Performance, meat and carcass traits of fattening pigs with organic versus conventional housing and nutrition

The effects of organic housing and nutrition on growth performance, meat and carcass quality traits were studied in a 2_2 factorial trial with two ways of housing and two types of feed, i.e. conventional housing and feeding practices in Belgium versus housing and feeding according to regulations for organic farming. In both housing types, 32 pigs were kept in eight pens with four pigs per pen. One half of the groups received an organic diet, the other half a conventional diet. Both feeds were isocaloric, neither of them contained antibiotic growth promoters. Three-phase feeding was applied. The conventional feed led to a more rapid growth ( P < 0.05) during the first phase, due to a better feed conversion rate ( P < 0.001). This effect disappeared during the second and third phase. Throughout the experiment, the pigs in organic housing showed a markedly higher feed intake ( P < 0.001). Clear interactions between housing and nutrition could not be demonstrated. The pigs from the organic stable did not differ in carcass lean meat percentage, although they had a higher muscle and back fat thickness. Organic nutrition led to a higher intramuscular fat content ( P < 0.05), a lower ultimate pH in ham and loin ( P= 0.02 and < 0.001, respectively) and redder meat ( P= 0.013). The pigs from the organic stable showed a lower ultimate pH in ham and loin ( P= 0.066 and 0.015, respectively) and redder meat. It was concluded that organic pig fattening does not necessarily affect growth performance negatively, but meat quality traits can be influenced by both organic nutrition and housing type.