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

Abstract Text: Using alternative feedstuffs to replace cereal grains in swine diets is economically important for pork producers. To explore biological limits for young pigs to ingest high-fiber feedstuffs, 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 BW = 7.5 kg) starting 1 wk after weaning at 19 d of age were fed Phase 1 diets for 2 wk (d 1–14) and sequentially Phase 2 diets for 3 wk (d 15–35). Five pelleted wheat-based diets including 0, 6, 12, 18, and 24% SBP in substitution of wheat were fed. The SBP contained (as-fed) 10.0% CP, 27.1% ADF, and 40.9% NDF. Phase 1 and 2 diets were formulated to provide 2.29 and 2.24 Mcal NE/kg, and 5.26 and 5.12 g standardized ileal digestible (SID) Lys/Mcal NE, respectively. Diets were balanced for NE by increasing canola oil from 0.5 to 5% for Phase 1 and 2 diets, and for AA by increasing crystalline AA. Increasing inclusion of SBP up to 24% linearly reduced (P<0.001) apparent total tract digestibility (ATTD) of GE by 4.4%-units and of CP by 7.7%-units in Phase 1 diets, and linearly decreased the ATTD of GE by 1.3%-units (P<0.001) and of CP by 6.0%-units (P<0.001) in Phase 2 diets. Increasing inclusion of SBP up to 24% linearly reduced (P<0.001) calculated diet NE values by 0.12 Mcal/kg in Phase 1, and quadratically increased (P<0.0001) calculated diet NE values by 0.02 Mcal/kg in Phase 2. Increasing inclusion of SBP tended to reduce (P<0.06) ADFI for d 1–7 and linearly reduced ADFI (P<0.05) for d 8–14 and 22–28. The ADG for d 15–35 was linearly decreased (P<0.01) from 711 to 647 g/d. The G:F was linearly increased (P<0.01) for d 1–7, but was quadratically reduced (P<0.05) for d 15–28. Overall (d 1–35), increasing dietary inclusion of SBP linearly reduced (P<0.01) ADFI by 50.7 g/d and ADG by 46.1 g/d, and quadratically reduced (P=0.02) G:F by 0.03. Increasing inclusion of SBP up to 24% linearly reduced (P<0.001) final BW at d 35 by 1.6 kg. In conclusion, young pigs had difficulty to digest SBP and pigs fed increasing inclusion of SBP had a reduced growth performance.

Keywords: growth performance, pig, sugar beet pulp