Effects of dietary fermentable carbohydrates on energy metabolism in group-housed sows

The effect of dietary nonstarch polysaccharide (NSP) content on the metabol ic rate in group-housed sows was studied. Twelve groups of six nonpregnant sows were each fed one of four experimental diets similar in composition ex cept for the starch and NSP content. Exchanging sugar beet pulp silage (SBP S) for tapioca created the difference in starch and NSP ratio in the diet. On a DM basis, diets contained 0, 10, 20, or 30% SBPS. Sows were group-hous ed and fed at 1.30 times the assumed maintenance energy requirements. Nitro gen and energy balances were measured per group during a 7-d experimental p eriod, which was preceded by a 33-d adaptation period. Both digestibility a nd metabolizability of energy decreased with increasing dietary SBPS conten t (P < 0.05). Heat production and energy retention were unaffected by the e xchange of starch for NSP (P > 0.1). Based on energy retention data and app arent fecal digestibilities of crude protein, crude fat, starch, and NSP, t he estimated net energy value of fermented NSP was 13.4 kJ/g. The present s tudy shows that group-housed sows are capable of using energy from fermente d NSP (i.e., NSP from SBPS) as efficiently as energy from digested starch ( i.e., starch from tapioca).