The nutritive value of sugar beet pulp-substituted lucerne for equids

Two experiments were conducted to evaluate the nutritive value of sugar-beet-substituted lucerne for equids. In both experiments four mature Welsh-cross pony geldings were used in a 4 × 4 Latin-square design to assess the effect of sugar beet pulp (SB) on the nutritive value of either high-temperature dried (HT) lucerne (Experiment 1) or ensiled lucerne (Experiment 2) for equids. Both experiments consisted of four levels of SB substitution: 0 [DC], 100 [SB10], 200 [SB20] and 300 [SB30] g/kg DM for Experiment 1, and 0 [WS], 100 [SB1], 200 [SB2] and 300 [SB3] g/kg DM for Experiment 2. Each diet was fed to give a total DM intake of 17.5 g/kg of liveweight per day, offered in two equal meals at 12-h intervals. Digestibility was determined by total faecal collection. SB substitution of HT and ensiled lucerne increased (P<0.01) total diet total non-starch polysaccharide (TNSP) digestibility compared to the control: 0.63, 0.65, 0.71 and 0.58 for SB10, SB20, SB30 and DC, respectively; and 0.62, 0.62, 0.69 and 0.55 for SB1, SB2, SB3 and WS, respectively. Furthermore, TNSP digestibility values for SB as a sole feed (calculated ‘by difference’ and predicted by regression) were greater than unity, indicating an increase in the digestibility of the cell wall fraction of the lucerne.