Whole plant silage of vetch in growing-finishing pigs : effect on growth performance and carcass characteristics, and determination of its apparent total tract digestibility

Abstract

A study was conducted to investigate, if 3 different vetch species contribute to the protein supply of growing-finishing pigs while maintaining carcass composition. In a feeding trial with 2 consecutive replications, 140 mixed sex pigs (females and castrates, (Landrace x Large White) × Piétrain)) with an initial body mass of 51.7 ± 6.78 kg were provided with an organic on-farm formulated compound feed for growing-finishing pigs and either triticale straw or a silage derived from 1 of 3 vetch species (Vicia sativa, Vicia pannonica and Vicia villosa). Experimental unit was individual pig for body mass gain and carcass characteristics and pen (10 pigs) for data related to feed intake. The total tract nutrient digestibility of the vetch species was studied using the difference method with 16 pigs of the same origin in 2 replications with 8 animals each. In each replication 2 animals were subjected to either a control diet or a diet with 1 of the 3 silages. Experimental unit for the digestibility trial was the individual pig. Pigs fed additional silage to a compound feed had a greater average body mass gain and gain:feed in the finishing phase than pigs fed triticale straw as roughage (P< 0.05), while total crude protein needed to achieve a kilogram of body mass gain increased (P< 0.05). Carcass characteristics were not affected by the type of roughage. The apparent total tract digestibility of organic matter and crude protein ranged from 51 to 66 % and 55 to 70 %, respectively, and did not differ among vetch species. The findings of this study indicate that whole plant silage of vetch serves as a valuable roughage for growing-finishing pigs and contributes to the animals' protein supply.