Consequences of the use of ensiled sugar beet-pulp in the diet of heavy pigs on performances, carcass characteristics and nitrogen balance: a review

Data collected from several studies including unpublished data, carried out since 1988 at the University of Bologna, on the incorporation of pressed beet pulp silage (PBPS) in the diet of heavy pigs (160 kg live weight (LW)) have been analysed collectively. Large amounts of PBPS (0.5 of dry matter (DM) intake) in the diet were well tolerated by pigs (ranging in LW from 34 to 144 kg) and were associated with a marked reduction of gastric lesions. When used in practical diets from 44 to 153 kg LW at 170 g kg−1 DM basis, PBPS did not modify either growing parameters or slaughtering performances of heavy pigs in comparison with animals receiving a concentrated diet mainly based on cereals and soyabean meal. The use of PBPS did not modify the weight losses of hams (Parma ham) during their seasoning process, lasting more than 12 months for this typical product. Similarly, the fatty acid composition of cured ham fat was not influenced by the dietary inclusion of beet pulp. When replacing barley (150 g kg−1 DM basis), both plain or molassed PBPS did not modify slaughtering parameters of heavy pigs and fatty acid composition of hams. Plain PBPS resulted in a significant (P<0.05) increase of ADG in comparison with molassed PBPS and control diets. e-added PBPS replacing barley (100 g kg−1 DM basis) did not result in any modification of growing and slaughtering parameters of heavy pigs ranging in LW from 55 to 160 kg. At the inclusion level of 200 g kg−1, vinasse-added PBPS resulted in a significant (P<0.05) reduction of feed intake and in a slight worsening of growth rate. Increasing levels (up to 240 g kg−1 DM basis) of PBPS resulted in a significant (P<0.01) reduction in organic matter digestibility while significantly (P<0.01) reduced nitrogen excretion in urine. The significant (P<0.05) trophic effect on large intestine mucosa and the high quality of PBPS fibrous fractions may explain the positive role of this by-product in pig feeding and justify the possibility of a partial replacement of cereals such as barley in feed formulation.