Effect of cereal soaking and carbohydrase supplementation on growth, nutrient digestibility and intestinal microbiota in liquid-fed grow-finishing pigs

Abstract

Soaking the cereal fraction of a liquid diet prior to feeding (C soak), and/or carbohydrase enzyme supplementation (ENZ) are likely to modulate both feed and intestinal microbial populations and improve feed efficiency (FE) in pigs. To test this hypothesis, a total of 392 grow-finisher pigs (~33.4 kg, 7 pigs/pen) were randomly allocated to 4 treatments in a 2 × 2 factorial arrangement for 70 days as follows: (1) fresh liquid feed (Fresh); (2) Cereal soaked liquid feed (Soak); (3) Fresh + ENZ and (4) Soak + ENZ. An interaction between ENZ and C soak was found for average daily gain (ADG) during the growing phase (day 0 to 21; P < 0.05) where pigs fed the Soak + ENZ diet had higher ADG than pigs fed the Fresh + ENZ diet. No treatment effect was found for ADG thereafter. Enzyme supplementation increased total tract nutrient digestibility (P < 0.05) and reduced caecal VFA concentrations (P < 0.05) but did not improve pig growth or FE. Both C soak and ENZ modulated intestinal microbiota composition; increasing abundance of bacterial taxa that were negatively correlated with pig growth and reducing abundance of taxa positively correlated with pig growth and caecal butyrate concentration. In conclusion, both strategies (C soak and ENZ) improved nutrient digestibility in pigs and modulated intestinal microbiota composition.

Effect of cereal fermentation and carbohydrase supplementation on growth, nutrient digestibility and intestinal microbiota in liquid-fed grow-finishing pigs

“…Contrary to our results, the Megasphaera genus was more abundant in the ileum and caecum of pigs with improved FE in a previous study 9 in which pigs were fed a dry corn-based diet. In a recent study of ours also performed with liquid-fed pigs using the same facilities as in the current study 31 the caecal abundance of Megasphaera elsdenii was positively correlated with pig growth and its relative abundance was lower in pigs fed fresh liquid diets supplemented with the same ENZ complex. In the current study, the abundance of the Megasphaera genus tended to be reduced when the ENZ complex was supplemented to the diets, but in the ileum.…”

“…High acetate concentration in liquid feed is associated with reduced palatability 45 ; however, in the current experiment feed refusal was not observed. We also found evidence of spontaneous fermentation in the troughs with this type of liquid feeding system when fresh liquid diets were fed 31 . No impact of dietary treatments on the main macronutrients analysed (CP, oil, ash, CF, NDF, ADF or GE) in samples collected at the trough was observed.…”

“…Therefore, exogenous enzyme supplementation to liquid diets www.nature.com/scientificreports/ appears to have positively modulated the intestinal microbiota of pigs. It is interesting to note that in a similar study (conducted in the same facility and using the same diet composition where the cereals were soaked for 3 h instead of fermented) supplementation with the same exogenous enzyme appeared to negatively modulate the intestinal microbial profile 31 . Bacterial taxa that were negatively correlated with pig growth were more abundant in the ileal and caecal digesta of pigs fed the enzyme-supplemented diets (in the case of fresh diets, Prevotellaceae sp., Oscillibacter sp.…”

“…Experimental facilities, experimental set-up, analysis of feed, faeces and digesta samples, and statistical analyses were essentially as described by Torres-Pitarch et al 31 except that in the current experiment the cereal fraction of the diet was fermented for an initial 52 h period and thereafter back-slopped (fermentation technique in which some of the previous fermentate is used as the inoculum for the next cereal fermentation) daily throughout the feeding trial. An initial fermentation time of 52 h was chosen based on best practice used in the pig industry.…”

“…A third aliquot of the sample (~ 50 mL) was stored on ice for microbiological analysis on the day of collection (within 3 h). The other feed and faecal sampling procedures and storage of samples were performed as outlined by Torres-Pitarch et al 31 . Briefly, after the feed trough sample aliquots above were taken, the rest of the sample was frozen at − 20 °C in aluminium foil trays for subsequent freeze-drying prior to chemical analysis.…”