Interactive effect of dietary fermented corn and nutrient density of diets on growth performance, nutrient digestibility, ileal microorganisms and fecal noxious gas emission in growing pigs

Abstract Text: We conducted this experiment to evaluate the effects of fermented corn (FC) on performance of growing pigs fed with different nutrient density diets. A total of 128 crossbred growing pigs [(Landrace × Yorkshire) × Duroc)] with an initial BW of 29.59 ± 1.34 kg were used in this 42-d trial. Pigs were distributed into 1 of 4 dietary treatments in a 2 × 2 factorial arrangement of treatments with two levels of nutrient density (high or low energy and crude protein density) and FC (0 or 20%) according to their BW and sex (8 pens/treatment and 4 pigs with 2 gilts and 2 barrows/pen). During the experimental period, individual body weight and feed consumption per pen were measured on day 1 and 42 to monitor the ADG, ADFI and G:F. Apparent total tract digestibility (ATTD) was determined by adding chromic oxide (0.2%) as an indigestible marker in the diet 7 days before taking samples (during days 35 to 42). Fresh fecal samples collected from 2 pigs (BW approximate the pen average) per pen by rectal massage on day 42 for nutrient digestibility and fecal gas emission analysis. The same two pigs were sacrificed to get the ileal digesta for microbial analysis (E. coli and Lactobacillus). All data were analyzed as a 2 × 2 factorial arrangement of treatments by using the MIXED procedure of SAS (SAS Inst. Inc., Cary, NC). The final model included the main effects of FC and nutrient density, and their interaction. During the overall trial period, pigs fed with FC had a higher (P < 0.05) ADG than those without FC. The ATTD of dry matter, gross energy, and nitrogen in FC inclusion groups were significantly greater (P < 0.05) than those non-FC groups. Both low-nutrient-density and FC supplementation led to lower (P < 0.05) fecal NH₃ and H₂S emission content. Increased ileal Lactobacillus concentration and decreased E. coliconcentration were observed with FC supplementation. An interactive effect between nutrient density diet and FC was observed on the ADG, ileal microorganisms, nutrient digestibility and fecal noxious gas content. In conclusion, both high-nutrient-density diet and FC supplementation could improve growth performance, nutrient digestibility, and ileal microorganisms balance in growing pigs. The beneficial effect of FC supplementation in growing pigs could be enhanced with the high-nutrient-density diets.

Keywords: fermented corn, growing pigs, nutrient density