An experiment was conducted to determine the interactive effects of soy hulls (SH) and sugar beet pulp (SBP) on growth performance of nursery pigs. A total of 2,448 mixed sex pigs (initial BW = 6.3 kg), placed in pens of 36 pigs each, were used in a 40-d trial. Treatments were arranged in a 2 × 3 factorial with two levels of SBP (0 or 5%) and 3 levels of SH (0, 3.75, or 7.5%) with 11 replicates per treatment. Corn and a fermented soybean meal product (ME-Pro, Prairie AquaTech, Brookings, SD) were replaced by the fiber sources to achieve the desired fiber concentration, whereas soybean meal inclusion rate was held constant across treatments. Diets were not balanced for net energy. Experimental diets were fed from d 0 to 18 and a common corn-soybean meal-based diet was fed from d 18 to 40. Pigs were weighed on d 0, 18, and 40 to calculate ADG, ADFI, and G:F. Data was analyzed with the MIXED procedure in SAS. From d 0 to 18, there was a SH × SBP interaction for ADG (P = 0.016) and ADFI (P = 0.023). Pigs fed diets with the highest inclusion of SH without SBP had increased ADG and ADFI; however, pigs fed diets containing SBP had improved performance up to 3.75% SH inclusion, and decreased ADG and ADFI with the highest SH inclusion. From d 18 to 40 and overall (d 0 to 40), there was an interaction (P ≤ 0.007) for G:F, where pigs fed diets containing 3.75% SH without SBP had improved G:F, while pigs fed diets with 3.75% SH containing SBP had worsened G:F.
In summary, these results suggests that both fiber sources can be safely fed to nursery pigs, although the interactive effects must be considered when determining inclusion rates.