximise their growth at different stages of production.

Risk factor analysis for a large dataset showed that, in particular, low birth and weaning weight result in poor growth to finishing. Some light pigs do, however, have the capacity to compensate for low weight at earlier stages of production. Preweaning intervention demonstrated that low birth weight pigs cross fostered into litters with similar weight littermates had a significantly higher weaning weight than those in mixed litters with heavier pigs; however the provision of supplementary milk to such litters had no further beneficial effect. A post weaning feeding regime formulated for low birth weight pigs, with a higher nutrient specification diet based on more digestible ingredients, not only showed improved performance to 10 weeks of age, but also enabled low birth weight pigs to meet the BW of heavier birth weight pigs. In contrast, a high specification diet (higher in amino acid: energy content) had no effect on the growth of low birth weight pigs when offered from 9 weeks of age, suggesting a critical window for intervention.

Overall, the crucial stages of postnatal growth for light pigs have been identified, and preweaning and early post weaning treatments have been developed. These not only improve the performance of low birth weight pigs but also allow them to catch up with heavier birth weight pigs.