The effect of straw based housing on selected quality attributes of pork – a meta-analysis.

The aim of the research was to estimate the effect of straw-based housing on selected quality attributes of pork, using a meta-analytical approach. Meta-analysis is statistical procedure that combines the results of individual, independent studies into one common treatment effect, called the effect size. Data were extracted from 17 independent studies (20 experiments) and analysed using a random-effect model to estimate the effect of straw-based housing on the pH (initial pH at 45 min post mortem and ultimate pH), drip loss, colour (L*, a*, b*) and Warner-Bratzler shear force of pork loins. The meta-analysis of the available results showed that pigs from straw-based systems may produce pork with a faster early post-mortem pH decline (pH45), higher drip loss, and greater lightness than those reared under barren conditions with concrete (slatted) floors. A subgroup analysis showed that greater space allowance for straw-housed pigs had a greater negative effect on initial pH (pH45), drip loss, and lightness than straw housing with normal/minimal floor space requirements.