Growth performance and nitrogen balance of growing pigs farms in North Italy

Growth performance and N balance of pigs were studied using data from 51 farms located in Northern Italy, mainly differing for the pig final live weight (heavy, P 150 kg, medium-heavy, MP 150 kg and medium, M 130 kg). Data, collected from 1997 to 2003, regarded feed consumption, feed chemical composition and growth performance of 141 batches, for a total of 161,278 heads. Heavy pig production, compared to the other two productions, required a longer period in farm, since the commercial maturity is obtained at 9 months of age. Respectively, for P, MP and M farms, the numbers of rounds/year were 1.6, 2.1 and 2.1, daily weight gains were 0.65, 0.72 and 0.72 kg/d and the mean crude protein contents of feeds were 15.3, 16.2 and 16.3%; these differences were always significant. N balance (ERM, 1999) showed that N net excretion net on field was, respectively for P, MP and M, 9.9, 9.4 and 8.0 kg/place/year and the rsd was about 10% of the mean value (en)