Determination of organic lamb fattening performance and slaughter characteristics in the South Marmara conditions in Turkey.

This research was carried out to determine the effects of conventional and organic fattening systems on fattening performance, some slaughter and carcass characteristics of lambs in the South Marmara conditions. Conventional fattening groups were fed with concentrate feed mixtures based on conventional barley as ad-libitum and dry alfalfa hay was given at 100 g/day/head level to lambs. Organic fattening groups were grazed on pasture and fed with concentrate feed mixtures based on organic barley in the barn. Organic barley haylage was offered in the short period of pasture. All the lambs in the groups were slaughtered when the average live weight of the groups reached 35 kg in the experiment. Organic lambs reached the targeted live weight sooner than conventional lambs. The daily average live weight gain during fattening periods of organic lambs (155.26 g) was higher than that of conventional lambs (114.83 g) (P<0.05). The daily average concentrate feed consumptions of organic and conventional groups were close to each other during fattening periods. The fattening system had an effect on the back fat thickness and back fat thickness of organic lambs was lower than that of conventional lambs (P <0.05).