Diet nutrient digestibility and growth performance of weaned pigs fed sugar beet pulp

Abstract

Dietary inclusion of fibrous alternative feedstuffs in swine diets to replace cereal grains can be economically important for pork producers; however, limits for young pigs to ingest high-fibre diets are not well established. The effects of increasing inclusion of sugar beet pulp (SBP) by substituting wheat grain on diet nutrient digestibility and growth performance of young pigs were evaluated. In total, 220 pigs (initial body weight 7.5kg) were fed Phase 1 diets for 2 weeks (day 1–14) starting 1 week after weaning at 19 days of age and sequentially Phase 2 diets for 3 weeks (day 15–35). Five pelleted wheat-based diets including 0, 60, 120, 180 and 240g SBP/kg were fed. The SBP contained (as-fed) 90g crude protein (CP) and 249g acid detergent fibre (ADF)/kg. Phase 1 and 2 diets were formulated to provide 9.6 and 9.4MJ NE/kg and 1.3 and 1.2g standardised ileal digestible (SID) Lys/MJ NE, respectively. Diets were balanced for NE by increasing canola oil from 5 to 50g/kg for Phase 1 and 2 diets and for AA by increasing crystalline AA. Increasing dietary inclusion of SBP up to 240g/kg increased ADF content of diets to 101g/kg, linearly reduced (P<0.001) apparent total tract digestibility coefficient (CATTD) of gross energy (GE) by 0.04 and of CP by 0.08 feeding Phase 1 diets, quadratically reduced (P<0.001) CATTD of GE by 0.01 and linearly reduced (P<0.001) CATTD of CP by 0.06 feeding Phase 2 diets. Increasing inclusion of SBP up to 240g/kg linearly reduced (P<0.001) calculated diet NE value by 0.35MJ/kg in Phase 1 and quadratically increased (P<0.001) calculated diet NE value by 0.29MJ/kg in Phase 2. Increasing inclusion of SBP quadratically reduced ADFI (P<0.05) for day 29–35 and linearly reduced average daily gain (ADG; P<0.05) for day 15–35. The G:F was linearly increased (P<0.05) for day 1–7, linearly reduced (P=0.01) for day 15–21 and quadratically reduced (P<0.05) for day 15–28. Overall (day 1–35), increasing dietary inclusion of SBP up to 240g/kg linearly reduced (P<0.05) ADFI and ADG by 46g/d, quadratically reduced (P<0.01) G:F and linearly reduced (P<0.05) final BW at day 35 by 1.1kg. However, growth performance did not differ (P>0.05) between pigs fed diets containing 0 or 60g SBP/kg. In conclusion, weaned pigs maintained growth performance with diets containing 65g ADF/kg, but not for diets containing up to 101g ADF/kg.