Pigs were individually weighted at the beginning of the trial (day 0), on day 49, and at the end of the trial (day 124) to calculate average daily weight gain (ADG). Feed intake of every pen was recorded, in order to calculate feed conversion rate (FCR). Data collection of growth E. Nannoni et al. / Livestock Science 151 (2013) 21–28 22 parameters stopped on day 124, when half of the pigs reached the required slaughtering BW of 160 kg. The remaining pigs were kept under the experimental conditions up to the day in which these pigs in turn attained the final body weight of about 160 kg. Blood samples were collected at the end of the trial from a total of 30 randomly-chosen animals (15 from each group). Samples were analysed for Hematoctrit (HCT), Haemoglobin (Hb), Red Blood cells (RBC) and White Blood Cells (WBC) counts. Smears of whole blood were made, air-dried and stained with May-Gr¨ unwald–Giemsa. Differential cell count was performed by two independent operators under light microscope in order to obtain Neutrophil-to-Lymphocyte ratio (N:L).