Space allowance determination by considering its coeffect with toy provision on production performance, behavior and physiology for grouped growing pigs

Abstract Increasing space allowance and enhancing environmental enrichment are two approved solutions to improve pig welfare in modern housing systems, while limited research regarding their interactions could be found. To determine the proper stocking density for growing pigs under China's production conditions, an experiment with a 3 × 2 factorial arrangement (three levels of space allowance × with/without toys) was conducted to evaluate the effects of space allowance and toy provision on the production performance, behavior and physiology of the pigs from the 7th to 13th week of age. Two hundred and sixteen pigs were randomly allocated to pens with the space allowances of 0.5, 0.7 and 0.9 m2/pig, and the group size in each pen was fixed at 18. The results showed that the average daily gain (ADG) and feed conversion ratio (FCR) of the pigs with a space allowance of 0.5 m2/pig significantly decreased (P 0.05). Pigs gained more weight with toy provision, and their impact was especially enhanced as floor area decreased. Significant interacting effects of space allowance and toy provision on excessive drinker and feeder occupation and negative social behavior were observed (P