Effects of nursery and finishing pen shape on pig performance and welfare

Modern commercial pig production systems are currently facing several challenges like market prices volatility, high production and environmental costs. Responding to public demand and the legal requirements for improving the welfare standards is leading to further growth of the farming costs and lower profit margins for the pig industry. Due to its impact on key production performance indicators and on welfare, space allowance for nursery and finishing pigs has been the subject of extensive research over the past decades. However, space allowance per pig is just a relative approach, pen side ratio and shape being important as well as it interferes with the free movement and several behaviors expressed by pigs. This study is focused on the impact of pen shape by comparing implications of housing pigs in pens with different perimeter to area ratios at the same level of surface allowed per pig. Results are suggesting that the pen shape design might have an influence on the rearing performance indicators like average daily gain (ADG) and feed conversion ratio (FCR) both in nursery and finishing stages. It seems as well that a welfare indicator, namely the recorded number of skin lesions, differ according to the pen shape, in the favor of pens with lower length to width ratio, even if the pig density per surface unit, feeding, ventilation and enrichment patterns are the same.