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Impact of an endo 1,4 β-d mannanase in nursery diets on two genetic populations of pigs selected for soybean meal allergic response
A trial was conducted to evaluate 28% soybean meal (SBM) inclusion, with or without endo-1, 4-β-D-mannanase (Hemicell®HT 1.5X, Elanco Animal Health, Greenfield, IN) enzyme on nursery pigs from two genetic lines selected for high (HL) and low (LL) sensitivity to soy proteins. Forty-eight pigs (initial BW = 5.87 kg ± 0.05; 23 d age) were weaned into group pens with free access to a soy-free corn-milk product based diet. After a 4d adaptation, pigs were allocated in a randomized complete block design into individual pens, 12 pen replications per treatment, blocked by ancestry and BW, assigned to one of two dietary treatments in a 2 x 2 factorial arrangement for 14 days. Experimental diets consisted of: 28% SBM and 28% SBM + 0.08 MU/kg mannanase. Feed intake and BW were recorded at d7 and d14. Data were analyzed using PROC MIXED of SAS. There were no interactions to report for the study. For week 1, there were no differences between genetic lines for ADG (P=0.67; 137 vs 157 g) and GF (P=0.70; 0.383 vs 0.432) HL and LL, respectively. Week 1 ADFI was different (P < 0.05) for HL and LL (273 vs 348 g, respectively). During week 1, enzyme supplementation had no significant effect on ADG (P=0.35; 130 vs 169 g) and GF (P=0.21; 0.326 vs 0.488) for without and with mannanase, respectively. During week 2, there were no differences between genetic lines for ADG (P=0.92; 422 vs 419 g), ADFI (P=0.54; 558 vs 586 g), or GF (P=0.44; 0.754 vs 0.728) of HL and LL, respectively. Week 2 ADG (P=0.32; 404 vs 438 g) was similar without enzyme supplementation versus with, respectively. Overall, there was no effect of genetic line on ADG (P= 0.80; 280 vs 288 g), ADFI (P=0.14; 432 vs 467 g), or GF (P=0.36; 0.652 vs 0.617) for HL and LL, respectively. Overall, enzyme supplementation had no significant effect on final BW (P=0.26; 10.54 vs 11.08 kg), ADG (P=0.26; 265 vs 303 g), ADFI (P=0.15; 416 vs 467 g), and GF (P=0.56; 0.623 vs 0.646) for without and with mannanase, respectively. The inclusion of mannanse had no significant effect on growth performance of weaned pigs fed soybean based diets, regardless of genetic sensitivity from day 4 to 18 post-weaning. Although increases in numerical differences were present for pigs fed mannanase, study design potentially lacks the power to pick up these differences as significant.
Keywords: Soybean; Allergy; Mannanase; Pigs; Genetic lines