Study of the assessment method for N excretion in sustainable heavy pigs production

Italian heavy pigs, with an average slaughtering body weight of 150-170 kg, are world-wide famous for its Parma ham production. Because the requirement of market diversity, producers are interested in ham production following the procedure of Italian pork industry. However, with ever growing public concern about nitrogen (N) pollution in the environment, it is necessary to determine a suitable method to measure N excretion from heavy pig production. The N retention was calculated by factorial method and compared with estimations of other methods available in literature. The results showed that the N percentage of heavy pigs is 2.43% ± 0.07% on body weight basis and the percentage of N excretion was approximately 69.62% ± 0.20 of N intake. Regarding the N excretion of estimation methods, the proposal of Xiccato et al. was closer to reality of the heavy pig production than other methods and could be used as a standard way to calculate the N excretion. Besides the overall standard, it is opportune to make a N balance sheet for every individual farm under specific conditions. Only in this way, the farmers can realize their deficiencies and will voluntarily follow the Good Management Practice (GMP) indications so as to guarantee a sustainable development of pig production.