Xylanase Supplementation Improved Digestibility and Performance of Growing Pigs Fed Chinese Double-low Rapeseed Meal Inclusion Diets: In vitro and In vivo Studies

Abstract

An in vitro and a feeding trial were conducted to investigate the effect of xylanase supplementation on the feeding value of growing pig diets containing high proportions of Chinese double-low rapeseed meals (DLRM). Seven diets were formulated to meet NRC (1998) nutrient requirements. Diet 1 based on corn-soybean meal was used as positive control 1, and diet 2, a practical diet which incorporated a conventional level of Chinese DLRM (60 g/kg diet), as positive control 2. Diet 3 contained a higher level of DLRM (100 g/kg diet) as the negative control. Diet 3 plus xylanase at 0.10, 0.25, 0.50 and 0.70 g/kg diet created diets 4, 5, 6 and 7, respectively. The seven diets were incubated in triplicate with the in vitro two-stage enzyme incubation method to predict responses of diets to xylanase in terms of digestibility of dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF). In vitro, the negative control had the lowest CP and NDF digestibility. Both DM and CP digestibility were increased (p<0.05) owing to xylanase supplementation either at 0.50 or 0.70 g/kg diet, and NDF digestibility was improved following xylanase addition at all of the test levels. There was a high linear correlation (r 2 >0.90, p<0.05) between the activity concentration of the enzyme when transformed into its logarithmic value and in vitro digestibility coefficients of DM, CP or NDF. In the feeding trial, 112 crossbred pigs were randomly assigned to seven dietary treatments with 16 replicate pens of one pig each. An obvious dose effect on growth rate was observed (r 2 = 0.79, p<0.05) within the inclusion levels of xylanase. Compared with the negative control, xylanase addition at 0.70 g/kg diet resulted in significantly increased ADG (878 g/d vs. 828 g/d, p<0.05), and a tendency towards improved growth rate (868 g/d vs. 828 g/d, p = 0.10) was also observed following the inclusion of xylanase at 0.50 g/kg diet. It would appear that the nutrient utilization of corn and Chinese DLRM diets by pigs could be enhanced by an appropriate amount of xylanase addition. The in vitro and in vivo results suggested that the in vitro incubation method is feasible for predicting responses of pigs to exogenous enzymes and identifying those preparations that possess potential for improvement of the nutritive values of feedstuffs.

Effects of enzyme addition on the nutritive value of broiler diets containing hulled or dehulled Chinese double‐low rapeseed meals

“…(1996) successfully evaluated and identified those preparations that possess potential for improvement of the nutritive value of feedstuffs for broilers using in vitro enzyme incubation method. In recent years, there has been increasing interest in using this method to assess a variety of enzyme preparations regarding activities towards dietary components (Meng et al., 2002; Tang, 2003; Fang et al., 2007b).…”

“…Therefore, the observed difference in enzyme effect may be related to the difference in enzyme sources. Interestingly, a positive NDF digestibility was also observed in the negative control diet with no xylanase addition which may be associated with the degradation of proteins contained in the NDF residue for sufficient protease was provided in the diet (Fang et al., 2007b).…”

“…In vitro enzyme hydrolysis procedures were carried out as described in detail by Fang et al. (2007b).…”

“…In vitro enzyme hydrolysis procedures were carried out as described in detail by Fang et al (2007b). In brief, a 5.0 g diet sample was placed in a 100 ml Erlenmeyer flask, 500 mg of pepsin and 50 ml hydrochloric acid (0.1 m, pH 2.0) containing 0.054 m sodium chloride were added and the mixture was incubated for 1 h at 40°C.…”

Effects of enzyme cocktails on in vitro digestibility of palm kernel cake

“…This may be the reason for the highest digestibility values obtained with the multipurpose enzyme among the three enzymes individually. The activity of the enzyme constituent in each enzyme complex is also an important factor in the level of digestion (Fang et al, 2007).…”